1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Facilitate override of interface linkage and calling conventions.
47** Be aware that these macros may not be used within this particular
48** translation of the amalgamation and its associated header file.
49**
50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51** compiler that the target identifier should have external linkage.
52**
53** The SQLITE_CDECL macro is used to set the calling convention for
54** public functions that accept a variable number of arguments.
55**
56** The SQLITE_APICALL macro is used to set the calling convention for
57** public functions that accept a fixed number of arguments.
58**
59** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60**
61** The SQLITE_CALLBACK macro is used to set the calling convention for
62** function pointers.
63**
64** The SQLITE_SYSAPI macro is used to set the calling convention for
65** functions provided by the operating system.
66**
67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68** SQLITE_SYSAPI macros are used only when building for environments
69** that require non-default calling conventions.
70*/
71#ifndef SQLITE_EXTERN
72# define SQLITE_EXTERN extern
73#endif
74#ifndef SQLITE_API
75# define SQLITE_API
76#endif
77#ifndef SQLITE_CDECL
78# define SQLITE_CDECL
79#endif
80#ifndef SQLITE_APICALL
81# define SQLITE_APICALL
82#endif
83#ifndef SQLITE_STDCALL
84# define SQLITE_STDCALL SQLITE_APICALL
85#endif
86#ifndef SQLITE_CALLBACK
87# define SQLITE_CALLBACK
88#endif
89#ifndef SQLITE_SYSAPI
90# define SQLITE_SYSAPI
91#endif
92
93/*
94** These no-op macros are used in front of interfaces to mark those
95** interfaces as either deprecated or experimental. New applications
96** should not use deprecated interfaces - they are supported for backwards
97** compatibility only. Application writers should be aware that
98** experimental interfaces are subject to change in point releases.
99**
100** These macros used to resolve to various kinds of compiler magic that
101** would generate warning messages when they were used. But that
102** compiler magic ended up generating such a flurry of bug reports
103** that we have taken it all out and gone back to using simple
104** noop macros.
105*/
106#define SQLITE_DEPRECATED
107#define SQLITE_EXPERIMENTAL
108
109/*
110** Ensure these symbols were not defined by some previous header file.
111*/
112#ifdef SQLITE_VERSION
113# undef SQLITE_VERSION
114#endif
115#ifdef SQLITE_VERSION_NUMBER
116# undef SQLITE_VERSION_NUMBER
117#endif
118
119/*
120** CAPI3REF: Compile-Time Library Version Numbers
121**
122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123** evaluates to a string literal that is the SQLite version in the
124** format "X.Y.Z" where X is the major version number (always 3 for
125** SQLite3) and Y is the minor version number and Z is the release number.)^
126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128** numbers used in [SQLITE_VERSION].)^
129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130** be larger than the release from which it is derived. Either Y will
131** be held constant and Z will be incremented or else Y will be incremented
132** and Z will be reset to zero.
133**
134** Since [version 3.6.18] ([dateof:3.6.18]),
135** SQLite source code has been stored in the
136** <a href="http://fossil-scm.org/">Fossil configuration management
137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138** a string which identifies a particular check-in of SQLite
139** within its configuration management system. ^The SQLITE_SOURCE_ID
140** string contains the date and time of the check-in (UTC) and a SHA1
141** or SHA3-256 hash of the entire source tree. If the source code has
142** been edited in any way since it was last checked in, then the last
143** four hexadecimal digits of the hash may be modified.
144**
145** See also: [sqlite3_libversion()],
146** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147** [sqlite_version()] and [sqlite_source_id()].
148*/
149#define SQLITE_VERSION "3.53.0"
150#define SQLITE_VERSION_NUMBER 3053000
151#define SQLITE_SOURCE_ID "2026-04-09 11:41:38 4525003a53a7fc63ca75c59b22c79608659ca12f0131f52c18637f829977alt1"
152#define SQLITE_SCM_BRANCH "trunk"
153#define SQLITE_SCM_TAGS "release major-release version-3.53.0"
154#define SQLITE_SCM_DATETIME "2026-04-09T11:41:38.498Z"
155
156/*
157** CAPI3REF: Run-Time Library Version Numbers
158** KEYWORDS: sqlite3_version sqlite3_sourceid
159**
160** These interfaces provide the same information as the [SQLITE_VERSION],
161** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
162** but are associated with the library instead of the header file. ^(Cautious
163** programmers might include assert() statements in their application to
164** verify that values returned by these interfaces match the macros in
165** the header, and thus ensure that the application is
166** compiled with matching library and header files.
167**
168** <blockquote><pre>
169** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
170** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
171** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
172** </pre></blockquote>)^
173**
174** ^The sqlite3_version[] string constant contains the text of the
175** [SQLITE_VERSION] macro. ^The sqlite3_libversion() function returns a
176** pointer to the sqlite3_version[] string constant. The sqlite3_libversion()
177** function is provided for use in DLLs since DLL users usually do not have
178** direct access to string constants within the DLL. ^The
179** sqlite3_libversion_number() function returns an integer equal to
180** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
181** a pointer to a string constant whose value is the same as the
182** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
183** using an edited copy of [the amalgamation], then the last four characters
184** of the hash might be different from [SQLITE_SOURCE_ID].)^
185**
186** See also: [sqlite_version()] and [sqlite_source_id()].
187*/
188SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
189SQLITE_API const char *sqlite3_libversion(void);
190SQLITE_API const char *sqlite3_sourceid(void);
191SQLITE_API int sqlite3_libversion_number(void);
192
193/*
194** CAPI3REF: Run-Time Library Compilation Options Diagnostics
195**
196** ^The sqlite3_compileoption_used() function returns 0 or 1
197** indicating whether the specified option was defined at
198** compile time. ^The SQLITE_ prefix may be omitted from the
199** option name passed to sqlite3_compileoption_used().
200**
201** ^The sqlite3_compileoption_get() function allows iterating
202** over the list of options that were defined at compile time by
203** returning the N-th compile time option string. ^If N is out of range,
204** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
205** prefix is omitted from any strings returned by
206** sqlite3_compileoption_get().
207**
208** ^Support for the diagnostic functions sqlite3_compileoption_used()
209** and sqlite3_compileoption_get() may be omitted by specifying the
210** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
211**
212** See also: SQL functions [sqlite_compileoption_used()] and
213** [sqlite_compileoption_get()] and the [compile_options pragma].
214*/
215#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
216SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
217SQLITE_API const char *sqlite3_compileoption_get(int N);
218#else
219# define sqlite3_compileoption_used(X) 0
220# define sqlite3_compileoption_get(X) ((void*)0)
221#endif
222
223/*
224** CAPI3REF: Test To See If The Library Is Threadsafe
225**
226** ^The sqlite3_threadsafe() function returns zero if and only if
227** SQLite was compiled with mutexing code omitted due to the
228** [SQLITE_THREADSAFE] compile-time option being set to 0.
229**
230** SQLite can be compiled with or without mutexes. When
231** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
232** are enabled and SQLite is threadsafe. When the
233** [SQLITE_THREADSAFE] macro is 0,
234** the mutexes are omitted. Without the mutexes, it is not safe
235** to use SQLite concurrently from more than one thread.
236**
237** Enabling mutexes incurs a measurable performance penalty.
238** So if speed is of utmost importance, it makes sense to disable
239** the mutexes. But for maximum safety, mutexes should be enabled.
240** ^The default behavior is for mutexes to be enabled.
241**
242** This interface can be used by an application to make sure that the
243** version of SQLite that it is linking against was compiled with
244** the desired setting of the [SQLITE_THREADSAFE] macro.
245**
246** This interface only reports on the compile-time mutex setting
247** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
248** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
249** can be fully or partially disabled using a call to [sqlite3_config()]
250** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
251** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
252** sqlite3_threadsafe() function shows only the compile-time setting of
253** thread safety, not any run-time changes to that setting made by
254** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
255** is unchanged by calls to sqlite3_config().)^
256**
257** See the [threading mode] documentation for additional information.
258*/
259SQLITE_API int sqlite3_threadsafe(void);
260
261/*
262** CAPI3REF: Database Connection Handle
263** KEYWORDS: {database connection} {database connections}
264**
265** Each open SQLite database is represented by a pointer to an instance of
266** the opaque structure named "sqlite3". It is useful to think of an sqlite3
267** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
268** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
269** and [sqlite3_close_v2()] are its destructors. There are many other
270** interfaces (such as
271** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
272** [sqlite3_busy_timeout()] to name but three) that are methods on an
273** sqlite3 object.
274*/
275typedef struct sqlite3 sqlite3;
276
277/*
278** CAPI3REF: 64-Bit Integer Types
279** KEYWORDS: sqlite_int64 sqlite_uint64
280**
281** Because there is no cross-platform way to specify 64-bit integer types
282** SQLite includes typedefs for 64-bit signed and unsigned integers.
283**
284** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
285** The sqlite_int64 and sqlite_uint64 types are supported for backwards
286** compatibility only.
287**
288** ^The sqlite3_int64 and sqlite_int64 types can store integer values
289** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
290** sqlite3_uint64 and sqlite_uint64 types can store integer values
291** between 0 and +18446744073709551615 inclusive.
292*/
293#ifdef SQLITE_INT64_TYPE
294 typedef SQLITE_INT64_TYPE sqlite_int64;
295# ifdef SQLITE_UINT64_TYPE
296 typedef SQLITE_UINT64_TYPE sqlite_uint64;
297# else
298 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
299# endif
300#elif defined(_MSC_VER) || defined(__BORLANDC__)
301 typedef __int64 sqlite_int64;
302 typedef unsigned __int64 sqlite_uint64;
303#else
304 typedef long long int sqlite_int64;
305 typedef unsigned long long int sqlite_uint64;
306#endif
307typedef sqlite_int64 sqlite3_int64;
308typedef sqlite_uint64 sqlite3_uint64;
309
310/*
311** If compiling for a processor that lacks floating point support,
312** substitute integer for floating-point.
313*/
314#ifdef SQLITE_OMIT_FLOATING_POINT
315# define double sqlite3_int64
316#endif
317
318/*
319** CAPI3REF: Closing A Database Connection
320** DESTRUCTOR: sqlite3
321**
322** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
323** for the [sqlite3] object.
324** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
325** the [sqlite3] object is successfully destroyed and all associated
326** resources are deallocated.
327**
328** Ideally, applications should [sqlite3_finalize | finalize] all
329** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
330** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
331** with the [sqlite3] object prior to attempting to close the object.
332** ^If the database connection is associated with unfinalized prepared
333** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
334** sqlite3_close() will leave the database connection open and return
335** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
336** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
337** it returns [SQLITE_OK] regardless, but instead of deallocating the database
338** connection immediately, it marks the database connection as an unusable
339** "zombie" and makes arrangements to automatically deallocate the database
340** connection after all prepared statements are finalized, all BLOB handles
341** are closed, and all backups have finished. The sqlite3_close_v2() interface
342** is intended for use with host languages that are garbage collected, and
343** where the order in which destructors are called is arbitrary.
344**
345** ^If an [sqlite3] object is destroyed while a transaction is open,
346** the transaction is automatically rolled back.
347**
348** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
349** must be either a NULL
350** pointer or an [sqlite3] object pointer obtained
351** from [sqlite3_open()], [sqlite3_open16()], or
352** [sqlite3_open_v2()], and not previously closed.
353** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
354** argument is a harmless no-op.
355*/
356SQLITE_API int sqlite3_close(sqlite3*);
357SQLITE_API int sqlite3_close_v2(sqlite3*);
358
359/*
360** The type for a callback function.
361** This is legacy and deprecated. It is included for historical
362** compatibility and is not documented.
363*/
364typedef int (*sqlite3_callback)(void*,int,char**, char**);
365
366/*
367** CAPI3REF: One-Step Query Execution Interface
368** METHOD: sqlite3
369**
370** The sqlite3_exec() interface is a convenience wrapper around
371** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
372** that allows an application to run multiple statements of SQL
373** without having to use a lot of C code.
374**
375** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
376** semicolon-separated SQL statements passed into its 2nd argument,
377** in the context of the [database connection] passed in as its 1st
378** argument. ^If the callback function of the 3rd argument to
379** sqlite3_exec() is not NULL, then it is invoked for each result row
380** coming out of the evaluated SQL statements. ^The 4th argument to
381** sqlite3_exec() is relayed through to the 1st argument of each
382** callback invocation. ^If the callback pointer to sqlite3_exec()
383** is NULL, then no callback is ever invoked and result rows are
384** ignored.
385**
386** ^If an error occurs while evaluating the SQL statements passed into
387** sqlite3_exec(), then execution of the current statement stops and
388** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
389** is not NULL then any error message is written into memory obtained
390** from [sqlite3_malloc()] and passed back through the 5th parameter.
391** To avoid memory leaks, the application should invoke [sqlite3_free()]
392** on error message strings returned through the 5th parameter of
393** sqlite3_exec() after the error message string is no longer needed.
394** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
395** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
396** NULL before returning.
397**
398** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
399** routine returns SQLITE_ABORT without invoking the callback again and
400** without running any subsequent SQL statements.
401**
402** ^The 2nd argument to the sqlite3_exec() callback function is the
403** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
404** callback is an array of pointers to strings obtained as if from
405** [sqlite3_column_text()], one for each column. ^If an element of a
406** result row is NULL then the corresponding string pointer for the
407** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
408** sqlite3_exec() callback is an array of pointers to strings where each
409** entry represents the name of a corresponding result column as obtained
410** from [sqlite3_column_name()].
411**
412** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
413** to an empty string, or a pointer that contains only whitespace and/or
414** SQL comments, then no SQL statements are evaluated and the database
415** is not changed.
416**
417** Restrictions:
418**
419** <ul>
420** <li> The application must ensure that the 1st parameter to sqlite3_exec()
421** is a valid and open [database connection].
422** <li> The application must not close the [database connection] specified by
423** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
424** <li> The application must not modify the SQL statement text passed into
425** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
426** <li> The application must not dereference the arrays or string pointers
427** passed as the 3rd and 4th callback parameters after it returns.
428** </ul>
429*/
430SQLITE_API int sqlite3_exec(
431 sqlite3*, /* An open database */
432 const char *sql, /* SQL to be evaluated */
433 int (*callback)(void*,int,char**,char**), /* Callback function */
434 void *, /* 1st argument to callback */
435 char **errmsg /* Error msg written here */
436);
437
438/*
439** CAPI3REF: Result Codes
440** KEYWORDS: {result code definitions}
441**
442** Many SQLite functions return an integer result code from the set shown
443** here in order to indicate success or failure.
444**
445** New error codes may be added in future versions of SQLite.
446**
447** See also: [extended result code definitions]
448*/
449#define SQLITE_OK 0 /* Successful result */
450/* beginning-of-error-codes */
451#define SQLITE_ERROR 1 /* Generic error */
452#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
453#define SQLITE_PERM 3 /* Access permission denied */
454#define SQLITE_ABORT 4 /* Callback routine requested an abort */
455#define SQLITE_BUSY 5 /* The database file is locked */
456#define SQLITE_LOCKED 6 /* A table in the database is locked */
457#define SQLITE_NOMEM 7 /* A malloc() failed */
458#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
459#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
460#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
461#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
462#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
463#define SQLITE_FULL 13 /* Insertion failed because database is full */
464#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
465#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
466#define SQLITE_EMPTY 16 /* Internal use only */
467#define SQLITE_SCHEMA 17 /* The database schema changed */
468#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
469#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
470#define SQLITE_MISMATCH 20 /* Data type mismatch */
471#define SQLITE_MISUSE 21 /* Library used incorrectly */
472#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
473#define SQLITE_AUTH 23 /* Authorization denied */
474#define SQLITE_FORMAT 24 /* Not used */
475#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
476#define SQLITE_NOTADB 26 /* File opened that is not a database file */
477#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
478#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
479#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
480#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
481/* end-of-error-codes */
482
483/*
484** CAPI3REF: Extended Result Codes
485** KEYWORDS: {extended result code definitions}
486**
487** In its default configuration, SQLite API routines return one of 30 integer
488** [result codes]. However, experience has shown that many of
489** these result codes are too coarse-grained. They do not provide as
490** much information about problems as programmers might like. In an effort to
491** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
492** and later) include
493** support for additional result codes that provide more detailed information
494** about errors. These [extended result codes] are enabled or disabled
495** on a per database connection basis using the
496** [sqlite3_extended_result_codes()] API. Or, the extended code for
497** the most recent error can be obtained using
498** [sqlite3_extended_errcode()].
499*/
500#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
501#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
502#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
503#define SQLITE_ERROR_RESERVESIZE (SQLITE_ERROR | (4<<8))
504#define SQLITE_ERROR_KEY (SQLITE_ERROR | (5<<8))
505#define SQLITE_ERROR_UNABLE (SQLITE_ERROR | (6<<8))
506#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
507#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
508#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
509#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
510#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
511#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
512#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
513#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
514#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
515#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
516#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
517#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
518#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
519#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
520#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
521#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
522#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
523#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
524#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
525#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
526#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
527#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
528#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
529#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
530#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
531#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
532#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
533#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
534#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
535#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
536#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
537#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
538#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
539#define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
540#define SQLITE_IOERR_BADKEY (SQLITE_IOERR | (35<<8))
541#define SQLITE_IOERR_CODEC (SQLITE_IOERR | (36<<8))
542#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
543#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
544#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
545#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
546#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
547#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
548#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
549#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
550#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
551#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
552#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
553#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
554#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
555#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
556#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
557#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
558#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
559#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
560#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
561#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
562#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
563#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
564#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
565#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
566#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
567#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
568#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
569#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
570#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
571#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
572#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
573#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
574#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
575#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
576#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
577#define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
578#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
579#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
580#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
581#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal only */
582
583/*
584** CAPI3REF: Flags For File Open Operations
585**
586** These bit values are intended for use in the
587** 3rd parameter to the [sqlite3_open_v2()] interface and
588** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
589**
590** Only those flags marked as "Ok for sqlite3_open_v2()" may be
591** used as the third argument to the [sqlite3_open_v2()] interface.
592** The other flags have historically been ignored by sqlite3_open_v2(),
593** though future versions of SQLite might change so that an error is
594** raised if any of the disallowed bits are passed into sqlite3_open_v2().
595** Applications should not depend on the historical behavior.
596**
597** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
598** [sqlite3_open_v2()] does *not* cause the underlying database file
599** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
600** [sqlite3_open_v2()] has historically been a no-op and might become an
601** error in future versions of SQLite.
602*/
603#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
604#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
605#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
606#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
607#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
608#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
609#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
610#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
611#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
612#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
613#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
614#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
615#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
616#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
617#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
618#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
619#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
620#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
621#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
622#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
623#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
624#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
625
626/* Reserved: 0x00F00000 */
627/* Legacy compatibility: */
628#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
629
630
631/*
632** CAPI3REF: Device Characteristics
633**
634** The xDeviceCharacteristics method of the [sqlite3_io_methods]
635** object returns an integer which is a vector of these
636** bit values expressing I/O characteristics of the mass storage
637** device that holds the file that the [sqlite3_io_methods]
638** refers to.
639**
640** The SQLITE_IOCAP_ATOMIC property means that all writes of
641** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
642** mean that writes of blocks that are nnn bytes in size and
643** are aligned to an address which is an integer multiple of
644** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
645** that when data is appended to a file, the data is appended
646** first then the size of the file is extended, never the other
647** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
648** information is written to disk in the same order as calls
649** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
650** after reboot following a crash or power loss, the only bytes in a
651** file that were written at the application level might have changed
652** and that adjacent bytes, even bytes within the same sector are
653** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
654** flag indicates that a file cannot be deleted when open. The
655** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
656** read-only media and cannot be changed even by processes with
657** elevated privileges.
658**
659** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
660** filesystem supports doing multiple write operations atomically when those
661** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
662** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
663**
664** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read
665** from the database file in amounts that are not a multiple of the
666** page size and that do not begin at a page boundary. Without this
667** property, SQLite is careful to only do full-page reads and write
668** on aligned pages, with the one exception that it will do a sub-page
669** read of the first page to access the database header.
670*/
671#define SQLITE_IOCAP_ATOMIC 0x00000001
672#define SQLITE_IOCAP_ATOMIC512 0x00000002
673#define SQLITE_IOCAP_ATOMIC1K 0x00000004
674#define SQLITE_IOCAP_ATOMIC2K 0x00000008
675#define SQLITE_IOCAP_ATOMIC4K 0x00000010
676#define SQLITE_IOCAP_ATOMIC8K 0x00000020
677#define SQLITE_IOCAP_ATOMIC16K 0x00000040
678#define SQLITE_IOCAP_ATOMIC32K 0x00000080
679#define SQLITE_IOCAP_ATOMIC64K 0x00000100
680#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
681#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
682#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
683#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
684#define SQLITE_IOCAP_IMMUTABLE 0x00002000
685#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
686#define SQLITE_IOCAP_SUBPAGE_READ 0x00008000
687
688/*
689** CAPI3REF: File Locking Levels
690**
691** SQLite uses one of these integer values as the second
692** argument to calls it makes to the xLock() and xUnlock() methods
693** of an [sqlite3_io_methods] object. These values are ordered from
694** least restrictive to most restrictive.
695**
696** The argument to xLock() is always SHARED or higher. The argument to
697** xUnlock is either SHARED or NONE.
698*/
699#define SQLITE_LOCK_NONE 0 /* xUnlock() only */
700#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
701#define SQLITE_LOCK_RESERVED 2 /* xLock() only */
702#define SQLITE_LOCK_PENDING 3 /* xLock() only */
703#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
704
705/*
706** CAPI3REF: Synchronization Type Flags
707**
708** When SQLite invokes the xSync() method of an
709** [sqlite3_io_methods] object it uses a combination of
710** these integer values as the second argument.
711**
712** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
713** sync operation only needs to flush data to mass storage. Inode
714** information need not be flushed. If the lower four bits of the flag
715** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
716** If the lower four bits equal SQLITE_SYNC_FULL, that means
717** to use Mac OS X style fullsync instead of fsync().
718**
719** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
720** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
721** settings. The [synchronous pragma] determines when calls to the
722** xSync VFS method occur and applies uniformly across all platforms.
723** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
724** energetic or rigorous or forceful the sync operations are and
725** only make a difference on Mac OSX for the default SQLite code.
726** (Third-party VFS implementations might also make the distinction
727** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
728** operating systems natively supported by SQLite, only Mac OSX
729** cares about the difference.)
730*/
731#define SQLITE_SYNC_NORMAL 0x00002
732#define SQLITE_SYNC_FULL 0x00003
733#define SQLITE_SYNC_DATAONLY 0x00010
734
735/*
736** CAPI3REF: OS Interface Open File Handle
737**
738** An [sqlite3_file] object represents an open file in the
739** [sqlite3_vfs | OS interface layer]. Individual OS interface
740** implementations will
741** want to subclass this object by appending additional fields
742** for their own use. The pMethods entry is a pointer to an
743** [sqlite3_io_methods] object that defines methods for performing
744** I/O operations on the open file.
745*/
746typedef struct sqlite3_file sqlite3_file;
747struct sqlite3_file {
748 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
749};
750
751/*
752** CAPI3REF: OS Interface File Virtual Methods Object
753**
754** Every file opened by the [sqlite3_vfs.xOpen] method populates an
755** [sqlite3_file] object (or, more commonly, a subclass of the
756** [sqlite3_file] object) with a pointer to an instance of this object.
757** This object defines the methods used to perform various operations
758** against the open file represented by the [sqlite3_file] object.
759**
760** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
761** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
762** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
763** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
764** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
765** to NULL.
766**
767** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
768** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
769** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
770** flag may be ORed in to indicate that only the data of the file
771** and not its inode needs to be synced.
772**
773** The integer values to xLock() and xUnlock() are one of
774** <ul>
775** <li> [SQLITE_LOCK_NONE],
776** <li> [SQLITE_LOCK_SHARED],
777** <li> [SQLITE_LOCK_RESERVED],
778** <li> [SQLITE_LOCK_PENDING], or
779** <li> [SQLITE_LOCK_EXCLUSIVE].
780** </ul>
781** xLock() upgrades the database file lock. In other words, xLock() moves the
782** database file lock in the direction NONE toward EXCLUSIVE. The argument to
783** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
784** SQLITE_LOCK_NONE. If the database file lock is already at or above the
785** requested lock, then the call to xLock() is a no-op.
786** xUnlock() downgrades the database file lock to either SHARED or NONE.
787** If the lock is already at or below the requested lock state, then the call
788** to xUnlock() is a no-op.
789** The xCheckReservedLock() method checks whether any database connection,
790** either in this process or in some other process, is holding a RESERVED,
791** PENDING, or EXCLUSIVE lock on the file. It returns, via its output
792** pointer parameter, true if such a lock exists and false otherwise.
793**
794** The xFileControl() method is a generic interface that allows custom
795** VFS implementations to directly control an open file using the
796** [sqlite3_file_control()] interface. The second "op" argument is an
797** integer opcode. The third argument is a generic pointer intended to
798** point to a structure that may contain arguments or space in which to
799** write return values. Potential uses for xFileControl() might be
800** functions to enable blocking locks with timeouts, to change the
801** locking strategy (for example to use dot-file locks), to inquire
802** about the status of a lock, or to break stale locks. The SQLite
803** core reserves all opcodes less than 100 for its own use.
804** A [file control opcodes | list of opcodes] less than 100 is available.
805** Applications that define a custom xFileControl method should use opcodes
806** greater than 100 to avoid conflicts. VFS implementations should
807** return [SQLITE_NOTFOUND] for file control opcodes that they do not
808** recognize.
809**
810** The xSectorSize() method returns the sector size of the
811** device that underlies the file. The sector size is the
812** minimum write that can be performed without disturbing
813** other bytes in the file. The xDeviceCharacteristics()
814** method returns a bit vector describing behaviors of the
815** underlying device:
816**
817** <ul>
818** <li> [SQLITE_IOCAP_ATOMIC]
819** <li> [SQLITE_IOCAP_ATOMIC512]
820** <li> [SQLITE_IOCAP_ATOMIC1K]
821** <li> [SQLITE_IOCAP_ATOMIC2K]
822** <li> [SQLITE_IOCAP_ATOMIC4K]
823** <li> [SQLITE_IOCAP_ATOMIC8K]
824** <li> [SQLITE_IOCAP_ATOMIC16K]
825** <li> [SQLITE_IOCAP_ATOMIC32K]
826** <li> [SQLITE_IOCAP_ATOMIC64K]
827** <li> [SQLITE_IOCAP_SAFE_APPEND]
828** <li> [SQLITE_IOCAP_SEQUENTIAL]
829** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
830** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
831** <li> [SQLITE_IOCAP_IMMUTABLE]
832** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
833** <li> [SQLITE_IOCAP_SUBPAGE_READ]
834** </ul>
835**
836** The SQLITE_IOCAP_ATOMIC property means that all writes of
837** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
838** mean that writes of blocks that are nnn bytes in size and
839** are aligned to an address which is an integer multiple of
840** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
841** that when data is appended to a file, the data is appended
842** first then the size of the file is extended, never the other
843** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
844** information is written to disk in the same order as calls
845** to xWrite().
846**
847** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
848** in the unread portions of the buffer with zeros. A VFS that
849** fails to zero-fill short reads might seem to work. However,
850** failure to zero-fill short reads will eventually lead to
851** database corruption.
852*/
853typedef struct sqlite3_io_methods sqlite3_io_methods;
854struct sqlite3_io_methods {
855 int iVersion;
856 int (*xClose)(sqlite3_file*);
857 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
858 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
859 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
860 int (*xSync)(sqlite3_file*, int flags);
861 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
862 int (*xLock)(sqlite3_file*, int);
863 int (*xUnlock)(sqlite3_file*, int);
864 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
865 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
866 int (*xSectorSize)(sqlite3_file*);
867 int (*xDeviceCharacteristics)(sqlite3_file*);
868 /* Methods above are valid for version 1 */
869 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
870 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
871 void (*xShmBarrier)(sqlite3_file*);
872 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
873 /* Methods above are valid for version 2 */
874 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
875 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
876 /* Methods above are valid for version 3 */
877 /* Additional methods may be added in future releases */
878};
879
880/*
881** CAPI3REF: Standard File Control Opcodes
882** KEYWORDS: {file control opcodes} {file control opcode}
883**
884** These integer constants are opcodes for the xFileControl method
885** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
886** interface.
887**
888** <ul>
889** <li>[[SQLITE_FCNTL_LOCKSTATE]]
890** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
891** opcode causes the xFileControl method to write the current state of
892** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
893** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
894** into an integer that the pArg argument points to.
895** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
896**
897** <li>[[SQLITE_FCNTL_SIZE_HINT]]
898** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
899** layer a hint of how large the database file will grow to be during the
900** current transaction. This hint is not guaranteed to be accurate but it
901** is often close. The underlying VFS might choose to preallocate database
902** file space based on this hint in order to help writes to the database
903** file run faster.
904**
905** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
906** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
907** implements [sqlite3_deserialize()] to set an upper bound on the size
908** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
909** If the integer pointed to is negative, then it is filled in with the
910** current limit. Otherwise the limit is set to the larger of the value
911** of the integer pointed to and the current database size. The integer
912** pointed to is set to the new limit.
913**
914** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
915** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
916** extends and truncates the database file in chunks of a size specified
917** by the user. The fourth argument to [sqlite3_file_control()] should
918** point to an integer (type int) containing the new chunk-size to use
919** for the nominated database. Allocating database file space in large
920** chunks (say 1MB at a time), may reduce file-system fragmentation and
921** improve performance on some systems.
922**
923** <li>[[SQLITE_FCNTL_FILE_POINTER]]
924** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
925** to the [sqlite3_file] object associated with a particular database
926** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
927**
928** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
929** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
930** to the [sqlite3_file] object associated with the journal file (either
931** the [rollback journal] or the [write-ahead log]) for a particular database
932** connection. See also [SQLITE_FCNTL_FILE_POINTER].
933**
934** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
935** The SQLITE_FCNTL_SYNC_OMITTED file-control is no longer used.
936**
937** <li>[[SQLITE_FCNTL_SYNC]]
938** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
939** sent to the VFS immediately before the xSync method is invoked on a
940** database file descriptor. Or, if the xSync method is not invoked
941** because the user has configured SQLite with
942** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
943** of the xSync method. In most cases, the pointer argument passed with
944** this file-control is NULL. However, if the database file is being synced
945** as part of a multi-database commit, the argument points to a nul-terminated
946** string containing the transactions super-journal file name. VFSes that
947** do not need this signal should silently ignore this opcode. Applications
948** should not call [sqlite3_file_control()] with this opcode as doing so may
949** disrupt the operation of the specialized VFSes that do require it.
950**
951** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
952** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
953** and sent to the VFS after a transaction has been committed immediately
954** but before the database is unlocked. VFSes that do not need this signal
955** should silently ignore this opcode. Applications should not call
956** [sqlite3_file_control()] with this opcode as doing so may disrupt the
957** operation of the specialized VFSes that do require it.
958**
959** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
960** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
961** retry counts and intervals for certain disk I/O operations for the
962** windows [VFS] in order to provide robustness in the presence of
963** anti-virus programs. By default, the windows VFS will retry file read,
964** file write, and file delete operations up to 10 times, with a delay
965** of 25 milliseconds before the first retry and with the delay increasing
966** by an additional 25 milliseconds with each subsequent retry. This
967** opcode allows these two values (10 retries and 25 milliseconds of delay)
968** to be adjusted. The values are changed for all database connections
969** within the same process. The argument is a pointer to an array of two
970** integers where the first integer is the new retry count and the second
971** integer is the delay. If either integer is negative, then the setting
972** is not changed but instead the prior value of that setting is written
973** into the array entry, allowing the current retry settings to be
974** interrogated. The zDbName parameter is ignored.
975**
976** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
977** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
978** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
979** write ahead log ([WAL file]) and shared memory
980** files used for transaction control
981** are automatically deleted when the latest connection to the database
982** closes. Setting persistent WAL mode causes those files to persist after
983** close. Persisting the files is useful when other processes that do not
984** have write permission on the directory containing the database file want
985** to read the database file, as the WAL and shared memory files must exist
986** in order for the database to be readable. The fourth parameter to
987** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
988** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
989** WAL mode. If the integer is -1, then it is overwritten with the current
990** WAL persistence setting.
991**
992** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
993** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
994** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
995** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
996** xDeviceCharacteristics methods. The fourth parameter to
997** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
998** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
999** mode. If the integer is -1, then it is overwritten with the current
1000** zero-damage mode setting.
1001**
1002** <li>[[SQLITE_FCNTL_OVERWRITE]]
1003** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
1004** a write transaction to indicate that, unless it is rolled back for some
1005** reason, the entire database file will be overwritten by the current
1006** transaction. This is used by VACUUM operations.
1007**
1008** <li>[[SQLITE_FCNTL_VFSNAME]]
1009** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
1010** all [VFSes] in the VFS stack. The names of all VFS shims and the
1011** final bottom-level VFS are written into memory obtained from
1012** [sqlite3_malloc()] and the result is stored in the char* variable
1013** that the fourth parameter of [sqlite3_file_control()] points to.
1014** The caller is responsible for freeing the memory when done. As with
1015** all file-control actions, there is no guarantee that this will actually
1016** do anything. Callers should initialize the char* variable to a NULL
1017** pointer in case this file-control is not implemented. This file-control
1018** is intended for diagnostic use only.
1019**
1020** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1021** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1022** [VFSes] currently in use. ^(The argument X in
1023** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1024** of type "[sqlite3_vfs] **". This opcode will set *X
1025** to a pointer to the top-level VFS.)^
1026** ^When there are multiple VFS shims in the stack, this opcode finds the
1027** upper-most shim only.
1028**
1029** <li>[[SQLITE_FCNTL_PRAGMA]]
1030** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1031** file control is sent to the open [sqlite3_file] object corresponding
1032** to the database file to which the pragma statement refers. ^The argument
1033** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1034** pointers to strings (char**) in which the second element of the array
1035** is the name of the pragma and the third element is the argument to the
1036** pragma or NULL if the pragma has no argument. ^The handler for an
1037** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1038** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1039** or the equivalent and that string will become the result of the pragma or
1040** the error message if the pragma fails. ^If the
1041** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1042** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1043** file control returns [SQLITE_OK], then the parser assumes that the
1044** VFS has handled the PRAGMA itself and the parser generates a no-op
1045** prepared statement if result string is NULL, or that returns a copy
1046** of the result string if the string is non-NULL.
1047** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1048** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1049** that the VFS encountered an error while handling the [PRAGMA] and the
1050** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1051** file control occurs at the beginning of pragma statement analysis and so
1052** it is able to override built-in [PRAGMA] statements.
1053**
1054** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1055** ^The [SQLITE_FCNTL_BUSYHANDLER]
1056** file-control may be invoked by SQLite on the database file handle
1057** shortly after it is opened in order to provide a custom VFS with access
1058** to the connection's busy-handler callback. The argument is of type (void**)
1059** - an array of two (void *) values. The first (void *) actually points
1060** to a function of type (int (*)(void *)). In order to invoke the connection's
1061** busy-handler, this function should be invoked with the second (void *) in
1062** the array as the only argument. If it returns non-zero, then the operation
1063** should be retried. If it returns zero, the custom VFS should abandon the
1064** current operation.
1065**
1066** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1067** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1068** to have SQLite generate a
1069** temporary filename using the same algorithm that is followed to generate
1070** temporary filenames for TEMP tables and other internal uses. The
1071** argument should be a char** which will be filled with the filename
1072** written into memory obtained from [sqlite3_malloc()]. The caller should
1073** invoke [sqlite3_free()] on the result to avoid a memory leak.
1074**
1075** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1076** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1077** maximum number of bytes that will be used for memory-mapped I/O.
1078** The argument is a pointer to a value of type sqlite3_int64 that
1079** is an advisory maximum number of bytes in the file to memory map. The
1080** pointer is overwritten with the old value. The limit is not changed if
1081** the value originally pointed to is negative, and so the current limit
1082** can be queried by passing in a pointer to a negative number. This
1083** file-control is used internally to implement [PRAGMA mmap_size].
1084**
1085** <li>[[SQLITE_FCNTL_TRACE]]
1086** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1087** to the VFS about what the higher layers of the SQLite stack are doing.
1088** This file control is used by some VFS activity tracing [shims].
1089** The argument is a zero-terminated string. Higher layers in the
1090** SQLite stack may generate instances of this file control if
1091** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1092**
1093** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1094** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1095** pointer to an integer and it writes a boolean into that integer depending
1096** on whether or not the file has been renamed, moved, or deleted since it
1097** was first opened.
1098**
1099** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1100** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1101** underlying native file handle associated with a file handle. This file
1102** control interprets its argument as a pointer to a native file handle and
1103** writes the resulting value there.
1104**
1105** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1106** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1107** opcode causes the xFileControl method to swap the file handle with the one
1108** pointed to by the pArg argument. This capability is used during testing
1109** and only needs to be supported when SQLITE_TEST is defined.
1110**
1111** <li>[[SQLITE_FCNTL_NULL_IO]]
1112** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
1113** or file handle for the [sqlite3_file] object such that it will no longer
1114** read or write to the database file.
1115**
1116** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1117** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1118** be advantageous to block on the next WAL lock if the lock is not immediately
1119** available. The WAL subsystem issues this signal during rare
1120** circumstances in order to fix a problem with priority inversion.
1121** Applications should <em>not</em> use this file-control.
1122**
1123** <li>[[SQLITE_FCNTL_ZIPVFS]]
1124** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1125** VFS should return SQLITE_NOTFOUND for this opcode.
1126**
1127** <li>[[SQLITE_FCNTL_RBU]]
1128** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1129** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1130** this opcode.
1131**
1132** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1133** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1134** the file descriptor is placed in "batch write mode", which
1135** means all subsequent write operations will be deferred and done
1136** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1137** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1138** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1139** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1140** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1141** no VFS interface calls on the same [sqlite3_file] file descriptor
1142** except for calls to the xWrite method and the xFileControl method
1143** with [SQLITE_FCNTL_SIZE_HINT].
1144**
1145** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1146** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1147** operations since the previous successful call to
1148** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1149** This file control returns [SQLITE_OK] if and only if the writes were
1150** all performed successfully and have been committed to persistent storage.
1151** ^Regardless of whether or not it is successful, this file control takes
1152** the file descriptor out of batch write mode so that all subsequent
1153** write operations are independent.
1154** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1155** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1156**
1157** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1158** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1159** operations since the previous successful call to
1160** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1161** ^This file control takes the file descriptor out of batch write mode
1162** so that all subsequent write operations are independent.
1163** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1164** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1165**
1166** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1167** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1168** to block for up to M milliseconds before failing when attempting to
1169** obtain a file lock using the xLock or xShmLock methods of the VFS.
1170** The parameter is a pointer to a 32-bit signed integer that contains
1171** the value that M is to be set to. Before returning, the 32-bit signed
1172** integer is overwritten with the previous value of M.
1173**
1174** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]]
1175** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the
1176** VFS to block when taking a SHARED lock to connect to a wal mode database.
1177** This is used to implement the functionality associated with
1178** SQLITE_SETLK_BLOCK_ON_CONNECT.
1179**
1180** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1181** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1182** a database file. The argument is a pointer to a 32-bit unsigned integer.
1183** The "data version" for the pager is written into the pointer. The
1184** "data version" changes whenever any change occurs to the corresponding
1185** database file, either through SQL statements on the same database
1186** connection or through transactions committed by separate database
1187** connections possibly in other processes. The [sqlite3_total_changes()]
1188** interface can be used to find if any database on the connection has changed,
1189** but that interface responds to changes on TEMP as well as MAIN and does
1190** not provide a mechanism to detect changes to MAIN only. Also, the
1191** [sqlite3_total_changes()] interface responds to internal changes only and
1192** omits changes made by other database connections. The
1193** [PRAGMA data_version] command provides a mechanism to detect changes to
1194** a single attached database that occur due to other database connections,
1195** but omits changes implemented by the database connection on which it is
1196** called. This file control is the only mechanism to detect changes that
1197** happen either internally or externally and that are associated with
1198** a particular attached database.
1199**
1200** <li>[[SQLITE_FCNTL_CKPT_START]]
1201** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1202** in wal mode before the client starts to copy pages from the wal
1203** file to the database file.
1204**
1205** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1206** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1207** in wal mode after the client has finished copying pages from the wal
1208** file to the database file, but before the *-shm file is updated to
1209** record the fact that the pages have been checkpointed.
1210**
1211** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1212** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1213** whether or not there is a database client in another process with a wal-mode
1214** transaction open on the database or not. It is only available on unix. The
1215** (void*) argument passed with this file-control should be a pointer to a
1216** value of type (int). The integer value is set to 1 if the database is a wal
1217** mode database and there exists at least one client in another process that
1218** currently has an SQL transaction open on the database. It is set to 0 if
1219** the database is not a wal-mode db, or if there is no such connection in any
1220** other process. This opcode cannot be used to detect transactions opened
1221** by clients within the current process, only within other processes.
1222**
1223** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1224** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1225** [checksum VFS shim] only.
1226**
1227** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1228** If there is currently no transaction open on the database, and the
1229** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1230** purges the contents of the in-memory page cache. If there is an open
1231** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1232**
1233** <li>[[SQLITE_FCNTL_FILESTAT]]
1234** The [SQLITE_FCNTL_FILESTAT] opcode returns low-level diagnostic information
1235** about the [sqlite3_file] objects used access the database and journal files
1236** for the given schema. The fourth parameter to [sqlite3_file_control()]
1237** should be an initialized [sqlite3_str] pointer. JSON text describing
1238** various aspects of the sqlite3_file object is appended to the sqlite3_str.
1239** The SQLITE_FCNTL_FILESTAT opcode is usually a no-op, unless compile-time
1240** options are used to enable it.
1241** </ul>
1242*/
1243#define SQLITE_FCNTL_LOCKSTATE 1
1244#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1245#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1246#define SQLITE_FCNTL_LAST_ERRNO 4
1247#define SQLITE_FCNTL_SIZE_HINT 5
1248#define SQLITE_FCNTL_CHUNK_SIZE 6
1249#define SQLITE_FCNTL_FILE_POINTER 7
1250#define SQLITE_FCNTL_SYNC_OMITTED 8
1251#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1252#define SQLITE_FCNTL_PERSIST_WAL 10
1253#define SQLITE_FCNTL_OVERWRITE 11
1254#define SQLITE_FCNTL_VFSNAME 12
1255#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1256#define SQLITE_FCNTL_PRAGMA 14
1257#define SQLITE_FCNTL_BUSYHANDLER 15
1258#define SQLITE_FCNTL_TEMPFILENAME 16
1259#define SQLITE_FCNTL_MMAP_SIZE 18
1260#define SQLITE_FCNTL_TRACE 19
1261#define SQLITE_FCNTL_HAS_MOVED 20
1262#define SQLITE_FCNTL_SYNC 21
1263#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1264#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1265#define SQLITE_FCNTL_WAL_BLOCK 24
1266#define SQLITE_FCNTL_ZIPVFS 25
1267#define SQLITE_FCNTL_RBU 26
1268#define SQLITE_FCNTL_VFS_POINTER 27
1269#define SQLITE_FCNTL_JOURNAL_POINTER 28
1270#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1271#define SQLITE_FCNTL_PDB 30
1272#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1273#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1274#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1275#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1276#define SQLITE_FCNTL_DATA_VERSION 35
1277#define SQLITE_FCNTL_SIZE_LIMIT 36
1278#define SQLITE_FCNTL_CKPT_DONE 37
1279#define SQLITE_FCNTL_RESERVE_BYTES 38
1280#define SQLITE_FCNTL_CKPT_START 39
1281#define SQLITE_FCNTL_EXTERNAL_READER 40
1282#define SQLITE_FCNTL_CKSM_FILE 41
1283#define SQLITE_FCNTL_RESET_CACHE 42
1284#define SQLITE_FCNTL_NULL_IO 43
1285#define SQLITE_FCNTL_BLOCK_ON_CONNECT 44
1286#define SQLITE_FCNTL_FILESTAT 45
1287
1288/* deprecated names */
1289#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1290#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1291#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1292
1293/* reserved file-control numbers:
1294** 101
1295** 102
1296** 103
1297*/
1298
1299
1300/*
1301** CAPI3REF: Mutex Handle
1302**
1303** The mutex module within SQLite defines [sqlite3_mutex] to be an
1304** abstract type for a mutex object. The SQLite core never looks
1305** at the internal representation of an [sqlite3_mutex]. It only
1306** deals with pointers to the [sqlite3_mutex] object.
1307**
1308** Mutexes are created using [sqlite3_mutex_alloc()].
1309*/
1310typedef struct sqlite3_mutex sqlite3_mutex;
1311
1312/*
1313** CAPI3REF: Loadable Extension Thunk
1314**
1315** A pointer to the opaque sqlite3_api_routines structure is passed as
1316** the third parameter to entry points of [loadable extensions]. This
1317** structure must be typedefed in order to work around compiler warnings
1318** on some platforms.
1319*/
1320typedef struct sqlite3_api_routines sqlite3_api_routines;
1321
1322/*
1323** CAPI3REF: File Name
1324**
1325** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1326** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1327** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1328** may also be passed to special APIs such as:
1329**
1330** <ul>
1331** <li> sqlite3_filename_database()
1332** <li> sqlite3_filename_journal()
1333** <li> sqlite3_filename_wal()
1334** <li> sqlite3_uri_parameter()
1335** <li> sqlite3_uri_boolean()
1336** <li> sqlite3_uri_int64()
1337** <li> sqlite3_uri_key()
1338** </ul>
1339*/
1340typedef const char *sqlite3_filename;
1341
1342/*
1343** CAPI3REF: OS Interface Object
1344**
1345** An instance of the sqlite3_vfs object defines the interface between
1346** the SQLite core and the underlying operating system. The "vfs"
1347** in the name of the object stands for "virtual file system". See
1348** the [VFS | VFS documentation] for further information.
1349**
1350** The VFS interface is sometimes extended by adding new methods onto
1351** the end. Each time such an extension occurs, the iVersion field
1352** is incremented. The iVersion value started out as 1 in
1353** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1354** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1355** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1356** may be appended to the sqlite3_vfs object and the iVersion value
1357** may increase again in future versions of SQLite.
1358** Note that due to an oversight, the structure
1359** of the sqlite3_vfs object changed in the transition from
1360** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1361** and yet the iVersion field was not increased.
1362**
1363** The szOsFile field is the size of the subclassed [sqlite3_file]
1364** structure used by this VFS. mxPathname is the maximum length of
1365** a pathname in this VFS.
1366**
1367** Registered sqlite3_vfs objects are kept on a linked list formed by
1368** the pNext pointer. The [sqlite3_vfs_register()]
1369** and [sqlite3_vfs_unregister()] interfaces manage this list
1370** in a thread-safe way. The [sqlite3_vfs_find()] interface
1371** searches the list. Neither the application code nor the VFS
1372** implementation should use the pNext pointer.
1373**
1374** The pNext field is the only field in the sqlite3_vfs
1375** structure that SQLite will ever modify. SQLite will only access
1376** or modify this field while holding a particular static mutex.
1377** The application should never modify anything within the sqlite3_vfs
1378** object once the object has been registered.
1379**
1380** The zName field holds the name of the VFS module. The name must
1381** be unique across all VFS modules.
1382**
1383** [[sqlite3_vfs.xOpen]]
1384** ^SQLite guarantees that the zFilename parameter to xOpen
1385** is either a NULL pointer or string obtained
1386** from xFullPathname() with an optional suffix added.
1387** ^If a suffix is added to the zFilename parameter, it will
1388** consist of a single "-" character followed by no more than
1389** 11 alphanumeric and/or "-" characters.
1390** ^SQLite further guarantees that
1391** the string will be valid and unchanged until xClose() is
1392** called. Because of the previous sentence,
1393** the [sqlite3_file] can safely store a pointer to the
1394** filename if it needs to remember the filename for some reason.
1395** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1396** must invent its own temporary name for the file. ^Whenever the
1397** xFilename parameter is NULL it will also be the case that the
1398** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1399**
1400** The flags argument to xOpen() includes all bits set in
1401** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1402** or [sqlite3_open16()] is used, then flags includes at least
1403** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1404** If xOpen() opens a file read-only then it sets *pOutFlags to
1405** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1406**
1407** ^(SQLite will also add one of the following flags to the xOpen()
1408** call, depending on the object being opened:
1409**
1410** <ul>
1411** <li> [SQLITE_OPEN_MAIN_DB]
1412** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1413** <li> [SQLITE_OPEN_TEMP_DB]
1414** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1415** <li> [SQLITE_OPEN_TRANSIENT_DB]
1416** <li> [SQLITE_OPEN_SUBJOURNAL]
1417** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1418** <li> [SQLITE_OPEN_WAL]
1419** </ul>)^
1420**
1421** The file I/O implementation can use the object type flags to
1422** change the way it deals with files. For example, an application
1423** that does not care about crash recovery or rollback might make
1424** the open of a journal file a no-op. Writes to this journal would
1425** also be no-ops, and any attempt to read the journal would return
1426** SQLITE_IOERR. Or the implementation might recognize that a database
1427** file will be doing page-aligned sector reads and writes in a random
1428** order and set up its I/O subsystem accordingly.
1429**
1430** SQLite might also add one of the following flags to the xOpen method:
1431**
1432** <ul>
1433** <li> [SQLITE_OPEN_DELETEONCLOSE]
1434** <li> [SQLITE_OPEN_EXCLUSIVE]
1435** </ul>
1436**
1437** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1438** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1439** will be set for TEMP databases and their journals, transient
1440** databases, and subjournals.
1441**
1442** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1443** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1444** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1445** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1446** SQLITE_OPEN_CREATE, is used to indicate that file should always
1447** be created, and that it is an error if it already exists.
1448** It is <i>not</i> used to indicate the file should be opened
1449** for exclusive access.
1450**
1451** ^At least szOsFile bytes of memory are allocated by SQLite
1452** to hold the [sqlite3_file] structure passed as the third
1453** argument to xOpen. The xOpen method does not have to
1454** allocate the structure; it should just fill it in. Note that
1455** the xOpen method must set the sqlite3_file.pMethods to either
1456** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1457** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1458** element will be valid after xOpen returns regardless of the success
1459** or failure of the xOpen call.
1460**
1461** [[sqlite3_vfs.xAccess]]
1462** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1463** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1464** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1465** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1466** flag is never actually used and is not implemented in the built-in
1467** VFSes of SQLite. The file is named by the second argument and can be a
1468** directory. The xAccess method returns [SQLITE_OK] on success or some
1469** non-zero error code if there is an I/O error or if the name of
1470** the file given in the second argument is illegal. If SQLITE_OK
1471** is returned, then non-zero or zero is written into *pResOut to indicate
1472** whether or not the file is accessible.
1473**
1474** ^SQLite will always allocate at least mxPathname+1 bytes for the
1475** output buffer xFullPathname. The exact size of the output buffer
1476** is also passed as a parameter to both methods. If the output buffer
1477** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1478** handled as a fatal error by SQLite, vfs implementations should endeavor
1479** to prevent this by setting mxPathname to a sufficiently large value.
1480**
1481** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1482** interfaces are not strictly a part of the filesystem, but they are
1483** included in the VFS structure for completeness.
1484** The xRandomness() function attempts to return nBytes bytes
1485** of good-quality randomness into zOut. The return value is
1486** the actual number of bytes of randomness obtained.
1487** The xSleep() method causes the calling thread to sleep for at
1488** least the number of microseconds given. ^The xCurrentTime()
1489** method returns a Julian Day Number for the current date and time as
1490** a floating point value.
1491** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1492** Day Number multiplied by 86400000 (the number of milliseconds in
1493** a 24-hour day).
1494** ^SQLite will use the xCurrentTimeInt64() method to get the current
1495** date and time if that method is available (if iVersion is 2 or
1496** greater and the function pointer is not NULL) and will fall back
1497** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1498**
1499** ^The xSetSystemCall(), xGetSystemCall(), and xNextSystemCall() interfaces
1500** are not used by the SQLite core. These optional interfaces are provided
1501** by some VFSes to facilitate testing of the VFS code. By overriding
1502** system calls with functions under its control, a test program can
1503** simulate faults and error conditions that would otherwise be difficult
1504** or impossible to induce. The set of system calls that can be overridden
1505** varies from one VFS to another, and from one version of the same VFS to the
1506** next. Applications that use these interfaces must be prepared for any
1507** or all of these interfaces to be NULL or for their behavior to change
1508** from one release to the next. Applications must not attempt to access
1509** any of these methods if the iVersion of the VFS is less than 3.
1510*/
1511typedef struct sqlite3_vfs sqlite3_vfs;
1512typedef void (*sqlite3_syscall_ptr)(void);
1513struct sqlite3_vfs {
1514 int iVersion; /* Structure version number (currently 3) */
1515 int szOsFile; /* Size of subclassed sqlite3_file */
1516 int mxPathname; /* Maximum file pathname length */
1517 sqlite3_vfs *pNext; /* Next registered VFS */
1518 const char *zName; /* Name of this virtual file system */
1519 void *pAppData; /* Pointer to application-specific data */
1520 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1521 int flags, int *pOutFlags);
1522 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1523 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1524 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1525 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1526 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1527 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1528 void (*xDlClose)(sqlite3_vfs*, void*);
1529 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1530 int (*xSleep)(sqlite3_vfs*, int microseconds);
1531 int (*xCurrentTime)(sqlite3_vfs*, double*);
1532 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1533 /*
1534 ** The methods above are in version 1 of the sqlite_vfs object
1535 ** definition. Those that follow are added in version 2 or later
1536 */
1537 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1538 /*
1539 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1540 ** Those below are for version 3 and greater.
1541 */
1542 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1543 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1544 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1545 /*
1546 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1547 ** New fields may be appended in future versions. The iVersion
1548 ** value will increment whenever this happens.
1549 */
1550};
1551
1552/*
1553** CAPI3REF: Flags for the xAccess VFS method
1554**
1555** These integer constants can be used as the third parameter to
1556** the xAccess method of an [sqlite3_vfs] object. They determine
1557** what kind of permissions the xAccess method is looking for.
1558** With SQLITE_ACCESS_EXISTS, the xAccess method
1559** simply checks whether the file exists.
1560** With SQLITE_ACCESS_READWRITE, the xAccess method
1561** checks whether the named directory is both readable and writable
1562** (in other words, if files can be added, removed, and renamed within
1563** the directory).
1564** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1565** [temp_store_directory pragma], though this could change in a future
1566** release of SQLite.
1567** With SQLITE_ACCESS_READ, the xAccess method
1568** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1569** currently unused, though it might be used in a future release of
1570** SQLite.
1571*/
1572#define SQLITE_ACCESS_EXISTS 0
1573#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1574#define SQLITE_ACCESS_READ 2 /* Unused */
1575
1576/*
1577** CAPI3REF: Flags for the xShmLock VFS method
1578**
1579** These integer constants define the various locking operations
1580** allowed by the xShmLock method of [sqlite3_io_methods]. The
1581** following are the only legal combinations of flags to the
1582** xShmLock method:
1583**
1584** <ul>
1585** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1586** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1587** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1588** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1589** </ul>
1590**
1591** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1592** was given on the corresponding lock.
1593**
1594** The xShmLock method can transition between unlocked and SHARED or
1595** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1596** and EXCLUSIVE.
1597*/
1598#define SQLITE_SHM_UNLOCK 1
1599#define SQLITE_SHM_LOCK 2
1600#define SQLITE_SHM_SHARED 4
1601#define SQLITE_SHM_EXCLUSIVE 8
1602
1603/*
1604** CAPI3REF: Maximum xShmLock index
1605**
1606** The xShmLock method on [sqlite3_io_methods] may use values
1607** between 0 and this upper bound as its "offset" argument.
1608** The SQLite core will never attempt to acquire or release a
1609** lock outside of this range
1610*/
1611#define SQLITE_SHM_NLOCK 8
1612
1613
1614/*
1615** CAPI3REF: Initialize The SQLite Library
1616**
1617** ^The sqlite3_initialize() routine initializes the
1618** SQLite library. ^The sqlite3_shutdown() routine
1619** deallocates any resources that were allocated by sqlite3_initialize().
1620** These routines are designed to aid in process initialization and
1621** shutdown on embedded systems. Workstation applications using
1622** SQLite normally do not need to invoke either of these routines.
1623**
1624** A call to sqlite3_initialize() is an "effective" call if it is
1625** the first time sqlite3_initialize() is invoked during the lifetime of
1626** the process, or if it is the first time sqlite3_initialize() is invoked
1627** following a call to sqlite3_shutdown(). ^(Only an effective call
1628** of sqlite3_initialize() does any initialization. All other calls
1629** are harmless no-ops.)^
1630**
1631** A call to sqlite3_shutdown() is an "effective" call if it is the first
1632** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1633** an effective call to sqlite3_shutdown() does any deinitialization.
1634** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1635**
1636** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1637** is not. The sqlite3_shutdown() interface must only be called from a
1638** single thread. All open [database connections] must be closed and all
1639** other SQLite resources must be deallocated prior to invoking
1640** sqlite3_shutdown().
1641**
1642** Among other things, ^sqlite3_initialize() will invoke
1643** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1644** will invoke sqlite3_os_end().
1645**
1646** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1647** ^If for some reason, sqlite3_initialize() is unable to initialize
1648** the library (perhaps it is unable to allocate a needed resource such
1649** as a mutex) it returns an [error code] other than [SQLITE_OK].
1650**
1651** ^The sqlite3_initialize() routine is called internally by many other
1652** SQLite interfaces so that an application usually does not need to
1653** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1654** calls sqlite3_initialize() so the SQLite library will be automatically
1655** initialized when [sqlite3_open()] is called if it has not been initialized
1656** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1657** compile-time option, then the automatic calls to sqlite3_initialize()
1658** are omitted and the application must call sqlite3_initialize() directly
1659** prior to using any other SQLite interface. For maximum portability,
1660** it is recommended that applications always invoke sqlite3_initialize()
1661** directly prior to using any other SQLite interface. Future releases
1662** of SQLite may require this. In other words, the behavior exhibited
1663** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1664** default behavior in some future release of SQLite.
1665**
1666** The sqlite3_os_init() routine does operating-system specific
1667** initialization of the SQLite library. The sqlite3_os_end()
1668** routine undoes the effect of sqlite3_os_init(). Typical tasks
1669** performed by these routines include allocation or deallocation
1670** of static resources, initialization of global variables,
1671** setting up a default [sqlite3_vfs] module, or setting up
1672** a default configuration using [sqlite3_config()].
1673**
1674** The application should never invoke either sqlite3_os_init()
1675** or sqlite3_os_end() directly. The application should only invoke
1676** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1677** interface is called automatically by sqlite3_initialize() and
1678** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1679** implementations for sqlite3_os_init() and sqlite3_os_end()
1680** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1681** When [custom builds | built for other platforms]
1682** (using the [SQLITE_OS_OTHER=1] compile-time
1683** option) the application must supply a suitable implementation for
1684** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1685** implementation of sqlite3_os_init() or sqlite3_os_end()
1686** must return [SQLITE_OK] on success and some other [error code] upon
1687** failure.
1688*/
1689SQLITE_API int sqlite3_initialize(void);
1690SQLITE_API int sqlite3_shutdown(void);
1691SQLITE_API int sqlite3_os_init(void);
1692SQLITE_API int sqlite3_os_end(void);
1693
1694/*
1695** CAPI3REF: Configuring The SQLite Library
1696**
1697** The sqlite3_config() interface is used to make global configuration
1698** changes to SQLite in order to tune SQLite to the specific needs of
1699** the application. The default configuration is recommended for most
1700** applications and so this routine is usually not necessary. It is
1701** provided to support rare applications with unusual needs.
1702**
1703** <b>The sqlite3_config() interface is not threadsafe. The application
1704** must ensure that no other SQLite interfaces are invoked by other
1705** threads while sqlite3_config() is running.</b>
1706**
1707** The first argument to sqlite3_config() is an integer
1708** [configuration option] that determines
1709** what property of SQLite is to be configured. Subsequent arguments
1710** vary depending on the [configuration option]
1711** in the first argument.
1712**
1713** For most configuration options, the sqlite3_config() interface
1714** may only be invoked prior to library initialization using
1715** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1716** The exceptional configuration options that may be invoked at any time
1717** are called "anytime configuration options".
1718** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1719** [sqlite3_shutdown()] with a first argument that is not an anytime
1720** configuration option, then the sqlite3_config() call will
1721** return SQLITE_MISUSE.
1722** Note, however, that ^sqlite3_config() can be called as part of the
1723** implementation of an application-defined [sqlite3_os_init()].
1724**
1725** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1726** ^If the option is unknown or SQLite is unable to set the option
1727** then this routine returns a non-zero [error code].
1728*/
1729SQLITE_API int sqlite3_config(int, ...);
1730
1731/*
1732** CAPI3REF: Configure database connections
1733** METHOD: sqlite3
1734**
1735** The sqlite3_db_config() interface is used to make configuration
1736** changes to a [database connection]. The interface is similar to
1737** [sqlite3_config()] except that the changes apply to a single
1738** [database connection] (specified in the first argument).
1739**
1740** The second argument to sqlite3_db_config(D,V,...) is the
1741** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1742** that indicates what aspect of the [database connection] is being configured.
1743** Subsequent arguments vary depending on the configuration verb.
1744**
1745** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1746** the call is considered successful.
1747*/
1748SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1749
1750/*
1751** CAPI3REF: Memory Allocation Routines
1752**
1753** An instance of this object defines the interface between SQLite
1754** and low-level memory allocation routines.
1755**
1756** This object is used in only one place in the SQLite interface.
1757** A pointer to an instance of this object is the argument to
1758** [sqlite3_config()] when the configuration option is
1759** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1760** By creating an instance of this object
1761** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1762** during configuration, an application can specify an alternative
1763** memory allocation subsystem for SQLite to use for all of its
1764** dynamic memory needs.
1765**
1766** Note that SQLite comes with several [built-in memory allocators]
1767** that are perfectly adequate for the overwhelming majority of applications
1768** and that this object is only useful to a tiny minority of applications
1769** with specialized memory allocation requirements. This object is
1770** also used during testing of SQLite in order to specify an alternative
1771** memory allocator that simulates memory out-of-memory conditions in
1772** order to verify that SQLite recovers gracefully from such
1773** conditions.
1774**
1775** The xMalloc, xRealloc, and xFree methods must work like the
1776** malloc(), realloc() and free() functions from the standard C library.
1777** ^SQLite guarantees that the second argument to
1778** xRealloc is always a value returned by a prior call to xRoundup.
1779**
1780** xSize should return the allocated size of a memory allocation
1781** previously obtained from xMalloc or xRealloc. The allocated size
1782** is always at least as big as the requested size but may be larger.
1783**
1784** The xRoundup method returns what would be the allocated size of
1785** a memory allocation given a particular requested size. Most memory
1786** allocators round up memory allocations at least to the next multiple
1787** of 8. Some allocators round up to a larger multiple or to a power of 2.
1788** Every memory allocation request coming in through [sqlite3_malloc()]
1789** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1790** that causes the corresponding memory allocation to fail.
1791**
1792** The xInit method initializes the memory allocator. For example,
1793** it might allocate any required mutexes or initialize internal data
1794** structures. The xShutdown method is invoked (indirectly) by
1795** [sqlite3_shutdown()] and should deallocate any resources acquired
1796** by xInit. The pAppData pointer is used as the only parameter to
1797** xInit and xShutdown.
1798**
1799** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1800** the xInit method, so the xInit method need not be threadsafe. The
1801** xShutdown method is only called from [sqlite3_shutdown()] so it does
1802** not need to be threadsafe either. For all other methods, SQLite
1803** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1804** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1805** it is by default) and so the methods are automatically serialized.
1806** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1807** methods must be threadsafe or else make their own arrangements for
1808** serialization.
1809**
1810** SQLite will never invoke xInit() more than once without an intervening
1811** call to xShutdown().
1812*/
1813typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1814struct sqlite3_mem_methods {
1815 void *(*xMalloc)(int); /* Memory allocation function */
1816 void (*xFree)(void*); /* Free a prior allocation */
1817 void *(*xRealloc)(void*,int); /* Resize an allocation */
1818 int (*xSize)(void*); /* Return the size of an allocation */
1819 int (*xRoundup)(int); /* Round up request size to allocation size */
1820 int (*xInit)(void*); /* Initialize the memory allocator */
1821 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1822 void *pAppData; /* Argument to xInit() and xShutdown() */
1823};
1824
1825/*
1826** CAPI3REF: Configuration Options
1827** KEYWORDS: {configuration option}
1828**
1829** These constants are the available integer configuration options that
1830** can be passed as the first argument to the [sqlite3_config()] interface.
1831**
1832** Most of the configuration options for sqlite3_config()
1833** will only work if invoked prior to [sqlite3_initialize()] or after
1834** [sqlite3_shutdown()]. The few exceptions to this rule are called
1835** "anytime configuration options".
1836** ^Calling [sqlite3_config()] with a first argument that is not an
1837** anytime configuration option in between calls to [sqlite3_initialize()] and
1838** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1839**
1840** The set of anytime configuration options can change (by insertions
1841** and/or deletions) from one release of SQLite to the next.
1842** As of SQLite version 3.42.0, the complete set of anytime configuration
1843** options is:
1844** <ul>
1845** <li> SQLITE_CONFIG_LOG
1846** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1847** </ul>
1848**
1849** New configuration options may be added in future releases of SQLite.
1850** Existing configuration options might be discontinued. Applications
1851** should check the return code from [sqlite3_config()] to make sure that
1852** the call worked. The [sqlite3_config()] interface will return a
1853** non-zero [error code] if a discontinued or unsupported configuration option
1854** is invoked.
1855**
1856** <dl>
1857** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1858** <dd>There are no arguments to this option. ^This option sets the
1859** [threading mode] to Single-thread. In other words, it disables
1860** all mutexing and puts SQLite into a mode where it can only be used
1861** by a single thread. ^If SQLite is compiled with
1862** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1863** it is not possible to change the [threading mode] from its default
1864** value of Single-thread and so [sqlite3_config()] will return
1865** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1866** configuration option.</dd>
1867**
1868** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1869** <dd>There are no arguments to this option. ^This option sets the
1870** [threading mode] to Multi-thread. In other words, it disables
1871** mutexing on [database connection] and [prepared statement] objects.
1872** The application is responsible for serializing access to
1873** [database connections] and [prepared statements]. But other mutexes
1874** are enabled so that SQLite will be safe to use in a multi-threaded
1875** environment as long as no two threads attempt to use the same
1876** [database connection] at the same time. ^If SQLite is compiled with
1877** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1878** it is not possible to set the Multi-thread [threading mode] and
1879** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1880** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1881**
1882** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1883** <dd>There are no arguments to this option. ^This option sets the
1884** [threading mode] to Serialized. In other words, this option enables
1885** all mutexes including the recursive
1886** mutexes on [database connection] and [prepared statement] objects.
1887** In this mode (which is the default when SQLite is compiled with
1888** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1889** to [database connections] and [prepared statements] so that the
1890** application is free to use the same [database connection] or the
1891** same [prepared statement] in different threads at the same time.
1892** ^If SQLite is compiled with
1893** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1894** it is not possible to set the Serialized [threading mode] and
1895** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1896** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1897**
1898** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1899** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1900** a pointer to an instance of the [sqlite3_mem_methods] structure.
1901** The argument specifies
1902** alternative low-level memory allocation routines to be used in place of
1903** the memory allocation routines built into SQLite.)^ ^SQLite makes
1904** its own private copy of the content of the [sqlite3_mem_methods] structure
1905** before the [sqlite3_config()] call returns.</dd>
1906**
1907** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1908** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1909** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1910** The [sqlite3_mem_methods]
1911** structure is filled with the currently defined memory allocation routines.)^
1912** This option can be used to overload the default memory allocation
1913** routines with a wrapper that simulates memory allocation failure or
1914** tracks memory usage, for example. </dd>
1915**
1916** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1917** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes a single argument of
1918** type int, interpreted as a boolean, which if true provides a hint to
1919** SQLite that it should avoid large memory allocations if possible.
1920** SQLite will run faster if it is free to make large memory allocations,
1921** but some applications might prefer to run slower in exchange for
1922** guarantees about memory fragmentation that are possible if large
1923** allocations are avoided. This hint is normally off.
1924** </dd>
1925**
1926** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1927** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes a single argument of type int,
1928** interpreted as a boolean, which enables or disables the collection of
1929** memory allocation statistics. ^(When memory allocation statistics are
1930** disabled, the following SQLite interfaces become non-operational:
1931** <ul>
1932** <li> [sqlite3_hard_heap_limit64()]
1933** <li> [sqlite3_memory_used()]
1934** <li> [sqlite3_memory_highwater()]
1935** <li> [sqlite3_soft_heap_limit64()]
1936** <li> [sqlite3_status64()]
1937** </ul>)^
1938** ^Memory allocation statistics are enabled by default unless SQLite is
1939** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1940** allocation statistics are disabled by default.
1941** </dd>
1942**
1943** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1944** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1945** </dd>
1946**
1947** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1948** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1949** that SQLite can use for the database page cache with the default page
1950** cache implementation.
1951** This configuration option is a no-op if an application-defined page
1952** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1953** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1954** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1955** and the number of cache lines (N).
1956** The sz argument should be the size of the largest database page
1957** (a power of two between 512 and 65536) plus some extra bytes for each
1958** page header. ^The number of extra bytes needed by the page header
1959** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1960** ^It is harmless, apart from the wasted memory,
1961** for the sz parameter to be larger than necessary. The pMem
1962** argument must be either a NULL pointer or a pointer to an 8-byte
1963** aligned block of memory of at least sz*N bytes, otherwise
1964** subsequent behavior is undefined.
1965** ^When pMem is not NULL, SQLite will strive to use the memory provided
1966** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1967** a page cache line is larger than sz bytes or if all of the pMem buffer
1968** is exhausted.
1969** ^If pMem is NULL and N is non-zero, then each database connection
1970** does an initial bulk allocation for page cache memory
1971** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1972** of -1024*N bytes if N is negative. ^If additional
1973** page cache memory is needed beyond what is provided by the initial
1974** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1975** additional cache line. </dd>
1976**
1977** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1978** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1979** that SQLite will use for all of its dynamic memory allocation needs
1980** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1981** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1982** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1983** [SQLITE_ERROR] if invoked otherwise.
1984** ^There are three arguments to SQLITE_CONFIG_HEAP:
1985** An 8-byte aligned pointer to the memory,
1986** the number of bytes in the memory buffer, and the minimum allocation size.
1987** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1988** to using its default memory allocator (the system malloc() implementation),
1989** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1990** memory pointer is not NULL then the alternative memory
1991** allocator is engaged to handle all of SQLites memory allocation needs.
1992** The first pointer (the memory pointer) must be aligned to an 8-byte
1993** boundary or subsequent behavior of SQLite will be undefined.
1994** The minimum allocation size is capped at 2**12. Reasonable values
1995** for the minimum allocation size are 2**5 through 2**8.</dd>
1996**
1997** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1998** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1999** pointer to an instance of the [sqlite3_mutex_methods] structure.
2000** The argument specifies alternative low-level mutex routines to be used
2001** in place of the mutex routines built into SQLite.)^ ^SQLite makes a copy of
2002** the content of the [sqlite3_mutex_methods] structure before the call to
2003** [sqlite3_config()] returns. ^If SQLite is compiled with
2004** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
2005** the entire mutexing subsystem is omitted from the build and hence calls to
2006** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
2007** return [SQLITE_ERROR].</dd>
2008**
2009** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
2010** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
2011** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
2012** [sqlite3_mutex_methods]
2013** structure is filled with the currently defined mutex routines.)^
2014** This option can be used to overload the default mutex allocation
2015** routines with a wrapper used to track mutex usage for performance
2016** profiling or testing, for example. ^If SQLite is compiled with
2017** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
2018** the entire mutexing subsystem is omitted from the build and hence calls to
2019** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
2020** return [SQLITE_ERROR].</dd>
2021**
2022** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
2023** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
2024** the default size of [lookaside memory] on each [database connection].
2025** The first argument is the
2026** size of each lookaside buffer slot ("sz") and the second is the number of
2027** slots allocated to each database connection ("cnt").)^
2028** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
2029** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
2030** be used to change the lookaside configuration on individual connections.)^
2031** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
2032** default lookaside configuration at compile-time.
2033** </dd>
2034**
2035** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
2036** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
2037** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
2038** the interface to a custom page cache implementation.)^
2039** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
2040**
2041** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
2042** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
2043** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies off
2044** the current page cache implementation into that object.)^ </dd>
2045**
2046** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
2047** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
2048** global [error log].
2049** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2050** function with a call signature of void(*)(void*,int,const char*),
2051** and a pointer to void. ^If the function pointer is not NULL, it is
2052** invoked by [sqlite3_log()] to process each logging event. ^If the
2053** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2054** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2055** passed through as the first parameter to the application-defined logger
2056** function whenever that function is invoked. ^The second parameter to
2057** the logger function is a copy of the first parameter to the corresponding
2058** [sqlite3_log()] call and is intended to be a [result code] or an
2059** [extended result code]. ^The third parameter passed to the logger is
2060** a log message after formatting via [sqlite3_snprintf()].
2061** The SQLite logging interface is not reentrant; the logger function
2062** supplied by the application must not invoke any SQLite interface.
2063** In a multi-threaded application, the application-defined logger
2064** function must be threadsafe. </dd>
2065**
2066** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2067** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2068** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2069** then URI handling is globally disabled.)^ ^If URI handling is globally
2070** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2071** [sqlite3_open16()] or
2072** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2073** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2074** connection is opened. ^If it is globally disabled, filenames are
2075** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2076** database connection is opened. ^(By default, URI handling is globally
2077** disabled. The default value may be changed by compiling with the
2078** [SQLITE_USE_URI] symbol defined.)^
2079**
2080** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2081** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2082** argument which is interpreted as a boolean in order to enable or disable
2083** the use of covering indices for full table scans in the query optimizer.
2084** ^The default setting is determined
2085** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2086** if that compile-time option is omitted.
2087** The ability to disable the use of covering indices for full table scans
2088** is because some incorrectly coded legacy applications might malfunction
2089** when the optimization is enabled. Providing the ability to
2090** disable the optimization allows the older, buggy application code to work
2091** without change even with newer versions of SQLite.
2092**
2093** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2094** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2095** <dd> These options are obsolete and should not be used by new code.
2096** They are retained for backwards compatibility but are now no-ops.
2097** </dd>
2098**
2099** [[SQLITE_CONFIG_SQLLOG]]
2100** <dt>SQLITE_CONFIG_SQLLOG
2101** <dd>This option is only available if sqlite is compiled with the
2102** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2103** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2104** The second should be of type (void*). The callback is invoked by the library
2105** in three separate circumstances, identified by the value passed as the
2106** fourth parameter. If the fourth parameter is 0, then the database connection
2107** passed as the second argument has just been opened. The third argument
2108** points to a buffer containing the name of the main database file. If the
2109** fourth parameter is 1, then the SQL statement that the third parameter
2110** points to has just been executed. Or, if the fourth parameter is 2, then
2111** the connection being passed as the second parameter is being closed. The
2112** third parameter is passed NULL In this case. An example of using this
2113** configuration option can be seen in the "test_sqllog.c" source file in
2114** the canonical SQLite source tree.</dd>
2115**
2116** [[SQLITE_CONFIG_MMAP_SIZE]]
2117** <dt>SQLITE_CONFIG_MMAP_SIZE
2118** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2119** that are the default mmap size limit (the default setting for
2120** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2121** ^The default setting can be overridden by each database connection using
2122** either the [PRAGMA mmap_size] command, or by using the
2123** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2124** will be silently truncated if necessary so that it does not exceed the
2125** compile-time maximum mmap size set by the
2126** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2127** ^If either argument to this option is negative, then that argument is
2128** changed to its compile-time default.
2129**
2130** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2131** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2132** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2133** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2134** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2135** that specifies the maximum size of the created heap.
2136**
2137** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2138** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2139** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2140** is a pointer to an integer and writes into that integer the number of extra
2141** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2142** The amount of extra space required can change depending on the compiler,
2143** target platform, and SQLite version.
2144**
2145** [[SQLITE_CONFIG_PMASZ]]
2146** <dt>SQLITE_CONFIG_PMASZ
2147** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2148** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2149** sorter to that integer. The default minimum PMA Size is set by the
2150** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2151** to help with sort operations when multithreaded sorting
2152** is enabled (using the [PRAGMA threads] command) and the amount of content
2153** to be sorted exceeds the page size times the minimum of the
2154** [PRAGMA cache_size] setting and this value.
2155**
2156** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2157** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2158** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2159** becomes the [statement journal] spill-to-disk threshold.
2160** [Statement journals] are held in memory until their size (in bytes)
2161** exceeds this threshold, at which point they are written to disk.
2162** Or if the threshold is -1, statement journals are always held
2163** exclusively in memory.
2164** Since many statement journals never become large, setting the spill
2165** threshold to a value such as 64KiB can greatly reduce the amount of
2166** I/O required to support statement rollback.
2167** The default value for this setting is controlled by the
2168** [SQLITE_STMTJRNL_SPILL] compile-time option.
2169**
2170** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2171** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2172** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2173** of type (int) - the new value of the sorter-reference size threshold.
2174** Usually, when SQLite uses an external sort to order records according
2175** to an ORDER BY clause, all fields required by the caller are present in the
2176** sorted records. However, if SQLite determines based on the declared type
2177** of a table column that its values are likely to be very large - larger
2178** than the configured sorter-reference size threshold - then a reference
2179** is stored in each sorted record and the required column values loaded
2180** from the database as records are returned in sorted order. The default
2181** value for this option is to never use this optimization. Specifying a
2182** negative value for this option restores the default behavior.
2183** This option is only available if SQLite is compiled with the
2184** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2185**
2186** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2187** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2188** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2189** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2190** database created using [sqlite3_deserialize()]. This default maximum
2191** size can be adjusted up or down for individual databases using the
2192** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2193** configuration setting is never used, then the default maximum is determined
2194** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2195** compile-time option is not set, then the default maximum is 1073741824.
2196**
2197** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2198** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2199** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2200** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2201** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2202** defaults to on. This configuration option queries the current setting or
2203** changes the setting to off or on. The argument is a pointer to an integer.
2204** If that integer initially holds a value of 1, then the ability for VIEWs to
2205** have ROWIDs is activated. If the integer initially holds zero, then the
2206** ability is deactivated. Any other initial value for the integer leaves the
2207** setting unchanged. After changes, if any, the integer is written with
2208** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2209** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2210** recommended case) then the integer is always filled with zero, regardless
2211** if its initial value.
2212** </dl>
2213*/
2214#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2215#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2216#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2217#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2218#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2219#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2220#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2221#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2222#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2223#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2224#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2225/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2226#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2227#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2228#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2229#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2230#define SQLITE_CONFIG_URI 17 /* int */
2231#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2232#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2233#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2234#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2235#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2236#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2237#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2238#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2239#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2240#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2241#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2242#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2243#define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2244
2245/*
2246** CAPI3REF: Database Connection Configuration Options
2247**
2248** These constants are the available integer configuration options that
2249** can be passed as the second parameter to the [sqlite3_db_config()] interface.
2250**
2251** The [sqlite3_db_config()] interface is a var-args function. It takes a
2252** variable number of parameters, though always at least two. The number of
2253** parameters passed into sqlite3_db_config() depends on which of these
2254** constants is given as the second parameter. This documentation page
2255** refers to parameters beyond the second as "arguments". Thus, when this
2256** page says "the N-th argument" it means "the N-th parameter past the
2257** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
2258**
2259** New configuration options may be added in future releases of SQLite.
2260** Existing configuration options might be discontinued. Applications
2261** should check the return code from [sqlite3_db_config()] to make sure that
2262** the call worked. ^The [sqlite3_db_config()] interface will return a
2263** non-zero [error code] if a discontinued or unsupported configuration option
2264** is invoked.
2265**
2266** <dl>
2267** [[SQLITE_DBCONFIG_LOOKASIDE]]
2268** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2269** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
2270** configuration of the [lookaside memory allocator] within a database
2271** connection.
2272** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
2273** in the [DBCONFIG arguments|usual format].
2274** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
2275** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
2276** should have a total of five parameters.
2277** <ol>
2278** <li><p>The first argument ("buf") is a
2279** pointer to a memory buffer to use for lookaside memory.
2280** The first argument may be NULL in which case SQLite will allocate the
2281** lookaside buffer itself using [sqlite3_malloc()].
2282** <li><P>The second argument ("sz") is the
2283** size of each lookaside buffer slot. Lookaside is disabled if "sz"
2284** is less than 8. The "sz" argument should be a multiple of 8 less than
2285** 65536. If "sz" does not meet this constraint, it is reduced in size until
2286** it does.
2287** <li><p>The third argument ("cnt") is the number of slots.
2288** Lookaside is disabled if "cnt"is less than 1.
2289* The "cnt" value will be reduced, if necessary, so
2290** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt"
2291** parameter is usually chosen so that the product of "sz" and "cnt" is less
2292** than 1,000,000.
2293** </ol>
2294** <p>If the "buf" argument is not NULL, then it must
2295** point to a memory buffer with a size that is greater than
2296** or equal to the product of "sz" and "cnt".
2297** The buffer must be aligned to an 8-byte boundary.
2298** The lookaside memory
2299** configuration for a database connection can only be changed when that
2300** connection is not currently using lookaside memory, or in other words
2301** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
2302** Any attempt to change the lookaside memory configuration when lookaside
2303** memory is in use leaves the configuration unchanged and returns
2304** [SQLITE_BUSY].
2305** If the "buf" argument is NULL and an attempt
2306** to allocate memory based on "sz" and "cnt" fails, then
2307** lookaside is silently disabled.
2308** <p>
2309** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
2310** default lookaside configuration at initialization. The
2311** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
2312** configuration at compile-time. Typical values for lookaside are 1200 for
2313** "sz" and 40 to 100 for "cnt".
2314** </dd>
2315**
2316** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2317** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2318** <dd> ^This option is used to enable or disable the enforcement of
2319** [foreign key constraints]. This is the same setting that is
2320** enabled or disabled by the [PRAGMA foreign_keys] statement.
2321** The first argument is an integer which is 0 to disable FK enforcement,
2322** positive to enable FK enforcement or negative to leave FK enforcement
2323** unchanged. The second parameter is a pointer to an integer into which
2324** is written 0 or 1 to indicate whether FK enforcement is off or on
2325** following this call. The second parameter may be a NULL pointer, in
2326** which case the FK enforcement setting is not reported back. </dd>
2327**
2328** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2329** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2330** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2331** There should be two additional arguments.
2332** The first argument is an integer which is 0 to disable triggers,
2333** positive to enable triggers or negative to leave the setting unchanged.
2334** The second parameter is a pointer to an integer into which
2335** is written 0 or 1 to indicate whether triggers are disabled or enabled
2336** following this call. The second parameter may be a NULL pointer, in
2337** which case the trigger setting is not reported back.
2338**
2339** <p>Originally this option disabled all triggers. ^(However, since
2340** SQLite version 3.35.0, TEMP triggers are still allowed even if
2341** this option is off. So, in other words, this option now only disables
2342** triggers in the main database schema or in the schemas of [ATTACH]-ed
2343** databases.)^ </dd>
2344**
2345** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2346** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2347** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2348** There must be two additional arguments.
2349** The first argument is an integer which is 0 to disable views,
2350** positive to enable views or negative to leave the setting unchanged.
2351** The second parameter is a pointer to an integer into which
2352** is written 0 or 1 to indicate whether views are disabled or enabled
2353** following this call. The second parameter may be a NULL pointer, in
2354** which case the view setting is not reported back.
2355**
2356** <p>Originally this option disabled all views. ^(However, since
2357** SQLite version 3.35.0, TEMP views are still allowed even if
2358** this option is off. So, in other words, this option now only disables
2359** views in the main database schema or in the schemas of ATTACH-ed
2360** databases.)^ </dd>
2361**
2362** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2363** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2364** <dd> ^This option is used to enable or disable using the
2365** [fts3_tokenizer()] function - part of the [FTS3] full-text search engine
2366** extension - without using bound parameters as the parameters. Doing so
2367** is disabled by default. There must be two additional arguments. The first
2368** argument is an integer. If it is passed 0, then using fts3_tokenizer()
2369** without bound parameters is disabled. If it is passed a positive value,
2370** then calling fts3_tokenizer without bound parameters is enabled. If it
2371** is passed a negative value, this setting is not modified - this can be
2372** used to query for the current setting. The second parameter is a pointer
2373** to an integer into which is written 0 or 1 to indicate the current value
2374** of this setting (after it is modified, if applicable). The second
2375** parameter may be a NULL pointer, in which case the value of the setting
2376** is not reported back. Refer to [FTS3] documentation for further details.
2377** </dd>
2378**
2379** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2380** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2381** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2382** interface independently of the [load_extension()] SQL function.
2383** The [sqlite3_enable_load_extension()] API enables or disables both the
2384** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2385** There must be two additional arguments.
2386** When the first argument to this interface is 1, then only the C-API is
2387** enabled and the SQL function remains disabled. If the first argument to
2388** this interface is 0, then both the C-API and the SQL function are disabled.
2389** If the first argument is -1, then no changes are made to the state of either
2390** the C-API or the SQL function.
2391** The second parameter is a pointer to an integer into which
2392** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2393** is disabled or enabled following this call. The second parameter may
2394** be a NULL pointer, in which case the new setting is not reported back.
2395** </dd>
2396**
2397** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2398** <dd> ^This option is used to change the name of the "main" database
2399** schema. This option does not follow the
2400** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
2401** This option takes exactly one additional argument so that the
2402** [sqlite3_db_config()] call has a total of three parameters. The
2403** extra argument must be a pointer to a constant UTF8 string which
2404** will become the new schema name in place of "main". ^SQLite does
2405** not make a copy of the new main schema name string, so the application
2406** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
2407** is unchanged until after the database connection closes.
2408** </dd>
2409**
2410** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2411** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2412** <dd> Usually, when a database in [WAL mode] is closed or detached from a
2413** database handle, SQLite checks if if there are other connections to the
2414** same database, and if there are no other database connection (if the
2415** connection being closed is the last open connection to the database),
2416** then SQLite performs a [checkpoint] before closing the connection and
2417** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
2418** be used to override that behavior. The first argument passed to this
2419** operation (the third parameter to [sqlite3_db_config()]) is an integer
2420** which is positive to disable checkpoints-on-close, or zero (the default)
2421** to enable them, and negative to leave the setting unchanged.
2422** The second argument (the fourth parameter) is a pointer to an integer
2423** into which is written 0 or 1 to indicate whether checkpoints-on-close
2424** have been disabled - 0 if they are not disabled, 1 if they are.
2425** </dd>
2426**
2427** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2428** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2429** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2430** a single SQL query statement will always use the same algorithm regardless
2431** of values of [bound parameters].)^ The QPSG disables some query optimizations
2432** that look at the values of bound parameters, which can make some queries
2433** slower. But the QPSG has the advantage of more predictable behavior. With
2434** the QPSG active, SQLite will always use the same query plan in the field as
2435** was used during testing in the lab.
2436** The first argument to this setting is an integer which is 0 to disable
2437** the QPSG, positive to enable QPSG, or negative to leave the setting
2438** unchanged. The second parameter is a pointer to an integer into which
2439** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2440** following this call.
2441** </dd>
2442**
2443** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2444** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2445** include output for any operations performed by trigger programs. This
2446** option is used to set or clear (the default) a flag that governs this
2447** behavior. The first parameter passed to this operation is an integer -
2448** positive to enable output for trigger programs, or zero to disable it,
2449** or negative to leave the setting unchanged.
2450** The second parameter is a pointer to an integer into which is written
2451** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2452** it is not disabled, 1 if it is.
2453** </dd>
2454**
2455** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2456** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2457** [VACUUM] in order to reset a database back to an empty database
2458** with no schema and no content. The following process works even for
2459** a badly corrupted database file:
2460** <ol>
2461** <li> If the database connection is newly opened, make sure it has read the
2462** database schema by preparing then discarding some query against the
2463** database, or calling sqlite3_table_column_metadata(), ignoring any
2464** errors. This step is only necessary if the application desires to keep
2465** the database in WAL mode after the reset if it was in WAL mode before
2466** the reset.
2467** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2468** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2469** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2470** </ol>
2471** Because resetting a database is destructive and irreversible, the
2472** process requires the use of this obscure API and multiple steps to
2473** help ensure that it does not happen by accident. Because this
2474** feature must be capable of resetting corrupt databases, and
2475** shutting down virtual tables may require access to that corrupt
2476** storage, the library must abandon any installed virtual tables
2477** without calling their xDestroy() methods.
2478**
2479** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2480** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2481** "defensive" flag for a database connection. When the defensive
2482** flag is enabled, language features that allow ordinary SQL to
2483** deliberately corrupt the database file are disabled. The disabled
2484** features include but are not limited to the following:
2485** <ul>
2486** <li> The [PRAGMA writable_schema=ON] statement.
2487** <li> The [PRAGMA journal_mode=OFF] statement.
2488** <li> The [PRAGMA schema_version=N] statement.
2489** <li> Writes to the [sqlite_dbpage] virtual table.
2490** <li> Direct writes to [shadow tables].
2491** </ul>
2492** </dd>
2493**
2494** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2495** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2496** "writable_schema" flag. This has the same effect and is logically equivalent
2497** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2498** The first argument to this setting is an integer which is 0 to disable
2499** the writable_schema, positive to enable writable_schema, or negative to
2500** leave the setting unchanged. The second parameter is a pointer to an
2501** integer into which is written 0 or 1 to indicate whether the writable_schema
2502** is enabled or disabled following this call.
2503** </dd>
2504**
2505** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2506** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2507** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2508** the legacy behavior of the [ALTER TABLE RENAME] command such that it
2509** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2510** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2511** additional information. This feature can also be turned on and off
2512** using the [PRAGMA legacy_alter_table] statement.
2513** </dd>
2514**
2515** [[SQLITE_DBCONFIG_DQS_DML]]
2516** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2517** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2518** the legacy [double-quoted string literal] misfeature for DML statements
2519** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2520** default value of this setting is determined by the [-DSQLITE_DQS]
2521** compile-time option.
2522** </dd>
2523**
2524** [[SQLITE_DBCONFIG_DQS_DDL]]
2525** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2526** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2527** the legacy [double-quoted string literal] misfeature for DDL statements,
2528** such as CREATE TABLE and CREATE INDEX. The
2529** default value of this setting is determined by the [-DSQLITE_DQS]
2530** compile-time option.
2531** </dd>
2532**
2533** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2534** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2535** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2536** assume that database schemas are untainted by malicious content.
2537** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2538** takes additional defensive steps to protect the application from harm
2539** including:
2540** <ul>
2541** <li> Prohibit the use of SQL functions inside triggers, views,
2542** CHECK constraints, DEFAULT clauses, expression indexes,
2543** partial indexes, or generated columns
2544** unless those functions are tagged with [SQLITE_INNOCUOUS].
2545** <li> Prohibit the use of virtual tables inside of triggers or views
2546** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2547** </ul>
2548** This setting defaults to "on" for legacy compatibility, however
2549** all applications are advised to turn it off if possible. This setting
2550** can also be controlled using the [PRAGMA trusted_schema] statement.
2551** </dd>
2552**
2553** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2554** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2555** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2556** the legacy file format flag. When activated, this flag causes all newly
2557** created database files to have a schema format version number (the 4-byte
2558** integer found at offset 44 into the database header) of 1. This in turn
2559** means that the resulting database file will be readable and writable by
2560** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2561** newly created databases are generally not understandable by SQLite versions
2562** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2563** is now scarcely any need to generate database files that are compatible
2564** all the way back to version 3.0.0, and so this setting is of little
2565** practical use, but is provided so that SQLite can continue to claim the
2566** ability to generate new database files that are compatible with version
2567** 3.0.0.
2568** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2569** the [VACUUM] command will fail with an obscure error when attempting to
2570** process a table with generated columns and a descending index. This is
2571** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2572** either generated columns or descending indexes.
2573** </dd>
2574**
2575** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2576** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2577** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2578** [SQLITE_ENABLE_STMT_SCANSTATUS] builds. In this case, it sets or clears
2579** a flag that enables collection of run-time performance statistics
2580** used by [sqlite3_stmt_scanstatus_v2()] and the [nexec and ncycle]
2581** columns of the [bytecode virtual table].
2582** For statistics to be collected, the flag must be set on
2583** the database handle both when the SQL statement is
2584** [sqlite3_prepare|prepared] and when it is [sqlite3_step|stepped].
2585** The flag is set (collection of statistics is enabled) by default.
2586** <p>This option takes two arguments: an integer and a pointer to
2587** an integer. The first argument is 1, 0, or -1 to enable, disable, or
2588** leave unchanged the statement scanstatus option. If the second argument
2589** is not NULL, then the value of the statement scanstatus setting after
2590** processing the first argument is written into the integer that the second
2591** argument points to.
2592** </dd>
2593**
2594** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2595** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2596** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2597** in which tables and indexes are scanned so that the scans start at the end
2598** and work toward the beginning rather than starting at the beginning and
2599** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2600** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2601** two arguments which are an integer and a pointer to an integer. The first
2602** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2603** reverse scan order flag, respectively. If the second argument is not NULL,
2604** then 0 or 1 is written into the integer that the second argument points to
2605** depending on if the reverse scan order flag is set after processing the
2606** first argument.
2607** </dd>
2608**
2609** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2610** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2611** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2612** the ability of the [ATTACH DATABASE] SQL command to create a new database
2613** file if the database filed named in the ATTACH command does not already
2614** exist. This ability of ATTACH to create a new database is enabled by
2615** default. Applications can disable or reenable the ability for ATTACH to
2616** create new database files using this DBCONFIG option.<p>
2617** This option takes two arguments which are an integer and a pointer
2618** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2619** leave unchanged the attach-create flag, respectively. If the second
2620** argument is not NULL, then 0 or 1 is written into the integer that the
2621** second argument points to depending on if the attach-create flag is set
2622** after processing the first argument.
2623** </dd>
2624**
2625** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2626** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2627** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2628** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2629** This capability is enabled by default. Applications can disable or
2630** reenable this capability using the current DBCONFIG option. If
2631** this capability is disabled, the [ATTACH] command will still work,
2632** but the database will be opened read-only. If this option is disabled,
2633** then the ability to create a new database using [ATTACH] is also disabled,
2634** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2635** option.<p>
2636** This option takes two arguments which are an integer and a pointer
2637** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2638** leave unchanged the ability to ATTACH another database for writing,
2639** respectively. If the second argument is not NULL, then 0 or 1 is written
2640** into the integer to which the second argument points, depending on whether
2641** the ability to ATTACH a read/write database is enabled or disabled
2642** after processing the first argument.
2643** </dd>
2644**
2645** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2646** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2647** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2648** ability to include comments in SQL text. Comments are enabled by default.
2649** An application can disable or reenable comments in SQL text using this
2650** DBCONFIG option.<p>
2651** This option takes two arguments which are an integer and a pointer
2652** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2653** leave unchanged the ability to use comments in SQL text,
2654** respectively. If the second argument is not NULL, then 0 or 1 is written
2655** into the integer that the second argument points to depending on if
2656** comments are allowed in SQL text after processing the first argument.
2657** </dd>
2658**
2659** [[SQLITE_DBCONFIG_FP_DIGITS]]
2660** <dt>SQLITE_DBCONFIG_FP_DIGITS</dt>
2661** <dd>The SQLITE_DBCONFIG_FP_DIGITS setting is a small integer that determines
2662** the number of significant digits that SQLite will attempt to preserve when
2663** converting floating point numbers (IEEE 754 "doubles") into text. The
2664** default value 17, as of SQLite version 3.52.0. The value was 15 in all
2665** prior versions.<p>
2666** This option takes two arguments which are an integer and a pointer
2667** to an integer. The first argument is a small integer, between 3 and 23, or
2668** zero. The FP_DIGITS setting is changed to that small integer, or left
2669** unaltered if the first argument is zero or out of range. The second argument
2670** is a pointer to an integer. If the pointer is not NULL, then the value of
2671** the FP_DIGITS setting, after possibly being modified by the first
2672** arguments, is written into the integer to which the second argument points.
2673** </dd>
2674**
2675** </dl>
2676**
2677** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2678**
2679** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2680** overall call to [sqlite3_db_config()] has a total of four parameters.
2681** The first argument (the third parameter to sqlite3_db_config()) is
2682** an integer.
2683** The second argument is a pointer to an integer. If the first argument is 1,
2684** then the option becomes enabled. If the first integer argument is 0,
2685** then the option is disabled.
2686** If the first argument is -1, then the option setting
2687** is unchanged. The second argument, the pointer to an integer, may be NULL.
2688** If the second argument is not NULL, then a value of 0 or 1 is written into
2689** the integer to which the second argument points, depending on whether the
2690** setting is disabled or enabled after applying any changes specified by
2691** the first argument.
2692**
2693** <p>While most SQLITE_DBCONFIG options use the argument format
2694** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME],
2695** [SQLITE_DBCONFIG_LOOKASIDE], and [SQLITE_DBCONFIG_FP_DIGITS] options
2696** are different. See the documentation of those exceptional options for
2697** details.
2698*/
2699#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2700#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2701#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2702#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2703#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2704#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2705#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2706#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2707#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2708#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2709#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2710#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2711#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2712#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2713#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2714#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2715#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2716#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2717#define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2718#define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2719#define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2720#define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2721#define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2722#define SQLITE_DBCONFIG_FP_DIGITS 1023 /* int int* */
2723#define SQLITE_DBCONFIG_MAX 1023 /* Largest DBCONFIG */
2724
2725/*
2726** CAPI3REF: Enable Or Disable Extended Result Codes
2727** METHOD: sqlite3
2728**
2729** ^The sqlite3_extended_result_codes() routine enables or disables the
2730** [extended result codes] feature of SQLite. ^The extended result
2731** codes are disabled by default for historical compatibility.
2732*/
2733SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2734
2735/*
2736** CAPI3REF: Last Insert Rowid
2737** METHOD: sqlite3
2738**
2739** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2740** has a unique 64-bit signed
2741** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2742** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2743** names are not also used by explicitly declared columns. ^If
2744** the table has a column of type [INTEGER PRIMARY KEY] then that column
2745** is another alias for the rowid.
2746**
2747** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2748** the most recent successful [INSERT] into a rowid table or [virtual table]
2749** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2750** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2751** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2752** zero.
2753**
2754** As well as being set automatically as rows are inserted into database
2755** tables, the value returned by this function may be set explicitly by
2756** [sqlite3_set_last_insert_rowid()]
2757**
2758** Some virtual table implementations may INSERT rows into rowid tables as
2759** part of committing a transaction (e.g. to flush data accumulated in memory
2760** to disk). In this case subsequent calls to this function return the rowid
2761** associated with these internal INSERT operations, which leads to
2762** unintuitive results. Virtual table implementations that do write to rowid
2763** tables in this way can avoid this problem by restoring the original
2764** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2765** control to the user.
2766**
2767** ^(If an [INSERT] occurs within a trigger then this routine will
2768** return the [rowid] of the inserted row as long as the trigger is
2769** running. Once the trigger program ends, the value returned
2770** by this routine reverts to what it was before the trigger was fired.)^
2771**
2772** ^An [INSERT] that fails due to a constraint violation is not a
2773** successful [INSERT] and does not change the value returned by this
2774** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2775** and INSERT OR ABORT make no changes to the return value of this
2776** routine when their insertion fails. ^(When INSERT OR REPLACE
2777** encounters a constraint violation, it does not fail. The
2778** INSERT continues to completion after deleting rows that caused
2779** the constraint problem so INSERT OR REPLACE will always change
2780** the return value of this interface.)^
2781**
2782** ^For the purposes of this routine, an [INSERT] is considered to
2783** be successful even if it is subsequently rolled back.
2784**
2785** This function is accessible to SQL statements via the
2786** [last_insert_rowid() SQL function].
2787**
2788** If a separate thread performs a new [INSERT] on the same
2789** database connection while the [sqlite3_last_insert_rowid()]
2790** function is running and thus changes the last insert [rowid],
2791** then the value returned by [sqlite3_last_insert_rowid()] is
2792** unpredictable and might not equal either the old or the new
2793** last insert [rowid].
2794*/
2795SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2796
2797/*
2798** CAPI3REF: Set the Last Insert Rowid value.
2799** METHOD: sqlite3
2800**
2801** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2802** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2803** without inserting a row into the database.
2804*/
2805SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2806
2807/*
2808** CAPI3REF: Count The Number Of Rows Modified
2809** METHOD: sqlite3
2810**
2811** ^These functions return the number of rows modified, inserted or
2812** deleted by the most recently completed INSERT, UPDATE or DELETE
2813** statement on the database connection specified by the only parameter.
2814** The two functions are identical except for the type of the return value
2815** and that if the number of rows modified by the most recent INSERT, UPDATE,
2816** or DELETE is greater than the maximum value supported by type "int", then
2817** the return value of sqlite3_changes() is undefined. ^Executing any other
2818** type of SQL statement does not modify the value returned by these functions.
2819** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2820** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2821** added to the new table by the CREATE TABLE AS SELECT statement are not
2822** counted.
2823**
2824** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2825** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2826** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2827**
2828** Changes to a view that are intercepted by
2829** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2830** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2831** DELETE statement run on a view is always zero. Only changes made to real
2832** tables are counted.
2833**
2834** Things are more complicated if the sqlite3_changes() function is
2835** executed while a trigger program is running. This may happen if the
2836** program uses the [changes() SQL function], or if some other callback
2837** function invokes sqlite3_changes() directly. Essentially:
2838**
2839** <ul>
2840** <li> ^(Before entering a trigger program the value returned by
2841** sqlite3_changes() function is saved. After the trigger program
2842** has finished, the original value is restored.)^
2843**
2844** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2845** statement sets the value returned by sqlite3_changes()
2846** upon completion as normal. Of course, this value will not include
2847** any changes performed by sub-triggers, as the sqlite3_changes()
2848** value will be saved and restored after each sub-trigger has run.)^
2849** </ul>
2850**
2851** ^This means that if the changes() SQL function (or similar) is used
2852** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2853** returns the value as set when the calling statement began executing.
2854** ^If it is used by the second or subsequent such statement within a trigger
2855** program, the value returned reflects the number of rows modified by the
2856** previous INSERT, UPDATE or DELETE statement within the same trigger.
2857**
2858** If a separate thread makes changes on the same database connection
2859** while [sqlite3_changes()] is running then the value returned
2860** is unpredictable and not meaningful.
2861**
2862** See also:
2863** <ul>
2864** <li> the [sqlite3_total_changes()] interface
2865** <li> the [count_changes pragma]
2866** <li> the [changes() SQL function]
2867** <li> the [data_version pragma]
2868** </ul>
2869*/
2870SQLITE_API int sqlite3_changes(sqlite3*);
2871SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2872
2873/*
2874** CAPI3REF: Total Number Of Rows Modified
2875** METHOD: sqlite3
2876**
2877** ^These functions return the total number of rows inserted, modified or
2878** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2879** since the database connection was opened, including those executed as
2880** part of trigger programs. The two functions are identical except for the
2881** type of the return value and that if the number of rows modified by the
2882** connection exceeds the maximum value supported by type "int", then
2883** the return value of sqlite3_total_changes() is undefined. ^Executing
2884** any other type of SQL statement does not affect the value returned by
2885** sqlite3_total_changes().
2886**
2887** ^Changes made as part of [foreign key actions] are included in the
2888** count, but those made as part of REPLACE constraint resolution are
2889** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2890** are not counted.
2891**
2892** The [sqlite3_total_changes(D)] interface only reports the number
2893** of rows that changed due to SQL statement run against database
2894** connection D. Any changes by other database connections are ignored.
2895** To detect changes against a database file from other database
2896** connections use the [PRAGMA data_version] command or the
2897** [SQLITE_FCNTL_DATA_VERSION] [file control].
2898**
2899** If a separate thread makes changes on the same database connection
2900** while [sqlite3_total_changes()] is running then the value
2901** returned is unpredictable and not meaningful.
2902**
2903** See also:
2904** <ul>
2905** <li> the [sqlite3_changes()] interface
2906** <li> the [count_changes pragma]
2907** <li> the [changes() SQL function]
2908** <li> the [data_version pragma]
2909** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2910** </ul>
2911*/
2912SQLITE_API int sqlite3_total_changes(sqlite3*);
2913SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2914
2915/*
2916** CAPI3REF: Interrupt A Long-Running Query
2917** METHOD: sqlite3
2918**
2919** ^This function causes any pending database operation to abort and
2920** return at its earliest opportunity. This routine is typically
2921** called in response to a user action such as pressing "Cancel"
2922** or Ctrl-C where the user wants a long query operation to halt
2923** immediately.
2924**
2925** ^It is safe to call this routine from a thread different from the
2926** thread that is currently running the database operation. But it
2927** is not safe to call this routine with a [database connection] that
2928** is closed or might close before sqlite3_interrupt() returns.
2929**
2930** ^If an SQL operation is very nearly finished at the time when
2931** sqlite3_interrupt() is called, then it might not have an opportunity
2932** to be interrupted and might continue to completion.
2933**
2934** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2935** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2936** that is inside an explicit transaction, then the entire transaction
2937** will be rolled back automatically.
2938**
2939** ^The sqlite3_interrupt(D) call is in effect until all currently running
2940** SQL statements on [database connection] D complete. ^Any new SQL statements
2941** that are started after the sqlite3_interrupt() call and before the
2942** running statement count reaches zero are interrupted as if they had been
2943** running prior to the sqlite3_interrupt() call. ^New SQL statements
2944** that are started after the running statement count reaches zero are
2945** not effected by the sqlite3_interrupt().
2946** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2947** SQL statements is a no-op and has no effect on SQL statements
2948** that are started after the sqlite3_interrupt() call returns.
2949**
2950** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2951** or not an interrupt is currently in effect for [database connection] D.
2952** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2953*/
2954SQLITE_API void sqlite3_interrupt(sqlite3*);
2955SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2956
2957/*
2958** CAPI3REF: Determine If An SQL Statement Is Complete
2959**
2960** These routines are useful during command-line input to determine if the
2961** currently entered text seems to form a complete SQL statement or
2962** if additional input is needed before sending the text into
2963** SQLite for parsing. ^These routines return 1 if the input string
2964** appears to be a complete SQL statement. ^A statement is judged to be
2965** complete if it ends with a semicolon token and is not a prefix of a
2966** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2967** string literals or quoted identifier names or comments are not
2968** independent tokens (they are part of the token in which they are
2969** embedded) and thus do not count as a statement terminator. ^Whitespace
2970** and comments that follow the final semicolon are ignored.
2971**
2972** ^These routines return 0 if the statement is incomplete. ^If a
2973** memory allocation fails, then SQLITE_NOMEM is returned.
2974**
2975** ^These routines do not parse the SQL statements and thus
2976** will not detect syntactically incorrect SQL.
2977**
2978** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2979** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2980** automatically by sqlite3_complete16(). If that initialization fails,
2981** then the return value from sqlite3_complete16() will be non-zero
2982** regardless of whether or not the input SQL is complete.)^
2983**
2984** The input to [sqlite3_complete()] must be a zero-terminated
2985** UTF-8 string.
2986**
2987** The input to [sqlite3_complete16()] must be a zero-terminated
2988** UTF-16 string in native byte order.
2989*/
2990SQLITE_API int sqlite3_complete(const char *sql);
2991SQLITE_API int sqlite3_complete16(const void *sql);
2992
2993/*
2994** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2995** KEYWORDS: {busy-handler callback} {busy handler}
2996** METHOD: sqlite3
2997**
2998** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2999** that might be invoked with argument P whenever
3000** an attempt is made to access a database table associated with
3001** [database connection] D when another thread
3002** or process has the table locked.
3003** The sqlite3_busy_handler() interface is used to implement
3004** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
3005**
3006** ^If the busy callback is NULL, then [SQLITE_BUSY]
3007** is returned immediately upon encountering the lock. ^If the busy callback
3008** is not NULL, then the callback might be invoked with two arguments.
3009**
3010** ^The first argument to the busy handler is a copy of the void* pointer which
3011** is the third argument to sqlite3_busy_handler(). ^The second argument to
3012** the busy handler callback is the number of times that the busy handler has
3013** been invoked previously for the same locking event. ^If the
3014** busy callback returns 0, then no additional attempts are made to
3015** access the database and [SQLITE_BUSY] is returned
3016** to the application.
3017** ^If the callback returns non-zero, then another attempt
3018** is made to access the database and the cycle repeats.
3019**
3020** The presence of a busy handler does not guarantee that it will be invoked
3021** when there is lock contention. ^If SQLite determines that invoking the busy
3022** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
3023** to the application instead of invoking the
3024** busy handler.
3025** Consider a scenario where one process is holding a read lock that
3026** it is trying to promote to a reserved lock and
3027** a second process is holding a reserved lock that it is trying
3028** to promote to an exclusive lock. The first process cannot proceed
3029** because it is blocked by the second and the second process cannot
3030** proceed because it is blocked by the first. If both processes
3031** invoke the busy handlers, neither will make any progress. Therefore,
3032** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
3033** will induce the first process to release its read lock and allow
3034** the second process to proceed.
3035**
3036** ^The default busy callback is NULL.
3037**
3038** ^(There can only be a single busy handler defined for each
3039** [database connection]. Setting a new busy handler clears any
3040** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
3041** or evaluating [PRAGMA busy_timeout=N] will change the
3042** busy handler and thus clear any previously set busy handler.
3043**
3044** The busy callback should not take any actions which modify the
3045** database connection that invoked the busy handler. In other words,
3046** the busy handler is not reentrant. Any such actions
3047** result in undefined behavior.
3048**
3049** A busy handler must not close the database connection
3050** or [prepared statement] that invoked the busy handler.
3051*/
3052SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3053
3054/*
3055** CAPI3REF: Set A Busy Timeout
3056** METHOD: sqlite3
3057**
3058** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3059** for a specified amount of time when a table is locked. ^The handler
3060** will sleep multiple times until at least "ms" milliseconds of sleeping
3061** have accumulated. ^After at least "ms" milliseconds of sleeping,
3062** the handler returns 0 which causes [sqlite3_step()] to return
3063** [SQLITE_BUSY].
3064**
3065** ^Calling this routine with an argument less than or equal to zero
3066** turns off all busy handlers.
3067**
3068** ^(There can only be a single busy handler for a particular
3069** [database connection] at any given moment. If another busy handler
3070** was defined (using [sqlite3_busy_handler()]) prior to calling
3071** this routine, that other busy handler is cleared.)^
3072**
3073** See also: [PRAGMA busy_timeout]
3074*/
3075SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3076
3077/*
3078** CAPI3REF: Set the Setlk Timeout
3079** METHOD: sqlite3
3080**
3081** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3082** the VFS supports blocking locks, it sets the timeout in ms used by
3083** eligible locks taken on wal mode databases by the specified database
3084** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3085** not support blocking locks, this function is a no-op.
3086**
3087** Passing 0 to this function disables blocking locks altogether. Passing
3088** -1 to this function requests that the VFS blocks for a long time -
3089** indefinitely if possible. The results of passing any other negative value
3090** are undefined.
3091**
3092** Internally, each SQLite database handle stores two timeout values - the
3093** busy-timeout (used for rollback mode databases, or if the VFS does not
3094** support blocking locks) and the setlk-timeout (used for blocking locks
3095** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3096** values, this function sets only the setlk-timeout value. Therefore,
3097** to configure separate busy-timeout and setlk-timeout values for a single
3098** database handle, call sqlite3_busy_timeout() followed by this function.
3099**
3100** Whenever the number of connections to a wal mode database falls from
3101** 1 to 0, the last connection takes an exclusive lock on the database,
3102** then checkpoints and deletes the wal file. While it is doing this, any
3103** new connection that tries to read from the database fails with an
3104** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3105** passed to this API, the new connection blocks until the exclusive lock
3106** has been released.
3107*/
3108SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3109
3110/*
3111** CAPI3REF: Flags for sqlite3_setlk_timeout()
3112*/
3113#define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3114
3115/*
3116** CAPI3REF: Convenience Routines For Running Queries
3117** METHOD: sqlite3
3118**
3119** This is a legacy interface that is preserved for backwards compatibility.
3120** Use of this interface is not recommended.
3121**
3122** Definition: A <b>result table</b> is a memory data structure created by the
3123** [sqlite3_get_table()] interface. A result table records the
3124** complete query results from one or more queries.
3125**
3126** The table conceptually has a number of rows and columns. But
3127** these numbers are not part of the result table itself. These
3128** numbers are obtained separately. Let N be the number of rows
3129** and M be the number of columns.
3130**
3131** A result table is an array of pointers to zero-terminated UTF-8 strings.
3132** There are (N+1)*M elements in the array. The first M pointers point
3133** to zero-terminated strings that contain the names of the columns.
3134** The remaining entries all point to query results. NULL values result
3135** in NULL pointers. All other values are in their UTF-8 zero-terminated
3136** string representation as returned by [sqlite3_column_text()].
3137**
3138** A result table might consist of one or more memory allocations.
3139** It is not safe to pass a result table directly to [sqlite3_free()].
3140** A result table should be deallocated using [sqlite3_free_table()].
3141**
3142** ^(As an example of the result table format, suppose a query result
3143** is as follows:
3144**
3145** <blockquote><pre>
3146** Name | Age
3147** -----------------------
3148** Alice | 43
3149** Bob | 28
3150** Cindy | 21
3151** </pre></blockquote>
3152**
3153** There are two columns (M==2) and three rows (N==3). Thus the
3154** result table has 8 entries. Suppose the result table is stored
3155** in an array named azResult. Then azResult holds this content:
3156**
3157** <blockquote><pre>
3158** azResult&#91;0] = "Name";
3159** azResult&#91;1] = "Age";
3160** azResult&#91;2] = "Alice";
3161** azResult&#91;3] = "43";
3162** azResult&#91;4] = "Bob";
3163** azResult&#91;5] = "28";
3164** azResult&#91;6] = "Cindy";
3165** azResult&#91;7] = "21";
3166** </pre></blockquote>)^
3167**
3168** ^The sqlite3_get_table() function evaluates one or more
3169** semicolon-separated SQL statements in the zero-terminated UTF-8
3170** string of its 2nd parameter and returns a result table to the
3171** pointer given in its 3rd parameter.
3172**
3173** After the application has finished with the result from sqlite3_get_table(),
3174** it must pass the result table pointer to sqlite3_free_table() in order to
3175** release the memory that was malloced. Because of the way the
3176** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3177** function must not try to call [sqlite3_free()] directly. Only
3178** [sqlite3_free_table()] is able to release the memory properly and safely.
3179**
3180** The sqlite3_get_table() interface is implemented as a wrapper around
3181** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3182** to any internal data structures of SQLite. It uses only the public
3183** interface defined here. As a consequence, errors that occur in the
3184** wrapper layer outside of the internal [sqlite3_exec()] call are not
3185** reflected in subsequent calls to [sqlite3_errcode()] or
3186** [sqlite3_errmsg()].
3187*/
3188SQLITE_API int sqlite3_get_table(
3189 sqlite3 *db, /* An open database */
3190 const char *zSql, /* SQL to be evaluated */
3191 char ***pazResult, /* Results of the query */
3192 int *pnRow, /* Number of result rows written here */
3193 int *pnColumn, /* Number of result columns written here */
3194 char **pzErrmsg /* Error msg written here */
3195);
3196SQLITE_API void sqlite3_free_table(char **result);
3197
3198/*
3199** CAPI3REF: Formatted String Printing Functions
3200**
3201** These routines are work-alikes of the "printf()" family of functions
3202** from the standard C library.
3203** These routines understand most of the common formatting options from
3204** the standard library printf()
3205** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3206** See the [built-in printf()] documentation for details.
3207**
3208** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3209** results into memory obtained from [sqlite3_malloc64()].
3210** The strings returned by these two routines should be
3211** released by [sqlite3_free()]. ^Both routines return a
3212** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3213** memory to hold the resulting string.
3214**
3215** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3216** the standard C library. The result is written into the
3217** buffer supplied as the second parameter whose size is given by
3218** the first parameter. Note that the order of the
3219** first two parameters is reversed from snprintf().)^ This is an
3220** historical accident that cannot be fixed without breaking
3221** backwards compatibility. ^(Note also that sqlite3_snprintf()
3222** returns a pointer to its buffer instead of the number of
3223** characters actually written into the buffer.)^ We admit that
3224** the number of characters written would be a more useful return
3225** value but we cannot change the implementation of sqlite3_snprintf()
3226** now without breaking compatibility.
3227**
3228** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3229** guarantees that the buffer is always zero-terminated. ^The first
3230** parameter "n" is the total size of the buffer, including space for
3231** the zero terminator. So the longest string that can be completely
3232** written will be n-1 characters.
3233**
3234** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3235**
3236** See also: [built-in printf()], [printf() SQL function]
3237*/
3238SQLITE_API char *sqlite3_mprintf(const char*,...);
3239SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3240SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3241SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3242
3243/*
3244** CAPI3REF: Memory Allocation Subsystem
3245**
3246** The SQLite core uses these three routines for all of its own
3247** internal memory allocation needs. "Core" in the previous sentence
3248** does not include operating-system specific [VFS] implementation. The
3249** Windows VFS uses native malloc() and free() for some operations.
3250**
3251** ^The sqlite3_malloc() routine returns a pointer to a block
3252** of memory at least N bytes in length, where N is the parameter.
3253** ^If sqlite3_malloc() is unable to obtain sufficient free
3254** memory, it returns a NULL pointer. ^If the parameter N to
3255** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3256** a NULL pointer.
3257**
3258** ^The sqlite3_malloc64(N) routine works just like
3259** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3260** of a signed 32-bit integer.
3261**
3262** ^Calling sqlite3_free() with a pointer previously returned
3263** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3264** that it might be reused. ^The sqlite3_free() routine is
3265** a no-op if it is called with a NULL pointer. Passing a NULL pointer
3266** to sqlite3_free() is harmless. After being freed, memory
3267** should neither be read nor written. Even reading previously freed
3268** memory might result in a segmentation fault or other severe error.
3269** Memory corruption, a segmentation fault, or other severe error
3270** might result if sqlite3_free() is called with a non-NULL pointer that
3271** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3272**
3273** ^The sqlite3_realloc(X,N) interface attempts to resize a
3274** prior memory allocation X to be at least N bytes.
3275** ^If the X parameter to sqlite3_realloc(X,N)
3276** is a NULL pointer then its behavior is identical to calling
3277** sqlite3_malloc(N).
3278** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3279** negative then the behavior is exactly the same as calling
3280** sqlite3_free(X).
3281** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3282** of at least N bytes in size or NULL if insufficient memory is available.
3283** ^If M is the size of the prior allocation, then min(N,M) bytes of the
3284** prior allocation are copied into the beginning of the buffer returned
3285** by sqlite3_realloc(X,N) and the prior allocation is freed.
3286** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3287** prior allocation is not freed.
3288**
3289** ^The sqlite3_realloc64(X,N) interface works the same as
3290** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3291** of a 32-bit signed integer.
3292**
3293** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3294** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3295** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3296** ^The value returned by sqlite3_msize(X) might be larger than the number
3297** of bytes requested when X was allocated. ^If X is a NULL pointer then
3298** sqlite3_msize(X) returns zero. If X points to something that is not
3299** the beginning of memory allocation, or if it points to a formerly
3300** valid memory allocation that has now been freed, then the behavior
3301** of sqlite3_msize(X) is undefined and possibly harmful.
3302**
3303** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3304** sqlite3_malloc64(), and sqlite3_realloc64()
3305** is always aligned to at least an 8 byte boundary, or to a
3306** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3307** option is used.
3308**
3309** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3310** must be either NULL or else pointers obtained from a prior
3311** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3312** not yet been released.
3313**
3314** The application must not read or write any part of
3315** a block of memory after it has been released using
3316** [sqlite3_free()] or [sqlite3_realloc()].
3317*/
3318SQLITE_API void *sqlite3_malloc(int);
3319SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3320SQLITE_API void *sqlite3_realloc(void*, int);
3321SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3322SQLITE_API void sqlite3_free(void*);
3323SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3324
3325/*
3326** CAPI3REF: Memory Allocator Statistics
3327**
3328** SQLite provides these two interfaces for reporting on the status
3329** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3330** routines, which form the built-in memory allocation subsystem.
3331**
3332** ^The [sqlite3_memory_used()] routine returns the number of bytes
3333** of memory currently outstanding (malloced but not freed).
3334** ^The [sqlite3_memory_highwater()] routine returns the maximum
3335** value of [sqlite3_memory_used()] since the high-water mark
3336** was last reset. ^The values returned by [sqlite3_memory_used()] and
3337** [sqlite3_memory_highwater()] include any overhead
3338** added by SQLite in its implementation of [sqlite3_malloc()],
3339** but not overhead added by any underlying system library
3340** routines that [sqlite3_malloc()] may call.
3341**
3342** ^The memory high-water mark is reset to the current value of
3343** [sqlite3_memory_used()] if and only if the parameter to
3344** [sqlite3_memory_highwater()] is true. ^The value returned
3345** by [sqlite3_memory_highwater(1)] is the high-water mark
3346** prior to the reset.
3347*/
3348SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3349SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3350
3351/*
3352** CAPI3REF: Pseudo-Random Number Generator
3353**
3354** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3355** select random [ROWID | ROWIDs] when inserting new records into a table that
3356** already uses the largest possible [ROWID]. The PRNG is also used for
3357** the built-in random() and randomblob() SQL functions. This interface allows
3358** applications to access the same PRNG for other purposes.
3359**
3360** ^A call to this routine stores N bytes of randomness into buffer P.
3361** ^The P parameter can be a NULL pointer.
3362**
3363** ^If this routine has not been previously called or if the previous
3364** call had N less than one or a NULL pointer for P, then the PRNG is
3365** seeded using randomness obtained from the xRandomness method of
3366** the default [sqlite3_vfs] object.
3367** ^If the previous call to this routine had an N of 1 or more and a
3368** non-NULL P then the pseudo-randomness is generated
3369** internally and without recourse to the [sqlite3_vfs] xRandomness
3370** method.
3371*/
3372SQLITE_API void sqlite3_randomness(int N, void *P);
3373
3374/*
3375** CAPI3REF: Compile-Time Authorization Callbacks
3376** METHOD: sqlite3
3377** KEYWORDS: {authorizer callback}
3378**
3379** ^This routine registers an authorizer callback with a particular
3380** [database connection], supplied in the first argument.
3381** ^The authorizer callback is invoked as SQL statements are being compiled
3382** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3383** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3384** and [sqlite3_prepare16_v3()]. ^At various
3385** points during the compilation process, as logic is being created
3386** to perform various actions, the authorizer callback is invoked to
3387** see if those actions are allowed. ^The authorizer callback should
3388** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3389** specific action but allow the SQL statement to continue to be
3390** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3391** rejected with an error. ^If the authorizer callback returns
3392** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3393** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3394** the authorizer will fail with an error message.
3395**
3396** When the callback returns [SQLITE_OK], that means the operation
3397** requested is ok. ^When the callback returns [SQLITE_DENY], the
3398** [sqlite3_prepare_v2()] or equivalent call that triggered the
3399** authorizer will fail with an error message explaining that
3400** access is denied.
3401**
3402** ^The first parameter to the authorizer callback is a copy of the third
3403** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3404** to the callback is an integer [SQLITE_COPY | action code] that specifies
3405** the particular action to be authorized. ^The third through sixth parameters
3406** to the callback are either NULL pointers or zero-terminated strings
3407** that contain additional details about the action to be authorized.
3408** Applications must always be prepared to encounter a NULL pointer in any
3409** of the third through the sixth parameters of the authorization callback.
3410**
3411** ^If the action code is [SQLITE_READ]
3412** and the callback returns [SQLITE_IGNORE] then the
3413** [prepared statement] statement is constructed to substitute
3414** a NULL value in place of the table column that would have
3415** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3416** return can be used to deny an untrusted user access to individual
3417** columns of a table.
3418** ^When a table is referenced by a [SELECT] but no column values are
3419** extracted from that table (for example in a query like
3420** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3421** is invoked once for that table with a column name that is an empty string.
3422** ^If the action code is [SQLITE_DELETE] and the callback returns
3423** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3424** [truncate optimization] is disabled and all rows are deleted individually.
3425**
3426** An authorizer is used when [sqlite3_prepare | preparing]
3427** SQL statements from an untrusted source, to ensure that the SQL statements
3428** do not try to access data they are not allowed to see, or that they do not
3429** try to execute malicious statements that damage the database. For
3430** example, an application may allow a user to enter arbitrary
3431** SQL queries for evaluation by a database. But the application does
3432** not want the user to be able to make arbitrary changes to the
3433** database. An authorizer could then be put in place while the
3434** user-entered SQL is being [sqlite3_prepare | prepared] that
3435** disallows everything except [SELECT] statements.
3436**
3437** Applications that need to process SQL from untrusted sources
3438** might also consider lowering resource limits using [sqlite3_limit()]
3439** and limiting database size using the [max_page_count] [PRAGMA]
3440** in addition to using an authorizer.
3441**
3442** ^(Only a single authorizer can be in place on a database connection
3443** at a time. Each call to sqlite3_set_authorizer overrides the
3444** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3445** The authorizer is disabled by default.
3446**
3447** The authorizer callback must not do anything that will modify
3448** the database connection that invoked the authorizer callback.
3449** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3450** database connections for the meaning of "modify" in this paragraph.
3451**
3452** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3453** statement might be re-prepared during [sqlite3_step()] due to a
3454** schema change. Hence, the application should ensure that the
3455** correct authorizer callback remains in place during the [sqlite3_step()].
3456**
3457** ^Note that the authorizer callback is invoked only during
3458** [sqlite3_prepare()] or its variants. Authorization is not
3459** performed during statement evaluation in [sqlite3_step()], unless
3460** as stated in the previous paragraph, sqlite3_step() invokes
3461** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3462*/
3463SQLITE_API int sqlite3_set_authorizer(
3464 sqlite3*,
3465 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3466 void *pUserData
3467);
3468
3469/*
3470** CAPI3REF: Authorizer Return Codes
3471**
3472** The [sqlite3_set_authorizer | authorizer callback function] must
3473** return either [SQLITE_OK] or one of these two constants in order
3474** to signal SQLite whether or not the action is permitted. See the
3475** [sqlite3_set_authorizer | authorizer documentation] for additional
3476** information.
3477**
3478** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3479** returned from the [sqlite3_vtab_on_conflict()] interface.
3480*/
3481#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3482#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3483
3484/*
3485** CAPI3REF: Authorizer Action Codes
3486**
3487** The [sqlite3_set_authorizer()] interface registers a callback function
3488** that is invoked to authorize certain SQL statement actions. The
3489** second parameter to the callback is an integer code that specifies
3490** what action is being authorized. These are the integer action codes that
3491** the authorizer callback may be passed.
3492**
3493** These action code values signify what kind of operation is to be
3494** authorized. The 3rd and 4th parameters to the authorization
3495** callback function will be parameters or NULL depending on which of these
3496** codes is used as the second parameter. ^(The 5th parameter to the
3497** authorizer callback is the name of the database ("main", "temp",
3498** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3499** is the name of the inner-most trigger or view that is responsible for
3500** the access attempt or NULL if this access attempt is directly from
3501** top-level SQL code.
3502*/
3503/******************************************* 3rd ************ 4th ***********/
3504#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3505#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3506#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3507#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3508#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3509#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3510#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3511#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3512#define SQLITE_DELETE 9 /* Table Name NULL */
3513#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3514#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3515#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3516#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3517#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3518#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3519#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3520#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3521#define SQLITE_INSERT 18 /* Table Name NULL */
3522#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3523#define SQLITE_READ 20 /* Table Name Column Name */
3524#define SQLITE_SELECT 21 /* NULL NULL */
3525#define SQLITE_TRANSACTION 22 /* Operation NULL */
3526#define SQLITE_UPDATE 23 /* Table Name Column Name */
3527#define SQLITE_ATTACH 24 /* Filename NULL */
3528#define SQLITE_DETACH 25 /* Database Name NULL */
3529#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3530#define SQLITE_REINDEX 27 /* Index Name NULL */
3531#define SQLITE_ANALYZE 28 /* Table Name NULL */
3532#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3533#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3534#define SQLITE_FUNCTION 31 /* NULL Function Name */
3535#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3536#define SQLITE_COPY 0 /* No longer used */
3537#define SQLITE_RECURSIVE 33 /* NULL NULL */
3538
3539/*
3540** CAPI3REF: Deprecated Tracing And Profiling Functions
3541** DEPRECATED
3542**
3543** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3544** instead of the routines described here.
3545**
3546** These routines register callback functions that can be used for
3547** tracing and profiling the execution of SQL statements.
3548**
3549** ^The callback function registered by sqlite3_trace() is invoked at
3550** various times when an SQL statement is being run by [sqlite3_step()].
3551** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3552** SQL statement text as the statement first begins executing.
3553** ^(Additional sqlite3_trace() callbacks might occur
3554** as each triggered subprogram is entered. The callbacks for triggers
3555** contain a UTF-8 SQL comment that identifies the trigger.)^
3556**
3557** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3558** the length of [bound parameter] expansion in the output of sqlite3_trace().
3559**
3560** ^The callback function registered by sqlite3_profile() is invoked
3561** as each SQL statement finishes. ^The profile callback contains
3562** the original statement text and an estimate of wall-clock time
3563** of how long that statement took to run. ^The profile callback
3564** time is in units of nanoseconds, however the current implementation
3565** is only capable of millisecond resolution so the six least significant
3566** digits in the time are meaningless. Future versions of SQLite
3567** might provide greater resolution on the profiler callback. Invoking
3568** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3569** profile callback.
3570*/
3571SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3572 void(*xTrace)(void*,const char*), void*);
3573SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3574 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3575
3576/*
3577** CAPI3REF: SQL Trace Event Codes
3578** KEYWORDS: SQLITE_TRACE
3579**
3580** These constants identify classes of events that can be monitored
3581** using the [sqlite3_trace_v2()] tracing logic. The M argument
3582** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3583** the following constants. ^The first argument to the trace callback
3584** is one of the following constants.
3585**
3586** New tracing constants may be added in future releases.
3587**
3588** ^A trace callback has four arguments: xCallback(T,C,P,X).
3589** ^The T argument is one of the integer type codes above.
3590** ^The C argument is a copy of the context pointer passed in as the
3591** fourth argument to [sqlite3_trace_v2()].
3592** The P and X arguments are pointers whose meanings depend on T.
3593**
3594** <dl>
3595** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3596** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3597** first begins running and possibly at other times during the
3598** execution of the prepared statement, such as at the start of each
3599** trigger subprogram. ^The P argument is a pointer to the
3600** [prepared statement]. ^The X argument is a pointer to a string which
3601** is the unexpanded SQL text of the prepared statement or an SQL comment
3602** that indicates the invocation of a trigger. ^The callback can compute
3603** the same text that would have been returned by the legacy [sqlite3_trace()]
3604** interface by using the X argument when X begins with "--" and invoking
3605** [sqlite3_expanded_sql(P)] otherwise.
3606**
3607** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3608** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3609** information as is provided by the [sqlite3_profile()] callback.
3610** ^The P argument is a pointer to the [prepared statement] and the
3611** X argument points to a 64-bit integer which is approximately
3612** the number of nanoseconds that the prepared statement took to run.
3613** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3614**
3615** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3616** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3617** statement generates a single row of result.
3618** ^The P argument is a pointer to the [prepared statement] and the
3619** X argument is unused.
3620**
3621** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3622** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3623** connection closes.
3624** ^The P argument is a pointer to the [database connection] object
3625** and the X argument is unused.
3626** </dl>
3627*/
3628#define SQLITE_TRACE_STMT 0x01
3629#define SQLITE_TRACE_PROFILE 0x02
3630#define SQLITE_TRACE_ROW 0x04
3631#define SQLITE_TRACE_CLOSE 0x08
3632
3633/*
3634** CAPI3REF: SQL Trace Hook
3635** METHOD: sqlite3
3636**
3637** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3638** function X against [database connection] D, using property mask M
3639** and context pointer P. ^If the X callback is
3640** NULL or if the M mask is zero, then tracing is disabled. The
3641** M argument should be the bitwise OR-ed combination of
3642** zero or more [SQLITE_TRACE] constants.
3643**
3644** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3645** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3646** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3647** database connection may have at most one trace callback.
3648**
3649** ^The X callback is invoked whenever any of the events identified by
3650** mask M occur. ^The integer return value from the callback is currently
3651** ignored, though this may change in future releases. Callback
3652** implementations should return zero to ensure future compatibility.
3653**
3654** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3655** ^The T argument is one of the [SQLITE_TRACE]
3656** constants to indicate why the callback was invoked.
3657** ^The C argument is a copy of the context pointer.
3658** The P and X arguments are pointers whose meanings depend on T.
3659**
3660** The sqlite3_trace_v2() interface is intended to replace the legacy
3661** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3662** are deprecated.
3663*/
3664SQLITE_API int sqlite3_trace_v2(
3665 sqlite3*,
3666 unsigned uMask,
3667 int(*xCallback)(unsigned,void*,void*,void*),
3668 void *pCtx
3669);
3670
3671/*
3672** CAPI3REF: Query Progress Callbacks
3673** METHOD: sqlite3
3674**
3675** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3676** function X to be invoked periodically during long running calls to
3677** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3678** database connection D. An example use for this
3679** interface is to keep a GUI updated during a large query.
3680**
3681** ^The parameter P is passed through as the only parameter to the
3682** callback function X. ^The parameter N is the approximate number of
3683** [virtual machine instructions] that are evaluated between successive
3684** invocations of the callback X. ^If N is less than one then the progress
3685** handler is disabled.
3686**
3687** ^Only a single progress handler may be defined at one time per
3688** [database connection]; setting a new progress handler cancels the
3689** old one. ^Setting parameter X to NULL disables the progress handler.
3690** ^The progress handler is also disabled by setting N to a value less
3691** than 1.
3692**
3693** ^If the progress callback returns non-zero, the operation is
3694** interrupted. This feature can be used to implement a
3695** "Cancel" button on a GUI progress dialog box.
3696**
3697** The progress handler callback must not do anything that will modify
3698** the database connection that invoked the progress handler.
3699** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3700** database connections for the meaning of "modify" in this paragraph.
3701**
3702** The progress handler callback would originally only be invoked from the
3703** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3704** and similar because those routines might force a reparse of the schema
3705** which involves running the bytecode engine. However, beginning with
3706** SQLite version 3.41.0, the progress handler callback might also be
3707** invoked directly from [sqlite3_prepare()] while analyzing and generating
3708** code for complex queries.
3709*/
3710SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3711
3712/*
3713** CAPI3REF: Opening A New Database Connection
3714** CONSTRUCTOR: sqlite3
3715**
3716** ^These routines open an SQLite database file as specified by the
3717** filename argument. ^The filename argument is interpreted as UTF-8 for
3718** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3719** order for sqlite3_open16(). ^(A [database connection] handle is usually
3720** returned in *ppDb, even if an error occurs. The only exception is that
3721** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3722** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3723** object.)^ ^(If the database is opened (and/or created) successfully, then
3724** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3725** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3726** an English language description of the error following a failure of any
3727** of the sqlite3_open() routines.
3728**
3729** ^The default encoding will be UTF-8 for databases created using
3730** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3731** created using sqlite3_open16() will be UTF-16 in the native byte order.
3732**
3733** Whether or not an error occurs when it is opened, resources
3734** associated with the [database connection] handle should be released by
3735** passing it to [sqlite3_close()] when it is no longer required.
3736**
3737** The sqlite3_open_v2() interface works like sqlite3_open()
3738** except that it accepts two additional parameters for additional control
3739** over the new database connection. ^(The flags parameter to
3740** sqlite3_open_v2() must include, at a minimum, one of the following
3741** three flag combinations:)^
3742**
3743** <dl>
3744** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3745** <dd>The database is opened in read-only mode. If the database does
3746** not already exist, an error is returned.</dd>)^
3747**
3748** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3749** <dd>The database is opened for reading and writing if possible, or
3750** reading only if the file is write protected by the operating
3751** system. In either case the database must already exist, otherwise
3752** an error is returned. For historical reasons, if opening in
3753** read-write mode fails due to OS-level permissions, an attempt is
3754** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3755** used to determine whether the database is actually
3756** read-write.</dd>)^
3757**
3758** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3759** <dd>The database is opened for reading and writing, and is created if
3760** it does not already exist. This is the behavior that is always used for
3761** sqlite3_open() and sqlite3_open16().</dd>)^
3762** </dl>
3763**
3764** In addition to the required flags, the following optional flags are
3765** also supported:
3766**
3767** <dl>
3768** ^(<dt>[SQLITE_OPEN_URI]</dt>
3769** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3770**
3771** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3772** <dd>The database will be opened as an in-memory database. The database
3773** is named by the "filename" argument for the purposes of cache-sharing,
3774** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3775** </dd>)^
3776**
3777** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3778** <dd>The new database connection will use the "multi-thread"
3779** [threading mode].)^ This means that separate threads are allowed
3780** to use SQLite at the same time, as long as each thread is using
3781** a different [database connection].
3782**
3783** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3784** <dd>The new database connection will use the "serialized"
3785** [threading mode].)^ This means the multiple threads can safely
3786** attempt to use the same database connection at the same time.
3787** (Mutexes will block any actual concurrency, but in this mode
3788** there is no harm in trying.)
3789**
3790** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3791** <dd>The database is opened with [shared cache] enabled, overriding
3792** the default shared cache setting provided by
3793** [sqlite3_enable_shared_cache()].)^
3794** The [use of shared cache mode is discouraged] and hence shared cache
3795** capabilities may be omitted from many builds of SQLite. In such cases,
3796** this option is a no-op.
3797**
3798** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3799** <dd>The database is opened with [shared cache] disabled, overriding
3800** the default shared cache setting provided by
3801** [sqlite3_enable_shared_cache()].)^
3802**
3803** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3804** <dd>The database connection comes up in "extended result code mode".
3805** In other words, the database behaves as if
3806** [sqlite3_extended_result_codes(db,1)] were called on the database
3807** connection as soon as the connection is created. In addition to setting
3808** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3809** to return an extended result code.</dd>
3810**
3811** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3812** <dd>The database filename is not allowed to contain a symbolic link</dd>
3813** </dl>)^
3814**
3815** If the 3rd parameter to sqlite3_open_v2() is not one of the
3816** required combinations shown above optionally combined with other
3817** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3818** then the behavior is undefined. Historic versions of SQLite
3819** have silently ignored surplus bits in the flags parameter to
3820** sqlite3_open_v2(), however that behavior might not be carried through
3821** into future versions of SQLite and so applications should not rely
3822** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3823** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3824** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3825** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3826** by sqlite3_open_v2().
3827**
3828** ^The fourth parameter to sqlite3_open_v2() is the name of the
3829** [sqlite3_vfs] object that defines the operating system interface that
3830** the new database connection should use. ^If the fourth parameter is
3831** a NULL pointer then the default [sqlite3_vfs] object is used.
3832**
3833** ^If the filename is ":memory:", then a private, temporary in-memory database
3834** is created for the connection. ^This in-memory database will vanish when
3835** the database connection is closed. Future versions of SQLite might
3836** make use of additional special filenames that begin with the ":" character.
3837** It is recommended that when a database filename actually does begin with
3838** a ":" character you should prefix the filename with a pathname such as
3839** "./" to avoid ambiguity.
3840**
3841** ^If the filename is an empty string, then a private, temporary
3842** on-disk database will be created. ^This private database will be
3843** automatically deleted as soon as the database connection is closed.
3844**
3845** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3846**
3847** ^If [URI filename] interpretation is enabled, and the filename argument
3848** begins with "file:", then the filename is interpreted as a URI. ^URI
3849** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3850** set in the third argument to sqlite3_open_v2(), or if it has
3851** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3852** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3853** URI filename interpretation is turned off
3854** by default, but future releases of SQLite might enable URI filename
3855** interpretation by default. See "[URI filenames]" for additional
3856** information.
3857**
3858** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3859** authority, then it must be either an empty string or the string
3860** "localhost". ^If the authority is not an empty string or "localhost", an
3861** error is returned to the caller. ^The fragment component of a URI, if
3862** present, is ignored.
3863**
3864** ^SQLite uses the path component of the URI as the name of the disk file
3865** which contains the database. ^If the path begins with a '/' character,
3866** then it is interpreted as an absolute path. ^If the path does not begin
3867** with a '/' (meaning that the authority section is omitted from the URI)
3868** then the path is interpreted as a relative path.
3869** ^(On windows, the first component of an absolute path
3870** is a drive specification (e.g. "C:").)^
3871**
3872** [[core URI query parameters]]
3873** The query component of a URI may contain parameters that are interpreted
3874** either by SQLite itself, or by a [VFS | custom VFS implementation].
3875** SQLite and its built-in [VFSes] interpret the
3876** following query parameters:
3877**
3878** <ul>
3879** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3880** a VFS object that provides the operating system interface that should
3881** be used to access the database file on disk. ^If this option is set to
3882** an empty string the default VFS object is used. ^Specifying an unknown
3883** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3884** present, then the VFS specified by the option takes precedence over
3885** the value passed as the fourth parameter to sqlite3_open_v2().
3886**
3887** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3888** "rwc", or "memory". Attempting to set it to any other value is
3889** an error)^.
3890** ^If "ro" is specified, then the database is opened for read-only
3891** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3892** third argument to sqlite3_open_v2(). ^If the mode option is set to
3893** "rw", then the database is opened for read-write (but not create)
3894** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3895** been set. ^Value "rwc" is equivalent to setting both
3896** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3897** set to "memory" then a pure [in-memory database] that never reads
3898** or writes from disk is used. ^It is an error to specify a value for
3899** the mode parameter that is less restrictive than that specified by
3900** the flags passed in the third parameter to sqlite3_open_v2().
3901**
3902** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3903** "private". ^Setting it to "shared" is equivalent to setting the
3904** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3905** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3906** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3907** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3908** a URI filename, its value overrides any behavior requested by setting
3909** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3910**
3911** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3912** [powersafe overwrite] property does or does not apply to the
3913** storage media on which the database file resides.
3914**
3915** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3916** which if set disables file locking in rollback journal modes. This
3917** is useful for accessing a database on a filesystem that does not
3918** support locking. Caution: Database corruption might result if two
3919** or more processes write to the same database and any one of those
3920** processes uses nolock=1.
3921**
3922** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3923** parameter that indicates that the database file is stored on
3924** read-only media. ^When immutable is set, SQLite assumes that the
3925** database file cannot be changed, even by a process with higher
3926** privilege, and so the database is opened read-only and all locking
3927** and change detection is disabled. Caution: Setting the immutable
3928** property on a database file that does in fact change can result
3929** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3930** See also: [SQLITE_IOCAP_IMMUTABLE].
3931**
3932** </ul>
3933**
3934** ^Specifying an unknown parameter in the query component of a URI is not an
3935** error. Future versions of SQLite might understand additional query
3936** parameters. See "[query parameters with special meaning to SQLite]" for
3937** additional information.
3938**
3939** [[URI filename examples]] <h3>URI filename examples</h3>
3940**
3941** <table border="1" align=center cellpadding=5>
3942** <tr><th> URI filenames <th> Results
3943** <tr><td> file:data.db <td>
3944** Open the file "data.db" in the current directory.
3945** <tr><td> file:/home/fred/data.db<br>
3946** file:///home/fred/data.db <br>
3947** file://localhost/home/fred/data.db <br> <td>
3948** Open the database file "/home/fred/data.db".
3949** <tr><td> file://darkstar/home/fred/data.db <td>
3950** An error. "darkstar" is not a recognized authority.
3951** <tr><td style="white-space:nowrap">
3952** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3953** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3954** C:. Note that the %20 escaping in this example is not strictly
3955** necessary - space characters can be used literally
3956** in URI filenames.
3957** <tr><td> file:data.db?mode=ro&cache=private <td>
3958** Open file "data.db" in the current directory for read-only access.
3959** Regardless of whether or not shared-cache mode is enabled by
3960** default, use a private cache.
3961** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3962** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3963** that uses dot-files in place of posix advisory locking.
3964** <tr><td> file:data.db?mode=readonly <td>
3965** An error. "readonly" is not a valid option for the "mode" parameter.
3966** Use "ro" instead: "file:data.db?mode=ro".
3967** </table>
3968**
3969** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3970** query components of a URI. A hexadecimal escape sequence consists of a
3971** percent sign - "%" - followed by exactly two hexadecimal digits
3972** specifying an octet value. ^Before the path or query components of a
3973** URI filename are interpreted, they are encoded using UTF-8 and all
3974** hexadecimal escape sequences replaced by a single byte containing the
3975** corresponding octet. If this process generates an invalid UTF-8 encoding,
3976** the results are undefined.
3977**
3978** <b>Note to Windows users:</b> The encoding used for the filename argument
3979** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3980** codepage is currently defined. Filenames containing international
3981** characters must be converted to UTF-8 prior to passing them into
3982** sqlite3_open() or sqlite3_open_v2().
3983**
3984** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3985** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3986** features that require the use of temporary files may fail.
3987**
3988** See also: [sqlite3_temp_directory]
3989*/
3990SQLITE_API int sqlite3_open(
3991 const char *filename, /* Database filename (UTF-8) */
3992 sqlite3 **ppDb /* OUT: SQLite db handle */
3993);
3994SQLITE_API int sqlite3_open16(
3995 const void *filename, /* Database filename (UTF-16) */
3996 sqlite3 **ppDb /* OUT: SQLite db handle */
3997);
3998SQLITE_API int sqlite3_open_v2(
3999 const char *filename, /* Database filename (UTF-8) */
4000 sqlite3 **ppDb, /* OUT: SQLite db handle */
4001 int flags, /* Flags */
4002 const char *zVfs /* Name of VFS module to use */
4003);
4004
4005/*
4006** CAPI3REF: Obtain Values For URI Parameters
4007**
4008** These are utility routines, useful to [VFS|custom VFS implementations],
4009** that check if a database file was a URI that contained a specific query
4010** parameter, and if so obtains the value of that query parameter.
4011**
4012** The first parameter to these interfaces (hereafter referred to
4013** as F) must be one of:
4014** <ul>
4015** <li> A database filename pointer created by the SQLite core and
4016** passed into the xOpen() method of a VFS implementation, or
4017** <li> A filename obtained from [sqlite3_db_filename()], or
4018** <li> A new filename constructed using [sqlite3_create_filename()].
4019** </ul>
4020** If the F parameter is not one of the above, then the behavior is
4021** undefined and probably undesirable. Older versions of SQLite were
4022** more tolerant of invalid F parameters than newer versions.
4023**
4024** If F is a suitable filename (as described in the previous paragraph)
4025** and if P is the name of the query parameter, then
4026** sqlite3_uri_parameter(F,P) returns the value of the P
4027** parameter if it exists or a NULL pointer if P does not appear as a
4028** query parameter on F. If P is a query parameter of F and it
4029** has no explicit value, then sqlite3_uri_parameter(F,P) returns
4030** a pointer to an empty string.
4031**
4032** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
4033** parameter and returns true (1) or false (0) according to the value
4034** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
4035** value of query parameter P is one of "yes", "true", or "on" in any
4036** case or if the value begins with a non-zero number. The
4037** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
4038** query parameter P is one of "no", "false", or "off" in any case or
4039** if the value begins with a numeric zero. If P is not a query
4040** parameter on F or if the value of P does not match any of the
4041** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
4042**
4043** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
4044** 64-bit signed integer and returns that integer, or D if P does not
4045** exist. If the value of P is something other than an integer, then
4046** zero is returned.
4047**
4048** The sqlite3_uri_key(F,N) returns a pointer to the name (not
4049** the value) of the N-th query parameter for filename F, or a NULL
4050** pointer if N is less than zero or greater than the number of query
4051** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4052** the name of the first query parameter, 1 for the second parameter, and
4053** so forth.
4054**
4055** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4056** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4057** is not a database file pathname pointer that the SQLite core passed
4058** into the xOpen VFS method, then the behavior of this routine is undefined
4059** and probably undesirable.
4060**
4061** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4062** parameter can also be the name of a rollback journal file or WAL file
4063** in addition to the main database file. Prior to version 3.31.0, these
4064** routines would only work if F was the name of the main database file.
4065** When the F parameter is the name of the rollback journal or WAL file,
4066** it has access to all the same query parameters as were found on the
4067** main database file.
4068**
4069** See the [URI filename] documentation for additional information.
4070*/
4071SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4072SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4073SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4074SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4075
4076/*
4077** CAPI3REF: Translate filenames
4078**
4079** These routines are available to [VFS|custom VFS implementations] for
4080** translating filenames between the main database file, the journal file,
4081** and the WAL file.
4082**
4083** If F is the name of an sqlite database file, journal file, or WAL file
4084** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4085** returns the name of the corresponding database file.
4086**
4087** If F is the name of an sqlite database file, journal file, or WAL file
4088** passed by the SQLite core into the VFS, or if F is a database filename
4089** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4090** returns the name of the corresponding rollback journal file.
4091**
4092** If F is the name of an sqlite database file, journal file, or WAL file
4093** that was passed by the SQLite core into the VFS, or if F is a database
4094** filename obtained from [sqlite3_db_filename()], then
4095** sqlite3_filename_wal(F) returns the name of the corresponding
4096** WAL file.
4097**
4098** In all of the above, if F is not the name of a database, journal or WAL
4099** filename passed into the VFS from the SQLite core and F is not the
4100** return value from [sqlite3_db_filename()], then the result is
4101** undefined and is likely a memory access violation.
4102*/
4103SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4104SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4105SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4106
4107/*
4108** CAPI3REF: Database File Corresponding To A Journal
4109**
4110** ^If X is the name of a rollback or WAL-mode journal file that is
4111** passed into the xOpen method of [sqlite3_vfs], then
4112** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4113** object that represents the main database file.
4114**
4115** This routine is intended for use in custom [VFS] implementations
4116** only. It is not a general-purpose interface.
4117** The argument sqlite3_file_object(X) must be a filename pointer that
4118** has been passed into [sqlite3_vfs].xOpen method where the
4119** flags parameter to xOpen contains one of the bits
4120** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4121** of this routine results in undefined and probably undesirable
4122** behavior.
4123*/
4124SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4125
4126/*
4127** CAPI3REF: Create and Destroy VFS Filenames
4128**
4129** These interfaces are provided for use by [VFS shim] implementations and
4130** are not useful outside of that context.
4131**
4132** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4133** database filename D with corresponding journal file J and WAL file W and
4134** an array P of N URI Key/Value pairs. The result from
4135** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4136** is safe to pass to routines like:
4137** <ul>
4138** <li> [sqlite3_uri_parameter()],
4139** <li> [sqlite3_uri_boolean()],
4140** <li> [sqlite3_uri_int64()],
4141** <li> [sqlite3_uri_key()],
4142** <li> [sqlite3_filename_database()],
4143** <li> [sqlite3_filename_journal()], or
4144** <li> [sqlite3_filename_wal()].
4145** </ul>
4146** If a memory allocation error occurs, sqlite3_create_filename() might
4147** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4148** must be released by a corresponding call to sqlite3_free_filename(Y).
4149**
4150** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4151** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4152** to a key and value for a query parameter. The P parameter may be a NULL
4153** pointer if N is zero. None of the 2*N pointers in the P array may be
4154** NULL pointers and key pointers should not be empty strings.
4155** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4156** be NULL pointers, though they can be empty strings.
4157**
4158** The sqlite3_free_filename(Y) routine releases a memory allocation
4159** previously obtained from sqlite3_create_filename(). Invoking
4160** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4161**
4162** If the Y parameter to sqlite3_free_filename(Y) is anything other
4163** than a NULL pointer or a pointer previously acquired from
4164** sqlite3_create_filename(), then bad things such as heap
4165** corruption or segfaults may occur. The value Y should not be
4166** used again after sqlite3_free_filename(Y) has been called. This means
4167** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4168** then the corresponding [sqlite3_module.xClose() method should also be
4169** invoked prior to calling sqlite3_free_filename(Y).
4170*/
4171SQLITE_API sqlite3_filename sqlite3_create_filename(
4172 const char *zDatabase,
4173 const char *zJournal,
4174 const char *zWal,
4175 int nParam,
4176 const char **azParam
4177);
4178SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4179
4180/*
4181** CAPI3REF: Error Codes And Messages
4182** METHOD: sqlite3
4183**
4184** ^If the most recent sqlite3_* API call associated with
4185** [database connection] D failed, then the sqlite3_errcode(D) interface
4186** returns the numeric [result code] or [extended result code] for that
4187** API call.
4188** ^The sqlite3_extended_errcode()
4189** interface is the same except that it always returns the
4190** [extended result code] even when extended result codes are
4191** disabled.
4192**
4193** The values returned by sqlite3_errcode() and/or
4194** sqlite3_extended_errcode() might change with each API call.
4195** Except, there are some interfaces that are guaranteed to never
4196** change the value of the error code. The error-code preserving
4197** interfaces include the following:
4198**
4199** <ul>
4200** <li> sqlite3_errcode()
4201** <li> sqlite3_extended_errcode()
4202** <li> sqlite3_errmsg()
4203** <li> sqlite3_errmsg16()
4204** <li> sqlite3_error_offset()
4205** <li> sqlite3_db_handle()
4206** </ul>
4207**
4208** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4209** text that describes the error, as either UTF-8 or UTF-16 respectively,
4210** or NULL if no error message is available.
4211** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4212** ^(Memory to hold the error message string is managed internally.
4213** The application does not need to worry about freeing the result.
4214** However, the error string might be overwritten or deallocated by
4215** subsequent calls to other SQLite interface functions.)^
4216**
4217** ^The sqlite3_errstr(E) interface returns the English-language text
4218** that describes the [result code] E, as UTF-8, or NULL if E is not a
4219** result code for which a text error message is available.
4220** ^(Memory to hold the error message string is managed internally
4221** and must not be freed by the application)^.
4222**
4223** ^If the most recent error references a specific token in the input
4224** SQL, the sqlite3_error_offset() interface returns the byte offset
4225** of the start of that token. ^The byte offset returned by
4226** sqlite3_error_offset() assumes that the input SQL is UTF-8.
4227** ^If the most recent error does not reference a specific token in the input
4228** SQL, then the sqlite3_error_offset() function returns -1.
4229**
4230** When the serialized [threading mode] is in use, it might be the
4231** case that a second error occurs on a separate thread in between
4232** the time of the first error and the call to these interfaces.
4233** When that happens, the second error will be reported since these
4234** interfaces always report the most recent result. To avoid
4235** this, each thread can obtain exclusive use of the [database connection] D
4236** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4237** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4238** all calls to the interfaces listed here are completed.
4239**
4240** If an interface fails with SQLITE_MISUSE, that means the interface
4241** was invoked incorrectly by the application. In that case, the
4242** error code and message may or may not be set.
4243*/
4244SQLITE_API int sqlite3_errcode(sqlite3 *db);
4245SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4246SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4247SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4248SQLITE_API const char *sqlite3_errstr(int);
4249SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4250
4251/*
4252** CAPI3REF: Set Error Code And Message
4253** METHOD: sqlite3
4254**
4255** Set the error code of the database handle passed as the first argument
4256** to errcode, and the error message to a copy of nul-terminated string
4257** zErrMsg. If zErrMsg is passed NULL, then the error message is set to
4258** the default message associated with the supplied error code. Subsequent
4259** calls to [sqlite3_errcode()] and [sqlite3_errmsg()] and similar will
4260** return the values set by this routine in place of what was previously
4261** set by SQLite itself.
4262**
4263** This function returns SQLITE_OK if the error code and error message are
4264** successfully set, SQLITE_NOMEM if an OOM occurs, and SQLITE_MISUSE if
4265** the database handle is NULL or invalid.
4266**
4267** The error code and message set by this routine remains in effect until
4268** they are changed, either by another call to this routine or until they are
4269** changed to by SQLite itself to reflect the result of some subsquent
4270** API call.
4271**
4272** This function is intended for use by SQLite extensions or wrappers. The
4273** idea is that an extension or wrapper can use this routine to set error
4274** messages and error codes and thus behave more like a core SQLite
4275** feature from the point of view of an application.
4276*/
4277SQLITE_API int sqlite3_set_errmsg(sqlite3 *db, int errcode, const char *zErrMsg);
4278
4279/*
4280** CAPI3REF: Prepared Statement Object
4281** KEYWORDS: {prepared statement} {prepared statements}
4282**
4283** An instance of this object represents a single SQL statement that
4284** has been compiled into binary form and is ready to be evaluated.
4285**
4286** Think of each SQL statement as a separate computer program. The
4287** original SQL text is source code. A prepared statement object
4288** is the compiled object code. All SQL must be converted into a
4289** prepared statement before it can be run.
4290**
4291** The life-cycle of a prepared statement object usually goes like this:
4292**
4293** <ol>
4294** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4295** <li> Bind values to [parameters] using the sqlite3_bind_*()
4296** interfaces.
4297** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4298** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4299** to step 2. Do this zero or more times.
4300** <li> Destroy the object using [sqlite3_finalize()].
4301** </ol>
4302*/
4303typedef struct sqlite3_stmt sqlite3_stmt;
4304
4305/*
4306** CAPI3REF: Run-time Limits
4307** METHOD: sqlite3
4308**
4309** ^(This interface allows the size of various constructs to be limited
4310** on a connection by connection basis. The first parameter is the
4311** [database connection] whose limit is to be set or queried. The
4312** second parameter is one of the [limit categories] that define a
4313** class of constructs to be size limited. The third parameter is the
4314** new limit for that construct.)^
4315**
4316** ^If the new limit is a negative number, the limit is unchanged.
4317** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4318** [limits | hard upper bound]
4319** set at compile-time by a C preprocessor macro called
4320** [limits | SQLITE_MAX_<i>NAME</i>].
4321** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4322** ^Attempts to increase a limit above its hard upper bound are
4323** silently truncated to the hard upper bound.
4324**
4325** ^Regardless of whether or not the limit was changed, the
4326** [sqlite3_limit()] interface returns the prior value of the limit.
4327** ^Hence, to find the current value of a limit without changing it,
4328** simply invoke this interface with the third parameter set to -1.
4329**
4330** Run-time limits are intended for use in applications that manage
4331** both their own internal database and also databases that are controlled
4332** by untrusted external sources. An example application might be a
4333** web browser that has its own databases for storing history and
4334** separate databases controlled by JavaScript applications downloaded
4335** off the Internet. The internal databases can be given the
4336** large, default limits. Databases managed by external sources can
4337** be given much smaller limits designed to prevent a denial of service
4338** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4339** interface to further control untrusted SQL. The size of the database
4340** created by an untrusted script can be contained using the
4341** [max_page_count] [PRAGMA].
4342**
4343** New run-time limit categories may be added in future releases.
4344*/
4345SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4346
4347/*
4348** CAPI3REF: Run-Time Limit Categories
4349** KEYWORDS: {limit category} {*limit categories}
4350**
4351** These constants define various performance limits
4352** that can be lowered at run-time using [sqlite3_limit()].
4353** A concise description of these limits follows, and additional information
4354** is available at [limits | Limits in SQLite].
4355**
4356** <dl>
4357** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4358** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4359**
4360** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4361** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4362**
4363** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4364** <dd>The maximum number of columns in a table definition or in the
4365** result set of a [SELECT] or the maximum number of columns in an index
4366** or in an ORDER BY or GROUP BY clause.</dd>)^
4367**
4368** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4369** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4370**
4371** [[SQLITE_LIMIT_PARSER_DEPTH]] ^(<dt>SQLITE_LIMIT_PARSER_DEPTH</dt>
4372** <dd>The maximum depth of the LALR(1) parser stack used to analyze
4373** input SQL statements.</dd>)^
4374**
4375** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4376** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4377**
4378** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4379** <dd>The maximum number of instructions in a virtual machine program
4380** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4381** the equivalent tries to allocate space for more than this many opcodes
4382** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4383**
4384** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4385** <dd>The maximum number of arguments on a function.</dd>)^
4386**
4387** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4388** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4389**
4390** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4391** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4392** <dd>The maximum length of the pattern argument to the [LIKE] or
4393** [GLOB] operators.</dd>)^
4394**
4395** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4396** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4397** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4398**
4399** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4400** <dd>The maximum depth of recursion for triggers.</dd>)^
4401**
4402** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4403** <dd>The maximum number of auxiliary worker threads that a single
4404** [prepared statement] may start.</dd>)^
4405** </dl>
4406*/
4407#define SQLITE_LIMIT_LENGTH 0
4408#define SQLITE_LIMIT_SQL_LENGTH 1
4409#define SQLITE_LIMIT_COLUMN 2
4410#define SQLITE_LIMIT_EXPR_DEPTH 3
4411#define SQLITE_LIMIT_COMPOUND_SELECT 4
4412#define SQLITE_LIMIT_VDBE_OP 5
4413#define SQLITE_LIMIT_FUNCTION_ARG 6
4414#define SQLITE_LIMIT_ATTACHED 7
4415#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4416#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4417#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4418#define SQLITE_LIMIT_WORKER_THREADS 11
4419#define SQLITE_LIMIT_PARSER_DEPTH 12
4420
4421/*
4422** CAPI3REF: Prepare Flags
4423**
4424** These constants define various flags that can be passed into the
4425** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4426** [sqlite3_prepare16_v3()] interfaces.
4427**
4428** New flags may be added in future releases of SQLite.
4429**
4430** <dl>
4431** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4432** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4433** that the prepared statement will be retained for a long time and
4434** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4435** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4436** be used just once or at most a few times and then destroyed using
4437** [sqlite3_finalize()] relatively soon. The current implementation acts
4438** on this hint by avoiding the use of [lookaside memory] so as not to
4439** deplete the limited store of lookaside memory. Future versions of
4440** SQLite may act on this hint differently.
4441**
4442** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4443** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4444** to be required for any prepared statement that wanted to use the
4445** [sqlite3_normalized_sql()] interface. However, the
4446** [sqlite3_normalized_sql()] interface is now available to all
4447** prepared statements, regardless of whether or not they use this
4448** flag.
4449**
4450** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4451** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4452** to return an error (error code SQLITE_ERROR) if the statement uses
4453** any virtual tables.
4454**
4455** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4456** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4457** errors from being sent to the error log defined by
4458** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4459** compiles to see if some SQL syntax is well-formed, without generating
4460** messages on the global error log when it is not. If the test compile
4461** fails, the sqlite3_prepare_v3() call returns the same error indications
4462** with or without this flag; it just omits the call to [sqlite3_log()] that
4463** logs the error.
4464**
4465** [[SQLITE_PREPARE_FROM_DDL]] <dt>SQLITE_PREPARE_FROM_DDL</dt>
4466** <dd>The SQLITE_PREPARE_FROM_DDL flag causes the SQL compiler to enforce
4467** security constraints that would otherwise only be enforced when parsing
4468** the database schema. In other words, the SQLITE_PREPARE_FROM_DDL flag
4469** causes the SQL compiler to treat the SQL statement being prepared as if
4470** it had come from an attacker. When SQLITE_PREPARE_FROM_DDL is used and
4471** [SQLITE_DBCONFIG_TRUSTED_SCHEMA] is off, SQL functions may only be called
4472** if they are tagged with [SQLITE_INNOCUOUS] and virtual tables may only
4473** be used if they are tagged with [SQLITE_VTAB_INNOCUOUS]. Best practice
4474** is to use the SQLITE_PREPARE_FROM_DDL option when preparing any SQL that
4475** is derived from parts of the database schema. In particular, virtual
4476** table implementations that run SQL statements that are derived from
4477** arguments to their CREATE VIRTUAL TABLE statement should always use
4478** [sqlite3_prepare_v3()] and set the SQLITE_PREPARE_FROM_DDL flag to
4479** prevent bypass of the [SQLITE_DBCONFIG_TRUSTED_SCHEMA] security checks.
4480** </dl>
4481*/
4482#define SQLITE_PREPARE_PERSISTENT 0x01
4483#define SQLITE_PREPARE_NORMALIZE 0x02
4484#define SQLITE_PREPARE_NO_VTAB 0x04
4485#define SQLITE_PREPARE_DONT_LOG 0x10
4486#define SQLITE_PREPARE_FROM_DDL 0x20
4487
4488/*
4489** CAPI3REF: Compiling An SQL Statement
4490** KEYWORDS: {SQL statement compiler}
4491** METHOD: sqlite3
4492** CONSTRUCTOR: sqlite3_stmt
4493**
4494** To execute an SQL statement, it must first be compiled into a byte-code
4495** program using one of these routines. Or, in other words, these routines
4496** are constructors for the [prepared statement] object.
4497**
4498** The preferred routine to use is [sqlite3_prepare_v2()]. The
4499** [sqlite3_prepare()] interface is legacy and should be avoided.
4500** [sqlite3_prepare_v3()] has an extra
4501** [SQLITE_PREPARE_FROM_DDL|"prepFlags" option] that is sometimes
4502** needed for special purpose or to pass along security restrictions.
4503**
4504** The use of the UTF-8 interfaces is preferred, as SQLite currently
4505** does all parsing using UTF-8. The UTF-16 interfaces are provided
4506** as a convenience. The UTF-16 interfaces work by converting the
4507** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4508**
4509** The first argument, "db", is a [database connection] obtained from a
4510** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4511** [sqlite3_open16()]. The database connection must not have been closed.
4512**
4513** The second argument, "zSql", is the statement to be compiled, encoded
4514** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4515** and sqlite3_prepare_v3()
4516** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4517** and sqlite3_prepare16_v3() use UTF-16.
4518**
4519** ^If the nByte argument is negative, then zSql is read up to the
4520** first zero terminator. ^If nByte is positive, then it is the maximum
4521** number of bytes read from zSql. When nByte is positive, zSql is read
4522** up to the first zero terminator or until the nByte bytes have been read,
4523** whichever comes first. ^If nByte is zero, then no prepared
4524** statement is generated.
4525** If the caller knows that the supplied string is nul-terminated, then
4526** there is a small performance advantage to passing an nByte parameter that
4527** is the number of bytes in the input string <i>including</i>
4528** the nul-terminator.
4529** Note that nByte measures the length of the input in bytes, not
4530** characters, even for the UTF-16 interfaces.
4531**
4532** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4533** past the end of the first SQL statement in zSql. These routines only
4534** compile the first statement in zSql, so *pzTail is left pointing to
4535** what remains uncompiled.
4536**
4537** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4538** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4539** to NULL. ^If the input text contains no SQL (if the input is an empty
4540** string or a comment) then *ppStmt is set to NULL.
4541** The calling procedure is responsible for deleting the compiled
4542** SQL statement using [sqlite3_finalize()] after it has finished with it.
4543** ppStmt may not be NULL.
4544**
4545** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4546** otherwise an [error code] is returned.
4547**
4548** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4549** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4550** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4551** are retained for backwards compatibility, but their use is discouraged.
4552** ^In the "vX" interfaces, the prepared statement
4553** that is returned (the [sqlite3_stmt] object) contains a copy of the
4554** original SQL text. This causes the [sqlite3_step()] interface to
4555** behave differently in three ways:
4556**
4557** <ol>
4558** <li>
4559** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4560** always used to do, [sqlite3_step()] will automatically recompile the SQL
4561** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4562** retries will occur before sqlite3_step() gives up and returns an error.
4563** </li>
4564**
4565** <li>
4566** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4567** [error codes] or [extended error codes]. ^The legacy behavior was that
4568** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4569** and the application would have to make a second call to [sqlite3_reset()]
4570** in order to find the underlying cause of the problem. With the "v2" prepare
4571** interfaces, the underlying reason for the error is returned immediately.
4572** </li>
4573**
4574** <li>
4575** ^If the specific value bound to a [parameter | host parameter] in the
4576** WHERE clause might influence the choice of query plan for a statement,
4577** then the statement will be automatically recompiled, as if there had been
4578** a schema change, on the first [sqlite3_step()] call following any change
4579** to the [sqlite3_bind_text | bindings] of that [parameter].
4580** ^The specific value of a WHERE-clause [parameter] might influence the
4581** choice of query plan if the parameter is the left-hand side of a [LIKE]
4582** or [GLOB] operator or if the parameter is compared to an indexed column
4583** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4584** </li>
4585** </ol>
4586**
4587** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4588** the extra prepFlags parameter, which is a bit array consisting of zero or
4589** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4590** sqlite3_prepare_v2() interface works exactly the same as
4591** sqlite3_prepare_v3() with a zero prepFlags parameter.
4592*/
4593SQLITE_API int sqlite3_prepare(
4594 sqlite3 *db, /* Database handle */
4595 const char *zSql, /* SQL statement, UTF-8 encoded */
4596 int nByte, /* Maximum length of zSql in bytes. */
4597 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4598 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4599);
4600SQLITE_API int sqlite3_prepare_v2(
4601 sqlite3 *db, /* Database handle */
4602 const char *zSql, /* SQL statement, UTF-8 encoded */
4603 int nByte, /* Maximum length of zSql in bytes. */
4604 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4605 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4606);
4607SQLITE_API int sqlite3_prepare_v3(
4608 sqlite3 *db, /* Database handle */
4609 const char *zSql, /* SQL statement, UTF-8 encoded */
4610 int nByte, /* Maximum length of zSql in bytes. */
4611 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4612 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4613 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4614);
4615SQLITE_API int sqlite3_prepare16(
4616 sqlite3 *db, /* Database handle */
4617 const void *zSql, /* SQL statement, UTF-16 encoded */
4618 int nByte, /* Maximum length of zSql in bytes. */
4619 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4620 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4621);
4622SQLITE_API int sqlite3_prepare16_v2(
4623 sqlite3 *db, /* Database handle */
4624 const void *zSql, /* SQL statement, UTF-16 encoded */
4625 int nByte, /* Maximum length of zSql in bytes. */
4626 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4627 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4628);
4629SQLITE_API int sqlite3_prepare16_v3(
4630 sqlite3 *db, /* Database handle */
4631 const void *zSql, /* SQL statement, UTF-16 encoded */
4632 int nByte, /* Maximum length of zSql in bytes. */
4633 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4634 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4635 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4636);
4637
4638/*
4639** CAPI3REF: Retrieving Statement SQL
4640** METHOD: sqlite3_stmt
4641**
4642** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4643** SQL text used to create [prepared statement] P if P was
4644** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4645** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4646** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4647** string containing the SQL text of prepared statement P with
4648** [bound parameters] expanded.
4649** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4650** string containing the normalized SQL text of prepared statement P. The
4651** semantics used to normalize a SQL statement are unspecified and subject
4652** to change. At a minimum, literal values will be replaced with suitable
4653** placeholders.
4654**
4655** ^(For example, if a prepared statement is created using the SQL
4656** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4657** and parameter :xyz is unbound, then sqlite3_sql() will return
4658** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4659** will return "SELECT 2345,NULL".)^
4660**
4661** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4662** is available to hold the result, or if the result would exceed the
4663** maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4664**
4665** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4666** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4667** option causes sqlite3_expanded_sql() to always return NULL.
4668**
4669** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4670** are managed by SQLite and are automatically freed when the prepared
4671** statement is finalized.
4672** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4673** is obtained from [sqlite3_malloc()] and must be freed by the application
4674** by passing it to [sqlite3_free()].
4675**
4676** ^The sqlite3_normalized_sql() interface is only available if
4677** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4678*/
4679SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4680SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4681#ifdef SQLITE_ENABLE_NORMALIZE
4682SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4683#endif
4684
4685/*
4686** CAPI3REF: Determine If An SQL Statement Writes The Database
4687** METHOD: sqlite3_stmt
4688**
4689** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4690** and only if the [prepared statement] X makes no direct changes to
4691** the content of the database file.
4692**
4693** Note that [application-defined SQL functions] or
4694** [virtual tables] might change the database indirectly as a side effect.
4695** ^(For example, if an application defines a function "eval()" that
4696** calls [sqlite3_exec()], then the following SQL statement would
4697** change the database file through side-effects:
4698**
4699** <blockquote><pre>
4700** SELECT eval('DELETE FROM t1') FROM t2;
4701** </pre></blockquote>
4702**
4703** But because the [SELECT] statement does not change the database file
4704** directly, sqlite3_stmt_readonly() would still return true.)^
4705**
4706** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4707** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4708** since the statements themselves do not actually modify the database but
4709** rather they control the timing of when other statements modify the
4710** database. ^The [ATTACH] and [DETACH] statements also cause
4711** sqlite3_stmt_readonly() to return true since, while those statements
4712** change the configuration of a database connection, they do not make
4713** changes to the content of the database files on disk.
4714** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4715** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4716** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4717** sqlite3_stmt_readonly() returns false for those commands.
4718**
4719** ^This routine returns false if there is any possibility that the
4720** statement might change the database file. ^A false return does
4721** not guarantee that the statement will change the database file.
4722** ^For example, an UPDATE statement might have a WHERE clause that
4723** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4724** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4725** read-only no-op if the table already exists, but
4726** sqlite3_stmt_readonly() still returns false for such a statement.
4727**
4728** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4729** statement, then sqlite3_stmt_readonly(X) returns the same value as
4730** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4731*/
4732SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4733
4734/*
4735** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4736** METHOD: sqlite3_stmt
4737**
4738** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4739** prepared statement S is an EXPLAIN statement, or 2 if the
4740** statement S is an EXPLAIN QUERY PLAN.
4741** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4742** an ordinary statement or a NULL pointer.
4743*/
4744SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4745
4746/*
4747** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4748** METHOD: sqlite3_stmt
4749**
4750** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4751** setting for [prepared statement] S. If E is zero, then S becomes
4752** a normal prepared statement. If E is 1, then S behaves as if
4753** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4754** its SQL text began with "[EXPLAIN QUERY PLAN]".
4755**
4756** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4757** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4758** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4759**
4760** Because of the potential need to reprepare, a call to
4761** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4762** reprepared because it was created using [sqlite3_prepare()] instead of
4763** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4764** hence has no saved SQL text with which to reprepare.
4765**
4766** Changing the explain setting for a prepared statement does not change
4767** the original SQL text for the statement. Hence, if the SQL text originally
4768** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4769** is called to convert the statement into an ordinary statement, the EXPLAIN
4770** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4771** output, even though the statement now acts like a normal SQL statement.
4772**
4773** This routine returns SQLITE_OK if the explain mode is successfully
4774** changed, or an error code if the explain mode could not be changed.
4775** The explain mode cannot be changed while a statement is active.
4776** Hence, it is good practice to call [sqlite3_reset(S)]
4777** immediately prior to calling sqlite3_stmt_explain(S,E).
4778*/
4779SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4780
4781/*
4782** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4783** METHOD: sqlite3_stmt
4784**
4785** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4786** [prepared statement] S has been stepped at least once using
4787** [sqlite3_step(S)] but has neither run to completion (returned
4788** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4789** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4790** interface returns false if S is a NULL pointer. If S is not a
4791** NULL pointer and is not a pointer to a valid [prepared statement]
4792** object, then the behavior is undefined and probably undesirable.
4793**
4794** This interface can be used in combination [sqlite3_next_stmt()]
4795** to locate all prepared statements associated with a database
4796** connection that are in need of being reset. This can be used,
4797** for example, in diagnostic routines to search for prepared
4798** statements that are holding a transaction open.
4799*/
4800SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4801
4802/*
4803** CAPI3REF: Dynamically Typed Value Object
4804** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4805**
4806** SQLite uses the sqlite3_value object to represent all values
4807** that can be stored in a database table. SQLite uses dynamic typing
4808** for the values it stores. ^Values stored in sqlite3_value objects
4809** can be integers, floating point values, strings, BLOBs, or NULL.
4810**
4811** An sqlite3_value object may be either "protected" or "unprotected".
4812** Some interfaces require a protected sqlite3_value. Other interfaces
4813** will accept either a protected or an unprotected sqlite3_value.
4814** Every interface that accepts sqlite3_value arguments specifies
4815** whether or not it requires a protected sqlite3_value. The
4816** [sqlite3_value_dup()] interface can be used to construct a new
4817** protected sqlite3_value from an unprotected sqlite3_value.
4818**
4819** The terms "protected" and "unprotected" refer to whether or not
4820** a mutex is held. An internal mutex is held for a protected
4821** sqlite3_value object but no mutex is held for an unprotected
4822** sqlite3_value object. If SQLite is compiled to be single-threaded
4823** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4824** or if SQLite is run in one of reduced mutex modes
4825** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4826** then there is no distinction between protected and unprotected
4827** sqlite3_value objects and they can be used interchangeably. However,
4828** for maximum code portability it is recommended that applications
4829** still make the distinction between protected and unprotected
4830** sqlite3_value objects even when not strictly required.
4831**
4832** ^The sqlite3_value objects that are passed as parameters into the
4833** implementation of [application-defined SQL functions] are protected.
4834** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4835** are protected.
4836** ^The sqlite3_value object returned by
4837** [sqlite3_column_value()] is unprotected.
4838** Unprotected sqlite3_value objects may only be used as arguments
4839** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4840** [sqlite3_value_dup()].
4841** The [sqlite3_value_blob | sqlite3_value_type()] family of
4842** interfaces require protected sqlite3_value objects.
4843*/
4844typedef struct sqlite3_value sqlite3_value;
4845
4846/*
4847** CAPI3REF: SQL Function Context Object
4848**
4849** The context in which an SQL function executes is stored in an
4850** sqlite3_context object. ^A pointer to an sqlite3_context object
4851** is always the first parameter to [application-defined SQL functions].
4852** The application-defined SQL function implementation will pass this
4853** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4854** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4855** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4856** and/or [sqlite3_set_auxdata()].
4857*/
4858typedef struct sqlite3_context sqlite3_context;
4859
4860/*
4861** CAPI3REF: Binding Values To Prepared Statements
4862** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4863** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4864** METHOD: sqlite3_stmt
4865**
4866** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4867** literals may be replaced by a [parameter] that matches one of the following
4868** templates:
4869**
4870** <ul>
4871** <li> ?
4872** <li> ?NNN
4873** <li> :VVV
4874** <li> @VVV
4875** <li> $VVV
4876** </ul>
4877**
4878** In the templates above, NNN represents an integer literal,
4879** and VVV represents an alphanumeric identifier.)^ ^The values of these
4880** parameters (also called "host parameter names" or "SQL parameters")
4881** can be set using the sqlite3_bind_*() routines defined here.
4882**
4883** ^The first argument to the sqlite3_bind_*() routines is always
4884** a pointer to the [sqlite3_stmt] object returned from
4885** [sqlite3_prepare_v2()] or its variants.
4886**
4887** ^The second argument is the index of the SQL parameter to be set.
4888** ^The leftmost SQL parameter has an index of 1. ^When the same named
4889** SQL parameter is used more than once, second and subsequent
4890** occurrences have the same index as the first occurrence.
4891** ^The index for named parameters can be looked up using the
4892** [sqlite3_bind_parameter_index()] API if desired. ^The index
4893** for "?NNN" parameters is the value of NNN.
4894** ^The NNN value must be between 1 and the [sqlite3_limit()]
4895** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4896**
4897** ^The third argument is the value to bind to the parameter.
4898** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4899** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4900** is ignored and the end result is the same as sqlite3_bind_null().
4901** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4902** it should be a pointer to well-formed UTF8 text.
4903** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4904** it should be a pointer to well-formed UTF16 text.
4905** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4906** it should be a pointer to a well-formed unicode string that is
4907** either UTF8 if the sixth parameter is SQLITE_UTF8 or SQLITE_UTF8_ZT,
4908** or UTF16 otherwise.
4909**
4910** [[byte-order determination rules]] ^The byte-order of
4911** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4912** found in the first character, which is removed, or in the absence of a BOM
4913** the byte order is the native byte order of the host
4914** machine for sqlite3_bind_text16() or the byte order specified in
4915** the 6th parameter for sqlite3_bind_text64().)^
4916** ^If UTF16 input text contains invalid unicode
4917** characters, then SQLite might change those invalid characters
4918** into the unicode replacement character: U+FFFD.
4919**
4920** ^(In those routines that have a fourth argument, its value is the
4921** number of bytes in the parameter. To be clear: the value is the
4922** number of <u>bytes</u> in the value, not the number of characters.)^
4923** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4924** is negative, then the length of the string is
4925** the number of bytes up to the first zero terminator.
4926** If the fourth parameter to sqlite3_bind_blob() is negative, then
4927** the behavior is undefined.
4928** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4929** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4930** that parameter must be the byte offset
4931** where the NUL terminator would occur assuming the string were NUL
4932** terminated. If any NUL characters occur at byte offsets less than
4933** the value of the fourth parameter then the resulting string value will
4934** contain embedded NULs. The result of expressions involving strings
4935** with embedded NULs is undefined.
4936**
4937** ^The fifth argument to the BLOB and string binding interfaces controls
4938** or indicates the lifetime of the object referenced by the third parameter.
4939** These three options exist:
4940** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4941** with it may be passed. ^It is called to dispose of the BLOB or string even
4942** if the call to the bind API fails, except the destructor is not called if
4943** the third parameter is a NULL pointer or the fourth parameter is negative.
4944** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4945** the application remains responsible for disposing of the object. ^In this
4946** case, the object and the provided pointer to it must remain valid until
4947** either the prepared statement is finalized or the same SQL parameter is
4948** bound to something else, whichever occurs sooner.
4949** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4950** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4951** object and pointer to it must remain valid until then. ^SQLite will then
4952** manage the lifetime of its private copy.
4953**
4954** ^The sixth argument (the E argument)
4955** to sqlite3_bind_text64(S,K,Z,N,D,E) must be one of
4956** [SQLITE_UTF8], [SQLITE_UTF8_ZT], [SQLITE_UTF16], [SQLITE_UTF16BE],
4957** or [SQLITE_UTF16LE] to specify the encoding of the text in the
4958** third parameter, Z. The special value [SQLITE_UTF8_ZT] means that the
4959** string argument is both UTF-8 encoded and is zero-terminated. In other
4960** words, SQLITE_UTF8_ZT means that the Z array is allocated to hold at
4961** least N+1 bytes and that the Z&#91;N&#93; byte is zero. If
4962** the E argument to sqlite3_bind_text64(S,K,Z,N,D,E) is not one of the
4963** allowed values shown above, or if the text encoding is different
4964** from the encoding specified by the sixth parameter, then the behavior
4965** is undefined.
4966**
4967** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4968** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4969** (just an integer to hold its size) while it is being processed.
4970** Zeroblobs are intended to serve as placeholders for BLOBs whose
4971** content is later written using
4972** [sqlite3_blob_open | incremental BLOB I/O] routines.
4973** ^A negative value for the zeroblob results in a zero-length BLOB.
4974**
4975** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4976** [prepared statement] S to have an SQL value of NULL, but to also be
4977** associated with the pointer P of type T. ^D is either a NULL pointer or
4978** a pointer to a destructor function for P. ^SQLite will invoke the
4979** destructor D with a single argument of P when it is finished using
4980** P, even if the call to sqlite3_bind_pointer() fails. Due to a
4981** historical design quirk, results are undefined if D is
4982** SQLITE_TRANSIENT. The T parameter should be a static string,
4983** preferably a string literal. The sqlite3_bind_pointer() routine is
4984** part of the [pointer passing interface] added for SQLite 3.20.0.
4985**
4986** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4987** for the [prepared statement] or with a prepared statement for which
4988** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4989** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4990** routine is passed a [prepared statement] that has been finalized, the
4991** result is undefined and probably harmful.
4992**
4993** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4994** ^Unbound parameters are interpreted as NULL.
4995**
4996** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4997** [error code] if anything goes wrong.
4998** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4999** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
5000** [SQLITE_MAX_LENGTH].
5001** ^[SQLITE_RANGE] is returned if the parameter
5002** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
5003**
5004** See also: [sqlite3_bind_parameter_count()],
5005** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
5006*/
5007SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
5008SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
5009 void(*)(void*));
5010SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
5011SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
5012SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
5013SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
5014SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
5015SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
5016SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
5017 void(*)(void*), unsigned char encoding);
5018SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
5019SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
5020SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
5021SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
5022
5023/*
5024** CAPI3REF: Number Of SQL Parameters
5025** METHOD: sqlite3_stmt
5026**
5027** ^This routine can be used to find the number of [SQL parameters]
5028** in a [prepared statement]. SQL parameters are tokens of the
5029** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
5030** placeholders for values that are [sqlite3_bind_blob | bound]
5031** to the parameters at a later time.
5032**
5033** ^(This routine actually returns the index of the largest (rightmost)
5034** parameter. For all forms except ?NNN, this will correspond to the
5035** number of unique parameters. If parameters of the ?NNN form are used,
5036** there may be gaps in the list.)^
5037**
5038** See also: [sqlite3_bind_blob|sqlite3_bind()],
5039** [sqlite3_bind_parameter_name()], and
5040** [sqlite3_bind_parameter_index()].
5041*/
5042SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
5043
5044/*
5045** CAPI3REF: Name Of A Host Parameter
5046** METHOD: sqlite3_stmt
5047**
5048** ^The sqlite3_bind_parameter_name(P,N) interface returns
5049** the name of the N-th [SQL parameter] in the [prepared statement] P.
5050** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
5051** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
5052** respectively.
5053** In other words, the initial ":" or "$" or "@" or "?"
5054** is included as part of the name.)^
5055** ^Parameters of the form "?" without a following integer have no name
5056** and are referred to as "nameless" or "anonymous parameters".
5057**
5058** ^The first host parameter has an index of 1, not 0.
5059**
5060** ^If the value N is out of range or if the N-th parameter is
5061** nameless, then NULL is returned. ^The returned string is
5062** always in UTF-8 encoding even if the named parameter was
5063** originally specified as UTF-16 in [sqlite3_prepare16()],
5064** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
5065**
5066** See also: [sqlite3_bind_blob|sqlite3_bind()],
5067** [sqlite3_bind_parameter_count()], and
5068** [sqlite3_bind_parameter_index()].
5069*/
5070SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
5071
5072/*
5073** CAPI3REF: Index Of A Parameter With A Given Name
5074** METHOD: sqlite3_stmt
5075**
5076** ^Return the index of an SQL parameter given its name. ^The
5077** index value returned is suitable for use as the second
5078** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
5079** is returned if no matching parameter is found. ^The parameter
5080** name must be given in UTF-8 even if the original statement
5081** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
5082** [sqlite3_prepare16_v3()].
5083**
5084** See also: [sqlite3_bind_blob|sqlite3_bind()],
5085** [sqlite3_bind_parameter_count()], and
5086** [sqlite3_bind_parameter_name()].
5087*/
5088SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
5089
5090/*
5091** CAPI3REF: Reset All Bindings On A Prepared Statement
5092** METHOD: sqlite3_stmt
5093**
5094** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
5095** the [sqlite3_bind_blob | bindings] on a [prepared statement].
5096** ^Use this routine to reset all host parameters to NULL.
5097*/
5098SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
5099
5100/*
5101** CAPI3REF: Number Of Columns In A Result Set
5102** METHOD: sqlite3_stmt
5103**
5104** ^Return the number of columns in the result set returned by the
5105** [prepared statement]. ^If this routine returns 0, that means the
5106** [prepared statement] returns no data (for example an [UPDATE]).
5107** ^However, just because this routine returns a positive number does not
5108** mean that one or more rows of data will be returned. ^A SELECT statement
5109** will always have a positive sqlite3_column_count() but depending on the
5110** WHERE clause constraints and the table content, it might return no rows.
5111**
5112** See also: [sqlite3_data_count()]
5113*/
5114SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
5115
5116/*
5117** CAPI3REF: Column Names In A Result Set
5118** METHOD: sqlite3_stmt
5119**
5120** ^These routines return the name assigned to a particular column
5121** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
5122** interface returns a pointer to a zero-terminated UTF-8 string
5123** and sqlite3_column_name16() returns a pointer to a zero-terminated
5124** UTF-16 string. ^The first parameter is the [prepared statement]
5125** that implements the [SELECT] statement. ^The second parameter is the
5126** column number. ^The leftmost column is number 0.
5127**
5128** ^The returned string pointer is valid until either the [prepared statement]
5129** is destroyed by [sqlite3_finalize()] or until the statement is automatically
5130** reprepared by the first call to [sqlite3_step()] for a particular run
5131** or until the next call to
5132** sqlite3_column_name() or sqlite3_column_name16() on the same column.
5133**
5134** ^If sqlite3_malloc() fails during the processing of either routine
5135** (for example during a conversion from UTF-8 to UTF-16) then a
5136** NULL pointer is returned.
5137**
5138** ^The name of a result column is the value of the "AS" clause for
5139** that column, if there is an AS clause. If there is no AS clause
5140** then the name of the column is unspecified and may change from
5141** one release of SQLite to the next.
5142*/
5143SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
5144SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
5145
5146/*
5147** CAPI3REF: Source Of Data In A Query Result
5148** METHOD: sqlite3_stmt
5149**
5150** ^These routines provide a means to determine the database, table, and
5151** table column that is the origin of a particular result column in a
5152** [SELECT] statement.
5153** ^The name of the database or table or column can be returned as
5154** either a UTF-8 or UTF-16 string. ^The _database_ routines return
5155** the database name, the _table_ routines return the table name, and
5156** the origin_ routines return the column name.
5157** ^The returned string is valid until the [prepared statement] is destroyed
5158** using [sqlite3_finalize()] or until the statement is automatically
5159** reprepared by the first call to [sqlite3_step()] for a particular run
5160** or until the same information is requested
5161** again in a different encoding.
5162**
5163** ^The names returned are the original un-aliased names of the
5164** database, table, and column.
5165**
5166** ^The first argument to these interfaces is a [prepared statement].
5167** ^These functions return information about the Nth result column returned by
5168** the statement, where N is the second function argument.
5169** ^The left-most column is column 0 for these routines.
5170**
5171** ^If the Nth column returned by the statement is an expression or
5172** subquery and is not a column value, then all of these functions return
5173** NULL. ^These routines might also return NULL if a memory allocation error
5174** occurs. ^Otherwise, they return the name of the attached database, table,
5175** or column that query result column was extracted from.
5176**
5177** ^As with all other SQLite APIs, those whose names end with "16" return
5178** UTF-16 encoded strings and the other functions return UTF-8.
5179**
5180** ^These APIs are only available if the library was compiled with the
5181** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
5182**
5183** If two or more threads call one or more
5184** [sqlite3_column_database_name | column metadata interfaces]
5185** for the same [prepared statement] and result column
5186** at the same time then the results are undefined.
5187*/
5188SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
5189SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
5190SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
5191SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
5192SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
5193SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
5194
5195/*
5196** CAPI3REF: Declared Datatype Of A Query Result
5197** METHOD: sqlite3_stmt
5198**
5199** ^(The first parameter is a [prepared statement].
5200** If this statement is a [SELECT] statement and the Nth column of the
5201** returned result set of that [SELECT] is a table column (not an
5202** expression or subquery) then the declared type of the table
5203** column is returned.)^ ^If the Nth column of the result set is an
5204** expression or subquery, then a NULL pointer is returned.
5205** ^The returned string is always UTF-8 encoded.
5206**
5207** ^(For example, given the database schema:
5208**
5209** CREATE TABLE t1(c1 VARIANT);
5210**
5211** and the following statement to be compiled:
5212**
5213** SELECT c1 + 1, c1 FROM t1;
5214**
5215** this routine would return the string "VARIANT" for the second result
5216** column (i==1), and a NULL pointer for the first result column (i==0).)^
5217**
5218** ^SQLite uses dynamic run-time typing. ^So just because a column
5219** is declared to contain a particular type does not mean that the
5220** data stored in that column is of the declared type. SQLite is
5221** strongly typed, but the typing is dynamic not static. ^Type
5222** is associated with individual values, not with the containers
5223** used to hold those values.
5224*/
5225SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
5226SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
5227
5228/*
5229** CAPI3REF: Evaluate An SQL Statement
5230** METHOD: sqlite3_stmt
5231**
5232** After a [prepared statement] has been prepared using any of
5233** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
5234** or [sqlite3_prepare16_v3()] or one of the legacy
5235** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
5236** must be called one or more times to evaluate the statement.
5237**
5238** The details of the behavior of the sqlite3_step() interface depend
5239** on whether the statement was prepared using the newer "vX" interfaces
5240** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
5241** [sqlite3_prepare16_v2()] or the older legacy
5242** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
5243** new "vX" interface is recommended for new applications but the legacy
5244** interface will continue to be supported.
5245**
5246** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
5247** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
5248** ^With the "v2" interface, any of the other [result codes] or
5249** [extended result codes] might be returned as well.
5250**
5251** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
5252** database locks it needs to do its job. ^If the statement is a [COMMIT]
5253** or occurs outside of an explicit transaction, then you can retry the
5254** statement. If the statement is not a [COMMIT] and occurs within an
5255** explicit transaction then you should rollback the transaction before
5256** continuing.
5257**
5258** ^[SQLITE_DONE] means that the statement has finished executing
5259** successfully. sqlite3_step() should not be called again on this virtual
5260** machine without first calling [sqlite3_reset()] to reset the virtual
5261** machine back to its initial state.
5262**
5263** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
5264** is returned each time a new row of data is ready for processing by the
5265** caller. The values may be accessed using the [column access functions].
5266** sqlite3_step() is called again to retrieve the next row of data.
5267**
5268** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
5269** violation) has occurred. sqlite3_step() should not be called again on
5270** the VM. More information may be found by calling [sqlite3_errmsg()].
5271** ^With the legacy interface, a more specific error code (for example,
5272** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
5273** can be obtained by calling [sqlite3_reset()] on the
5274** [prepared statement]. ^In the "v2" interface,
5275** the more specific error code is returned directly by sqlite3_step().
5276**
5277** [SQLITE_MISUSE] means that the this routine was called inappropriately.
5278** Perhaps it was called on a [prepared statement] that has
5279** already been [sqlite3_finalize | finalized] or on one that had
5280** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
5281** be the case that the same database connection is being used by two or
5282** more threads at the same moment in time.
5283**
5284** For all versions of SQLite up to and including 3.6.23.1, a call to
5285** [sqlite3_reset()] was required after sqlite3_step() returned anything
5286** other than [SQLITE_ROW] before any subsequent invocation of
5287** sqlite3_step(). Failure to reset the prepared statement using
5288** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
5289** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]),
5290** sqlite3_step() began
5291** calling [sqlite3_reset()] automatically in this circumstance rather
5292** than returning [SQLITE_MISUSE]. This is not considered a compatibility
5293** break because any application that ever receives an SQLITE_MISUSE error
5294** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
5295** can be used to restore the legacy behavior.
5296**
5297** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
5298** API always returns a generic error code, [SQLITE_ERROR], following any
5299** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
5300** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
5301** specific [error codes] that better describes the error.
5302** We admit that this is a goofy design. The problem has been fixed
5303** with the "v2" interface. If you prepare all of your SQL statements
5304** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
5305** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5306** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5307** then the more specific [error codes] are returned directly
5308** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5309*/
5310SQLITE_API int sqlite3_step(sqlite3_stmt*);
5311
5312/*
5313** CAPI3REF: Number of columns in a result set
5314** METHOD: sqlite3_stmt
5315**
5316** ^The sqlite3_data_count(P) interface returns the number of columns in the
5317** current row of the result set of [prepared statement] P.
5318** ^If prepared statement P does not have results ready to return
5319** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5320** interfaces) then sqlite3_data_count(P) returns 0.
5321** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5322** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5323** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5324** will return non-zero if previous call to [sqlite3_step](P) returned
5325** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5326** where it always returns zero since each step of that multi-step
5327** pragma returns 0 columns of data.
5328**
5329** See also: [sqlite3_column_count()]
5330*/
5331SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5332
5333/*
5334** CAPI3REF: Fundamental Datatypes
5335** KEYWORDS: SQLITE_TEXT
5336**
5337** ^(Every value in SQLite has one of five fundamental datatypes:
5338**
5339** <ul>
5340** <li> 64-bit signed integer
5341** <li> 64-bit IEEE floating point number
5342** <li> string
5343** <li> BLOB
5344** <li> NULL
5345** </ul>)^
5346**
5347** These constants are codes for each of those types.
5348**
5349** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5350** for a completely different meaning. Software that links against both
5351** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5352** SQLITE_TEXT.
5353*/
5354#define SQLITE_INTEGER 1
5355#define SQLITE_FLOAT 2
5356#define SQLITE_BLOB 4
5357#define SQLITE_NULL 5
5358#ifdef SQLITE_TEXT
5359# undef SQLITE_TEXT
5360#else
5361# define SQLITE_TEXT 3
5362#endif
5363#define SQLITE3_TEXT 3
5364
5365/*
5366** CAPI3REF: Result Values From A Query
5367** KEYWORDS: {column access functions}
5368** METHOD: sqlite3_stmt
5369**
5370** <b>Summary:</b>
5371** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5372** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
5373** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
5374** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
5375** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
5376** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
5377** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
5378** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
5379** [sqlite3_value|unprotected sqlite3_value] object.
5380** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5381** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
5382** or a UTF-8 TEXT result in bytes
5383** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
5384** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5385** TEXT in bytes
5386** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
5387** datatype of the result
5388** </table></blockquote>
5389**
5390** <b>Details:</b>
5391**
5392** ^These routines return information about a single column of the current
5393** result row of a query. ^In every case the first argument is a pointer
5394** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5395** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5396** and the second argument is the index of the column for which information
5397** should be returned. ^The leftmost column of the result set has the index 0.
5398** ^The number of columns in the result can be determined using
5399** [sqlite3_column_count()].
5400**
5401** If the SQL statement does not currently point to a valid row, or if the
5402** column index is out of range, the result is undefined.
5403** These routines may only be called when the most recent call to
5404** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5405** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5406** If any of these routines are called after [sqlite3_reset()] or
5407** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5408** something other than [SQLITE_ROW], the results are undefined.
5409** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5410** are called from a different thread while any of these routines
5411** are pending, then the results are undefined.
5412**
5413** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5414** each return the value of a result column in a specific data format. If
5415** the result column is not initially in the requested format (for example,
5416** if the query returns an integer but the sqlite3_column_text() interface
5417** is used to extract the value) then an automatic type conversion is performed.
5418**
5419** ^The sqlite3_column_type() routine returns the
5420** [SQLITE_INTEGER | datatype code] for the initial data type
5421** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5422** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5423** The return value of sqlite3_column_type() can be used to decide which
5424** of the first six interface should be used to extract the column value.
5425** The value returned by sqlite3_column_type() is only meaningful if no
5426** automatic type conversions have occurred for the value in question.
5427** After a type conversion, the result of calling sqlite3_column_type()
5428** is undefined, though harmless. Future
5429** versions of SQLite may change the behavior of sqlite3_column_type()
5430** following a type conversion.
5431**
5432** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5433** or sqlite3_column_bytes16() interfaces can be used to determine the size
5434** of that BLOB or string.
5435**
5436** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5437** routine returns the number of bytes in that BLOB or string.
5438** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5439** the string to UTF-8 and then returns the number of bytes.
5440** ^If the result is a numeric value then sqlite3_column_bytes() uses
5441** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5442** the number of bytes in that string.
5443** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5444**
5445** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5446** routine returns the number of bytes in that BLOB or string.
5447** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5448** the string to UTF-16 and then returns the number of bytes.
5449** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5450** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5451** the number of bytes in that string.
5452** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5453**
5454** ^The values returned by [sqlite3_column_bytes()] and
5455** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5456** of the string. ^For clarity: the values returned by
5457** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5458** bytes in the string, not the number of characters.
5459**
5460** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5461** even empty strings, are always zero-terminated. ^The return
5462** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5463**
5464** ^Strings returned by sqlite3_column_text16() always have the endianness
5465** which is native to the platform, regardless of the text encoding set
5466** for the database.
5467**
5468** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5469** [unprotected sqlite3_value] object. In a multithreaded environment,
5470** an unprotected sqlite3_value object may only be used safely with
5471** [sqlite3_bind_value()] and [sqlite3_result_value()].
5472** If the [unprotected sqlite3_value] object returned by
5473** [sqlite3_column_value()] is used in any other way, including calls
5474** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5475** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5476** Hence, the sqlite3_column_value() interface
5477** is normally only useful within the implementation of
5478** [application-defined SQL functions] or [virtual tables], not within
5479** top-level application code.
5480**
5481** These routines may attempt to convert the datatype of the result.
5482** ^For example, if the internal representation is FLOAT and a text result
5483** is requested, [sqlite3_snprintf()] is used internally to perform the
5484** conversion automatically. ^(The following table details the conversions
5485** that are applied:
5486**
5487** <blockquote>
5488** <table border="1">
5489** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5490**
5491** <tr><td> NULL <td> INTEGER <td> Result is 0
5492** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5493** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5494** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5495** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5496** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5497** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5498** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5499** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5500** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5501** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5502** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5503** <tr><td> TEXT <td> BLOB <td> No change
5504** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5505** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5506** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5507** </table>
5508** </blockquote>)^
5509**
5510** Note that when type conversions occur, pointers returned by prior
5511** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5512** sqlite3_column_text16() may be invalidated.
5513** Type conversions and pointer invalidations might occur
5514** in the following cases:
5515**
5516** <ul>
5517** <li> The initial content is a BLOB and sqlite3_column_text() or
5518** sqlite3_column_text16() is called. A zero-terminator might
5519** need to be added to the string.</li>
5520** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5521** sqlite3_column_text16() is called. The content must be converted
5522** to UTF-16.</li>
5523** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5524** sqlite3_column_text() is called. The content must be converted
5525** to UTF-8.</li>
5526** </ul>
5527**
5528** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5529** not invalidate a prior pointer, though of course the content of the buffer
5530** that the prior pointer references will have been modified. Other kinds
5531** of conversion are done in place when it is possible, but sometimes they
5532** are not possible and in those cases prior pointers are invalidated.
5533**
5534** The safest policy is to invoke these routines
5535** in one of the following ways:
5536**
5537** <ul>
5538** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5539** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5540** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5541** </ul>
5542**
5543** In other words, you should call sqlite3_column_text(),
5544** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5545** into the desired format, then invoke sqlite3_column_bytes() or
5546** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5547** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5548** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5549** with calls to sqlite3_column_bytes().
5550**
5551** ^The pointers returned are valid until a type conversion occurs as
5552** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5553** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5554** and BLOBs is freed automatically. Do not pass the pointers returned
5555** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5556** [sqlite3_free()].
5557**
5558** As long as the input parameters are correct, these routines will only
5559** fail if an out-of-memory error occurs during a format conversion.
5560** Only the following subset of interfaces are subject to out-of-memory
5561** errors:
5562**
5563** <ul>
5564** <li> sqlite3_column_blob()
5565** <li> sqlite3_column_text()
5566** <li> sqlite3_column_text16()
5567** <li> sqlite3_column_bytes()
5568** <li> sqlite3_column_bytes16()
5569** </ul>
5570**
5571** If an out-of-memory error occurs, then the return value from these
5572** routines is the same as if the column had contained an SQL NULL value.
5573** Valid SQL NULL returns can be distinguished from out-of-memory errors
5574** by invoking the [sqlite3_errcode()] immediately after the suspect
5575** return value is obtained and before any
5576** other SQLite interface is called on the same [database connection].
5577*/
5578SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5579SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5580SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5581SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5582SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5583SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5584SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5585SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5586SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5587SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5588
5589/*
5590** CAPI3REF: Destroy A Prepared Statement Object
5591** DESTRUCTOR: sqlite3_stmt
5592**
5593** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5594** ^If the most recent evaluation of the statement encountered no errors
5595** or if the statement has never been evaluated, then sqlite3_finalize() returns
5596** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5597** sqlite3_finalize(S) returns the appropriate [error code] or
5598** [extended error code].
5599**
5600** ^The sqlite3_finalize(S) routine can be called at any point during
5601** the life cycle of [prepared statement] S:
5602** before statement S is ever evaluated, after
5603** one or more calls to [sqlite3_reset()], or after any call
5604** to [sqlite3_step()] regardless of whether or not the statement has
5605** completed execution.
5606**
5607** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5608**
5609** The application must finalize every [prepared statement] in order to avoid
5610** resource leaks. It is a grievous error for the application to try to use
5611** a prepared statement after it has been finalized. Any use of a prepared
5612** statement after it has been finalized can result in undefined and
5613** undesirable behavior such as segfaults and heap corruption.
5614*/
5615SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5616
5617/*
5618** CAPI3REF: Reset A Prepared Statement Object
5619** METHOD: sqlite3_stmt
5620**
5621** The sqlite3_reset() function is called to reset a [prepared statement]
5622** object back to its initial state, ready to be re-executed.
5623** ^Any SQL statement variables that had values bound to them using
5624** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5625** Use [sqlite3_clear_bindings()] to reset the bindings.
5626**
5627** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5628** back to the beginning of its program.
5629**
5630** ^The return code from [sqlite3_reset(S)] indicates whether or not
5631** the previous evaluation of prepared statement S completed successfully.
5632** ^If [sqlite3_step(S)] has never before been called on S or if
5633** [sqlite3_step(S)] has not been called since the previous call
5634** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5635** [SQLITE_OK].
5636**
5637** ^If the most recent call to [sqlite3_step(S)] for the
5638** [prepared statement] S indicated an error, then
5639** [sqlite3_reset(S)] returns an appropriate [error code].
5640** ^The [sqlite3_reset(S)] interface might also return an [error code]
5641** if there were no prior errors but the process of resetting
5642** the prepared statement caused a new error. ^For example, if an
5643** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5644** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5645** the overall statement might still fail and the [sqlite3_reset(S)] call
5646** might return SQLITE_BUSY if locking constraints prevent the
5647** database change from committing. Therefore, it is important that
5648** applications check the return code from [sqlite3_reset(S)] even if
5649** no prior call to [sqlite3_step(S)] indicated a problem.
5650**
5651** ^The [sqlite3_reset(S)] interface does not change the values
5652** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5653*/
5654SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5655
5656
5657/*
5658** CAPI3REF: Create Or Redefine SQL Functions
5659** KEYWORDS: {function creation routines}
5660** METHOD: sqlite3
5661**
5662** ^These functions (collectively known as "function creation routines")
5663** are used to add SQL functions or aggregates or to redefine the behavior
5664** of existing SQL functions or aggregates. The only differences between
5665** the three "sqlite3_create_function*" routines are the text encoding
5666** expected for the second parameter (the name of the function being
5667** created) and the presence or absence of a destructor callback for
5668** the application data pointer. Function sqlite3_create_window_function()
5669** is similar, but allows the user to supply the extra callback functions
5670** needed by [aggregate window functions].
5671**
5672** ^The first parameter is the [database connection] to which the SQL
5673** function is to be added. ^If an application uses more than one database
5674** connection then application-defined SQL functions must be added
5675** to each database connection separately.
5676**
5677** ^The second parameter is the name of the SQL function to be created or
5678** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5679** representation, exclusive of the zero-terminator. ^Note that the name
5680** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5681** ^Any attempt to create a function with a longer name
5682** will result in [SQLITE_MISUSE] being returned.
5683**
5684** ^The third parameter (nArg)
5685** is the number of arguments that the SQL function or
5686** aggregate takes. ^If this parameter is -1, then the SQL function or
5687** aggregate may take any number of arguments between 0 and the limit
5688** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5689** parameter is less than -1 or greater than 127 then the behavior is
5690** undefined.
5691**
5692** ^The fourth parameter, eTextRep, specifies what
5693** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5694** its parameters. The application should set this parameter to
5695** [SQLITE_UTF16LE] if the function implementation invokes
5696** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5697** implementation invokes [sqlite3_value_text16be()] on an input, or
5698** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5699** otherwise. ^The same SQL function may be registered multiple times using
5700** different preferred text encodings, with different implementations for
5701** each encoding.
5702** ^When multiple implementations of the same function are available, SQLite
5703** will pick the one that involves the least amount of data conversion.
5704**
5705** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5706** to signal that the function will always return the same result given
5707** the same inputs within a single SQL statement. Most SQL functions are
5708** deterministic. The built-in [random()] SQL function is an example of a
5709** function that is not deterministic. The SQLite query planner is able to
5710** perform additional optimizations on deterministic functions, so use
5711** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5712**
5713** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5714** flag, which if present prevents the function from being invoked from
5715** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5716** index expressions, or the WHERE clause of partial indexes.
5717**
5718** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5719** all application-defined SQL functions that do not need to be
5720** used inside of triggers, views, CHECK constraints, or other elements of
5721** the database schema. This flag is especially recommended for SQL
5722** functions that have side effects or reveal internal application state.
5723** Without this flag, an attacker might be able to modify the schema of
5724** a database file to include invocations of the function with parameters
5725** chosen by the attacker, which the application will then execute when
5726** the database file is opened and read.
5727**
5728** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5729** function can gain access to this pointer using [sqlite3_user_data()].)^
5730**
5731** ^The sixth, seventh and eighth parameters passed to the three
5732** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5733** pointers to C-language functions that implement the SQL function or
5734** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5735** callback only; NULL pointers must be passed as the xStep and xFinal
5736** parameters. ^An aggregate SQL function requires an implementation of xStep
5737** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5738** SQL function or aggregate, pass NULL pointers for all three function
5739** callbacks.
5740**
5741** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5742** and xInverse) passed to sqlite3_create_window_function are pointers to
5743** C-language callbacks that implement the new function. xStep and xFinal
5744** must both be non-NULL. xValue and xInverse may either both be NULL, in
5745** which case a regular aggregate function is created, or must both be
5746** non-NULL, in which case the new function may be used as either an aggregate
5747** or aggregate window function. More details regarding the implementation
5748** of aggregate window functions are
5749** [user-defined window functions|available here].
5750**
5751** ^(If the final parameter to sqlite3_create_function_v2() or
5752** sqlite3_create_window_function() is not NULL, then it is the destructor for
5753** the application data pointer. The destructor is invoked when the function
5754** is deleted, either by being overloaded or when the database connection
5755** closes.)^ ^The destructor is also invoked if the call to
5756** sqlite3_create_function_v2() fails. ^When the destructor callback is
5757** invoked, it is passed a single argument which is a copy of the application
5758** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5759**
5760** ^It is permitted to register multiple implementations of the same
5761** functions with the same name but with either differing numbers of
5762** arguments or differing preferred text encodings. ^SQLite will use
5763** the implementation that most closely matches the way in which the
5764** SQL function is used. ^A function implementation with a non-negative
5765** nArg parameter is a better match than a function implementation with
5766** a negative nArg. ^A function where the preferred text encoding
5767** matches the database encoding is a better
5768** match than a function where the encoding is different.
5769** ^A function where the encoding difference is between UTF16le and UTF16be
5770** is a closer match than a function where the encoding difference is
5771** between UTF8 and UTF16.
5772**
5773** ^Built-in functions may be overloaded by new application-defined functions.
5774**
5775** ^An application-defined function is permitted to call other
5776** SQLite interfaces. However, such calls must not
5777** close the database connection nor finalize or reset the prepared
5778** statement in which the function is running.
5779*/
5780SQLITE_API int sqlite3_create_function(
5781 sqlite3 *db,
5782 const char *zFunctionName,
5783 int nArg,
5784 int eTextRep,
5785 void *pApp,
5786 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5787 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5788 void (*xFinal)(sqlite3_context*)
5789);
5790SQLITE_API int sqlite3_create_function16(
5791 sqlite3 *db,
5792 const void *zFunctionName,
5793 int nArg,
5794 int eTextRep,
5795 void *pApp,
5796 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5797 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5798 void (*xFinal)(sqlite3_context*)
5799);
5800SQLITE_API int sqlite3_create_function_v2(
5801 sqlite3 *db,
5802 const char *zFunctionName,
5803 int nArg,
5804 int eTextRep,
5805 void *pApp,
5806 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5807 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5808 void (*xFinal)(sqlite3_context*),
5809 void(*xDestroy)(void*)
5810);
5811SQLITE_API int sqlite3_create_window_function(
5812 sqlite3 *db,
5813 const char *zFunctionName,
5814 int nArg,
5815 int eTextRep,
5816 void *pApp,
5817 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5818 void (*xFinal)(sqlite3_context*),
5819 void (*xValue)(sqlite3_context*),
5820 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5821 void(*xDestroy)(void*)
5822);
5823
5824/*
5825** CAPI3REF: Text Encodings
5826**
5827** These constants define integer codes that represent the various
5828** text encodings supported by SQLite.
5829**
5830** <dl>
5831** [[SQLITE_UTF8]] <dt>SQLITE_UTF8</dt><dd>Text is encoding as UTF-8</dd>
5832**
5833** [[SQLITE_UTF16LE]] <dt>SQLITE_UTF16LE</dt><dd>Text is encoding as UTF-16
5834** with each code point being expressed "little endian" - the least significant
5835** byte first. This is the usual encoding, for example on Windows.</dd>
5836**
5837** [[SQLITE_UTF16BE]] <dt>SQLITE_UTF16BE</dt><dd>Text is encoding as UTF-16
5838** with each code point being expressed "big endian" - the most significant
5839** byte first. This encoding is less common, but is still sometimes seen,
5840** specially on older systems.
5841**
5842** [[SQLITE_UTF16]] <dt>SQLITE_UTF16</dt><dd>Text is encoding as UTF-16
5843** with each code point being expressed either little endian or as big
5844** endian, according to the native endianness of the host computer.
5845**
5846** [[SQLITE_ANY]] <dt>SQLITE_ANY</dt><dd>This encoding value may only be used
5847** to declare the preferred text for [application-defined SQL functions]
5848** created using [sqlite3_create_function()] and similar. If the preferred
5849** encoding (the 4th parameter to sqlite3_create_function() - the eTextRep
5850** parameter) is SQLITE_ANY, that indicates that the function does not have
5851** a preference regarding the text encoding of its parameters and can take
5852** any text encoding that the SQLite core find convenient to supply. This
5853** option is deprecated. Please do not use it in new applications.
5854**
5855** [[SQLITE_UTF16_ALIGNED]] <dt>SQLITE_UTF16_ALIGNED</dt><dd>This encoding
5856** value may be used as the 3rd parameter (the eTextRep parameter) to
5857** [sqlite3_create_collation()] and similar. This encoding value means
5858** that the application-defined collating sequence created expects its
5859** input strings to be in UTF16 in native byte order, and that the start
5860** of the strings must be aligned to a 2-byte boundary.
5861**
5862** [[SQLITE_UTF8_ZT]] <dt>SQLITE_UTF8_ZT</dt><dd>This option can only be
5863** used to specify the text encoding to strings input to
5864** [sqlite3_result_text64()] and [sqlite3_bind_text64()].
5865** The SQLITE_UTF8_ZT encoding means that the input string (call it "z")
5866** is UTF-8 encoded and that it is zero-terminated. If the length parameter
5867** (call it "n") is non-negative, this encoding option means that the caller
5868** guarantees that z array contains at least n+1 bytes and that the z&#91;n&#93;
5869** byte has a value of zero.
5870** This option gives the same output as SQLITE_UTF8, but can be more efficient
5871** by avoiding the need to make a copy of the input string, in some cases.
5872** However, if z is allocated to hold fewer than n+1 bytes or if the
5873** z&#91;n&#93; byte is not zero, undefined behavior may result.
5874** </dl>
5875*/
5876#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5877#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5878#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5879#define SQLITE_UTF16 4 /* Use native byte order */
5880#define SQLITE_ANY 5 /* Deprecated */
5881#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5882#define SQLITE_UTF8_ZT 16 /* Zero-terminated UTF8 */
5883
5884/*
5885** CAPI3REF: Function Flags
5886**
5887** These constants may be ORed together with the
5888** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5889** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5890** [sqlite3_create_function_v2()].
5891**
5892** <dl>
5893** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5894** The SQLITE_DETERMINISTIC flag means that the new function always gives
5895** the same output when the input parameters are the same.
5896** The [abs|abs() function] is deterministic, for example, but
5897** [randomblob|randomblob()] is not. Functions must
5898** be deterministic in order to be used in certain contexts such as
5899** with the WHERE clause of [partial indexes] or in [generated columns].
5900** SQLite might also optimize deterministic functions by factoring them
5901** out of inner loops.
5902** </dd>
5903**
5904** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5905** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5906** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5907** schema structures such as [CHECK constraints], [DEFAULT clauses],
5908** [expression indexes], [partial indexes], or [generated columns].
5909** <p>
5910** The SQLITE_DIRECTONLY flag is recommended for any
5911** [application-defined SQL function]
5912** that has side-effects or that could potentially leak sensitive information.
5913** This will prevent attacks in which an application is tricked
5914** into using a database file that has had its schema surreptitiously
5915** modified to invoke the application-defined function in ways that are
5916** harmful.
5917** <p>
5918** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5919** [application-defined SQL functions], regardless of whether or not they
5920** are security sensitive, as doing so prevents those functions from being used
5921** inside of the database schema, and thus ensures that the database
5922** can be inspected and modified using generic tools (such as the [CLI])
5923** that do not have access to the application-defined functions.
5924** </dd>
5925**
5926** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5927** The SQLITE_INNOCUOUS flag means that the function is unlikely
5928** to cause problems even if misused. An innocuous function should have
5929** no side effects and should not depend on any values other than its
5930** input parameters. The [abs|abs() function] is an example of an
5931** innocuous function.
5932** The [load_extension() SQL function] is not innocuous because of its
5933** side effects.
5934** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5935** exactly the same. The [random|random() function] is an example of a
5936** function that is innocuous but not deterministic.
5937** <p>Some heightened security settings
5938** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5939** disable the use of SQL functions inside views and triggers and in
5940** schema structures such as [CHECK constraints], [DEFAULT clauses],
5941** [expression indexes], [partial indexes], and [generated columns] unless
5942** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5943** are innocuous. Developers are advised to avoid using the
5944** SQLITE_INNOCUOUS flag for application-defined functions unless the
5945** function has been carefully audited and found to be free of potentially
5946** security-adverse side-effects and information-leaks.
5947** </dd>
5948**
5949** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5950** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5951** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5952** This flag instructs SQLite to omit some corner-case optimizations that
5953** might disrupt the operation of the [sqlite3_value_subtype()] function,
5954** causing it to return zero rather than the correct subtype().
5955** All SQL functions that invoke [sqlite3_value_subtype()] should have this
5956** property. If the SQLITE_SUBTYPE property is omitted, then the return
5957** value from [sqlite3_value_subtype()] might sometimes be zero even though
5958** a non-zero subtype was specified by the function argument expression.
5959**
5960** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5961** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5962** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5963** result.
5964** Every function that invokes [sqlite3_result_subtype()] should have this
5965** property. If it does not, then the call to [sqlite3_result_subtype()]
5966** might become a no-op if the function is used as a term in an
5967** [expression index]. On the other hand, SQL functions that never invoke
5968** [sqlite3_result_subtype()] should avoid setting this property, as the
5969** purpose of this property is to disable certain optimizations that are
5970** incompatible with subtypes.
5971**
5972** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
5973** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
5974** that internally orders the values provided to the first argument. The
5975** ordered-set aggregate SQL notation with a single ORDER BY term can be
5976** used to invoke this function. If the ordered-set aggregate notation is
5977** used on a function that lacks this flag, then an error is raised. Note
5978** that the ordered-set aggregate syntax is only available if SQLite is
5979** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
5980** </dd>
5981** </dl>
5982*/
5983#define SQLITE_DETERMINISTIC 0x000000800
5984#define SQLITE_DIRECTONLY 0x000080000
5985#define SQLITE_SUBTYPE 0x000100000
5986#define SQLITE_INNOCUOUS 0x000200000
5987#define SQLITE_RESULT_SUBTYPE 0x001000000
5988#define SQLITE_SELFORDER1 0x002000000
5989
5990/*
5991** CAPI3REF: Deprecated Functions
5992** DEPRECATED
5993**
5994** These functions are [deprecated]. In order to maintain
5995** backwards compatibility with older code, these functions continue
5996** to be supported. However, new applications should avoid
5997** the use of these functions. To encourage programmers to avoid
5998** these functions, we will not explain what they do.
5999*/
6000#ifndef SQLITE_OMIT_DEPRECATED
6001SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
6002SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
6003SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
6004SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
6005SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
6006SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
6007 void*,sqlite3_int64);
6008#endif
6009
6010/*
6011** CAPI3REF: Obtaining SQL Values
6012** METHOD: sqlite3_value
6013**
6014** <b>Summary:</b>
6015** <blockquote><table border=0 cellpadding=0 cellspacing=0>
6016** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
6017** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
6018** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
6019** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
6020** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
6021** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
6022** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
6023** the native byteorder
6024** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
6025** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
6026** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
6027** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
6028** or a UTF-8 TEXT in bytes
6029** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
6030** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
6031** TEXT in bytes
6032** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
6033** datatype of the value
6034** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
6035** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
6036** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
6037** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
6038** against a virtual table.
6039** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
6040** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
6041** </table></blockquote>
6042**
6043** <b>Details:</b>
6044**
6045** These routines extract type, size, and content information from
6046** [protected sqlite3_value] objects. Protected sqlite3_value objects
6047** are used to pass parameter information into the functions that
6048** implement [application-defined SQL functions] and [virtual tables].
6049**
6050** These routines work only with [protected sqlite3_value] objects.
6051** Any attempt to use these routines on an [unprotected sqlite3_value]
6052** is not threadsafe.
6053**
6054** ^These routines work just like the corresponding [column access functions]
6055** except that these routines take a single [protected sqlite3_value] object
6056** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
6057**
6058** ^The sqlite3_value_text16() interface extracts a UTF-16 string
6059** in the native byte-order of the host machine. ^The
6060** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
6061** extract UTF-16 strings as big-endian and little-endian respectively.
6062**
6063** ^If [sqlite3_value] object V was initialized
6064** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
6065** and if X and Y are strings that compare equal according to strcmp(X,Y),
6066** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
6067** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
6068** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6069**
6070** ^(The sqlite3_value_type(V) interface returns the
6071** [SQLITE_INTEGER | datatype code] for the initial datatype of the
6072** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
6073** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
6074** Other interfaces might change the datatype for an sqlite3_value object.
6075** For example, if the datatype is initially SQLITE_INTEGER and
6076** sqlite3_value_text(V) is called to extract a text value for that
6077** integer, then subsequent calls to sqlite3_value_type(V) might return
6078** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
6079** occurs is undefined and may change from one release of SQLite to the next.
6080**
6081** ^(The sqlite3_value_numeric_type() interface attempts to apply
6082** numeric affinity to the value. This means that an attempt is
6083** made to convert the value to an integer or floating point. If
6084** such a conversion is possible without loss of information (in other
6085** words, if the value is a string that looks like a number)
6086** then the conversion is performed. Otherwise no conversion occurs.
6087** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
6088**
6089** ^Within the [xUpdate] method of a [virtual table], the
6090** sqlite3_value_nochange(X) interface returns true if and only if
6091** the column corresponding to X is unchanged by the UPDATE operation
6092** that the xUpdate method call was invoked to implement and if
6093** the prior [xColumn] method call that was invoked to extract
6094** the value for that column returned without setting a result (probably
6095** because it queried [sqlite3_vtab_nochange()] and found that the column
6096** was unchanging). ^Within an [xUpdate] method, any value for which
6097** sqlite3_value_nochange(X) is true will in all other respects appear
6098** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
6099** than within an [xUpdate] method call for an UPDATE statement, then
6100** the return value is arbitrary and meaningless.
6101**
6102** ^The sqlite3_value_frombind(X) interface returns non-zero if the
6103** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
6104** interfaces. ^If X comes from an SQL literal value, or a table column,
6105** or an expression, then sqlite3_value_frombind(X) returns zero.
6106**
6107** Please pay particular attention to the fact that the pointer returned
6108** from [sqlite3_value_blob()], [sqlite3_value_text()], or
6109** [sqlite3_value_text16()] can be invalidated by a subsequent call to
6110** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
6111** or [sqlite3_value_text16()].
6112**
6113** These routines must be called from the same thread as
6114** the SQL function that supplied the [sqlite3_value*] parameters.
6115**
6116** As long as the input parameter is correct, these routines can only
6117** fail if an out-of-memory error occurs while trying to do a
6118** UTF8&rarr;UTF16 or UTF16&rarr;UTF8 conversion.
6119** If an out-of-memory error occurs, then the return value from these
6120** routines is the same as if the column had contained an SQL NULL value.
6121** If the input sqlite3_value was not obtained from [sqlite3_value_dup()],
6122** then valid SQL NULL returns can also be distinguished from
6123** out-of-memory errors after extracting the value
6124** by invoking the [sqlite3_errcode()] immediately after the suspicious
6125** return value is obtained and before any
6126** other SQLite interface is called on the same [database connection].
6127** If the input sqlite3_value was obtained from sqlite3_value_dup() then
6128** it is disconnected from the database connection and so sqlite3_errcode()
6129** will not work.
6130** In that case, the only way to distinguish an out-of-memory
6131** condition from a true SQL NULL is to invoke sqlite3_value_type() on the
6132** input to see if it is NULL prior to trying to extract the value.
6133*/
6134SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
6135SQLITE_API double sqlite3_value_double(sqlite3_value*);
6136SQLITE_API int sqlite3_value_int(sqlite3_value*);
6137SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
6138SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
6139SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
6140SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
6141SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
6142SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
6143SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
6144SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
6145SQLITE_API int sqlite3_value_type(sqlite3_value*);
6146SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
6147SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
6148SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
6149
6150/*
6151** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
6152** METHOD: sqlite3_value
6153**
6154** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
6155** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
6156** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
6157** returns something other than SQLITE_TEXT, then the return value from
6158** sqlite3_value_encoding(X) is meaningless. ^Calls to
6159** [sqlite3_value_text(X)], [sqlite3_value_text16(X)],
6160** [sqlite3_value_text16be(X)],
6161** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
6162** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
6163** thus change the return from subsequent calls to sqlite3_value_encoding(X).
6164**
6165** This routine is intended for used by applications that test and validate
6166** the SQLite implementation. This routine is inquiring about the opaque
6167** internal state of an [sqlite3_value] object. Ordinary applications should
6168** not need to know what the internal state of an sqlite3_value object is and
6169** hence should not need to use this interface.
6170*/
6171SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
6172
6173/*
6174** CAPI3REF: Finding The Subtype Of SQL Values
6175** METHOD: sqlite3_value
6176**
6177** The sqlite3_value_subtype(V) function returns the subtype for
6178** an [application-defined SQL function] argument V. The subtype
6179** information can be used to pass a limited amount of context from
6180** one SQL function to another. Use the [sqlite3_result_subtype()]
6181** routine to set the subtype for the return value of an SQL function.
6182**
6183** Every [application-defined SQL function] that invokes this interface
6184** should include the [SQLITE_SUBTYPE] property in the text
6185** encoding argument when the function is [sqlite3_create_function|registered].
6186** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
6187** might return zero instead of the upstream subtype in some corner cases.
6188*/
6189SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
6190
6191/*
6192** CAPI3REF: Copy And Free SQL Values
6193** METHOD: sqlite3_value
6194**
6195** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
6196** object V and returns a pointer to that copy. ^The [sqlite3_value] returned
6197** is a [protected sqlite3_value] object even if the input is not.
6198** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
6199** memory allocation fails. ^If V is a [pointer value], then the result
6200** of sqlite3_value_dup(V) is a NULL value.
6201**
6202** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
6203** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
6204** then sqlite3_value_free(V) is a harmless no-op.
6205*/
6206SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
6207SQLITE_API void sqlite3_value_free(sqlite3_value*);
6208
6209/*
6210** CAPI3REF: Obtain Aggregate Function Context
6211** METHOD: sqlite3_context
6212**
6213** Implementations of aggregate SQL functions use this
6214** routine to allocate memory for storing their state.
6215**
6216** ^The first time the sqlite3_aggregate_context(C,N) routine is called
6217** for a particular aggregate function, SQLite allocates
6218** N bytes of memory, zeroes out that memory, and returns a pointer
6219** to the new memory. ^On second and subsequent calls to
6220** sqlite3_aggregate_context() for the same aggregate function instance,
6221** the same buffer is returned. Sqlite3_aggregate_context() is normally
6222** called once for each invocation of the xStep callback and then one
6223** last time when the xFinal callback is invoked. ^(When no rows match
6224** an aggregate query, the xStep() callback of the aggregate function
6225** implementation is never called and xFinal() is called exactly once.
6226** In those cases, sqlite3_aggregate_context() might be called for the
6227** first time from within xFinal().)^
6228**
6229** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
6230** when first called if N is less than or equal to zero or if a memory
6231** allocation error occurs.
6232**
6233** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
6234** determined by the N parameter on the first successful call. Changing the
6235** value of N in any subsequent call to sqlite3_aggregate_context() within
6236** the same aggregate function instance will not resize the memory
6237** allocation.)^ Within the xFinal callback, it is customary to set
6238** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
6239** pointless memory allocations occur.
6240**
6241** ^SQLite automatically frees the memory allocated by
6242** sqlite3_aggregate_context() when the aggregate query concludes.
6243**
6244** The first parameter must be a copy of the
6245** [sqlite3_context | SQL function context] that is the first parameter
6246** to the xStep or xFinal callback routine that implements the aggregate
6247** function.
6248**
6249** This routine must be called from the same thread in which
6250** the aggregate SQL function is running.
6251*/
6252SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
6253
6254/*
6255** CAPI3REF: User Data For Functions
6256** METHOD: sqlite3_context
6257**
6258** ^The sqlite3_user_data() interface returns a copy of
6259** the pointer that was the pUserData parameter (the 5th parameter)
6260** of the [sqlite3_create_function()]
6261** and [sqlite3_create_function16()] routines that originally
6262** registered the application defined function.
6263**
6264** This routine must be called from the same thread in which
6265** the application-defined function is running.
6266*/
6267SQLITE_API void *sqlite3_user_data(sqlite3_context*);
6268
6269/*
6270** CAPI3REF: Database Connection For Functions
6271** METHOD: sqlite3_context
6272**
6273** ^The sqlite3_context_db_handle() interface returns a copy of
6274** the pointer to the [database connection] (the 1st parameter)
6275** of the [sqlite3_create_function()]
6276** and [sqlite3_create_function16()] routines that originally
6277** registered the application defined function.
6278*/
6279SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
6280
6281/*
6282** CAPI3REF: Function Auxiliary Data
6283** METHOD: sqlite3_context
6284**
6285** These functions may be used by (non-aggregate) SQL functions to
6286** associate auxiliary data with argument values. If the same argument
6287** value is passed to multiple invocations of the same SQL function during
6288** query execution, under some circumstances the associated auxiliary data
6289** might be preserved. An example of where this might be useful is in a
6290** regular-expression matching function. The compiled version of the regular
6291** expression can be stored as auxiliary data associated with the pattern
6292** string. Then as long as the pattern string remains the same,
6293** the compiled regular expression can be reused on multiple
6294** invocations of the same function.
6295**
6296** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary
6297** data associated by the sqlite3_set_auxdata(C,N,P,X) function with the
6298** Nth argument value to the application-defined function. ^N is zero
6299** for the left-most function argument. ^If there is no auxiliary data
6300** associated with the function argument, the sqlite3_get_auxdata(C,N)
6301** interface returns a NULL pointer.
6302**
6303** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
6304** N-th argument of the application-defined function. ^Subsequent
6305** calls to sqlite3_get_auxdata(C,N) return P from the most recent
6306** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
6307** NULL if the auxiliary data has been discarded.
6308** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
6309** SQLite will invoke the destructor function X with parameter P exactly
6310** once, when the auxiliary data is discarded.
6311** SQLite is free to discard the auxiliary data at any time, including: <ul>
6312** <li> ^(when the corresponding function parameter changes)^, or
6313** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
6314** SQL statement)^, or
6315** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
6316** parameter)^, or
6317** <li> ^(during the original sqlite3_set_auxdata() call when a memory
6318** allocation error occurs.)^
6319** <li> ^(during the original sqlite3_set_auxdata() call if the function
6320** is evaluated during query planning instead of during query execution,
6321** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
6322**
6323** Note the last two bullets in particular. The destructor X in
6324** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
6325** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
6326** should be called near the end of the function implementation and the
6327** function implementation should not make any use of P after
6328** sqlite3_set_auxdata() has been called. Furthermore, a call to
6329** sqlite3_get_auxdata() that occurs immediately after a corresponding call
6330** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
6331** condition occurred during the sqlite3_set_auxdata() call or if the
6332** function is being evaluated during query planning rather than during
6333** query execution.
6334**
6335** ^(In practice, auxiliary data is preserved between function calls for
6336** function parameters that are compile-time constants, including literal
6337** values and [parameters] and expressions composed from the same.)^
6338**
6339** The value of the N parameter to these interfaces should be non-negative.
6340** Future enhancements may make use of negative N values to define new
6341** kinds of function caching behavior.
6342**
6343** These routines must be called from the same thread in which
6344** the SQL function is running.
6345**
6346** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
6347*/
6348SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
6349SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
6350
6351/*
6352** CAPI3REF: Database Connection Client Data
6353** METHOD: sqlite3
6354**
6355** These functions are used to associate one or more named pointers
6356** with a [database connection].
6357** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
6358** to be attached to [database connection] D using name N. Subsequent
6359** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6360** or a NULL pointer if there were no prior calls to
6361** sqlite3_set_clientdata() with the same values of D and N.
6362** Names are compared using strcmp() and are thus case sensitive.
6363** It returns 0 on success and SQLITE_NOMEM on allocation failure.
6364**
6365** If P and X are both non-NULL, then the destructor X is invoked with
6366** argument P on the first of the following occurrences:
6367** <ul>
6368** <li> An out-of-memory error occurs during the call to
6369** sqlite3_set_clientdata() which attempts to register pointer P.
6370** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6371** with the same D and N parameters.
6372** <li> The database connection closes. SQLite does not make any guarantees
6373** about the order in which destructors are called, only that all
6374** destructors will be called exactly once at some point during the
6375** database connection closing process.
6376** </ul>
6377**
6378** SQLite does not do anything with client data other than invoke
6379** destructors on the client data at the appropriate time. The intended
6380** use for client data is to provide a mechanism for wrapper libraries
6381** to store additional information about an SQLite database connection.
6382**
6383** There is no limit (other than available memory) on the number of different
6384** client data pointers (with different names) that can be attached to a
6385** single database connection. However, the current implementation stores
6386** the content on a linked list. Insert and retrieval performance will
6387** be proportional to the number of entries. The design use case, and
6388** the use case for which the implementation is optimized, is
6389** that an application will store only small number of client data names,
6390** typically just one or two. This interface is not intended to be a
6391** generalized key/value store for thousands or millions of keys. It
6392** will work for that, but performance might be disappointing.
6393**
6394** There is no way to enumerate the client data pointers
6395** associated with a database connection. The N parameter can be thought
6396** of as a secret key such that only code that knows the secret key is able
6397** to access the associated data.
6398**
6399** Security Warning: These interfaces should not be exposed in scripting
6400** languages or in other circumstances where it might be possible for an
6401** attacker to invoke them. Any agent that can invoke these interfaces
6402** can probably also take control of the process.
6403**
6404** Database connection client data is only available for SQLite
6405** version 3.44.0 ([dateof:3.44.0]) and later.
6406**
6407** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6408*/
6409SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6410SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6411
6412/*
6413** CAPI3REF: Constants Defining Special Destructor Behavior
6414**
6415** These are special values for the destructor that is passed in as the
6416** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6417** argument is SQLITE_STATIC, it means that the content pointer is constant
6418** and will never change. It does not need to be destroyed. ^The
6419** SQLITE_TRANSIENT value means that the content will likely change in
6420** the near future and that SQLite should make its own private copy of
6421** the content before returning.
6422**
6423** The typedef is necessary to work around problems in certain
6424** C++ compilers.
6425*/
6426typedef void (*sqlite3_destructor_type)(void*);
6427#define SQLITE_STATIC ((sqlite3_destructor_type)0)
6428#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6429
6430/*
6431** CAPI3REF: Setting The Result Of An SQL Function
6432** METHOD: sqlite3_context
6433**
6434** These routines are used by the xFunc or xFinal callbacks that
6435** implement SQL functions and aggregates. See
6436** [sqlite3_create_function()] and [sqlite3_create_function16()]
6437** for additional information.
6438**
6439** These functions work very much like the [parameter binding] family of
6440** functions used to bind values to host parameters in prepared statements.
6441** Refer to the [SQL parameter] documentation for additional information.
6442**
6443** ^The sqlite3_result_blob() interface sets the result from
6444** an application-defined function to be the BLOB whose content is pointed
6445** to by the second parameter and which is N bytes long where N is the
6446** third parameter.
6447**
6448** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6449** interfaces set the result of the application-defined function to be
6450** a BLOB containing all zero bytes and N bytes in size.
6451**
6452** ^The sqlite3_result_double() interface sets the result from
6453** an application-defined function to be a floating point value specified
6454** by its 2nd argument.
6455**
6456** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6457** cause the implemented SQL function to throw an exception.
6458** ^SQLite uses the string pointed to by the
6459** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6460** as the text of an error message. ^SQLite interprets the error
6461** message string from sqlite3_result_error() as UTF-8. ^SQLite
6462** interprets the string from sqlite3_result_error16() as UTF-16 using
6463** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6464** ^If the third parameter to sqlite3_result_error()
6465** or sqlite3_result_error16() is negative then SQLite takes as the error
6466** message all text up through the first zero character.
6467** ^If the third parameter to sqlite3_result_error() or
6468** sqlite3_result_error16() is non-negative then SQLite takes that many
6469** bytes (not characters) from the 2nd parameter as the error message.
6470** ^The sqlite3_result_error() and sqlite3_result_error16()
6471** routines make a private copy of the error message text before
6472** they return. Hence, the calling function can deallocate or
6473** modify the text after they return without harm.
6474** ^The sqlite3_result_error_code() function changes the error code
6475** returned by SQLite as a result of an error in a function. ^By default,
6476** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6477** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6478**
6479** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6480** error indicating that a string or BLOB is too long to represent.
6481**
6482** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6483** error indicating that a memory allocation failed.
6484**
6485** ^The sqlite3_result_int() interface sets the return value
6486** of the application-defined function to be the 32-bit signed integer
6487** value given in the 2nd argument.
6488** ^The sqlite3_result_int64() interface sets the return value
6489** of the application-defined function to be the 64-bit signed integer
6490** value given in the 2nd argument.
6491**
6492** ^The sqlite3_result_null() interface sets the return value
6493** of the application-defined function to be NULL.
6494**
6495** ^The sqlite3_result_text(), sqlite3_result_text16(),
6496** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6497** set the return value of the application-defined function to be
6498** a text string which is represented as UTF-8, UTF-16 native byte order,
6499** UTF-16 little endian, or UTF-16 big endian, respectively.
6500** ^The sqlite3_result_text64(C,Z,N,D,E) interface sets the return value of an
6501** application-defined function to be a text string in an encoding
6502** specified the E parameter, which must be one
6503** of [SQLITE_UTF8], [SQLITE_UTF8_ZT], [SQLITE_UTF16], [SQLITE_UTF16BE],
6504** or [SQLITE_UTF16LE]. ^The special value [SQLITE_UTF8_ZT] means that
6505** the result text is both UTF-8 and zero-terminated. In other words,
6506** SQLITE_UTF8_ZT means that the Z array holds at least N+1 bytes and that
6507** the Z&#91;N&#93; is zero.
6508** ^SQLite takes the text result from the application from
6509** the 2nd parameter of the sqlite3_result_text* interfaces.
6510** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6511** other than sqlite3_result_text64() is negative, then SQLite computes
6512** the string length itself by searching the 2nd parameter for the first
6513** zero character.
6514** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6515** is non-negative, then as many bytes (not characters) of the text
6516** pointed to by the 2nd parameter are taken as the application-defined
6517** function result. If the 3rd parameter is non-negative, then it
6518** must be the byte offset into the string where the NUL terminator would
6519** appear if the string were NUL terminated. If any NUL characters occur
6520** in the string at a byte offset that is less than the value of the 3rd
6521** parameter, then the resulting string will contain embedded NULs and the
6522** result of expressions operating on strings with embedded NULs is undefined.
6523** ^If the 4th parameter to the sqlite3_result_text* interfaces
6524** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6525** function as the destructor on the text or BLOB result when it has
6526** finished using that result.
6527** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6528** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6529** assumes that the text or BLOB result is in constant space and does not
6530** copy the content of the parameter nor call a destructor on the content
6531** when it has finished using that result.
6532** ^If the 4th parameter to the sqlite3_result_text* interfaces
6533** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6534** then SQLite makes a copy of the result into space obtained
6535** from [sqlite3_malloc()] before it returns.
6536**
6537** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6538** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6539** when the encoding is not UTF8, if the input UTF16 begins with a
6540** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6541** string and the rest of the string is interpreted according to the
6542** byte-order specified by the BOM. ^The byte-order specified by
6543** the BOM at the beginning of the text overrides the byte-order
6544** specified by the interface procedure. ^So, for example, if
6545** sqlite3_result_text16le() is invoked with text that begins
6546** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6547** first two bytes of input are skipped and the remaining input
6548** is interpreted as UTF16BE text.
6549**
6550** ^For UTF16 input text to the sqlite3_result_text16(),
6551** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6552** sqlite3_result_text64() routines, if the text contains invalid
6553** UTF16 characters, the invalid characters might be converted
6554** into the unicode replacement character, U+FFFD.
6555**
6556** ^The sqlite3_result_value() interface sets the result of
6557** the application-defined function to be a copy of the
6558** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6559** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6560** so that the [sqlite3_value] specified in the parameter may change or
6561** be deallocated after sqlite3_result_value() returns without harm.
6562** ^A [protected sqlite3_value] object may always be used where an
6563** [unprotected sqlite3_value] object is required, so either
6564** kind of [sqlite3_value] object can be used with this interface.
6565**
6566** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6567** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6568** also associates the host-language pointer P or type T with that
6569** NULL value such that the pointer can be retrieved within an
6570** [application-defined SQL function] using [sqlite3_value_pointer()].
6571** ^If the D parameter is not NULL, then it is a pointer to a destructor
6572** for the P parameter. ^SQLite invokes D with P as its only argument
6573** when SQLite is finished with P. The T parameter should be a static
6574** string and preferably a string literal. The sqlite3_result_pointer()
6575** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6576**
6577** If these routines are called from within a different thread
6578** than the one containing the application-defined function that received
6579** the [sqlite3_context] pointer, the results are undefined.
6580*/
6581SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6582SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6583 sqlite3_uint64,void(*)(void*));
6584SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6585SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6586SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6587SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6588SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6589SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6590SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6591SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6592SQLITE_API void sqlite3_result_null(sqlite3_context*);
6593SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6594SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char *z, sqlite3_uint64 n,
6595 void(*)(void*), unsigned char encoding);
6596SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6597SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6598SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6599SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6600SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6601SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6602SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6603
6604
6605/*
6606** CAPI3REF: Setting The Subtype Of An SQL Function
6607** METHOD: sqlite3_context
6608**
6609** The sqlite3_result_subtype(C,T) function causes the subtype of
6610** the result from the [application-defined SQL function] with
6611** [sqlite3_context] C to be the value T. Only the lower 8 bits
6612** of the subtype T are preserved in current versions of SQLite;
6613** higher order bits are discarded.
6614** The number of subtype bytes preserved by SQLite might increase
6615** in future releases of SQLite.
6616**
6617** Every [application-defined SQL function] that invokes this interface
6618** should include the [SQLITE_RESULT_SUBTYPE] property in its
6619** text encoding argument when the SQL function is
6620** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6621** property is omitted from the function that invokes sqlite3_result_subtype(),
6622** then in some cases the sqlite3_result_subtype() might fail to set
6623** the result subtype.
6624**
6625** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6626** SQL function that invokes the sqlite3_result_subtype() interface
6627** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6628** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6629** by default.
6630*/
6631SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6632
6633/*
6634** CAPI3REF: Define New Collating Sequences
6635** METHOD: sqlite3
6636**
6637** ^These functions add, remove, or modify a [collation] associated
6638** with the [database connection] specified as the first argument.
6639**
6640** ^The name of the collation is a UTF-8 string
6641** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6642** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6643** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6644** considered to be the same name.
6645**
6646** ^(The third argument (eTextRep) must be one of the constants:
6647** <ul>
6648** <li> [SQLITE_UTF8],
6649** <li> [SQLITE_UTF16LE],
6650** <li> [SQLITE_UTF16BE],
6651** <li> [SQLITE_UTF16], or
6652** <li> [SQLITE_UTF16_ALIGNED].
6653** </ul>)^
6654** ^The eTextRep argument determines the encoding of strings passed
6655** to the collating function callback, xCompare.
6656** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6657** force strings to be UTF16 with native byte order.
6658** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6659** on an even byte address.
6660**
6661** ^The fourth argument, pArg, is an application data pointer that is passed
6662** through as the first argument to the collating function callback.
6663**
6664** ^The fifth argument, xCompare, is a pointer to the collating function.
6665** ^Multiple collating functions can be registered using the same name but
6666** with different eTextRep parameters and SQLite will use whichever
6667** function requires the least amount of data transformation.
6668** ^If the xCompare argument is NULL then the collating function is
6669** deleted. ^When all collating functions having the same name are deleted,
6670** that collation is no longer usable.
6671**
6672** ^The collating function callback is invoked with a copy of the pArg
6673** application data pointer and with two strings in the encoding specified
6674** by the eTextRep argument. The two integer parameters to the collating
6675** function callback are the length of the two strings, in bytes. The collating
6676** function must return an integer that is negative, zero, or positive
6677** if the first string is less than, equal to, or greater than the second,
6678** respectively. A collating function must always return the same answer
6679** given the same inputs. If two or more collating functions are registered
6680** to the same collation name (using different eTextRep values) then all
6681** must give an equivalent answer when invoked with equivalent strings.
6682** The collating function must obey the following properties for all
6683** strings A, B, and C:
6684**
6685** <ol>
6686** <li> If A==B then B==A.
6687** <li> If A==B and B==C then A==C.
6688** <li> If A&lt;B THEN B&gt;A.
6689** <li> If A&lt;B and B&lt;C then A&lt;C.
6690** </ol>
6691**
6692** If a collating function fails any of the above constraints and that
6693** collating function is registered and used, then the behavior of SQLite
6694** is undefined.
6695**
6696** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6697** with the addition that the xDestroy callback is invoked on pArg when
6698** the collating function is deleted.
6699** ^Collating functions are deleted when they are overridden by later
6700** calls to the collation creation functions or when the
6701** [database connection] is closed using [sqlite3_close()].
6702**
6703** ^The xDestroy callback is <u>not</u> called if the
6704** sqlite3_create_collation_v2() function fails. Applications that invoke
6705** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6706** check the return code and dispose of the application data pointer
6707** themselves rather than expecting SQLite to deal with it for them.
6708** This is different from every other SQLite interface. The inconsistency
6709** is unfortunate but cannot be changed without breaking backwards
6710** compatibility.
6711**
6712** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6713*/
6714SQLITE_API int sqlite3_create_collation(
6715 sqlite3*,
6716 const char *zName,
6717 int eTextRep,
6718 void *pArg,
6719 int(*xCompare)(void*,int,const void*,int,const void*)
6720);
6721SQLITE_API int sqlite3_create_collation_v2(
6722 sqlite3*,
6723 const char *zName,
6724 int eTextRep,
6725 void *pArg,
6726 int(*xCompare)(void*,int,const void*,int,const void*),
6727 void(*xDestroy)(void*)
6728);
6729SQLITE_API int sqlite3_create_collation16(
6730 sqlite3*,
6731 const void *zName,
6732 int eTextRep,
6733 void *pArg,
6734 int(*xCompare)(void*,int,const void*,int,const void*)
6735);
6736
6737/*
6738** CAPI3REF: Collation Needed Callbacks
6739** METHOD: sqlite3
6740**
6741** ^To avoid having to register all collation sequences before a database
6742** can be used, a single callback function may be registered with the
6743** [database connection] to be invoked whenever an undefined collation
6744** sequence is required.
6745**
6746** ^If the function is registered using the sqlite3_collation_needed() API,
6747** then it is passed the names of undefined collation sequences as strings
6748** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6749** the names are passed as UTF-16 in machine native byte order.
6750** ^A call to either function replaces the existing collation-needed callback.
6751**
6752** ^(When the callback is invoked, the first argument passed is a copy
6753** of the second argument to sqlite3_collation_needed() or
6754** sqlite3_collation_needed16(). The second argument is the database
6755** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6756** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6757** sequence function required. The fourth parameter is the name of the
6758** required collation sequence.)^
6759**
6760** The callback function should register the desired collation using
6761** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6762** [sqlite3_create_collation_v2()].
6763*/
6764SQLITE_API int sqlite3_collation_needed(
6765 sqlite3*,
6766 void*,
6767 void(*)(void*,sqlite3*,int eTextRep,const char*)
6768);
6769SQLITE_API int sqlite3_collation_needed16(
6770 sqlite3*,
6771 void*,
6772 void(*)(void*,sqlite3*,int eTextRep,const void*)
6773);
6774
6775#ifdef SQLITE_ENABLE_CEROD
6776/*
6777** Specify the activation key for a CEROD database. Unless
6778** activated, none of the CEROD routines will work.
6779*/
6780SQLITE_API void sqlite3_activate_cerod(
6781 const char *zPassPhrase /* Activation phrase */
6782);
6783#endif
6784
6785/*
6786** CAPI3REF: Suspend Execution For A Short Time
6787**
6788** The sqlite3_sleep() function causes the current thread to suspend execution
6789** for at least a number of milliseconds specified in its parameter.
6790**
6791** If the operating system does not support sleep requests with
6792** millisecond time resolution, then the time will be rounded up to
6793** the nearest second. The number of milliseconds of sleep actually
6794** requested from the operating system is returned.
6795**
6796** ^SQLite implements this interface by calling the xSleep()
6797** method of the default [sqlite3_vfs] object. If the xSleep() method
6798** of the default VFS is not implemented correctly, or not implemented at
6799** all, then the behavior of sqlite3_sleep() may deviate from the description
6800** in the previous paragraphs.
6801**
6802** If a negative argument is passed to sqlite3_sleep() the results vary by
6803** VFS and operating system. Some system treat a negative argument as an
6804** instruction to sleep forever. Others understand it to mean do not sleep
6805** at all. ^In SQLite version 3.42.0 and later, a negative
6806** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6807** down into the xSleep method of the VFS.
6808*/
6809SQLITE_API int sqlite3_sleep(int);
6810
6811/*
6812** CAPI3REF: Name Of The Folder Holding Temporary Files
6813**
6814** ^(If this global variable is made to point to a string which is
6815** the name of a folder (a.k.a. directory), then all temporary files
6816** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6817** will be placed in that directory.)^ ^If this variable
6818** is a NULL pointer, then SQLite performs a search for an appropriate
6819** temporary file directory.
6820**
6821** Applications are strongly discouraged from using this global variable.
6822** It is required to set a temporary folder on Windows Runtime (WinRT).
6823** But for all other platforms, it is highly recommended that applications
6824** neither read nor write this variable. This global variable is a relic
6825** that exists for backwards compatibility of legacy applications and should
6826** be avoided in new projects.
6827**
6828** It is not safe to read or modify this variable in more than one
6829** thread at a time. It is not safe to read or modify this variable
6830** if a [database connection] is being used at the same time in a separate
6831** thread.
6832** It is intended that this variable be set once
6833** as part of process initialization and before any SQLite interface
6834** routines have been called and that this variable remain unchanged
6835** thereafter.
6836**
6837** ^The [temp_store_directory pragma] may modify this variable and cause
6838** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6839** the [temp_store_directory pragma] always assumes that any string
6840** that this variable points to is held in memory obtained from
6841** [sqlite3_malloc] and the pragma may attempt to free that memory
6842** using [sqlite3_free].
6843** Hence, if this variable is modified directly, either it should be
6844** made NULL or made to point to memory obtained from [sqlite3_malloc]
6845** or else the use of the [temp_store_directory pragma] should be avoided.
6846** Except when requested by the [temp_store_directory pragma], SQLite
6847** does not free the memory that sqlite3_temp_directory points to. If
6848** the application wants that memory to be freed, it must do
6849** so itself, taking care to only do so after all [database connection]
6850** objects have been destroyed.
6851**
6852** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6853** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6854** features that require the use of temporary files may fail. Here is an
6855** example of how to do this using C++ with the Windows Runtime:
6856**
6857** <blockquote><pre>
6858** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6859** &nbsp; TemporaryFolder->Path->Data();
6860** char zPathBuf&#91;MAX_PATH + 1&#93;;
6861** memset(zPathBuf, 0, sizeof(zPathBuf));
6862** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6863** &nbsp; NULL, NULL);
6864** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6865** </pre></blockquote>
6866*/
6867SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6868
6869/*
6870** CAPI3REF: Name Of The Folder Holding Database Files
6871**
6872** ^(If this global variable is made to point to a string which is
6873** the name of a folder (a.k.a. directory), then all database files
6874** specified with a relative pathname and created or accessed by
6875** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6876** to be relative to that directory.)^ ^If this variable is a NULL
6877** pointer, then SQLite assumes that all database files specified
6878** with a relative pathname are relative to the current directory
6879** for the process. Only the windows VFS makes use of this global
6880** variable; it is ignored by the unix VFS.
6881**
6882** Changing the value of this variable while a database connection is
6883** open can result in a corrupt database.
6884**
6885** It is not safe to read or modify this variable in more than one
6886** thread at a time. It is not safe to read or modify this variable
6887** if a [database connection] is being used at the same time in a separate
6888** thread.
6889** It is intended that this variable be set once
6890** as part of process initialization and before any SQLite interface
6891** routines have been called and that this variable remain unchanged
6892** thereafter.
6893**
6894** ^The [data_store_directory pragma] may modify this variable and cause
6895** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6896** the [data_store_directory pragma] always assumes that any string
6897** that this variable points to is held in memory obtained from
6898** [sqlite3_malloc] and the pragma may attempt to free that memory
6899** using [sqlite3_free].
6900** Hence, if this variable is modified directly, either it should be
6901** made NULL or made to point to memory obtained from [sqlite3_malloc]
6902** or else the use of the [data_store_directory pragma] should be avoided.
6903*/
6904SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6905
6906/*
6907** CAPI3REF: Win32 Specific Interface
6908**
6909** These interfaces are available only on Windows. The
6910** [sqlite3_win32_set_directory] interface is used to set the value associated
6911** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6912** zValue, depending on the value of the type parameter. The zValue parameter
6913** should be NULL to cause the previous value to be freed via [sqlite3_free];
6914** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6915** prior to being used. The [sqlite3_win32_set_directory] interface returns
6916** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6917** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6918** [sqlite3_data_directory] variable is intended to act as a replacement for
6919** the current directory on the sub-platforms of Win32 where that concept is
6920** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6921** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6922** sqlite3_win32_set_directory interface except the string parameter must be
6923** UTF-8 or UTF-16, respectively.
6924*/
6925SQLITE_API int sqlite3_win32_set_directory(
6926 unsigned long type, /* Identifier for directory being set or reset */
6927 void *zValue /* New value for directory being set or reset */
6928);
6929SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6930SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6931
6932/*
6933** CAPI3REF: Win32 Directory Types
6934**
6935** These macros are only available on Windows. They define the allowed values
6936** for the type argument to the [sqlite3_win32_set_directory] interface.
6937*/
6938#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6939#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6940
6941/*
6942** CAPI3REF: Test For Auto-Commit Mode
6943** KEYWORDS: {autocommit mode}
6944** METHOD: sqlite3
6945**
6946** ^The sqlite3_get_autocommit() interface returns non-zero or
6947** zero if the given database connection is or is not in autocommit mode,
6948** respectively. ^Autocommit mode is on by default.
6949** ^Autocommit mode is disabled by a [BEGIN] statement.
6950** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6951**
6952** If certain kinds of errors occur on a statement within a multi-statement
6953** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6954** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6955** transaction might be rolled back automatically. The only way to
6956** find out whether SQLite automatically rolled back the transaction after
6957** an error is to use this function.
6958**
6959** If another thread changes the autocommit status of the database
6960** connection while this routine is running, then the return value
6961** is undefined.
6962*/
6963SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6964
6965/*
6966** CAPI3REF: Find The Database Handle Of A Prepared Statement
6967** METHOD: sqlite3_stmt
6968**
6969** ^The sqlite3_db_handle interface returns the [database connection] handle
6970** to which a [prepared statement] belongs. ^The [database connection]
6971** returned by sqlite3_db_handle is the same [database connection]
6972** that was the first argument
6973** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6974** create the statement in the first place.
6975*/
6976SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6977
6978/*
6979** CAPI3REF: Return The Schema Name For A Database Connection
6980** METHOD: sqlite3
6981**
6982** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6983** for the N-th database on database connection D, or a NULL pointer if N is
6984** out of range. An N value of 0 means the main database file. An N of 1 is
6985** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6986** databases.
6987**
6988** Space to hold the string that is returned by sqlite3_db_name() is managed
6989** by SQLite itself. The string might be deallocated by any operation that
6990** changes the schema, including [ATTACH] or [DETACH] or calls to
6991** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6992** occur on a different thread. Applications that need to
6993** remember the string long-term should make their own copy. Applications that
6994** are accessing the same database connection simultaneously on multiple
6995** threads should mutex-protect calls to this API and should make their own
6996** private copy of the result prior to releasing the mutex.
6997*/
6998SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6999
7000/*
7001** CAPI3REF: Return The Filename For A Database Connection
7002** METHOD: sqlite3
7003**
7004** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
7005** associated with database N of connection D.
7006** ^If there is no attached database N on the database
7007** connection D, or if database N is a temporary or in-memory database, then
7008** this function will return either a NULL pointer or an empty string.
7009**
7010** ^The string value returned by this routine is owned and managed by
7011** the database connection. ^The value will be valid until the database N
7012** is [DETACH]-ed or until the database connection closes.
7013**
7014** ^The filename returned by this function is the output of the
7015** xFullPathname method of the [VFS]. ^In other words, the filename
7016** will be an absolute pathname, even if the filename used
7017** to open the database originally was a URI or relative pathname.
7018**
7019** If the filename pointer returned by this routine is not NULL, then it
7020** can be used as the filename input parameter to these routines:
7021** <ul>
7022** <li> [sqlite3_uri_parameter()]
7023** <li> [sqlite3_uri_boolean()]
7024** <li> [sqlite3_uri_int64()]
7025** <li> [sqlite3_filename_database()]
7026** <li> [sqlite3_filename_journal()]
7027** <li> [sqlite3_filename_wal()]
7028** </ul>
7029*/
7030SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
7031
7032/*
7033** CAPI3REF: Determine if a database is read-only
7034** METHOD: sqlite3
7035**
7036** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
7037** of connection D is read-only, 0 if it is read/write, or -1 if N is not
7038** the name of a database on connection D.
7039*/
7040SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
7041
7042/*
7043** CAPI3REF: Determine the transaction state of a database
7044** METHOD: sqlite3
7045**
7046** ^The sqlite3_txn_state(D,S) interface returns the current
7047** [transaction state] of schema S in database connection D. ^If S is NULL,
7048** then the highest transaction state of any schema on database connection D
7049** is returned. Transaction states are (in order of lowest to highest):
7050** <ol>
7051** <li value="0"> SQLITE_TXN_NONE
7052** <li value="1"> SQLITE_TXN_READ
7053** <li value="2"> SQLITE_TXN_WRITE
7054** </ol>
7055** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
7056** a valid schema, then -1 is returned.
7057*/
7058SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
7059
7060/*
7061** CAPI3REF: Allowed return values from sqlite3_txn_state()
7062** KEYWORDS: {transaction state}
7063**
7064** These constants define the current transaction state of a database file.
7065** ^The [sqlite3_txn_state(D,S)] interface returns one of these
7066** constants in order to describe the transaction state of schema S
7067** in [database connection] D.
7068**
7069** <dl>
7070** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
7071** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
7072** pending.</dd>
7073**
7074** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
7075** <dd>The SQLITE_TXN_READ state means that the database is currently
7076** in a read transaction. Content has been read from the database file
7077** but nothing in the database file has changed. The transaction state
7078** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
7079** no other conflicting concurrent write transactions. The transaction
7080** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
7081** [COMMIT].</dd>
7082**
7083** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
7084** <dd>The SQLITE_TXN_WRITE state means that the database is currently
7085** in a write transaction. Content has been written to the database file
7086** but has not yet committed. The transaction state will change to
7087** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
7088*/
7089#define SQLITE_TXN_NONE 0
7090#define SQLITE_TXN_READ 1
7091#define SQLITE_TXN_WRITE 2
7092
7093/*
7094** CAPI3REF: Find the next prepared statement
7095** METHOD: sqlite3
7096**
7097** ^This interface returns a pointer to the next [prepared statement] after
7098** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
7099** then this interface returns a pointer to the first prepared statement
7100** associated with the database connection pDb. ^If no prepared statement
7101** satisfies the conditions of this routine, it returns NULL.
7102**
7103** The [database connection] pointer D in a call to
7104** [sqlite3_next_stmt(D,S)] must refer to an open database
7105** connection and in particular must not be a NULL pointer.
7106*/
7107SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
7108
7109/*
7110** CAPI3REF: Commit And Rollback Notification Callbacks
7111** METHOD: sqlite3
7112**
7113** ^The sqlite3_commit_hook() interface registers a callback
7114** function to be invoked whenever a transaction is [COMMIT | committed].
7115** ^Any callback set by a previous call to sqlite3_commit_hook()
7116** for the same database connection is overridden.
7117** ^The sqlite3_rollback_hook() interface registers a callback
7118** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
7119** ^Any callback set by a previous call to sqlite3_rollback_hook()
7120** for the same database connection is overridden.
7121** ^The pArg argument is passed through to the callback.
7122** ^If the callback on a commit hook function returns non-zero,
7123** then the commit is converted into a rollback.
7124**
7125** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
7126** return the P argument from the previous call of the same function
7127** on the same [database connection] D, or NULL for
7128** the first call for each function on D.
7129**
7130** The commit and rollback hook callbacks are not reentrant.
7131** The callback implementation must not do anything that will modify
7132** the database connection that invoked the callback. Any actions
7133** to modify the database connection must be deferred until after the
7134** completion of the [sqlite3_step()] call that triggered the commit
7135** or rollback hook in the first place.
7136** Note that running any other SQL statements, including SELECT statements,
7137** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
7138** the database connections for the meaning of "modify" in this paragraph.
7139**
7140** ^Registering a NULL function disables the callback.
7141**
7142** ^When the commit hook callback routine returns zero, the [COMMIT]
7143** operation is allowed to continue normally. ^If the commit hook
7144** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
7145** ^The rollback hook is invoked on a rollback that results from a commit
7146** hook returning non-zero, just as it would be with any other rollback.
7147**
7148** ^For the purposes of this API, a transaction is said to have been
7149** rolled back if an explicit "ROLLBACK" statement is executed, or
7150** an error or constraint causes an implicit rollback to occur.
7151** ^The rollback callback is not invoked if a transaction is
7152** automatically rolled back because the database connection is closed.
7153**
7154** See also the [sqlite3_update_hook()] interface.
7155*/
7156SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
7157SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
7158
7159/*
7160** CAPI3REF: Autovacuum Compaction Amount Callback
7161** METHOD: sqlite3
7162**
7163** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
7164** function C that is invoked prior to each autovacuum of the database
7165** file. ^The callback is passed a copy of the generic data pointer (P),
7166** the schema-name of the attached database that is being autovacuumed,
7167** the size of the database file in pages, the number of free pages,
7168** and the number of bytes per page, respectively. The callback should
7169** return the number of free pages that should be removed by the
7170** autovacuum. ^If the callback returns zero, then no autovacuum happens.
7171** ^If the value returned is greater than or equal to the number of
7172** free pages, then a complete autovacuum happens.
7173**
7174** <p>^If there are multiple ATTACH-ed database files that are being
7175** modified as part of a transaction commit, then the autovacuum pages
7176** callback is invoked separately for each file.
7177**
7178** <p><b>The callback is not reentrant.</b> The callback function should
7179** not attempt to invoke any other SQLite interface. If it does, bad
7180** things may happen, including segmentation faults and corrupt database
7181** files. The callback function should be a simple function that
7182** does some arithmetic on its input parameters and returns a result.
7183**
7184** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
7185** destructor for the P parameter. ^If X is not NULL, then X(P) is
7186** invoked whenever the database connection closes or when the callback
7187** is overwritten by another invocation of sqlite3_autovacuum_pages().
7188**
7189** <p>^There is only one autovacuum pages callback per database connection.
7190** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
7191** previous invocations for that database connection. ^If the callback
7192** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
7193** then the autovacuum steps callback is canceled. The return value
7194** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
7195** be some other error code if something goes wrong. The current
7196** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
7197** return codes might be added in future releases.
7198**
7199** <p>If no autovacuum pages callback is specified (the usual case) or
7200** a NULL pointer is provided for the callback,
7201** then the default behavior is to vacuum all free pages. So, in other
7202** words, the default behavior is the same as if the callback function
7203** were something like this:
7204**
7205** <blockquote><pre>
7206** &nbsp; unsigned int demonstration_autovac_pages_callback(
7207** &nbsp; void *pClientData,
7208** &nbsp; const char *zSchema,
7209** &nbsp; unsigned int nDbPage,
7210** &nbsp; unsigned int nFreePage,
7211** &nbsp; unsigned int nBytePerPage
7212** &nbsp; ){
7213** &nbsp; return nFreePage;
7214** &nbsp; }
7215** </pre></blockquote>
7216*/
7217SQLITE_API int sqlite3_autovacuum_pages(
7218 sqlite3 *db,
7219 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
7220 void*,
7221 void(*)(void*)
7222);
7223
7224
7225/*
7226** CAPI3REF: Data Change Notification Callbacks
7227** METHOD: sqlite3
7228**
7229** ^The sqlite3_update_hook() interface registers a callback function
7230** with the [database connection] identified by the first argument
7231** to be invoked whenever a row is updated, inserted or deleted in
7232** a [rowid table].
7233** ^Any callback set by a previous call to this function
7234** for the same database connection is overridden.
7235**
7236** ^The second argument is a pointer to the function to invoke when a
7237** row is updated, inserted or deleted in a rowid table.
7238** ^The update hook is disabled by invoking sqlite3_update_hook()
7239** with a NULL pointer as the second parameter.
7240** ^The first argument to the callback is a copy of the third argument
7241** to sqlite3_update_hook().
7242** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
7243** or [SQLITE_UPDATE], depending on the operation that caused the callback
7244** to be invoked.
7245** ^The third and fourth arguments to the callback contain pointers to the
7246** database and table name containing the affected row.
7247** ^The final callback parameter is the [rowid] of the row.
7248** ^In the case of an update, this is the [rowid] after the update takes place.
7249**
7250** ^(The update hook is not invoked when internal system tables are
7251** modified (i.e. sqlite_sequence).)^
7252** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
7253**
7254** ^In the current implementation, the update hook
7255** is not invoked when conflicting rows are deleted because of an
7256** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
7257** invoked when rows are deleted using the [truncate optimization].
7258** The exceptions defined in this paragraph might change in a future
7259** release of SQLite.
7260**
7261** Whether the update hook is invoked before or after the
7262** corresponding change is currently unspecified and may differ
7263** depending on the type of change. Do not rely on the order of the
7264** hook call with regards to the final result of the operation which
7265** triggers the hook.
7266**
7267** The update hook implementation must not do anything that will modify
7268** the database connection that invoked the update hook. Any actions
7269** to modify the database connection must be deferred until after the
7270** completion of the [sqlite3_step()] call that triggered the update hook.
7271** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
7272** database connections for the meaning of "modify" in this paragraph.
7273**
7274** ^The sqlite3_update_hook(D,C,P) function
7275** returns the P argument from the previous call
7276** on the same [database connection] D, or NULL for
7277** the first call on D.
7278**
7279** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
7280** and [sqlite3_preupdate_hook()] interfaces.
7281*/
7282SQLITE_API void *sqlite3_update_hook(
7283 sqlite3*,
7284 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
7285 void*
7286);
7287
7288/*
7289** CAPI3REF: Enable Or Disable Shared Pager Cache
7290**
7291** ^(This routine enables or disables the sharing of the database cache
7292** and schema data structures between [database connection | connections]
7293** to the same database. Sharing is enabled if the argument is true
7294** and disabled if the argument is false.)^
7295**
7296** This interface is omitted if SQLite is compiled with
7297** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
7298** compile-time option is recommended because the
7299** [use of shared cache mode is discouraged].
7300**
7301** ^Cache sharing is enabled and disabled for an entire process.
7302** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
7303** In prior versions of SQLite,
7304** sharing was enabled or disabled for each thread separately.
7305**
7306** ^(The cache sharing mode set by this interface effects all subsequent
7307** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
7308** Existing database connections continue to use the sharing mode
7309** that was in effect at the time they were opened.)^
7310**
7311** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
7312** successfully. An [error code] is returned otherwise.)^
7313**
7314** ^Shared cache is disabled by default. It is recommended that it stay
7315** that way. In other words, do not use this routine. This interface
7316** continues to be provided for historical compatibility, but its use is
7317** discouraged. Any use of shared cache is discouraged. If shared cache
7318** must be used, it is recommended that shared cache only be enabled for
7319** individual database connections using the [sqlite3_open_v2()] interface
7320** with the [SQLITE_OPEN_SHAREDCACHE] flag.
7321**
7322** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
7323** and will always return SQLITE_MISUSE. On those systems,
7324** shared cache mode should be enabled per-database connection via
7325** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
7326**
7327** This interface is threadsafe on processors where writing a
7328** 32-bit integer is atomic.
7329**
7330** See Also: [SQLite Shared-Cache Mode]
7331*/
7332SQLITE_API int sqlite3_enable_shared_cache(int);
7333
7334/*
7335** CAPI3REF: Attempt To Free Heap Memory
7336**
7337** ^The sqlite3_release_memory() interface attempts to free N bytes
7338** of heap memory by deallocating non-essential memory allocations
7339** held by the database library. Memory used to cache database
7340** pages to improve performance is an example of non-essential memory.
7341** ^sqlite3_release_memory() returns the number of bytes actually freed,
7342** which might be more or less than the amount requested.
7343** ^The sqlite3_release_memory() routine is a no-op returning zero
7344** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
7345**
7346** See also: [sqlite3_db_release_memory()]
7347*/
7348SQLITE_API int sqlite3_release_memory(int);
7349
7350/*
7351** CAPI3REF: Free Memory Used By A Database Connection
7352** METHOD: sqlite3
7353**
7354** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
7355** memory as possible from database connection D. Unlike the
7356** [sqlite3_release_memory()] interface, this interface is in effect even
7357** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
7358** omitted.
7359**
7360** See also: [sqlite3_release_memory()]
7361*/
7362SQLITE_API int sqlite3_db_release_memory(sqlite3*);
7363
7364/*
7365** CAPI3REF: Impose A Limit On Heap Size
7366**
7367** These interfaces impose limits on the amount of heap memory that will be
7368** used by all database connections within a single process.
7369**
7370** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7371** soft limit on the amount of heap memory that may be allocated by SQLite.
7372** ^SQLite strives to keep heap memory utilization below the soft heap
7373** limit by reducing the number of pages held in the page cache
7374** as heap memory usages approaches the limit.
7375** ^The soft heap limit is "soft" because even though SQLite strives to stay
7376** below the limit, it will exceed the limit rather than generate
7377** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7378** is advisory only.
7379**
7380** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7381** N bytes on the amount of memory that will be allocated. ^The
7382** sqlite3_hard_heap_limit64(N) interface is similar to
7383** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7384** when the hard heap limit is reached.
7385**
7386** ^The return value from both sqlite3_soft_heap_limit64() and
7387** sqlite3_hard_heap_limit64() is the size of
7388** the heap limit prior to the call, or negative in the case of an
7389** error. ^If the argument N is negative
7390** then no change is made to the heap limit. Hence, the current
7391** size of heap limits can be determined by invoking
7392** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7393**
7394** ^Setting the heap limits to zero disables the heap limiter mechanism.
7395**
7396** ^The soft heap limit may not be greater than the hard heap limit.
7397** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7398** is invoked with a value of N that is greater than the hard heap limit,
7399** the soft heap limit is set to the value of the hard heap limit.
7400** ^The soft heap limit is automatically enabled whenever the hard heap
7401** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7402** the soft heap limit is outside the range of 1..N, then the soft heap
7403** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7404** hard heap limit is enabled makes the soft heap limit equal to the
7405** hard heap limit.
7406**
7407** The memory allocation limits can also be adjusted using
7408** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7409**
7410** ^(The heap limits are not enforced in the current implementation
7411** if one or more of following conditions are true:
7412**
7413** <ul>
7414** <li> The limit value is set to zero.
7415** <li> Memory accounting is disabled using a combination of the
7416** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7417** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7418** <li> An alternative page cache implementation is specified using
7419** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7420** <li> The page cache allocates from its own memory pool supplied
7421** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7422** from the heap.
7423** </ul>)^
7424**
7425** The circumstances under which SQLite will enforce the heap limits may
7426** change in future releases of SQLite.
7427*/
7428SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7429SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7430
7431/*
7432** CAPI3REF: Deprecated Soft Heap Limit Interface
7433** DEPRECATED
7434**
7435** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7436** interface. This routine is provided for historical compatibility
7437** only. All new applications should use the
7438** [sqlite3_soft_heap_limit64()] interface rather than this one.
7439*/
7440SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7441
7442
7443/*
7444** CAPI3REF: Extract Metadata About A Column Of A Table
7445** METHOD: sqlite3
7446**
7447** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7448** information about column C of table T in database D
7449** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7450** interface returns SQLITE_OK and fills in the non-NULL pointers in
7451** the final five arguments with appropriate values if the specified
7452** column exists. ^The sqlite3_table_column_metadata() interface returns
7453** SQLITE_ERROR if the specified column does not exist.
7454** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7455** NULL pointer, then this routine simply checks for the existence of the
7456** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7457** does not. If the table name parameter T in a call to
7458** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7459** undefined behavior.
7460**
7461** ^The column is identified by the second, third and fourth parameters to
7462** this function. ^(The second parameter is either the name of the database
7463** (i.e. "main", "temp", or an attached database) containing the specified
7464** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7465** for the table using the same algorithm used by the database engine to
7466** resolve unqualified table references.
7467**
7468** ^The third and fourth parameters to this function are the table and column
7469** name of the desired column, respectively.
7470**
7471** ^Metadata is returned by writing to the memory locations passed as the 5th
7472** and subsequent parameters to this function. ^Any of these arguments may be
7473** NULL, in which case the corresponding element of metadata is omitted.
7474**
7475** ^(<blockquote>
7476** <table border="1">
7477** <tr><th> Parameter <th> Output<br>Type <th> Description
7478**
7479** <tr><td> 5th <td> const char* <td> Data type
7480** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7481** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7482** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7483** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7484** </table>
7485** </blockquote>)^
7486**
7487** ^The memory pointed to by the character pointers returned for the
7488** declaration type and collation sequence is valid until the next
7489** call to any SQLite API function.
7490**
7491** ^If the specified table is actually a view, an [error code] is returned.
7492**
7493** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7494** is not a [WITHOUT ROWID] table and an
7495** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7496** parameters are set for the explicitly declared column. ^(If there is no
7497** [INTEGER PRIMARY KEY] column, then the outputs
7498** for the [rowid] are set as follows:
7499**
7500** <pre>
7501** data type: "INTEGER"
7502** collation sequence: "BINARY"
7503** not null: 0
7504** primary key: 1
7505** auto increment: 0
7506** </pre>)^
7507**
7508** ^This function causes all database schemas to be read from disk and
7509** parsed, if that has not already been done, and returns an error if
7510** any errors are encountered while loading the schema.
7511*/
7512SQLITE_API int sqlite3_table_column_metadata(
7513 sqlite3 *db, /* Connection handle */
7514 const char *zDbName, /* Database name or NULL */
7515 const char *zTableName, /* Table name */
7516 const char *zColumnName, /* Column name */
7517 char const **pzDataType, /* OUTPUT: Declared data type */
7518 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7519 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7520 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7521 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7522);
7523
7524/*
7525** CAPI3REF: Load An Extension
7526** METHOD: sqlite3
7527**
7528** ^This interface loads an SQLite extension library from the named file.
7529**
7530** ^The sqlite3_load_extension() interface attempts to load an
7531** [SQLite extension] library contained in the file zFile. If
7532** the file cannot be loaded directly, attempts are made to load
7533** with various operating-system specific filename extensions added.
7534** So for example, if "samplelib" cannot be loaded, then names like
7535** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7536** be tried also.
7537**
7538** ^The entry point is zProc.
7539** ^(zProc may be 0, in which case SQLite will try to come up with an
7540** entry point name on its own. It first tries "sqlite3_extension_init".
7541** If that does not work, it tries names of the form "sqlite3_X_init"
7542** where X consists of the lower-case equivalent of all ASCII alphabetic
7543** characters or all ASCII alphanumeric characters in the filename from
7544** the last "/" to the first following "." and omitting any initial "lib".)^
7545** ^The sqlite3_load_extension() interface returns
7546** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7547** ^If an error occurs and pzErrMsg is not 0, then the
7548** [sqlite3_load_extension()] interface shall attempt to
7549** fill *pzErrMsg with error message text stored in memory
7550** obtained from [sqlite3_malloc()]. The calling function
7551** should free this memory by calling [sqlite3_free()].
7552**
7553** ^Extension loading must be enabled using
7554** [sqlite3_enable_load_extension()] or
7555** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7556** prior to calling this API,
7557** otherwise an error will be returned.
7558**
7559** <b>Security warning:</b> It is recommended that the
7560** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7561** interface. The use of the [sqlite3_enable_load_extension()] interface
7562** should be avoided. This will keep the SQL function [load_extension()]
7563** disabled and prevent SQL injections from giving attackers
7564** access to extension loading capabilities.
7565**
7566** See also the [load_extension() SQL function].
7567*/
7568SQLITE_API int sqlite3_load_extension(
7569 sqlite3 *db, /* Load the extension into this database connection */
7570 const char *zFile, /* Name of the shared library containing extension */
7571 const char *zProc, /* Entry point. Derived from zFile if 0 */
7572 char **pzErrMsg /* Put error message here if not 0 */
7573);
7574
7575/*
7576** CAPI3REF: Enable Or Disable Extension Loading
7577** METHOD: sqlite3
7578**
7579** ^So as not to open security holes in older applications that are
7580** unprepared to deal with [extension loading], and as a means of disabling
7581** [extension loading] while evaluating user-entered SQL, the following API
7582** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7583**
7584** ^Extension loading is off by default.
7585** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7586** to turn extension loading on and call it with onoff==0 to turn
7587** it back off again.
7588**
7589** ^This interface enables or disables both the C-API
7590** [sqlite3_load_extension()] and the SQL function [load_extension()].
7591** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7592** to enable or disable only the C-API.)^
7593**
7594** <b>Security warning:</b> It is recommended that extension loading
7595** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7596** rather than this interface, so the [load_extension()] SQL function
7597** remains disabled. This will prevent SQL injections from giving attackers
7598** access to extension loading capabilities.
7599*/
7600SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7601
7602/*
7603** CAPI3REF: Automatically Load Statically Linked Extensions
7604**
7605** ^This interface causes the xEntryPoint() function to be invoked for
7606** each new [database connection] that is created. The idea here is that
7607** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7608** that is to be automatically loaded into all new database connections.
7609**
7610** ^(Even though the function prototype shows that xEntryPoint() takes
7611** no arguments and returns void, SQLite invokes xEntryPoint() with three
7612** arguments and expects an integer result as if the signature of the
7613** entry point were as follows:
7614**
7615** <blockquote><pre>
7616** &nbsp; int xEntryPoint(
7617** &nbsp; sqlite3 *db,
7618** &nbsp; char **pzErrMsg,
7619** &nbsp; const struct sqlite3_api_routines *pThunk
7620** &nbsp; );
7621** </pre></blockquote>)^
7622**
7623** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7624** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7625** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7626** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7627** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7628** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7629** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7630**
7631** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7632** on the list of automatic extensions is a harmless no-op. ^No entry point
7633** will be called more than once for each database connection that is opened.
7634**
7635** See also: [sqlite3_reset_auto_extension()]
7636** and [sqlite3_cancel_auto_extension()]
7637*/
7638SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7639
7640/*
7641** CAPI3REF: Cancel Automatic Extension Loading
7642**
7643** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7644** initialization routine X that was registered using a prior call to
7645** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7646** routine returns 1 if initialization routine X was successfully
7647** unregistered and it returns 0 if X was not on the list of initialization
7648** routines.
7649*/
7650SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7651
7652/*
7653** CAPI3REF: Reset Automatic Extension Loading
7654**
7655** ^This interface disables all automatic extensions previously
7656** registered using [sqlite3_auto_extension()].
7657*/
7658SQLITE_API void sqlite3_reset_auto_extension(void);
7659
7660/*
7661** Structures used by the virtual table interface
7662*/
7663typedef struct sqlite3_vtab sqlite3_vtab;
7664typedef struct sqlite3_index_info sqlite3_index_info;
7665typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7666typedef struct sqlite3_module sqlite3_module;
7667
7668/*
7669** CAPI3REF: Virtual Table Object
7670** KEYWORDS: sqlite3_module {virtual table module}
7671**
7672** This structure, sometimes called a "virtual table module",
7673** defines the implementation of a [virtual table].
7674** This structure consists mostly of methods for the module.
7675**
7676** ^A virtual table module is created by filling in a persistent
7677** instance of this structure and passing a pointer to that instance
7678** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7679** ^The registration remains valid until it is replaced by a different
7680** module or until the [database connection] closes. The content
7681** of this structure must not change while it is registered with
7682** any database connection.
7683*/
7684struct sqlite3_module {
7685 int iVersion;
7686 int (*xCreate)(sqlite3*, void *pAux,
7687 int argc, const char *const*argv,
7688 sqlite3_vtab **ppVTab, char**);
7689 int (*xConnect)(sqlite3*, void *pAux,
7690 int argc, const char *const*argv,
7691 sqlite3_vtab **ppVTab, char**);
7692 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7693 int (*xDisconnect)(sqlite3_vtab *pVTab);
7694 int (*xDestroy)(sqlite3_vtab *pVTab);
7695 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7696 int (*xClose)(sqlite3_vtab_cursor*);
7697 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7698 int argc, sqlite3_value **argv);
7699 int (*xNext)(sqlite3_vtab_cursor*);
7700 int (*xEof)(sqlite3_vtab_cursor*);
7701 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7702 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7703 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7704 int (*xBegin)(sqlite3_vtab *pVTab);
7705 int (*xSync)(sqlite3_vtab *pVTab);
7706 int (*xCommit)(sqlite3_vtab *pVTab);
7707 int (*xRollback)(sqlite3_vtab *pVTab);
7708 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7709 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7710 void **ppArg);
7711 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7712 /* The methods above are in version 1 of the sqlite_module object. Those
7713 ** below are for version 2 and greater. */
7714 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7715 int (*xRelease)(sqlite3_vtab *pVTab, int);
7716 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7717 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7718 ** Those below are for version 3 and greater. */
7719 int (*xShadowName)(const char*);
7720 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7721 ** Those below are for version 4 and greater. */
7722 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7723 const char *zTabName, int mFlags, char **pzErr);
7724};
7725
7726/*
7727** CAPI3REF: Virtual Table Indexing Information
7728** KEYWORDS: sqlite3_index_info
7729**
7730** The sqlite3_index_info structure and its substructures is used as part
7731** of the [virtual table] interface to
7732** pass information into and receive the reply from the [xBestIndex]
7733** method of a [virtual table module]. The fields under **Inputs** are the
7734** inputs to xBestIndex and are read-only. xBestIndex inserts its
7735** results into the **Outputs** fields.
7736**
7737** ^(The aConstraint[] array records WHERE clause constraints of the form:
7738**
7739** <blockquote>column OP expr</blockquote>
7740**
7741** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7742** stored in aConstraint[].op using one of the
7743** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7744** ^(The index of the column is stored in
7745** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7746** expr on the right-hand side can be evaluated (and thus the constraint
7747** is usable) and false if it cannot.)^
7748**
7749** ^The optimizer automatically inverts terms of the form "expr OP column"
7750** and makes other simplifications to the WHERE clause in an attempt to
7751** get as many WHERE clause terms into the form shown above as possible.
7752** ^The aConstraint[] array only reports WHERE clause terms that are
7753** relevant to the particular virtual table being queried.
7754**
7755** ^Information about the ORDER BY clause is stored in aOrderBy[].
7756** ^Each term of aOrderBy records a column of the ORDER BY clause.
7757**
7758** The colUsed field indicates which columns of the virtual table may be
7759** required by the current scan. Virtual table columns are numbered from
7760** zero in the order in which they appear within the CREATE TABLE statement
7761** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7762** the corresponding bit is set within the colUsed mask if the column may be
7763** required by SQLite. If the table has at least 64 columns and any column
7764** to the right of the first 63 is required, then bit 63 of colUsed is also
7765** set. In other words, column iCol may be required if the expression
7766** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7767** non-zero.
7768**
7769** The [xBestIndex] method must fill aConstraintUsage[] with information
7770** about what parameters to pass to xFilter. ^If argvIndex>0 then
7771** the right-hand side of the corresponding aConstraint[] is evaluated
7772** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7773** is true, then the constraint is assumed to be fully handled by the
7774** virtual table and might not be checked again by the byte code.)^ ^(The
7775** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7776** is left in its default setting of false, the constraint will always be
7777** checked separately in byte code. If the omit flag is changed to true, then
7778** the constraint may or may not be checked in byte code. In other words,
7779** when the omit flag is true there is no guarantee that the constraint will
7780** not be checked again using byte code.)^
7781**
7782** ^The idxNum and idxStr values are recorded and passed into the
7783** [xFilter] method.
7784** ^[sqlite3_free()] is used to free idxStr if and only if
7785** needToFreeIdxStr is true.
7786**
7787** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7788** the correct order to satisfy the ORDER BY clause so that no separate
7789** sorting step is required.
7790**
7791** ^The estimatedCost value is an estimate of the cost of a particular
7792** strategy. A cost of N indicates that the cost of the strategy is similar
7793** to a linear scan of an SQLite table with N rows. A cost of log(N)
7794** indicates that the expense of the operation is similar to that of a
7795** binary search on a unique indexed field of an SQLite table with N rows.
7796**
7797** ^The estimatedRows value is an estimate of the number of rows that
7798** will be returned by the strategy.
7799**
7800** The xBestIndex method may optionally populate the idxFlags field with a
7801** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
7802** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
7803** output to show the idxNum as hex instead of as decimal. Another flag is
7804** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
7805** return at most one row.
7806**
7807** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7808** SQLite also assumes that if a call to the xUpdate() method is made as
7809** part of the same statement to delete or update a virtual table row and the
7810** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7811** any database changes. In other words, if the xUpdate() returns
7812** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7813** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7814** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7815** the xUpdate method are automatically rolled back by SQLite.
7816**
7817** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7818** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7819** If a virtual table extension is
7820** used with an SQLite version earlier than 3.8.2, the results of attempting
7821** to read or write the estimatedRows field are undefined (but are likely
7822** to include crashing the application). The estimatedRows field should
7823** therefore only be used if [sqlite3_libversion_number()] returns a
7824** value greater than or equal to 3008002. Similarly, the idxFlags field
7825** was added for [version 3.9.0] ([dateof:3.9.0]).
7826** It may therefore only be used if
7827** sqlite3_libversion_number() returns a value greater than or equal to
7828** 3009000.
7829*/
7830struct sqlite3_index_info {
7831 /* Inputs */
7832 int nConstraint; /* Number of entries in aConstraint */
7833 struct sqlite3_index_constraint {
7834 int iColumn; /* Column constrained. -1 for ROWID */
7835 unsigned char op; /* Constraint operator */
7836 unsigned char usable; /* True if this constraint is usable */
7837 int iTermOffset; /* Used internally - xBestIndex should ignore */
7838 } *aConstraint; /* Table of WHERE clause constraints */
7839 int nOrderBy; /* Number of terms in the ORDER BY clause */
7840 struct sqlite3_index_orderby {
7841 int iColumn; /* Column number */
7842 unsigned char desc; /* True for DESC. False for ASC. */
7843 } *aOrderBy; /* The ORDER BY clause */
7844 /* Outputs */
7845 struct sqlite3_index_constraint_usage {
7846 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7847 unsigned char omit; /* Do not code a test for this constraint */
7848 } *aConstraintUsage;
7849 int idxNum; /* Number used to identify the index */
7850 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7851 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7852 int orderByConsumed; /* True if output is already ordered */
7853 double estimatedCost; /* Estimated cost of using this index */
7854 /* Fields below are only available in SQLite 3.8.2 and later */
7855 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7856 /* Fields below are only available in SQLite 3.9.0 and later */
7857 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7858 /* Fields below are only available in SQLite 3.10.0 and later */
7859 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7860};
7861
7862/*
7863** CAPI3REF: Virtual Table Scan Flags
7864**
7865** Virtual table implementations are allowed to set the
7866** [sqlite3_index_info].idxFlags field to some combination of
7867** these bits.
7868*/
7869#define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
7870#define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */
7871 /* in EXPLAIN QUERY PLAN */
7872
7873/*
7874** CAPI3REF: Virtual Table Constraint Operator Codes
7875**
7876** These macros define the allowed values for the
7877** [sqlite3_index_info].aConstraint[].op field. Each value represents
7878** an operator that is part of a constraint term in the WHERE clause of
7879** a query that uses a [virtual table].
7880**
7881** ^The left-hand operand of the operator is given by the corresponding
7882** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7883** operand is the rowid.
7884** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7885** operators have no left-hand operand, and so for those operators the
7886** corresponding aConstraint[].iColumn is meaningless and should not be
7887** used.
7888**
7889** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7890** value 255 are reserved to represent functions that are overloaded
7891** by the [xFindFunction|xFindFunction method] of the virtual table
7892** implementation.
7893**
7894** The right-hand operands for each constraint might be accessible using
7895** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7896** operand is only available if it appears as a single constant literal
7897** in the input SQL. If the right-hand operand is another column or an
7898** expression (even a constant expression) or a parameter, then the
7899** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7900** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7901** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7902** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7903** always return SQLITE_NOTFOUND.
7904**
7905** The collating sequence to be used for comparison can be found using
7906** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7907** tables, the collating sequence of constraints does not matter (for example
7908** because the constraints are numeric) and so the sqlite3_vtab_collation()
7909** interface is not commonly needed.
7910*/
7911#define SQLITE_INDEX_CONSTRAINT_EQ 2
7912#define SQLITE_INDEX_CONSTRAINT_GT 4
7913#define SQLITE_INDEX_CONSTRAINT_LE 8
7914#define SQLITE_INDEX_CONSTRAINT_LT 16
7915#define SQLITE_INDEX_CONSTRAINT_GE 32
7916#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7917#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7918#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7919#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7920#define SQLITE_INDEX_CONSTRAINT_NE 68
7921#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7922#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7923#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7924#define SQLITE_INDEX_CONSTRAINT_IS 72
7925#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7926#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7927#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7928
7929/*
7930** CAPI3REF: Register A Virtual Table Implementation
7931** METHOD: sqlite3
7932**
7933** ^These routines are used to register a new [virtual table module] name.
7934** ^Module names must be registered before
7935** creating a new [virtual table] using the module and before using a
7936** preexisting [virtual table] for the module.
7937**
7938** ^The module name is registered on the [database connection] specified
7939** by the first parameter. ^The name of the module is given by the
7940** second parameter. ^The third parameter is a pointer to
7941** the implementation of the [virtual table module]. ^The fourth
7942** parameter is an arbitrary client data pointer that is passed through
7943** into the [xCreate] and [xConnect] methods of the virtual table module
7944** when a new virtual table is being created or reinitialized.
7945**
7946** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7947** is a pointer to a destructor for the pClientData. ^SQLite will
7948** invoke the destructor function (if it is not NULL) when SQLite
7949** no longer needs the pClientData pointer. ^The destructor will also
7950** be invoked if the call to sqlite3_create_module_v2() fails.
7951** ^The sqlite3_create_module()
7952** interface is equivalent to sqlite3_create_module_v2() with a NULL
7953** destructor.
7954**
7955** ^If the third parameter (the pointer to the sqlite3_module object) is
7956** NULL then no new module is created and any existing modules with the
7957** same name are dropped.
7958**
7959** See also: [sqlite3_drop_modules()]
7960*/
7961SQLITE_API int sqlite3_create_module(
7962 sqlite3 *db, /* SQLite connection to register module with */
7963 const char *zName, /* Name of the module */
7964 const sqlite3_module *p, /* Methods for the module */
7965 void *pClientData /* Client data for xCreate/xConnect */
7966);
7967SQLITE_API int sqlite3_create_module_v2(
7968 sqlite3 *db, /* SQLite connection to register module with */
7969 const char *zName, /* Name of the module */
7970 const sqlite3_module *p, /* Methods for the module */
7971 void *pClientData, /* Client data for xCreate/xConnect */
7972 void(*xDestroy)(void*) /* Module destructor function */
7973);
7974
7975/*
7976** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7977** METHOD: sqlite3
7978**
7979** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7980** table modules from database connection D except those named on list L.
7981** The L parameter must be either NULL or a pointer to an array of pointers
7982** to strings where the array is terminated by a single NULL pointer.
7983** ^If the L parameter is NULL, then all virtual table modules are removed.
7984**
7985** See also: [sqlite3_create_module()]
7986*/
7987SQLITE_API int sqlite3_drop_modules(
7988 sqlite3 *db, /* Remove modules from this connection */
7989 const char **azKeep /* Except, do not remove the ones named here */
7990);
7991
7992/*
7993** CAPI3REF: Virtual Table Instance Object
7994** KEYWORDS: sqlite3_vtab
7995**
7996** Every [virtual table module] implementation uses a subclass
7997** of this object to describe a particular instance
7998** of the [virtual table]. Each subclass will
7999** be tailored to the specific needs of the module implementation.
8000** The purpose of this superclass is to define certain fields that are
8001** common to all module implementations.
8002**
8003** ^Virtual tables methods can set an error message by assigning a
8004** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
8005** take care that any prior string is freed by a call to [sqlite3_free()]
8006** prior to assigning a new string to zErrMsg. ^After the error message
8007** is delivered up to the client application, the string will be automatically
8008** freed by sqlite3_free() and the zErrMsg field will be zeroed.
8009*/
8010struct sqlite3_vtab {
8011 const sqlite3_module *pModule; /* The module for this virtual table */
8012 int nRef; /* Number of open cursors */
8013 char *zErrMsg; /* Error message from sqlite3_mprintf() */
8014 /* Virtual table implementations will typically add additional fields */
8015};
8016
8017/*
8018** CAPI3REF: Virtual Table Cursor Object
8019** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
8020**
8021** Every [virtual table module] implementation uses a subclass of the
8022** following structure to describe cursors that point into the
8023** [virtual table] and are used
8024** to loop through the virtual table. Cursors are created using the
8025** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
8026** by the [sqlite3_module.xClose | xClose] method. Cursors are used
8027** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
8028** of the module. Each module implementation will define
8029** the content of a cursor structure to suit its own needs.
8030**
8031** This superclass exists in order to define fields of the cursor that
8032** are common to all implementations.
8033*/
8034struct sqlite3_vtab_cursor {
8035 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
8036 /* Virtual table implementations will typically add additional fields */
8037};
8038
8039/*
8040** CAPI3REF: Declare The Schema Of A Virtual Table
8041**
8042** ^The [xCreate] and [xConnect] methods of a
8043** [virtual table module] call this interface
8044** to declare the format (the names and datatypes of the columns) of
8045** the virtual tables they implement.
8046*/
8047SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
8048
8049/*
8050** CAPI3REF: Overload A Function For A Virtual Table
8051** METHOD: sqlite3
8052**
8053** ^(Virtual tables can provide alternative implementations of functions
8054** using the [xFindFunction] method of the [virtual table module].
8055** But global versions of those functions
8056** must exist in order to be overloaded.)^
8057**
8058** ^(This API makes sure a global version of a function with a particular
8059** name and number of parameters exists. If no such function exists
8060** before this API is called, a new function is created.)^ ^The implementation
8061** of the new function always causes an exception to be thrown. So
8062** the new function is not good for anything by itself. Its only
8063** purpose is to be a placeholder function that can be overloaded
8064** by a [virtual table].
8065*/
8066SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
8067
8068/*
8069** CAPI3REF: A Handle To An Open BLOB
8070** KEYWORDS: {BLOB handle} {BLOB handles}
8071**
8072** An instance of this object represents an open BLOB on which
8073** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
8074** ^Objects of this type are created by [sqlite3_blob_open()]
8075** and destroyed by [sqlite3_blob_close()].
8076** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
8077** can be used to read or write small subsections of the BLOB.
8078** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
8079*/
8080typedef struct sqlite3_blob sqlite3_blob;
8081
8082/*
8083** CAPI3REF: Open A BLOB For Incremental I/O
8084** METHOD: sqlite3
8085** CONSTRUCTOR: sqlite3_blob
8086**
8087** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
8088** in row iRow, column zColumn, table zTable in database zDb;
8089** in other words, the same BLOB that would be selected by:
8090**
8091** <pre>
8092** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
8093** </pre>)^
8094**
8095** ^(Parameter zDb is not the filename that contains the database, but
8096** rather the symbolic name of the database. For attached databases, this is
8097** the name that appears after the AS keyword in the [ATTACH] statement.
8098** For the main database file, the database name is "main". For TEMP
8099** tables, the database name is "temp".)^
8100**
8101** ^If the flags parameter is non-zero, then the BLOB is opened for read
8102** and write access. ^If the flags parameter is zero, the BLOB is opened for
8103** read-only access.
8104**
8105** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
8106** in *ppBlob. Otherwise an [error code] is returned and, unless the error
8107** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
8108** the API is not misused, it is always safe to call [sqlite3_blob_close()]
8109** on *ppBlob after this function returns.
8110**
8111** This function fails with SQLITE_ERROR if any of the following are true:
8112** <ul>
8113** <li> ^(Database zDb does not exist)^,
8114** <li> ^(Table zTable does not exist within database zDb)^,
8115** <li> ^(Table zTable is a WITHOUT ROWID table)^,
8116** <li> ^(Column zColumn does not exist)^,
8117** <li> ^(Row iRow is not present in the table)^,
8118** <li> ^(The specified column of row iRow contains a value that is not
8119** a TEXT or BLOB value)^,
8120** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
8121** constraint and the blob is being opened for read/write access)^,
8122** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
8123** column zColumn is part of a [child key] definition and the blob is
8124** being opened for read/write access)^.
8125** </ul>
8126**
8127** ^Unless it returns SQLITE_MISUSE, this function sets the
8128** [database connection] error code and message accessible via
8129** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8130**
8131** A BLOB referenced by sqlite3_blob_open() may be read using the
8132** [sqlite3_blob_read()] interface and modified by using
8133** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
8134** different row of the same table using the [sqlite3_blob_reopen()]
8135** interface. However, the column, table, or database of a [BLOB handle]
8136** cannot be changed after the [BLOB handle] is opened.
8137**
8138** ^(If the row that a BLOB handle points to is modified by an
8139** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
8140** then the BLOB handle is marked as "expired".
8141** This is true if any column of the row is changed, even a column
8142** other than the one the BLOB handle is open on.)^
8143** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
8144** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
8145** ^(Changes written into a BLOB prior to the BLOB expiring are not
8146** rolled back by the expiration of the BLOB. Such changes will eventually
8147** commit if the transaction continues to completion.)^
8148**
8149** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
8150** the opened blob. ^The size of a blob may not be changed by this
8151** interface. Use the [UPDATE] SQL command to change the size of a
8152** blob.
8153**
8154** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
8155** and the built-in [zeroblob] SQL function may be used to create a
8156** zero-filled blob to read or write using the incremental-blob interface.
8157**
8158** To avoid a resource leak, every open [BLOB handle] should eventually
8159** be released by a call to [sqlite3_blob_close()].
8160**
8161** See also: [sqlite3_blob_close()],
8162** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
8163** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
8164*/
8165SQLITE_API int sqlite3_blob_open(
8166 sqlite3*,
8167 const char *zDb,
8168 const char *zTable,
8169 const char *zColumn,
8170 sqlite3_int64 iRow,
8171 int flags,
8172 sqlite3_blob **ppBlob
8173);
8174
8175/*
8176** CAPI3REF: Move a BLOB Handle to a New Row
8177** METHOD: sqlite3_blob
8178**
8179** ^This function is used to move an existing [BLOB handle] so that it points
8180** to a different row of the same database table. ^The new row is identified
8181** by the rowid value passed as the second argument. Only the row can be
8182** changed. ^The database, table and column on which the blob handle is open
8183** remain the same. Moving an existing [BLOB handle] to a new row is
8184** faster than closing the existing handle and opening a new one.
8185**
8186** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
8187** it must exist and there must be either a blob or text value stored in
8188** the nominated column.)^ ^If the new row is not present in the table, or if
8189** it does not contain a blob or text value, or if another error occurs, an
8190** SQLite error code is returned and the blob handle is considered aborted.
8191** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
8192** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
8193** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
8194** always returns zero.
8195**
8196** ^This function sets the database handle error code and message.
8197*/
8198SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
8199
8200/*
8201** CAPI3REF: Close A BLOB Handle
8202** DESTRUCTOR: sqlite3_blob
8203**
8204** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
8205** unconditionally. Even if this routine returns an error code, the
8206** handle is still closed.)^
8207**
8208** ^If the blob handle being closed was opened for read-write access, and if
8209** the database is in auto-commit mode and there are no other open read-write
8210** blob handles or active write statements, the current transaction is
8211** committed. ^If an error occurs while committing the transaction, an error
8212** code is returned and the transaction rolled back.
8213**
8214** Calling this function with an argument that is not a NULL pointer or an
8215** open blob handle results in undefined behavior. ^Calling this routine
8216** with a null pointer (such as would be returned by a failed call to
8217** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
8218** is passed a valid open blob handle, the values returned by the
8219** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
8220*/
8221SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
8222
8223/*
8224** CAPI3REF: Return The Size Of An Open BLOB
8225** METHOD: sqlite3_blob
8226**
8227** ^Returns the size in bytes of the BLOB accessible via the
8228** successfully opened [BLOB handle] in its only argument. ^The
8229** incremental blob I/O routines can only read or overwrite existing
8230** blob content; they cannot change the size of a blob.
8231**
8232** This routine only works on a [BLOB handle] which has been created
8233** by a prior successful call to [sqlite3_blob_open()] and which has not
8234** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8235** to this routine results in undefined and probably undesirable behavior.
8236*/
8237SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
8238
8239/*
8240** CAPI3REF: Read Data From A BLOB Incrementally
8241** METHOD: sqlite3_blob
8242**
8243** ^(This function is used to read data from an open [BLOB handle] into a
8244** caller-supplied buffer. N bytes of data are copied into buffer Z
8245** from the open BLOB, starting at offset iOffset.)^
8246**
8247** ^If offset iOffset is less than N bytes from the end of the BLOB,
8248** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
8249** less than zero, [SQLITE_ERROR] is returned and no data is read.
8250** ^The size of the blob (and hence the maximum value of N+iOffset)
8251** can be determined using the [sqlite3_blob_bytes()] interface.
8252**
8253** ^An attempt to read from an expired [BLOB handle] fails with an
8254** error code of [SQLITE_ABORT].
8255**
8256** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
8257** Otherwise, an [error code] or an [extended error code] is returned.)^
8258**
8259** This routine only works on a [BLOB handle] which has been created
8260** by a prior successful call to [sqlite3_blob_open()] and which has not
8261** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8262** to this routine results in undefined and probably undesirable behavior.
8263**
8264** See also: [sqlite3_blob_write()].
8265*/
8266SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
8267
8268/*
8269** CAPI3REF: Write Data Into A BLOB Incrementally
8270** METHOD: sqlite3_blob
8271**
8272** ^(This function is used to write data into an open [BLOB handle] from a
8273** caller-supplied buffer. N bytes of data are copied from the buffer Z
8274** into the open BLOB, starting at offset iOffset.)^
8275**
8276** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
8277** Otherwise, an [error code] or an [extended error code] is returned.)^
8278** ^Unless SQLITE_MISUSE is returned, this function sets the
8279** [database connection] error code and message accessible via
8280** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8281**
8282** ^If the [BLOB handle] passed as the first argument was not opened for
8283** writing (the flags parameter to [sqlite3_blob_open()] was zero),
8284** this function returns [SQLITE_READONLY].
8285**
8286** This function may only modify the contents of the BLOB; it is
8287** not possible to increase the size of a BLOB using this API.
8288** ^If offset iOffset is less than N bytes from the end of the BLOB,
8289** [SQLITE_ERROR] is returned and no data is written. The size of the
8290** BLOB (and hence the maximum value of N+iOffset) can be determined
8291** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
8292** than zero [SQLITE_ERROR] is returned and no data is written.
8293**
8294** ^An attempt to write to an expired [BLOB handle] fails with an
8295** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
8296** before the [BLOB handle] expired are not rolled back by the
8297** expiration of the handle, though of course those changes might
8298** have been overwritten by the statement that expired the BLOB handle
8299** or by other independent statements.
8300**
8301** This routine only works on a [BLOB handle] which has been created
8302** by a prior successful call to [sqlite3_blob_open()] and which has not
8303** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8304** to this routine results in undefined and probably undesirable behavior.
8305**
8306** See also: [sqlite3_blob_read()].
8307*/
8308SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
8309
8310/*
8311** CAPI3REF: Virtual File System Objects
8312**
8313** A virtual filesystem (VFS) is an [sqlite3_vfs] object
8314** that SQLite uses to interact
8315** with the underlying operating system. Most SQLite builds come with a
8316** single default VFS that is appropriate for the host computer.
8317** New VFSes can be registered and existing VFSes can be unregistered.
8318** The following interfaces are provided.
8319**
8320** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
8321** ^Names are case sensitive.
8322** ^Names are zero-terminated UTF-8 strings.
8323** ^If there is no match, a NULL pointer is returned.
8324** ^If zVfsName is NULL then the default VFS is returned.
8325**
8326** ^New VFSes are registered with sqlite3_vfs_register().
8327** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
8328** ^The same VFS can be registered multiple times without injury.
8329** ^To make an existing VFS into the default VFS, register it again
8330** with the makeDflt flag set. If two different VFSes with the
8331** same name are registered, the behavior is undefined. If a
8332** VFS is registered with a name that is NULL or an empty string,
8333** then the behavior is undefined.
8334**
8335** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
8336** ^(If the default VFS is unregistered, another VFS is chosen as
8337** the default. The choice for the new VFS is arbitrary.)^
8338*/
8339SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
8340SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
8341SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
8342
8343/*
8344** CAPI3REF: Mutexes
8345**
8346** The SQLite core uses these routines for thread
8347** synchronization. Though they are intended for internal
8348** use by SQLite, code that links against SQLite is
8349** permitted to use any of these routines.
8350**
8351** The SQLite source code contains multiple implementations
8352** of these mutex routines. An appropriate implementation
8353** is selected automatically at compile-time. The following
8354** implementations are available in the SQLite core:
8355**
8356** <ul>
8357** <li> SQLITE_MUTEX_PTHREADS
8358** <li> SQLITE_MUTEX_W32
8359** <li> SQLITE_MUTEX_NOOP
8360** </ul>
8361**
8362** The SQLITE_MUTEX_NOOP implementation is a set of routines
8363** that does no real locking and is appropriate for use in
8364** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
8365** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
8366** and Windows.
8367**
8368**
8369** ^The sqlite3_mutex_alloc() routine allocates a new
8370** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8371** routine returns NULL if it is unable to allocate the requested
8372** mutex. The argument to sqlite3_mutex_alloc() must be one of these
8373** integer constants:
8374**
8375** <ul>
8376** <li> SQLITE_MUTEX_FAST
8377** <li> SQLITE_MUTEX_RECURSIVE
8378** <li> SQLITE_MUTEX_STATIC_MAIN
8379** <li> SQLITE_MUTEX_STATIC_MEM
8380** <li> SQLITE_MUTEX_STATIC_OPEN
8381** <li> SQLITE_MUTEX_STATIC_PRNG
8382** <li> SQLITE_MUTEX_STATIC_LRU
8383** <li> SQLITE_MUTEX_STATIC_PMEM
8384** <li> SQLITE_MUTEX_STATIC_APP1
8385** <li> SQLITE_MUTEX_STATIC_APP2
8386** <li> SQLITE_MUTEX_STATIC_APP3
8387** <li> SQLITE_MUTEX_STATIC_VFS1
8388** <li> SQLITE_MUTEX_STATIC_VFS2
8389** <li> SQLITE_MUTEX_STATIC_VFS3
8390** </ul>
8391**
8392** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8393** cause sqlite3_mutex_alloc() to create
8394** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8395** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8396** The mutex implementation does not need to make a distinction
8397** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8398** not want to. SQLite will only request a recursive mutex in
8399** cases where it really needs one. If a faster non-recursive mutex
8400** implementation is available on the host platform, the mutex subsystem
8401** might return such a mutex in response to SQLITE_MUTEX_FAST.
8402**
8403** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8404** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8405** a pointer to a static preexisting mutex. ^Nine static mutexes are
8406** used by the current version of SQLite. Future versions of SQLite
8407** may add additional static mutexes. Static mutexes are for internal
8408** use by SQLite only. Applications that use SQLite mutexes should
8409** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8410** SQLITE_MUTEX_RECURSIVE.
8411**
8412** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8413** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8414** returns a different mutex on every call. ^For the static
8415** mutex types, the same mutex is returned on every call that has
8416** the same type number.
8417**
8418** ^The sqlite3_mutex_free() routine deallocates a previously
8419** allocated dynamic mutex. Attempting to deallocate a static
8420** mutex results in undefined behavior.
8421**
8422** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8423** to enter a mutex. ^If another thread is already within the mutex,
8424** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8425** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8426** upon successful entry. ^(Mutexes created using
8427** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8428** In such cases, the
8429** mutex must be exited an equal number of times before another thread
8430** can enter.)^ If the same thread tries to enter any mutex other
8431** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8432**
8433** ^(Some systems (for example, Windows 95) do not support the operation
8434** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8435** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8436** sqlite3_mutex_try() as an optimization, so this is acceptable
8437** behavior. The exceptions are unix builds that set the
8438** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8439** sqlite3_mutex_try() is required.)^
8440**
8441** ^The sqlite3_mutex_leave() routine exits a mutex that was
8442** previously entered by the same thread. The behavior
8443** is undefined if the mutex is not currently entered by the
8444** calling thread or is not currently allocated.
8445**
8446** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8447** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8448** then any of the four routines behaves as a no-op.
8449**
8450** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8451*/
8452SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8453SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8454SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8455SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8456SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8457
8458/*
8459** CAPI3REF: Mutex Methods Object
8460**
8461** An instance of this structure defines the low-level routines
8462** used to allocate and use mutexes.
8463**
8464** Usually, the default mutex implementations provided by SQLite are
8465** sufficient, however the application has the option of substituting a custom
8466** implementation for specialized deployments or systems for which SQLite
8467** does not provide a suitable implementation. In this case, the application
8468** creates and populates an instance of this structure to pass
8469** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8470** Additionally, an instance of this structure can be used as an
8471** output variable when querying the system for the current mutex
8472** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8473**
8474** ^The xMutexInit method defined by this structure is invoked as
8475** part of system initialization by the sqlite3_initialize() function.
8476** ^The xMutexInit routine is called by SQLite exactly once for each
8477** effective call to [sqlite3_initialize()].
8478**
8479** ^The xMutexEnd method defined by this structure is invoked as
8480** part of system shutdown by the sqlite3_shutdown() function. The
8481** implementation of this method is expected to release all outstanding
8482** resources obtained by the mutex methods implementation, especially
8483** those obtained by the xMutexInit method. ^The xMutexEnd()
8484** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8485**
8486** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8487** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8488** xMutexNotheld) implement the following interfaces (respectively):
8489**
8490** <ul>
8491** <li> [sqlite3_mutex_alloc()] </li>
8492** <li> [sqlite3_mutex_free()] </li>
8493** <li> [sqlite3_mutex_enter()] </li>
8494** <li> [sqlite3_mutex_try()] </li>
8495** <li> [sqlite3_mutex_leave()] </li>
8496** <li> [sqlite3_mutex_held()] </li>
8497** <li> [sqlite3_mutex_notheld()] </li>
8498** </ul>)^
8499**
8500** The only difference is that the public sqlite3_XXX functions enumerated
8501** above silently ignore any invocations that pass a NULL pointer instead
8502** of a valid mutex handle. The implementations of the methods defined
8503** by this structure are not required to handle this case. The results
8504** of passing a NULL pointer instead of a valid mutex handle are undefined
8505** (i.e. it is acceptable to provide an implementation that segfaults if
8506** it is passed a NULL pointer).
8507**
8508** The xMutexInit() method must be threadsafe. It must be harmless to
8509** invoke xMutexInit() multiple times within the same process and without
8510** intervening calls to xMutexEnd(). Second and subsequent calls to
8511** xMutexInit() must be no-ops.
8512**
8513** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8514** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8515** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8516** memory allocation for a fast or recursive mutex.
8517**
8518** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8519** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8520** If xMutexInit fails in any way, it is expected to clean up after itself
8521** prior to returning.
8522*/
8523typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8524struct sqlite3_mutex_methods {
8525 int (*xMutexInit)(void);
8526 int (*xMutexEnd)(void);
8527 sqlite3_mutex *(*xMutexAlloc)(int);
8528 void (*xMutexFree)(sqlite3_mutex *);
8529 void (*xMutexEnter)(sqlite3_mutex *);
8530 int (*xMutexTry)(sqlite3_mutex *);
8531 void (*xMutexLeave)(sqlite3_mutex *);
8532 int (*xMutexHeld)(sqlite3_mutex *);
8533 int (*xMutexNotheld)(sqlite3_mutex *);
8534};
8535
8536/*
8537** CAPI3REF: Mutex Verification Routines
8538**
8539** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8540** are intended for use inside assert() statements. The SQLite core
8541** never uses these routines except inside an assert() and applications
8542** are advised to follow the lead of the core. The SQLite core only
8543** provides implementations for these routines when it is compiled
8544** with the SQLITE_DEBUG flag. External mutex implementations
8545** are only required to provide these routines if SQLITE_DEBUG is
8546** defined and if NDEBUG is not defined.
8547**
8548** These routines should return true if the mutex in their argument
8549** is held or not held, respectively, by the calling thread.
8550**
8551** The implementation is not required to provide versions of these
8552** routines that actually work. If the implementation does not provide working
8553** versions of these routines, it should at least provide stubs that always
8554** return true so that one does not get spurious assertion failures.
8555**
8556** If the argument to sqlite3_mutex_held() is a NULL pointer then
8557** the routine should return 1. This seems counter-intuitive since
8558** clearly the mutex cannot be held if it does not exist. But
8559** the reason the mutex does not exist is because the build is not
8560** using mutexes. And we do not want the assert() containing the
8561** call to sqlite3_mutex_held() to fail, so a non-zero return is
8562** the appropriate thing to do. The sqlite3_mutex_notheld()
8563** interface should also return 1 when given a NULL pointer.
8564*/
8565#ifndef NDEBUG
8566SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8567SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8568#endif
8569
8570/*
8571** CAPI3REF: Mutex Types
8572**
8573** The [sqlite3_mutex_alloc()] interface takes a single argument
8574** which is one of these integer constants.
8575**
8576** The set of static mutexes may change from one SQLite release to the
8577** next. Applications that override the built-in mutex logic must be
8578** prepared to accommodate additional static mutexes.
8579*/
8580#define SQLITE_MUTEX_FAST 0
8581#define SQLITE_MUTEX_RECURSIVE 1
8582#define SQLITE_MUTEX_STATIC_MAIN 2
8583#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8584#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8585#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8586#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8587#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8588#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8589#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8590#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8591#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8592#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8593#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8594#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8595#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8596
8597/* Legacy compatibility: */
8598#define SQLITE_MUTEX_STATIC_MASTER 2
8599
8600
8601/*
8602** CAPI3REF: Retrieve the mutex for a database connection
8603** METHOD: sqlite3
8604**
8605** ^This interface returns a pointer to the [sqlite3_mutex] object that
8606** serializes access to the [database connection] given in the argument
8607** when the [threading mode] is Serialized.
8608** ^If the [threading mode] is Single-thread or Multi-thread then this
8609** routine returns a NULL pointer.
8610*/
8611SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8612
8613/*
8614** CAPI3REF: Low-Level Control Of Database Files
8615** METHOD: sqlite3
8616** KEYWORDS: {file control}
8617**
8618** ^The [sqlite3_file_control()] interface makes a direct call to the
8619** xFileControl method for the [sqlite3_io_methods] object associated
8620** with a particular database identified by the second argument. ^The
8621** name of the database is "main" for the main database or "temp" for the
8622** TEMP database, or the name that appears after the AS keyword for
8623** databases that are added using the [ATTACH] SQL command.
8624** ^A NULL pointer can be used in place of "main" to refer to the
8625** main database file.
8626** ^The third and fourth parameters to this routine
8627** are passed directly through to the second and third parameters of
8628** the xFileControl method. ^The return value of the xFileControl
8629** method becomes the return value of this routine.
8630**
8631** A few opcodes for [sqlite3_file_control()] are handled directly
8632** by the SQLite core and never invoke the
8633** sqlite3_io_methods.xFileControl method.
8634** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8635** a pointer to the underlying [sqlite3_file] object to be written into
8636** the space pointed to by the 4th parameter. The
8637** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8638** the [sqlite3_file] object associated with the journal file instead of
8639** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8640** a pointer to the underlying [sqlite3_vfs] object for the file.
8641** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8642** from the pager.
8643**
8644** ^If the second parameter (zDbName) does not match the name of any
8645** open database file, then SQLITE_ERROR is returned. ^This error
8646** code is not remembered and will not be recalled by [sqlite3_errcode()]
8647** or [sqlite3_errmsg()]. The underlying xFileControl method might
8648** also return SQLITE_ERROR. There is no way to distinguish between
8649** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8650** xFileControl method.
8651**
8652** See also: [file control opcodes]
8653*/
8654SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8655
8656/*
8657** CAPI3REF: Testing Interface
8658**
8659** ^The sqlite3_test_control() interface is used to read out internal
8660** state of SQLite and to inject faults into SQLite for testing
8661** purposes. ^The first parameter is an operation code that determines
8662** the number, meaning, and operation of all subsequent parameters.
8663**
8664** This interface is not for use by applications. It exists solely
8665** for verifying the correct operation of the SQLite library. Depending
8666** on how the SQLite library is compiled, this interface might not exist.
8667**
8668** The details of the operation codes, their meanings, the parameters
8669** they take, and what they do are all subject to change without notice.
8670** Unlike most of the SQLite API, this function is not guaranteed to
8671** operate consistently from one release to the next.
8672*/
8673SQLITE_API int sqlite3_test_control(int op, ...);
8674
8675/*
8676** CAPI3REF: Testing Interface Operation Codes
8677**
8678** These constants are the valid operation code parameters used
8679** as the first argument to [sqlite3_test_control()].
8680**
8681** These parameters and their meanings are subject to change
8682** without notice. These values are for testing purposes only.
8683** Applications should not use any of these parameters or the
8684** [sqlite3_test_control()] interface.
8685*/
8686#define SQLITE_TESTCTRL_FIRST 5
8687#define SQLITE_TESTCTRL_PRNG_SAVE 5
8688#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8689#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8690#define SQLITE_TESTCTRL_FK_NO_ACTION 7
8691#define SQLITE_TESTCTRL_BITVEC_TEST 8
8692#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8693#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8694#define SQLITE_TESTCTRL_PENDING_BYTE 11
8695#define SQLITE_TESTCTRL_ASSERT 12
8696#define SQLITE_TESTCTRL_ALWAYS 13
8697#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8698#define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8699#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8700#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8701#define SQLITE_TESTCTRL_GETOPT 16
8702#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8703#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8704#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8705#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8706#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8707#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8708#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8709#define SQLITE_TESTCTRL_BYTEORDER 22
8710#define SQLITE_TESTCTRL_ISINIT 23
8711#define SQLITE_TESTCTRL_SORTER_MMAP 24
8712#define SQLITE_TESTCTRL_IMPOSTER 25
8713#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8714#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8715#define SQLITE_TESTCTRL_PRNG_SEED 28
8716#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8717#define SQLITE_TESTCTRL_SEEK_COUNT 30
8718#define SQLITE_TESTCTRL_TRACEFLAGS 31
8719#define SQLITE_TESTCTRL_TUNE 32
8720#define SQLITE_TESTCTRL_LOGEST 33
8721#define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */
8722#define SQLITE_TESTCTRL_ATOF 34
8723#define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8724
8725/*
8726** CAPI3REF: SQL Keyword Checking
8727**
8728** These routines provide access to the set of SQL language keywords
8729** recognized by SQLite. Applications can use these routines to determine
8730** whether or not a specific identifier needs to be escaped (for example,
8731** by enclosing in double-quotes) so as not to confuse the parser.
8732**
8733** The sqlite3_keyword_count() interface returns the number of distinct
8734** keywords understood by SQLite.
8735**
8736** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8737** makes *Z point to that keyword expressed as UTF8 and writes the number
8738** of bytes in the keyword into *L. The string that *Z points to is not
8739** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8740** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8741** or L are NULL or invalid pointers then calls to
8742** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8743**
8744** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8745** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8746** if it is and zero if not.
8747**
8748** The parser used by SQLite is forgiving. It is often possible to use
8749** a keyword as an identifier as long as such use does not result in a
8750** parsing ambiguity. For example, the statement
8751** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8752** creates a new table named "BEGIN" with three columns named
8753** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8754** using keywords as identifiers. Common techniques used to avoid keyword
8755** name collisions include:
8756** <ul>
8757** <li> Put all identifier names inside double-quotes. This is the official
8758** SQL way to escape identifier names.
8759** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8760** but it is what SQL Server does and so lots of programmers use this
8761** technique.
8762** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8763** with "Z".
8764** <li> Include a digit somewhere in every identifier name.
8765** </ul>
8766**
8767** Note that the number of keywords understood by SQLite can depend on
8768** compile-time options. For example, "VACUUM" is not a keyword if
8769** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8770** new keywords may be added to future releases of SQLite.
8771*/
8772SQLITE_API int sqlite3_keyword_count(void);
8773SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8774SQLITE_API int sqlite3_keyword_check(const char*,int);
8775
8776/*
8777** CAPI3REF: Dynamic String Object
8778** KEYWORDS: {dynamic string}
8779**
8780** An instance of the sqlite3_str object contains a dynamically-sized
8781** string under construction.
8782**
8783** The lifecycle of an sqlite3_str object is as follows:
8784** <ol>
8785** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8786** <li> ^Text is appended to the sqlite3_str object using various
8787** methods, such as [sqlite3_str_appendf()].
8788** <li> ^The sqlite3_str object is destroyed and the string it created
8789** is returned using the [sqlite3_str_finish()] interface.
8790** </ol>
8791*/
8792typedef struct sqlite3_str sqlite3_str;
8793
8794/*
8795** CAPI3REF: Create A New Dynamic String Object
8796** CONSTRUCTOR: sqlite3_str
8797**
8798** ^The [sqlite3_str_new(D)] interface allocates and initializes
8799** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8800** [sqlite3_str_new()] must be freed by a subsequent call to
8801** [sqlite3_str_finish(X)].
8802**
8803** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8804** valid [sqlite3_str] object, though in the event of an out-of-memory
8805** error the returned object might be a special singleton that will
8806** silently reject new text, always return SQLITE_NOMEM from
8807** [sqlite3_str_errcode()], always return 0 for
8808** [sqlite3_str_length()], and always return NULL from
8809** [sqlite3_str_finish(X)]. It is always safe to use the value
8810** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8811** to any of the other [sqlite3_str] methods.
8812**
8813** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8814** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8815** length of the string contained in the [sqlite3_str] object will be
8816** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8817** of [SQLITE_MAX_LENGTH].
8818*/
8819SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8820
8821/*
8822** CAPI3REF: Finalize A Dynamic String
8823** DESTRUCTOR: sqlite3_str
8824**
8825** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8826** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8827** that contains the constructed string. The calling application should
8828** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8829** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8830** errors were encountered during construction of the string. ^The
8831** [sqlite3_str_finish(X)] interface might also return a NULL pointer if the
8832** string in [sqlite3_str] object X is zero bytes long.
8833**
8834** ^The [sqlite3_str_free(X)] interface destroys both the sqlite3_str object
8835** X and the string content it contains. Calling sqlite3_str_free(X) is
8836** the equivalent of calling [sqlite3_free](sqlite3_str_finish(X)).
8837*/
8838SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8839SQLITE_API void sqlite3_str_free(sqlite3_str*);
8840
8841/*
8842** CAPI3REF: Add Content To A Dynamic String
8843** METHOD: sqlite3_str
8844**
8845** These interfaces add or remove content to an sqlite3_str object
8846** previously obtained from [sqlite3_str_new()].
8847**
8848** ^The [sqlite3_str_appendf(X,F,...)] and
8849** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8850** functionality of SQLite to append formatted text onto the end of
8851** [sqlite3_str] object X.
8852**
8853** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8854** onto the end of the [sqlite3_str] object X. N must be non-negative.
8855** S must contain at least N non-zero bytes of content. To append a
8856** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8857** method instead.
8858**
8859** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8860** zero-terminated string S onto the end of [sqlite3_str] object X.
8861**
8862** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8863** single-byte character C onto the end of [sqlite3_str] object X.
8864** ^This method can be used, for example, to add whitespace indentation.
8865**
8866** ^The [sqlite3_str_reset(X)] method resets the string under construction
8867** inside [sqlite3_str] object X back to zero bytes in length.
8868**
8869** ^The [sqlite3_str_truncate(X,N)] method changes the length of the string
8870** under construction to be N bytes or less. This routine is a no-op if
8871** N is negative or if the string is already N bytes or smaller in size.
8872**
8873** These methods do not return a result code. ^If an error occurs, that fact
8874** is recorded in the [sqlite3_str] object and can be recovered by a
8875** subsequent call to [sqlite3_str_errcode(X)].
8876*/
8877SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8878SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8879SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8880SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8881SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8882SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8883SQLITE_API void sqlite3_str_truncate(sqlite3_str*,int N);
8884
8885/*
8886** CAPI3REF: Status Of A Dynamic String
8887** METHOD: sqlite3_str
8888**
8889** These interfaces return the current status of an [sqlite3_str] object.
8890**
8891** ^If any prior errors have occurred while constructing the dynamic string
8892** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8893** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8894** [SQLITE_NOMEM] following any out-of-memory error, or
8895** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8896** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8897**
8898** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8899** of the dynamic string under construction in [sqlite3_str] object X.
8900** ^The length returned by [sqlite3_str_length(X)] does not include the
8901** zero-termination byte.
8902**
8903** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8904** content of the dynamic string under construction in X. The value
8905** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8906** and might be freed or altered by any subsequent method on the same
8907** [sqlite3_str] object. Applications must not use the pointer returned by
8908** [sqlite3_str_value(X)] after any subsequent method call on the same
8909** object. ^Applications may change the content of the string returned
8910** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8911** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8912** write any byte after any subsequent sqlite3_str method call.
8913*/
8914SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8915SQLITE_API int sqlite3_str_length(sqlite3_str*);
8916SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8917
8918/*
8919** CAPI3REF: SQLite Runtime Status
8920**
8921** ^These interfaces are used to retrieve runtime status information
8922** about the performance of SQLite, and optionally to reset various
8923** highwater marks. ^The first argument is an integer code for
8924** the specific parameter to measure. ^(Recognized integer codes
8925** are of the form [status parameters | SQLITE_STATUS_...].)^
8926** ^The current value of the parameter is returned into *pCurrent.
8927** ^The highest recorded value is returned in *pHighwater. ^If the
8928** resetFlag is true, then the highest record value is reset after
8929** *pHighwater is written. ^(Some parameters do not record the highest
8930** value. For those parameters
8931** nothing is written into *pHighwater and the resetFlag is ignored.)^
8932** ^(Other parameters record only the highwater mark and not the current
8933** value. For these latter parameters nothing is written into *pCurrent.)^
8934**
8935** ^The sqlite3_status() and sqlite3_status64() routines return
8936** SQLITE_OK on success and a non-zero [error code] on failure.
8937**
8938** If either the current value or the highwater mark is too large to
8939** be represented by a 32-bit integer, then the values returned by
8940** sqlite3_status() are undefined.
8941**
8942** See also: [sqlite3_db_status()]
8943*/
8944SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8945SQLITE_API int sqlite3_status64(
8946 int op,
8947 sqlite3_int64 *pCurrent,
8948 sqlite3_int64 *pHighwater,
8949 int resetFlag
8950);
8951
8952
8953/*
8954** CAPI3REF: Status Parameters
8955** KEYWORDS: {status parameters}
8956**
8957** These integer constants designate various run-time status parameters
8958** that can be returned by [sqlite3_status()].
8959**
8960** <dl>
8961** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8962** <dd>This parameter is the current amount of memory checked out
8963** using [sqlite3_malloc()], either directly or indirectly. The
8964** figure includes calls made to [sqlite3_malloc()] by the application
8965** and internal memory usage by the SQLite library. Auxiliary page-cache
8966** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8967** this parameter. The amount returned is the sum of the allocation
8968** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8969**
8970** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8971** <dd>This parameter records the largest memory allocation request
8972** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8973** internal equivalents). Only the value returned in the
8974** *pHighwater parameter to [sqlite3_status()] is of interest.
8975** The value written into the *pCurrent parameter is undefined.</dd>)^
8976**
8977** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8978** <dd>This parameter records the number of separate memory allocations
8979** currently checked out.</dd>)^
8980**
8981** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8982** <dd>This parameter returns the number of pages used out of the
8983** [pagecache memory allocator] that was configured using
8984** [SQLITE_CONFIG_PAGECACHE]. The
8985** value returned is in pages, not in bytes.</dd>)^
8986**
8987** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8988** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8989** <dd>This parameter returns the number of bytes of page cache
8990** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8991** buffer and where forced to overflow to [sqlite3_malloc()]. The
8992** returned value includes allocations that overflowed because they
8993** were too large (they were larger than the "sz" parameter to
8994** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8995** no space was left in the page cache.</dd>)^
8996**
8997** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8998** <dd>This parameter records the largest memory allocation request
8999** handed to the [pagecache memory allocator]. Only the value returned in the
9000** *pHighwater parameter to [sqlite3_status()] is of interest.
9001** The value written into the *pCurrent parameter is undefined.</dd>)^
9002**
9003** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
9004** <dd>No longer used.</dd>
9005**
9006** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
9007** <dd>No longer used.</dd>
9008**
9009** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
9010** <dd>No longer used.</dd>
9011**
9012** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
9013** <dd>The *pHighwater parameter records the deepest parser stack.
9014** The *pCurrent value is undefined. The *pHighwater value is only
9015** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
9016** </dl>
9017**
9018** New status parameters may be added from time to time.
9019*/
9020#define SQLITE_STATUS_MEMORY_USED 0
9021#define SQLITE_STATUS_PAGECACHE_USED 1
9022#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
9023#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
9024#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
9025#define SQLITE_STATUS_MALLOC_SIZE 5
9026#define SQLITE_STATUS_PARSER_STACK 6
9027#define SQLITE_STATUS_PAGECACHE_SIZE 7
9028#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
9029#define SQLITE_STATUS_MALLOC_COUNT 9
9030
9031/*
9032** CAPI3REF: Database Connection Status
9033** METHOD: sqlite3
9034**
9035** ^This interface is used to retrieve runtime status information
9036** about a single [database connection]. ^The first argument is the
9037** database connection object to be interrogated. ^The second argument
9038** is an integer constant, taken from the set of
9039** [SQLITE_DBSTATUS options], that
9040** determines the parameter to interrogate. The set of
9041** [SQLITE_DBSTATUS options] is likely
9042** to grow in future releases of SQLite.
9043**
9044** ^The current value of the requested parameter is written into *pCur
9045** and the highest instantaneous value is written into *pHiwtr. ^If
9046** the resetFlg is true, then the highest instantaneous value is
9047** reset back down to the current value.
9048**
9049** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
9050** non-zero [error code] on failure.
9051**
9052** ^The sqlite3_db_status64(D,O,C,H,R) routine works exactly the same
9053** way as sqlite3_db_status(D,O,C,H,R) routine except that the C and H
9054** parameters are pointer to 64-bit integers (type: sqlite3_int64) instead
9055** of pointers to 32-bit integers, which allows larger status values
9056** to be returned. If a status value exceeds 2,147,483,647 then
9057** sqlite3_db_status() will truncate the value whereas sqlite3_db_status64()
9058** will return the full value.
9059**
9060** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
9061*/
9062SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
9063SQLITE_API int sqlite3_db_status64(sqlite3*,int,sqlite3_int64*,sqlite3_int64*,int);
9064
9065/*
9066** CAPI3REF: Status Parameters for database connections
9067** KEYWORDS: {SQLITE_DBSTATUS options}
9068**
9069** These constants are the available integer "verbs" that can be passed as
9070** the second argument to the [sqlite3_db_status()] interface.
9071**
9072** New verbs may be added in future releases of SQLite. Existing verbs
9073** might be discontinued. Applications should check the return code from
9074** [sqlite3_db_status()] to make sure that the call worked.
9075** The [sqlite3_db_status()] interface will return a non-zero error code
9076** if a discontinued or unsupported verb is invoked.
9077**
9078** <dl>
9079** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
9080** <dd>This parameter returns the number of lookaside memory slots currently
9081** checked out.</dd>)^
9082**
9083** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
9084** <dd>This parameter returns the number of malloc attempts that were
9085** satisfied using lookaside memory. Only the high-water value is meaningful;
9086** the current value is always zero.</dd>)^
9087**
9088** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
9089** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
9090** <dd>This parameter returns the number of malloc attempts that might have
9091** been satisfied using lookaside memory but failed due to the amount of
9092** memory requested being larger than the lookaside slot size.
9093** Only the high-water value is meaningful;
9094** the current value is always zero.</dd>)^
9095**
9096** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
9097** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
9098** <dd>This parameter returns the number of malloc attempts that might have
9099** been satisfied using lookaside memory but failed due to all lookaside
9100** memory already being in use.
9101** Only the high-water value is meaningful;
9102** the current value is always zero.</dd>)^
9103**
9104** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
9105** <dd>This parameter returns the approximate number of bytes of heap
9106** memory used by all pager caches associated with the database connection.)^
9107** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
9108** </dd>
9109**
9110** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
9111** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
9112** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
9113** pager cache is shared between two or more connections the bytes of heap
9114** memory used by that pager cache is divided evenly between the attached
9115** connections.)^ In other words, if none of the pager caches associated
9116** with the database connection are shared, this request returns the same
9117** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
9118** shared, the value returned by this call will be smaller than that returned
9119** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
9120** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
9121**
9122** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
9123** <dd>This parameter returns the approximate number of bytes of heap
9124** memory used to store the schema for all databases associated
9125** with the connection - main, temp, and any [ATTACH]-ed databases.)^
9126** ^The full amount of memory used by the schemas is reported, even if the
9127** schema memory is shared with other database connections due to
9128** [shared cache mode] being enabled.
9129** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
9130** </dd>
9131**
9132** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
9133** <dd>This parameter returns the approximate number of bytes of heap
9134** and lookaside memory used by all prepared statements associated with
9135** the database connection.)^
9136** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
9137** </dd>
9138**
9139** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
9140** <dd>This parameter returns the number of pager cache hits that have
9141** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
9142** is always 0.
9143** </dd>
9144**
9145** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
9146** <dd>This parameter returns the number of pager cache misses that have
9147** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
9148** is always 0.
9149** </dd>
9150**
9151** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
9152** <dd>This parameter returns the number of dirty cache entries that have
9153** been written to disk. Specifically, the number of pages written to the
9154** wal file in wal mode databases, or the number of pages written to the
9155** database file in rollback mode databases. Any pages written as part of
9156** transaction rollback or database recovery operations are not included.
9157** If an IO or other error occurs while writing a page to disk, the effect
9158** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
9159** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
9160** <p>
9161** ^(There is overlap between the quantities measured by this parameter
9162** (SQLITE_DBSTATUS_CACHE_WRITE) and SQLITE_DBSTATUS_TEMPBUF_SPILL.
9163** Resetting one will reduce the other.)^
9164** </dd>
9165**
9166** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
9167** <dd>This parameter returns the number of dirty cache entries that have
9168** been written to disk in the middle of a transaction due to the page
9169** cache overflowing. Transactions are more efficient if they are written
9170** to disk all at once. When pages spill mid-transaction, that introduces
9171** additional overhead. This parameter can be used to help identify
9172** inefficiencies that can be resolved by increasing the cache size.
9173** </dd>
9174**
9175** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
9176** <dd>This parameter returns zero for the current value if and only if
9177** all foreign key constraints (deferred or immediate) have been
9178** resolved.)^ ^The highwater mark is always 0.
9179**
9180** [[SQLITE_DBSTATUS_TEMPBUF_SPILL] ^(<dt>SQLITE_DBSTATUS_TEMPBUF_SPILL</dt>
9181** <dd>^(This parameter returns the number of bytes written to temporary
9182** files on disk that could have been kept in memory had sufficient memory
9183** been available. This value includes writes to intermediate tables that
9184** are part of complex queries, external sorts that spill to disk, and
9185** writes to TEMP tables.)^
9186** ^The highwater mark is always 0.
9187** <p>
9188** ^(There is overlap between the quantities measured by this parameter
9189** (SQLITE_DBSTATUS_TEMPBUF_SPILL) and SQLITE_DBSTATUS_CACHE_WRITE.
9190** Resetting one will reduce the other.)^
9191** </dd>
9192** </dl>
9193*/
9194#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
9195#define SQLITE_DBSTATUS_CACHE_USED 1
9196#define SQLITE_DBSTATUS_SCHEMA_USED 2
9197#define SQLITE_DBSTATUS_STMT_USED 3
9198#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
9199#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
9200#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
9201#define SQLITE_DBSTATUS_CACHE_HIT 7
9202#define SQLITE_DBSTATUS_CACHE_MISS 8
9203#define SQLITE_DBSTATUS_CACHE_WRITE 9
9204#define SQLITE_DBSTATUS_DEFERRED_FKS 10
9205#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
9206#define SQLITE_DBSTATUS_CACHE_SPILL 12
9207#define SQLITE_DBSTATUS_TEMPBUF_SPILL 13
9208#define SQLITE_DBSTATUS_MAX 13 /* Largest defined DBSTATUS */
9209
9210
9211/*
9212** CAPI3REF: Prepared Statement Status
9213** METHOD: sqlite3_stmt
9214**
9215** ^(Each prepared statement maintains various
9216** [SQLITE_STMTSTATUS counters] that measure the number
9217** of times it has performed specific operations.)^ These counters can
9218** be used to monitor the performance characteristics of the prepared
9219** statements. For example, if the number of table steps greatly exceeds
9220** the number of table searches or result rows, that would tend to indicate
9221** that the prepared statement is using a full table scan rather than
9222** an index.
9223**
9224** ^(This interface is used to retrieve and reset counter values from
9225** a [prepared statement]. The first argument is the prepared statement
9226** object to be interrogated. The second argument
9227** is an integer code for a specific [SQLITE_STMTSTATUS counter]
9228** to be interrogated.)^
9229** ^The current value of the requested counter is returned.
9230** ^If the resetFlg is true, then the counter is reset to zero after this
9231** interface call returns.
9232**
9233** See also: [sqlite3_status()] and [sqlite3_db_status()].
9234*/
9235SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
9236
9237/*
9238** CAPI3REF: Status Parameters for prepared statements
9239** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
9240**
9241** These preprocessor macros define integer codes that name counter
9242** values associated with the [sqlite3_stmt_status()] interface.
9243** The meanings of the various counters are as follows:
9244**
9245** <dl>
9246** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
9247** <dd>^This is the number of times that SQLite has stepped forward in
9248** a table as part of a full table scan. Large numbers for this counter
9249** may indicate opportunities for performance improvement through
9250** careful use of indices.</dd>
9251**
9252** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
9253** <dd>^This is the number of sort operations that have occurred.
9254** A non-zero value in this counter may indicate an opportunity to
9255** improve performance through careful use of indices.</dd>
9256**
9257** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
9258** <dd>^This is the number of rows inserted into transient indices that
9259** were created automatically in order to help joins run faster.
9260** A non-zero value in this counter may indicate an opportunity to
9261** improve performance by adding permanent indices that do not
9262** need to be reinitialized each time the statement is run.</dd>
9263**
9264** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
9265** <dd>^This is the number of virtual machine operations executed
9266** by the prepared statement if that number is less than or equal
9267** to 2147483647. The number of virtual machine operations can be
9268** used as a proxy for the total work done by the prepared statement.
9269** If the number of virtual machine operations exceeds 2147483647
9270** then the value returned by this statement status code is undefined.</dd>
9271**
9272** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
9273** <dd>^This is the number of times that the prepare statement has been
9274** automatically regenerated due to schema changes or changes to
9275** [bound parameters] that might affect the query plan.</dd>
9276**
9277** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
9278** <dd>^This is the number of times that the prepared statement has
9279** been run. A single "run" for the purposes of this counter is one
9280** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
9281** The counter is incremented on the first [sqlite3_step()] call of each
9282** cycle.</dd>
9283**
9284** [[SQLITE_STMTSTATUS_FILTER_MISS]]
9285** [[SQLITE_STMTSTATUS_FILTER HIT]]
9286** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
9287** SQLITE_STMTSTATUS_FILTER_MISS</dt>
9288** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
9289** step was bypassed because a Bloom filter returned not-found. The
9290** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
9291** times that the Bloom filter returned a find, and thus the join step
9292** had to be processed as normal.</dd>
9293**
9294** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
9295** <dd>^This is the approximate number of bytes of heap memory
9296** used to store the prepared statement. ^This value is not actually
9297** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
9298** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
9299** </dd>
9300** </dl>
9301*/
9302#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
9303#define SQLITE_STMTSTATUS_SORT 2
9304#define SQLITE_STMTSTATUS_AUTOINDEX 3
9305#define SQLITE_STMTSTATUS_VM_STEP 4
9306#define SQLITE_STMTSTATUS_REPREPARE 5
9307#define SQLITE_STMTSTATUS_RUN 6
9308#define SQLITE_STMTSTATUS_FILTER_MISS 7
9309#define SQLITE_STMTSTATUS_FILTER_HIT 8
9310#define SQLITE_STMTSTATUS_MEMUSED 99
9311
9312/*
9313** CAPI3REF: Custom Page Cache Object
9314**
9315** The sqlite3_pcache type is opaque. It is implemented by
9316** the pluggable module. The SQLite core has no knowledge of
9317** its size or internal structure and never deals with the
9318** sqlite3_pcache object except by holding and passing pointers
9319** to the object.
9320**
9321** See [sqlite3_pcache_methods2] for additional information.
9322*/
9323typedef struct sqlite3_pcache sqlite3_pcache;
9324
9325/*
9326** CAPI3REF: Custom Page Cache Object
9327**
9328** The sqlite3_pcache_page object represents a single page in the
9329** page cache. The page cache will allocate instances of this
9330** object. Various methods of the page cache use pointers to instances
9331** of this object as parameters or as their return value.
9332**
9333** See [sqlite3_pcache_methods2] for additional information.
9334*/
9335typedef struct sqlite3_pcache_page sqlite3_pcache_page;
9336struct sqlite3_pcache_page {
9337 void *pBuf; /* The content of the page */
9338 void *pExtra; /* Extra information associated with the page */
9339};
9340
9341/*
9342** CAPI3REF: Application Defined Page Cache.
9343** KEYWORDS: {page cache}
9344**
9345** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
9346** register an alternative page cache implementation by passing in an
9347** instance of the sqlite3_pcache_methods2 structure.)^
9348** In many applications, most of the heap memory allocated by
9349** SQLite is used for the page cache.
9350** By implementing a
9351** custom page cache using this API, an application can better control
9352** the amount of memory consumed by SQLite, the way in which
9353** that memory is allocated and released, and the policies used to
9354** determine exactly which parts of a database file are cached and for
9355** how long.
9356**
9357** The alternative page cache mechanism is an
9358** extreme measure that is only needed by the most demanding applications.
9359** The built-in page cache is recommended for most uses.
9360**
9361** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
9362** internal buffer by SQLite within the call to [sqlite3_config]. Hence
9363** the application may discard the parameter after the call to
9364** [sqlite3_config()] returns.)^
9365**
9366** [[the xInit() page cache method]]
9367** ^(The xInit() method is called once for each effective
9368** call to [sqlite3_initialize()])^
9369** (usually only once during the lifetime of the process). ^(The xInit()
9370** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
9371** The intent of the xInit() method is to set up global data structures
9372** required by the custom page cache implementation.
9373** ^(If the xInit() method is NULL, then the
9374** built-in default page cache is used instead of the application defined
9375** page cache.)^
9376**
9377** [[the xShutdown() page cache method]]
9378** ^The xShutdown() method is called by [sqlite3_shutdown()].
9379** It can be used to clean up
9380** any outstanding resources before process shutdown, if required.
9381** ^The xShutdown() method may be NULL.
9382**
9383** ^SQLite automatically serializes calls to the xInit method,
9384** so the xInit method need not be threadsafe. ^The
9385** xShutdown method is only called from [sqlite3_shutdown()] so it does
9386** not need to be threadsafe either. All other methods must be threadsafe
9387** in multithreaded applications.
9388**
9389** ^SQLite will never invoke xInit() more than once without an intervening
9390** call to xShutdown().
9391**
9392** [[the xCreate() page cache methods]]
9393** ^SQLite invokes the xCreate() method to construct a new cache instance.
9394** SQLite will typically create one cache instance for each open database file,
9395** though this is not guaranteed. ^The
9396** first parameter, szPage, is the size in bytes of the pages that must
9397** be allocated by the cache. ^szPage will always be a power of two. ^The
9398** second parameter szExtra is a number of bytes of extra storage
9399** associated with each page cache entry. ^The szExtra parameter will be
9400** a number less than 250. SQLite will use the
9401** extra szExtra bytes on each page to store metadata about the underlying
9402** database page on disk. The value passed into szExtra depends
9403** on the SQLite version, the target platform, and how SQLite was compiled.
9404** ^The third argument to xCreate(), bPurgeable, is true if the cache being
9405** created will be used to cache database pages of a file stored on disk, or
9406** false if it is used for an in-memory database. The cache implementation
9407** does not have to do anything special based upon the value of bPurgeable;
9408** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9409** never invoke xUnpin() except to deliberately delete a page.
9410** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9411** false will always have the "discard" flag set to true.
9412** ^Hence, a cache created with bPurgeable set to false will
9413** never contain any unpinned pages.
9414**
9415** [[the xCachesize() page cache method]]
9416** ^(The xCachesize() method may be called at any time by SQLite to set the
9417** suggested maximum cache-size (number of pages stored) for the cache
9418** instance passed as the first argument. This is the value configured using
9419** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9420** parameter, the implementation is not required to do anything with this
9421** value; it is advisory only.
9422**
9423** [[the xPagecount() page cache methods]]
9424** The xPagecount() method must return the number of pages currently
9425** stored in the cache, both pinned and unpinned.
9426**
9427** [[the xFetch() page cache methods]]
9428** The xFetch() method locates a page in the cache and returns a pointer to
9429** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9430** The pBuf element of the returned sqlite3_pcache_page object will be a
9431** pointer to a buffer of szPage bytes used to store the content of a
9432** single database page. The pExtra element of sqlite3_pcache_page will be
9433** a pointer to the szExtra bytes of extra storage that SQLite has requested
9434** for each entry in the page cache.
9435**
9436** The page to be fetched is determined by the key. ^The minimum key value
9437** is 1. After it has been retrieved using xFetch, the page is considered
9438** to be "pinned".
9439**
9440** If the requested page is already in the page cache, then the page cache
9441** implementation must return a pointer to the page buffer with its content
9442** intact. If the requested page is not already in the cache, then the
9443** cache implementation should use the value of the createFlag
9444** parameter to help it determine what action to take:
9445**
9446** <table border=1 width=85% align=center>
9447** <tr><th> createFlag <th> Behavior when page is not already in cache
9448** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9449** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so.
9450** Otherwise return NULL.
9451** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9452** NULL if allocating a new page is effectively impossible.
9453** </table>
9454**
9455** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9456** will only use a createFlag of 2 after a prior call with a createFlag of 1
9457** failed.)^ In between the xFetch() calls, SQLite may
9458** attempt to unpin one or more cache pages by spilling the content of
9459** pinned pages to disk and synching the operating system disk cache.
9460**
9461** [[the xUnpin() page cache method]]
9462** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9463** as its second argument. If the third parameter, discard, is non-zero,
9464** then the page must be evicted from the cache.
9465** ^If the discard parameter is
9466** zero, then the page may be discarded or retained at the discretion of the
9467** page cache implementation. ^The page cache implementation
9468** may choose to evict unpinned pages at any time.
9469**
9470** The cache must not perform any reference counting. A single
9471** call to xUnpin() unpins the page regardless of the number of prior calls
9472** to xFetch().
9473**
9474** [[the xRekey() page cache methods]]
9475** The xRekey() method is used to change the key value associated with the
9476** page passed as the second argument. If the cache
9477** previously contains an entry associated with newKey, it must be
9478** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9479** to be pinned.
9480**
9481** When SQLite calls the xTruncate() method, the cache must discard all
9482** existing cache entries with page numbers (keys) greater than or equal
9483** to the value of the iLimit parameter passed to xTruncate(). If any
9484** of these pages are pinned, they become implicitly unpinned, meaning that
9485** they can be safely discarded.
9486**
9487** [[the xDestroy() page cache method]]
9488** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9489** All resources associated with the specified cache should be freed. ^After
9490** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9491** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9492** functions.
9493**
9494** [[the xShrink() page cache method]]
9495** ^SQLite invokes the xShrink() method when it wants the page cache to
9496** free up as much of heap memory as possible. The page cache implementation
9497** is not obligated to free any memory, but well-behaved implementations should
9498** do their best.
9499*/
9500typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9501struct sqlite3_pcache_methods2 {
9502 int iVersion;
9503 void *pArg;
9504 int (*xInit)(void*);
9505 void (*xShutdown)(void*);
9506 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9507 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9508 int (*xPagecount)(sqlite3_pcache*);
9509 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9510 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9511 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9512 unsigned oldKey, unsigned newKey);
9513 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9514 void (*xDestroy)(sqlite3_pcache*);
9515 void (*xShrink)(sqlite3_pcache*);
9516};
9517
9518/*
9519** This is the obsolete pcache_methods object that has now been replaced
9520** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9521** retained in the header file for backwards compatibility only.
9522*/
9523typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9524struct sqlite3_pcache_methods {
9525 void *pArg;
9526 int (*xInit)(void*);
9527 void (*xShutdown)(void*);
9528 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9529 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9530 int (*xPagecount)(sqlite3_pcache*);
9531 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9532 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9533 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9534 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9535 void (*xDestroy)(sqlite3_pcache*);
9536};
9537
9538
9539/*
9540** CAPI3REF: Online Backup Object
9541**
9542** The sqlite3_backup object records state information about an ongoing
9543** online backup operation. ^The sqlite3_backup object is created by
9544** a call to [sqlite3_backup_init()] and is destroyed by a call to
9545** [sqlite3_backup_finish()].
9546**
9547** See Also: [Using the SQLite Online Backup API]
9548*/
9549typedef struct sqlite3_backup sqlite3_backup;
9550
9551/*
9552** CAPI3REF: Online Backup API.
9553**
9554** The backup API copies the content of one database into another.
9555** It is useful either for creating backups of databases or
9556** for copying in-memory databases to or from persistent files.
9557**
9558** See Also: [Using the SQLite Online Backup API]
9559**
9560** ^SQLite holds a write transaction open on the destination database file
9561** for the duration of the backup operation.
9562** ^The source database is read-locked only while it is being read;
9563** it is not locked continuously for the entire backup operation.
9564** ^Thus, the backup may be performed on a live source database without
9565** preventing other database connections from
9566** reading or writing to the source database while the backup is underway.
9567**
9568** ^(To perform a backup operation:
9569** <ol>
9570** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9571** backup,
9572** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9573** the data between the two databases, and finally
9574** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9575** associated with the backup operation.
9576** </ol>)^
9577** There should be exactly one call to sqlite3_backup_finish() for each
9578** successful call to sqlite3_backup_init().
9579**
9580** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9581**
9582** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9583** [database connection] associated with the destination database
9584** and the database name, respectively.
9585** ^The database name is "main" for the main database, "temp" for the
9586** temporary database, or the name specified after the AS keyword in
9587** an [ATTACH] statement for an attached database.
9588** ^The S and M arguments passed to
9589** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9590** and database name of the source database, respectively.
9591** ^The source and destination [database connections] (parameters S and D)
9592** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9593** an error.
9594**
9595** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9596** there is already a read or read-write transaction open on the
9597** destination database.
9598**
9599** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9600** returned and an error code and error message are stored in the
9601** destination [database connection] D.
9602** ^The error code and message for the failed call to sqlite3_backup_init()
9603** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9604** [sqlite3_errmsg16()] functions.
9605** ^A successful call to sqlite3_backup_init() returns a pointer to an
9606** [sqlite3_backup] object.
9607** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9608** sqlite3_backup_finish() functions to perform the specified backup
9609** operation.
9610**
9611** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9612**
9613** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9614** the source and destination databases specified by [sqlite3_backup] object B.
9615** ^If N is negative, all remaining source pages are copied.
9616** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9617** are still more pages to be copied, then the function returns [SQLITE_OK].
9618** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9619** from source to destination, then it returns [SQLITE_DONE].
9620** ^If an error occurs while running sqlite3_backup_step(B,N),
9621** then an [error code] is returned. ^As well as [SQLITE_OK] and
9622** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9623** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9624** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9625**
9626** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9627** <ol>
9628** <li> the destination database was opened read-only, or
9629** <li> the destination database is using write-ahead-log journaling
9630** and the destination and source page sizes differ, or
9631** <li> the destination database is an in-memory database and the
9632** destination and source page sizes differ.
9633** </ol>)^
9634**
9635** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9636** the [sqlite3_busy_handler | busy-handler function]
9637** is invoked (if one is specified). ^If the
9638** busy-handler returns non-zero before the lock is available, then
9639** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9640** sqlite3_backup_step() can be retried later. ^If the source
9641** [database connection]
9642** is being used to write to the source database when sqlite3_backup_step()
9643** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9644** case the call to sqlite3_backup_step() can be retried later on. ^(If
9645** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9646** [SQLITE_READONLY] is returned, then
9647** there is no point in retrying the call to sqlite3_backup_step(). These
9648** errors are considered fatal.)^ The application must accept
9649** that the backup operation has failed and pass the backup operation handle
9650** to the sqlite3_backup_finish() to release associated resources.
9651**
9652** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9653** on the destination file. ^The exclusive lock is not released until either
9654** sqlite3_backup_finish() is called or the backup operation is complete
9655** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9656** sqlite3_backup_step() obtains a [shared lock] on the source database that
9657** lasts for the duration of the sqlite3_backup_step() call.
9658** ^Because the source database is not locked between calls to
9659** sqlite3_backup_step(), the source database may be modified mid-way
9660** through the backup process. ^If the source database is modified by an
9661** external process or via a database connection other than the one being
9662** used by the backup operation, then the backup will be automatically
9663** restarted by the next call to sqlite3_backup_step(). ^If the source
9664** database is modified by using the same database connection as is used
9665** by the backup operation, then the backup database is automatically
9666** updated at the same time.
9667**
9668** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9669**
9670** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9671** application wishes to abandon the backup operation, the application
9672** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9673** ^The sqlite3_backup_finish() interfaces releases all
9674** resources associated with the [sqlite3_backup] object.
9675** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9676** active write-transaction on the destination database is rolled back.
9677** The [sqlite3_backup] object is invalid
9678** and may not be used following a call to sqlite3_backup_finish().
9679**
9680** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9681** sqlite3_backup_step() errors occurred, regardless of whether or not
9682** sqlite3_backup_step() completed.
9683** ^If an out-of-memory condition or IO error occurred during any prior
9684** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9685** sqlite3_backup_finish() returns the corresponding [error code].
9686**
9687** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9688** is not a permanent error and does not affect the return value of
9689** sqlite3_backup_finish().
9690**
9691** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9692** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9693**
9694** ^The sqlite3_backup_remaining() routine returns the number of pages still
9695** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9696** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9697** in the source database at the conclusion of the most recent
9698** sqlite3_backup_step().
9699** ^(The values returned by these functions are only updated by
9700** sqlite3_backup_step(). If the source database is modified in a way that
9701** changes the size of the source database or the number of pages remaining,
9702** those changes are not reflected in the output of sqlite3_backup_pagecount()
9703** and sqlite3_backup_remaining() until after the next
9704** sqlite3_backup_step().)^
9705**
9706** <b>Concurrent Usage of Database Handles</b>
9707**
9708** ^The source [database connection] may be used by the application for other
9709** purposes while a backup operation is underway or being initialized.
9710** ^If SQLite is compiled and configured to support threadsafe database
9711** connections, then the source database connection may be used concurrently
9712** from within other threads.
9713**
9714** However, the application must guarantee that the destination
9715** [database connection] is not passed to any other API (by any thread) after
9716** sqlite3_backup_init() is called and before the corresponding call to
9717** sqlite3_backup_finish(). SQLite does not currently check to see
9718** if the application incorrectly accesses the destination [database connection]
9719** and so no error code is reported, but the operations may malfunction
9720** nevertheless. Use of the destination database connection while a
9721** backup is in progress might also cause a mutex deadlock.
9722**
9723** If running in [shared cache mode], the application must
9724** guarantee that the shared cache used by the destination database
9725** is not accessed while the backup is running. In practice this means
9726** that the application must guarantee that the disk file being
9727** backed up to is not accessed by any connection within the process,
9728** not just the specific connection that was passed to sqlite3_backup_init().
9729**
9730** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9731** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9732** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9733** APIs are not strictly speaking threadsafe. If they are invoked at the
9734** same time as another thread is invoking sqlite3_backup_step() it is
9735** possible that they return invalid values.
9736**
9737** <b>Alternatives To Using The Backup API</b>
9738**
9739** Other techniques for safely creating a consistent backup of an SQLite
9740** database include:
9741**
9742** <ul>
9743** <li> The [VACUUM INTO] command.
9744** <li> The [sqlite3_rsync] utility program.
9745** </ul>
9746*/
9747SQLITE_API sqlite3_backup *sqlite3_backup_init(
9748 sqlite3 *pDest, /* Destination database handle */
9749 const char *zDestName, /* Destination database name */
9750 sqlite3 *pSource, /* Source database handle */
9751 const char *zSourceName /* Source database name */
9752);
9753SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9754SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9755SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9756SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9757
9758/*
9759** CAPI3REF: Unlock Notification
9760** METHOD: sqlite3
9761**
9762** ^When running in shared-cache mode, a database operation may fail with
9763** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9764** individual tables within the shared-cache cannot be obtained. See
9765** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9766** ^This API may be used to register a callback that SQLite will invoke
9767** when the connection currently holding the required lock relinquishes it.
9768** ^This API is only available if the library was compiled with the
9769** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9770**
9771** See Also: [Using the SQLite Unlock Notification Feature].
9772**
9773** ^Shared-cache locks are released when a database connection concludes
9774** its current transaction, either by committing it or rolling it back.
9775**
9776** ^When a connection (known as the blocked connection) fails to obtain a
9777** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9778** identity of the database connection (the blocking connection) that
9779** has locked the required resource is stored internally. ^After an
9780** application receives an SQLITE_LOCKED error, it may call the
9781** sqlite3_unlock_notify() method with the blocked connection handle as
9782** the first argument to register for a callback that will be invoked
9783** when the blocking connection's current transaction is concluded. ^The
9784** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9785** call that concludes the blocking connection's transaction.
9786**
9787** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9788** there is a chance that the blocking connection will have already
9789** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9790** If this happens, then the specified callback is invoked immediately,
9791** from within the call to sqlite3_unlock_notify().)^
9792**
9793** ^If the blocked connection is attempting to obtain a write-lock on a
9794** shared-cache table, and more than one other connection currently holds
9795** a read-lock on the same table, then SQLite arbitrarily selects one of
9796** the other connections to use as the blocking connection.
9797**
9798** ^(There may be at most one unlock-notify callback registered by a
9799** blocked connection. If sqlite3_unlock_notify() is called when the
9800** blocked connection already has a registered unlock-notify callback,
9801** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9802** called with a NULL pointer as its second argument, then any existing
9803** unlock-notify callback is canceled. ^The blocked connection's
9804** unlock-notify callback may also be canceled by closing the blocked
9805** connection using [sqlite3_close()].
9806**
9807** The unlock-notify callback is not reentrant. If an application invokes
9808** any sqlite3_xxx API functions from within an unlock-notify callback, a
9809** crash or deadlock may be the result.
9810**
9811** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9812** returns SQLITE_OK.
9813**
9814** <b>Callback Invocation Details</b>
9815**
9816** When an unlock-notify callback is registered, the application provides a
9817** single void* pointer that is passed to the callback when it is invoked.
9818** However, the signature of the callback function allows SQLite to pass
9819** it an array of void* context pointers. The first argument passed to
9820** an unlock-notify callback is a pointer to an array of void* pointers,
9821** and the second is the number of entries in the array.
9822**
9823** When a blocking connection's transaction is concluded, there may be
9824** more than one blocked connection that has registered for an unlock-notify
9825** callback. ^If two or more such blocked connections have specified the
9826** same callback function, then instead of invoking the callback function
9827** multiple times, it is invoked once with the set of void* context pointers
9828** specified by the blocked connections bundled together into an array.
9829** This gives the application an opportunity to prioritize any actions
9830** related to the set of unblocked database connections.
9831**
9832** <b>Deadlock Detection</b>
9833**
9834** Assuming that after registering for an unlock-notify callback a
9835** database waits for the callback to be issued before taking any further
9836** action (a reasonable assumption), then using this API may cause the
9837** application to deadlock. For example, if connection X is waiting for
9838** connection Y's transaction to be concluded, and similarly connection
9839** Y is waiting on connection X's transaction, then neither connection
9840** will proceed and the system may remain deadlocked indefinitely.
9841**
9842** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9843** detection. ^If a given call to sqlite3_unlock_notify() would put the
9844** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9845** unlock-notify callback is registered. The system is said to be in
9846** a deadlocked state if connection A has registered for an unlock-notify
9847** callback on the conclusion of connection B's transaction, and connection
9848** B has itself registered for an unlock-notify callback when connection
9849** A's transaction is concluded. ^Indirect deadlock is also detected, so
9850** the system is also considered to be deadlocked if connection B has
9851** registered for an unlock-notify callback on the conclusion of connection
9852** C's transaction, where connection C is waiting on connection A. ^Any
9853** number of levels of indirection are allowed.
9854**
9855** <b>The "DROP TABLE" Exception</b>
9856**
9857** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9858** always appropriate to call sqlite3_unlock_notify(). There is however,
9859** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9860** SQLite checks if there are any currently executing SELECT statements
9861** that belong to the same connection. If there are, SQLITE_LOCKED is
9862** returned. In this case there is no "blocking connection", so invoking
9863** sqlite3_unlock_notify() results in the unlock-notify callback being
9864** invoked immediately. If the application then re-attempts the "DROP TABLE"
9865** or "DROP INDEX" query, an infinite loop might be the result.
9866**
9867** One way around this problem is to check the extended error code returned
9868** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9869** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9870** the special "DROP TABLE/INDEX" case, the extended error code is just
9871** SQLITE_LOCKED.)^
9872*/
9873SQLITE_API int sqlite3_unlock_notify(
9874 sqlite3 *pBlocked, /* Waiting connection */
9875 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9876 void *pNotifyArg /* Argument to pass to xNotify */
9877);
9878
9879
9880/*
9881** CAPI3REF: String Comparison
9882**
9883** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9884** and extensions to compare the contents of two buffers containing UTF-8
9885** strings in a case-independent fashion, using the same definition of "case
9886** independence" that SQLite uses internally when comparing identifiers.
9887*/
9888SQLITE_API int sqlite3_stricmp(const char *, const char *);
9889SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9890
9891/*
9892** CAPI3REF: String Globbing
9893*
9894** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9895** string X matches the [GLOB] pattern P.
9896** ^The definition of [GLOB] pattern matching used in
9897** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9898** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9899** is case sensitive.
9900**
9901** Note that this routine returns zero on a match and non-zero if the strings
9902** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9903**
9904** See also: [sqlite3_strlike()].
9905*/
9906SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9907
9908/*
9909** CAPI3REF: String LIKE Matching
9910*
9911** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9912** string X matches the [LIKE] pattern P with escape character E.
9913** ^The definition of [LIKE] pattern matching used in
9914** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9915** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9916** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9917** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9918** insensitive - equivalent upper and lower case ASCII characters match
9919** one another.
9920**
9921** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9922** only ASCII characters are case folded.
9923**
9924** Note that this routine returns zero on a match and non-zero if the strings
9925** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9926**
9927** See also: [sqlite3_strglob()].
9928*/
9929SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9930
9931/*
9932** CAPI3REF: Error Logging Interface
9933**
9934** ^The [sqlite3_log()] interface writes a message into the [error log]
9935** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9936** ^If logging is enabled, the zFormat string and subsequent arguments are
9937** used with [sqlite3_snprintf()] to generate the final output string.
9938**
9939** The sqlite3_log() interface is intended for use by extensions such as
9940** virtual tables, collating functions, and SQL functions. While there is
9941** nothing to prevent an application from calling sqlite3_log(), doing so
9942** is considered bad form.
9943**
9944** The zFormat string must not be NULL.
9945**
9946** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9947** will not use dynamically allocated memory. The log message is stored in
9948** a fixed-length buffer on the stack. If the log message is longer than
9949** a few hundred characters, it will be truncated to the length of the
9950** buffer.
9951*/
9952SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9953
9954/*
9955** CAPI3REF: Write-Ahead Log Commit Hook
9956** METHOD: sqlite3
9957**
9958** ^The [sqlite3_wal_hook()] function is used to register a callback that
9959** is invoked each time data is committed to a database in wal mode.
9960**
9961** ^(The callback is invoked by SQLite after the commit has taken place and
9962** the associated write-lock on the database released)^, so the implementation
9963** may read, write or [checkpoint] the database as required.
9964**
9965** ^The first parameter passed to the callback function when it is invoked
9966** is a copy of the third parameter passed to sqlite3_wal_hook() when
9967** registering the callback. ^The second is a copy of the database handle.
9968** ^The third parameter is the name of the database that was written to -
9969** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9970** is the number of pages currently in the write-ahead log file,
9971** including those that were just committed.
9972**
9973** ^The callback function should normally return [SQLITE_OK]. ^If an error
9974** code is returned, that error will propagate back up through the
9975** SQLite code base to cause the statement that provoked the callback
9976** to report an error, though the commit will have still occurred. If the
9977** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9978** that does not correspond to any valid SQLite error code, the results
9979** are undefined.
9980**
9981** ^A single database handle may have at most a single write-ahead log
9982** callback registered at one time. ^Calling [sqlite3_wal_hook()]
9983** replaces the default behavior or previously registered write-ahead
9984** log callback.
9985**
9986** ^The return value is a copy of the third parameter from the
9987** previous call, if any, or 0.
9988**
9989** ^The [sqlite3_wal_autocheckpoint()] interface and the
9990** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and
9991** will overwrite any prior [sqlite3_wal_hook()] settings.
9992**
9993** ^If a write-ahead log callback is set using this function then
9994** [sqlite3_wal_checkpoint_v2()] or [PRAGMA wal_checkpoint]
9995** should be invoked periodically to keep the write-ahead log file
9996** from growing without bound.
9997**
9998** ^Passing a NULL pointer for the callback disables automatic
9999** checkpointing entirely. To re-enable the default behavior, call
10000** sqlite3_wal_autocheckpoint(db,1000) or use [PRAGMA wal_checkpoint].
10001*/
10002SQLITE_API void *sqlite3_wal_hook(
10003 sqlite3*,
10004 int(*)(void *,sqlite3*,const char*,int),
10005 void*
10006);
10007
10008/*
10009** CAPI3REF: Configure an auto-checkpoint
10010** METHOD: sqlite3
10011**
10012** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
10013** [sqlite3_wal_hook()] that causes any database on [database connection] D
10014** to automatically [checkpoint]
10015** after committing a transaction if there are N or
10016** more frames in the [write-ahead log] file. ^Passing zero or
10017** a negative value as the N parameter disables automatic
10018** checkpoints entirely.
10019**
10020** ^The callback registered by this function replaces any existing callback
10021** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
10022** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
10023** configured by this function.
10024**
10025** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
10026** from SQL.
10027**
10028** ^Checkpoints initiated by this mechanism are
10029** [sqlite3_wal_checkpoint_v2|PASSIVE].
10030**
10031** ^Every new [database connection] defaults to having the auto-checkpoint
10032** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
10033** pages.
10034**
10035** ^The use of this interface is only necessary if the default setting
10036** is found to be suboptimal for a particular application.
10037*/
10038SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
10039
10040/*
10041** CAPI3REF: Checkpoint a database
10042** METHOD: sqlite3
10043**
10044** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
10045** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
10046**
10047** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
10048** [write-ahead log] for database X on [database connection] D to be
10049** transferred into the database file and for the write-ahead log to
10050** be reset. See the [checkpointing] documentation for addition
10051** information.
10052**
10053** This interface used to be the only way to cause a checkpoint to
10054** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
10055** interface was added. This interface is retained for backwards
10056** compatibility and as a convenience for applications that need to manually
10057** start a callback but which do not need the full power (and corresponding
10058** complication) of [sqlite3_wal_checkpoint_v2()].
10059*/
10060SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
10061
10062/*
10063** CAPI3REF: Checkpoint a database
10064** METHOD: sqlite3
10065**
10066** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
10067** operation on database X of [database connection] D in mode M. Status
10068** information is written back into integers pointed to by L and C.)^
10069** ^(The M parameter must be a valid [checkpoint mode]:)^
10070**
10071** <dl>
10072** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
10073** ^Checkpoint as many frames as possible without waiting for any database
10074** readers or writers to finish, then sync the database file if all frames
10075** in the log were checkpointed. ^The [busy-handler callback]
10076** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
10077** ^On the other hand, passive mode might leave the checkpoint unfinished
10078** if there are concurrent readers or writers.
10079**
10080** <dt>SQLITE_CHECKPOINT_FULL<dd>
10081** ^This mode blocks (it invokes the
10082** [sqlite3_busy_handler|busy-handler callback]) until there is no
10083** database writer and all readers are reading from the most recent database
10084** snapshot. ^It then checkpoints all frames in the log file and syncs the
10085** database file. ^This mode blocks new database writers while it is pending,
10086** but new database readers are allowed to continue unimpeded.
10087**
10088** <dt>SQLITE_CHECKPOINT_RESTART<dd>
10089** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
10090** that after checkpointing the log file it blocks (calls the
10091** [busy-handler callback])
10092** until all readers are reading from the database file only. ^This ensures
10093** that the next writer will restart the log file from the beginning.
10094** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
10095** database writer attempts while it is pending, but does not impede readers.
10096**
10097** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
10098** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
10099** addition that it also truncates the log file to zero bytes just prior
10100** to a successful return.
10101**
10102** <dt>SQLITE_CHECKPOINT_NOOP<dd>
10103** ^This mode always checkpoints zero frames. The only reason to invoke
10104** a NOOP checkpoint is to access the values returned by
10105** sqlite3_wal_checkpoint_v2() via output parameters *pnLog and *pnCkpt.
10106** </dl>
10107**
10108** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
10109** the log file or to -1 if the checkpoint could not run because
10110** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
10111** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
10112** log file (including any that were already checkpointed before the function
10113** was called) or to -1 if the checkpoint could not run due to an error or
10114** because the database is not in WAL mode. ^Note that upon successful
10115** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
10116** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
10117**
10118** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
10119** any other process is running a checkpoint operation at the same time, the
10120** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
10121** busy-handler configured, it will not be invoked in this case.
10122**
10123** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
10124** exclusive "writer" lock on the database file. ^If the writer lock cannot be
10125** obtained immediately, and a busy-handler is configured, it is invoked and
10126** the writer lock retried until either the busy-handler returns 0 or the lock
10127** is successfully obtained. ^The busy-handler is also invoked while waiting for
10128** database readers as described above. ^If the busy-handler returns 0 before
10129** the writer lock is obtained or while waiting for database readers, the
10130** checkpoint operation proceeds from that point in the same way as
10131** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
10132** without blocking any further. ^SQLITE_BUSY is returned in this case.
10133**
10134** ^If parameter zDb is NULL or points to a zero length string, then the
10135** specified operation is attempted on all WAL databases [attached] to
10136** [database connection] db. In this case the
10137** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
10138** an SQLITE_BUSY error is encountered when processing one or more of the
10139** attached WAL databases, the operation is still attempted on any remaining
10140** attached databases and SQLITE_BUSY is returned at the end. ^If any other
10141** error occurs while processing an attached database, processing is abandoned
10142** and the error code is returned to the caller immediately. ^If no error
10143** (SQLITE_BUSY or otherwise) is encountered while processing the attached
10144** databases, SQLITE_OK is returned.
10145**
10146** ^If database zDb is the name of an attached database that is not in WAL
10147** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
10148** zDb is not NULL (or a zero length string) and is not the name of any
10149** attached database, SQLITE_ERROR is returned to the caller.
10150**
10151** ^Unless it returns SQLITE_MISUSE,
10152** the sqlite3_wal_checkpoint_v2() interface
10153** sets the error information that is queried by
10154** [sqlite3_errcode()] and [sqlite3_errmsg()].
10155**
10156** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
10157** from SQL.
10158*/
10159SQLITE_API int sqlite3_wal_checkpoint_v2(
10160 sqlite3 *db, /* Database handle */
10161 const char *zDb, /* Name of attached database (or NULL) */
10162 int eMode, /* SQLITE_CHECKPOINT_* value */
10163 int *pnLog, /* OUT: Size of WAL log in frames */
10164 int *pnCkpt /* OUT: Total number of frames checkpointed */
10165);
10166
10167/*
10168** CAPI3REF: Checkpoint Mode Values
10169** KEYWORDS: {checkpoint mode}
10170**
10171** These constants define all valid values for the "checkpoint mode" passed
10172** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
10173** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
10174** meaning of each of these checkpoint modes.
10175*/
10176#define SQLITE_CHECKPOINT_NOOP -1 /* Do no work at all */
10177#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
10178#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
10179#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
10180#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
10181
10182/*
10183** CAPI3REF: Virtual Table Interface Configuration
10184**
10185** This function may be called by either the [xConnect] or [xCreate] method
10186** of a [virtual table] implementation to configure
10187** various facets of the virtual table interface.
10188**
10189** If this interface is invoked outside the context of an xConnect or
10190** xCreate virtual table method then the behavior is undefined.
10191**
10192** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
10193** [database connection] in which the virtual table is being created and
10194** which is passed in as the first argument to the [xConnect] or [xCreate]
10195** method that is invoking sqlite3_vtab_config(). The C parameter is one
10196** of the [virtual table configuration options]. The presence and meaning
10197** of parameters after C depend on which [virtual table configuration option]
10198** is used.
10199*/
10200SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
10201
10202/*
10203** CAPI3REF: Virtual Table Configuration Options
10204** KEYWORDS: {virtual table configuration options}
10205** KEYWORDS: {virtual table configuration option}
10206**
10207** These macros define the various options to the
10208** [sqlite3_vtab_config()] interface that [virtual table] implementations
10209** can use to customize and optimize their behavior.
10210**
10211** <dl>
10212** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
10213** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
10214** <dd>Calls of the form
10215** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
10216** where X is an integer. If X is zero, then the [virtual table] whose
10217** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
10218** support constraints. In this configuration (which is the default) if
10219** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
10220** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
10221** specified as part of the user's SQL statement, regardless of the actual
10222** ON CONFLICT mode specified.
10223**
10224** If X is non-zero, then the virtual table implementation guarantees
10225** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
10226** any modifications to internal or persistent data structures have been made.
10227** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
10228** is able to roll back a statement or database transaction, and abandon
10229** or continue processing the current SQL statement as appropriate.
10230** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
10231** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
10232** had been ABORT.
10233**
10234** Virtual table implementations that are required to handle OR REPLACE
10235** must do so within the [xUpdate] method. If a call to the
10236** [sqlite3_vtab_on_conflict()] function indicates that the current ON
10237** CONFLICT policy is REPLACE, the virtual table implementation should
10238** silently replace the appropriate rows within the xUpdate callback and
10239** return SQLITE_OK. Or, if this is not possible, it may return
10240** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
10241** constraint handling.
10242** </dd>
10243**
10244** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
10245** <dd>Calls of the form
10246** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
10247** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10248** prohibits that virtual table from being used from within triggers and
10249** views.
10250** </dd>
10251**
10252** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
10253** <dd>Calls of the form
10254** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
10255** [xConnect] or [xCreate] methods of a [virtual table] implementation
10256** identify that virtual table as being safe to use from within triggers
10257** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
10258** virtual table can do no serious harm even if it is controlled by a
10259** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
10260** flag unless absolutely necessary.
10261** </dd>
10262**
10263** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
10264** <dd>Calls of the form
10265** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
10266** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10267** instruct the query planner to begin at least a read transaction on
10268** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
10269** virtual table is used.
10270** </dd>
10271** </dl>
10272*/
10273#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
10274#define SQLITE_VTAB_INNOCUOUS 2
10275#define SQLITE_VTAB_DIRECTONLY 3
10276#define SQLITE_VTAB_USES_ALL_SCHEMAS 4
10277
10278/*
10279** CAPI3REF: Determine The Virtual Table Conflict Policy
10280**
10281** This function may only be called from within a call to the [xUpdate] method
10282** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
10283** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
10284** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
10285** of the SQL statement that triggered the call to the [xUpdate] method of the
10286** [virtual table].
10287*/
10288SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
10289
10290/*
10291** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
10292**
10293** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
10294** method of a [virtual table], then it might return true if the
10295** column is being fetched as part of an UPDATE operation during which the
10296** column value will not change. The virtual table implementation can use
10297** this hint as permission to substitute a return value that is less
10298** expensive to compute and that the corresponding
10299** [xUpdate] method understands as a "no-change" value.
10300**
10301** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
10302** the column is not changed by the UPDATE statement, then the xColumn
10303** method can optionally return without setting a result, without calling
10304** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
10305** In that case, [sqlite3_value_nochange(X)] will return true for the
10306** same column in the [xUpdate] method.
10307**
10308** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
10309** implementations should continue to give a correct answer even if the
10310** sqlite3_vtab_nochange() interface were to always return false. In the
10311** current implementation, the sqlite3_vtab_nochange() interface does always
10312** returns false for the enhanced [UPDATE FROM] statement.
10313*/
10314SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
10315
10316/*
10317** CAPI3REF: Determine The Collation For a Virtual Table Constraint
10318** METHOD: sqlite3_index_info
10319**
10320** This function may only be called from within a call to the [xBestIndex]
10321** method of a [virtual table]. This function returns a pointer to a string
10322** that is the name of the appropriate collation sequence to use for text
10323** comparisons on the constraint identified by its arguments.
10324**
10325** The first argument must be the pointer to the [sqlite3_index_info] object
10326** that is the first parameter to the xBestIndex() method. The second argument
10327** must be an index into the aConstraint[] array belonging to the
10328** sqlite3_index_info structure passed to xBestIndex.
10329**
10330** Important:
10331** The first parameter must be the same pointer that is passed into the
10332** xBestMethod() method. The first parameter may not be a pointer to a
10333** different [sqlite3_index_info] object, even an exact copy.
10334**
10335** The return value is computed as follows:
10336**
10337** <ol>
10338** <li><p> If the constraint comes from a WHERE clause expression that contains
10339** a [COLLATE operator], then the name of the collation specified by
10340** that COLLATE operator is returned.
10341** <li><p> If there is no COLLATE operator, but the column that is the subject
10342** of the constraint specifies an alternative collating sequence via
10343** a [COLLATE clause] on the column definition within the CREATE TABLE
10344** statement that was passed into [sqlite3_declare_vtab()], then the
10345** name of that alternative collating sequence is returned.
10346** <li><p> Otherwise, "BINARY" is returned.
10347** </ol>
10348*/
10349SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
10350
10351/*
10352** CAPI3REF: Determine if a virtual table query is DISTINCT
10353** METHOD: sqlite3_index_info
10354**
10355** This API may only be used from within an [xBestIndex|xBestIndex method]
10356** of a [virtual table] implementation. The result of calling this
10357** interface from outside of xBestIndex() is undefined and probably harmful.
10358**
10359** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
10360** 3. The integer returned by sqlite3_vtab_distinct()
10361** gives the virtual table additional information about how the query
10362** planner wants the output to be ordered. As long as the virtual table
10363** can meet the ordering requirements of the query planner, it may set
10364** the "orderByConsumed" flag.
10365**
10366** <ol><li value="0"><p>
10367** ^If the sqlite3_vtab_distinct() interface returns 0, that means
10368** that the query planner needs the virtual table to return all rows in the
10369** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
10370** [sqlite3_index_info] object. This is the default expectation. If the
10371** virtual table outputs all rows in sorted order, then it is always safe for
10372** the xBestIndex method to set the "orderByConsumed" flag, regardless of
10373** the return value from sqlite3_vtab_distinct().
10374** <li value="1"><p>
10375** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
10376** that the query planner does not need the rows to be returned in sorted order
10377** as long as all rows with the same values in all columns identified by the
10378** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
10379** is doing a GROUP BY.
10380** <li value="2"><p>
10381** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
10382** that the query planner does not need the rows returned in any particular
10383** order, as long as rows with the same values in all columns identified
10384** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
10385** contain the same values for all columns identified by "colUsed", all but
10386** one such row may optionally be omitted from the result.)^
10387** The virtual table is not required to omit rows that are duplicates
10388** over the "colUsed" columns, but if the virtual table can do that without
10389** too much extra effort, it could potentially help the query to run faster.
10390** This mode is used for a DISTINCT query.
10391** <li value="3"><p>
10392** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
10393** virtual table must return rows in the order defined by "aOrderBy" as
10394** if the sqlite3_vtab_distinct() interface had returned 0. However if
10395** two or more rows in the result have the same values for all columns
10396** identified by "colUsed", then all but one such row may optionally be
10397** omitted.)^ Like when the return value is 2, the virtual table
10398** is not required to omit rows that are duplicates over the "colUsed"
10399** columns, but if the virtual table can do that without
10400** too much extra effort, it could potentially help the query to run faster.
10401** This mode is used for queries
10402** that have both DISTINCT and ORDER BY clauses.
10403** </ol>
10404**
10405** <p>The following table summarizes the conditions under which the
10406** virtual table is allowed to set the "orderByConsumed" flag based on
10407** the value returned by sqlite3_vtab_distinct(). This table is a
10408** restatement of the previous four paragraphs:
10409**
10410** <table border=1 cellspacing=0 cellpadding=10 width="90%">
10411** <tr>
10412** <td valign="top">sqlite3_vtab_distinct() return value
10413** <td valign="top">Rows are returned in aOrderBy order
10414** <td valign="top">Rows with the same value in all aOrderBy columns are
10415** adjacent
10416** <td valign="top">Duplicates over all colUsed columns may be omitted
10417** <tr><td>0<td>yes<td>yes<td>no
10418** <tr><td>1<td>no<td>yes<td>no
10419** <tr><td>2<td>no<td>yes<td>yes
10420** <tr><td>3<td>yes<td>yes<td>yes
10421** </table>
10422**
10423** ^For the purposes of comparing virtual table output values to see if the
10424** values are the same value for sorting purposes, two NULL values are
10425** considered to be the same. In other words, the comparison operator is "IS"
10426** (or "IS NOT DISTINCT FROM") and not "==".
10427**
10428** If a virtual table implementation is unable to meet the requirements
10429** specified above, then it must not set the "orderByConsumed" flag in the
10430** [sqlite3_index_info] object or an incorrect answer may result.
10431**
10432** ^A virtual table implementation is always free to return rows in any order
10433** it wants, as long as the "orderByConsumed" flag is not set. ^When the
10434** "orderByConsumed" flag is unset, the query planner will add extra
10435** [bytecode] to ensure that the final results returned by the SQL query are
10436** ordered correctly. The use of the "orderByConsumed" flag and the
10437** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
10438** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10439** flag might help queries against a virtual table to run faster. Being
10440** overly aggressive and setting the "orderByConsumed" flag when it is not
10441** valid to do so, on the other hand, might cause SQLite to return incorrect
10442** results.
10443*/
10444SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10445
10446/*
10447** CAPI3REF: Identify and handle IN constraints in xBestIndex
10448**
10449** This interface may only be used from within an
10450** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10451** The result of invoking this interface from any other context is
10452** undefined and probably harmful.
10453**
10454** ^(A constraint on a virtual table of the form
10455** "[IN operator|column IN (...)]" is
10456** communicated to the xBestIndex method as a
10457** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10458** this constraint, it must set the corresponding
10459** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10460** the usual mode of handling IN operators, SQLite generates [bytecode]
10461** that invokes the [xFilter|xFilter() method] once for each value
10462** on the right-hand side of the IN operator.)^ Thus the virtual table
10463** only sees a single value from the right-hand side of the IN operator
10464** at a time.
10465**
10466** In some cases, however, it would be advantageous for the virtual
10467** table to see all values on the right-hand of the IN operator all at
10468** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10469**
10470** <ol>
10471** <li><p>
10472** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10473** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10474** is an [IN operator] that can be processed all at once. ^In other words,
10475** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10476** by which the virtual table can ask SQLite if all-at-once processing
10477** of the IN operator is even possible.
10478**
10479** <li><p>
10480** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10481** to SQLite that the virtual table does or does not want to process
10482** the IN operator all-at-once, respectively. ^Thus when the third
10483** parameter (F) is non-negative, this interface is the mechanism by
10484** which the virtual table tells SQLite how it wants to process the
10485** IN operator.
10486** </ol>
10487**
10488** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10489** within the same xBestIndex method call. ^For any given P,N pair,
10490** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10491** within the same xBestIndex call. ^If the interface returns true
10492** (non-zero), that means that the constraint is an IN operator
10493** that can be processed all-at-once. ^If the constraint is not an IN
10494** operator or cannot be processed all-at-once, then the interface returns
10495** false.
10496**
10497** ^(All-at-once processing of the IN operator is selected if both of the
10498** following conditions are met:
10499**
10500** <ol>
10501** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10502** integer. This is how the virtual table tells SQLite that it wants to
10503** use the N-th constraint.
10504**
10505** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10506** non-negative had F>=1.
10507** </ol>)^
10508**
10509** ^If either or both of the conditions above are false, then SQLite uses
10510** the traditional one-at-a-time processing strategy for the IN constraint.
10511** ^If both conditions are true, then the argvIndex-th parameter to the
10512** xFilter method will be an [sqlite3_value] that appears to be NULL,
10513** but which can be passed to [sqlite3_vtab_in_first()] and
10514** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10515** of the IN constraint.
10516*/
10517SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10518
10519/*
10520** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10521**
10522** These interfaces are only useful from within the
10523** [xFilter|xFilter() method] of a [virtual table] implementation.
10524** The result of invoking these interfaces from any other context
10525** is undefined and probably harmful.
10526**
10527** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10528** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10529** xFilter method which invokes these routines, and specifically
10530** a parameter that was previously selected for all-at-once IN constraint
10531** processing using the [sqlite3_vtab_in()] interface in the
10532** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10533** an xFilter argument that was selected for all-at-once IN constraint
10534** processing, then these routines return [SQLITE_ERROR].)^
10535**
10536** ^(Use these routines to access all values on the right-hand side
10537** of the IN constraint using code like the following:
10538**
10539** <blockquote><pre>
10540** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
10541** &nbsp; rc==SQLITE_OK && pVal;
10542** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
10543** &nbsp; ){
10544** &nbsp; // do something with pVal
10545** &nbsp; }
10546** &nbsp; if( rc!=SQLITE_DONE ){
10547** &nbsp; // an error has occurred
10548** &nbsp; }
10549** </pre></blockquote>)^
10550**
10551** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10552** routines return SQLITE_OK and set *P to point to the first or next value
10553** on the RHS of the IN constraint. ^If there are no more values on the
10554** right hand side of the IN constraint, then *P is set to NULL and these
10555** routines return [SQLITE_DONE]. ^The return value might be
10556** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10557**
10558** The *ppOut values returned by these routines are only valid until the
10559** next call to either of these routines or until the end of the xFilter
10560** method from which these routines were called. If the virtual table
10561** implementation needs to retain the *ppOut values for longer, it must make
10562** copies. The *ppOut values are [protected sqlite3_value|protected].
10563*/
10564SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10565SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10566
10567/*
10568** CAPI3REF: Constraint values in xBestIndex()
10569** METHOD: sqlite3_index_info
10570**
10571** This API may only be used from within the [xBestIndex|xBestIndex method]
10572** of a [virtual table] implementation. The result of calling this interface
10573** from outside of an xBestIndex method are undefined and probably harmful.
10574**
10575** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10576** the [xBestIndex] method of a [virtual table] implementation, with P being
10577** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10578** J being a 0-based index into P->aConstraint[], then this routine
10579** attempts to set *V to the value of the right-hand operand of
10580** that constraint if the right-hand operand is known. ^If the
10581** right-hand operand is not known, then *V is set to a NULL pointer.
10582** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10583** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10584** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10585** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10586** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if
10587** something goes wrong.
10588**
10589** The sqlite3_vtab_rhs_value() interface is usually only successful if
10590** the right-hand operand of a constraint is a literal value in the original
10591** SQL statement. If the right-hand operand is an expression or a reference
10592** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10593** will probably return [SQLITE_NOTFOUND].
10594**
10595** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10596** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10597** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10598**
10599** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10600** and remains valid for the duration of the xBestIndex method call.
10601** ^When xBestIndex returns, the sqlite3_value object returned by
10602** sqlite3_vtab_rhs_value() is automatically deallocated.
10603**
10604** The "_rhs_" in the name of this routine is an abbreviation for
10605** "Right-Hand Side".
10606*/
10607SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10608
10609/*
10610** CAPI3REF: Conflict resolution modes
10611** KEYWORDS: {conflict resolution mode}
10612**
10613** These constants are returned by [sqlite3_vtab_on_conflict()] to
10614** inform a [virtual table] implementation of the [ON CONFLICT] mode
10615** for the SQL statement being evaluated.
10616**
10617** Note that the [SQLITE_IGNORE] constant is also used as a potential
10618** return value from the [sqlite3_set_authorizer()] callback and that
10619** [SQLITE_ABORT] is also a [result code].
10620*/
10621#define SQLITE_ROLLBACK 1
10622/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10623#define SQLITE_FAIL 3
10624/* #define SQLITE_ABORT 4 // Also an error code */
10625#define SQLITE_REPLACE 5
10626
10627/*
10628** CAPI3REF: Prepared Statement Scan Status Opcodes
10629** KEYWORDS: {scanstatus options}
10630**
10631** The following constants can be used for the T parameter to the
10632** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10633** different metric for sqlite3_stmt_scanstatus() to return.
10634**
10635** When the value returned to V is a string, space to hold that string is
10636** managed by the prepared statement S and will be automatically freed when
10637** S is finalized.
10638**
10639** Not all values are available for all query elements. When a value is
10640** not available, the output variable is set to -1 if the value is numeric,
10641** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10642**
10643** <dl>
10644** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10645** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10646** set to the total number of times that the X-th loop has run.</dd>
10647**
10648** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10649** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10650** to the total number of rows examined by all iterations of the X-th loop.</dd>
10651**
10652** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10653** <dd>^The "double" variable pointed to by the V parameter will be set to the
10654** query planner's estimate for the average number of rows output from each
10655** iteration of the X-th loop. If the query planner's estimate was accurate,
10656** then this value will approximate the quotient NVISIT/NLOOP and the
10657** product of this value for all prior loops with the same SELECTID will
10658** be the NLOOP value for the current loop.</dd>
10659**
10660** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10661** <dd>^The "const char *" variable pointed to by the V parameter will be set
10662** to a zero-terminated UTF-8 string containing the name of the index or table
10663** used for the X-th loop.</dd>
10664**
10665** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10666** <dd>^The "const char *" variable pointed to by the V parameter will be set
10667** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10668** description for the X-th loop.</dd>
10669**
10670** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10671** <dd>^The "int" variable pointed to by the V parameter will be set to the
10672** id for the X-th query plan element. The id value is unique within the
10673** statement. The select-id is the same value as is output in the first
10674** column of an [EXPLAIN QUERY PLAN] query.</dd>
10675**
10676** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10677** <dd>The "int" variable pointed to by the V parameter will be set to the
10678** id of the parent of the current query element, if applicable, or
10679** to zero if the query element has no parent. This is the same value as
10680** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd>
10681**
10682** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10683** <dd>The sqlite3_int64 output value is set to the number of cycles,
10684** according to the processor time-stamp counter, that elapsed while the
10685** query element was being processed. This value is not available for
10686** all query elements - if it is unavailable the output variable is
10687** set to -1.</dd>
10688** </dl>
10689*/
10690#define SQLITE_SCANSTAT_NLOOP 0
10691#define SQLITE_SCANSTAT_NVISIT 1
10692#define SQLITE_SCANSTAT_EST 2
10693#define SQLITE_SCANSTAT_NAME 3
10694#define SQLITE_SCANSTAT_EXPLAIN 4
10695#define SQLITE_SCANSTAT_SELECTID 5
10696#define SQLITE_SCANSTAT_PARENTID 6
10697#define SQLITE_SCANSTAT_NCYCLE 7
10698
10699/*
10700** CAPI3REF: Prepared Statement Scan Status
10701** METHOD: sqlite3_stmt
10702**
10703** These interfaces return information about the predicted and measured
10704** performance for pStmt. Advanced applications can use this
10705** interface to compare the predicted and the measured performance and
10706** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10707**
10708** Since this interface is expected to be rarely used, it is only
10709** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10710** compile-time option.
10711**
10712** The "iScanStatusOp" parameter determines which status information to return.
10713** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10714** of this interface is undefined. ^The requested measurement is written into
10715** a variable pointed to by the "pOut" parameter.
10716**
10717** The "flags" parameter must be passed a mask of flags. At present only
10718** one flag is defined - [SQLITE_SCANSTAT_COMPLEX]. If SQLITE_SCANSTAT_COMPLEX
10719** is specified, then status information is available for all elements
10720** of a query plan that are reported by "[EXPLAIN QUERY PLAN]" output. If
10721** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10722** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10723** the EXPLAIN QUERY PLAN output) are available. Invoking API
10724** sqlite3_stmt_scanstatus() is equivalent to calling
10725** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10726**
10727** Parameter "idx" identifies the specific query element to retrieve statistics
10728** for. Query elements are numbered starting from zero. A value of -1 may
10729** retrieve statistics for the entire query. ^If idx is out of range
10730** - less than -1 or greater than or equal to the total number of query
10731** elements used to implement the statement - a non-zero value is returned and
10732** the variable that pOut points to is unchanged.
10733**
10734** See also: [sqlite3_stmt_scanstatus_reset()] and the
10735** [nexec and ncycle] columns of the [bytecode virtual table].
10736*/
10737SQLITE_API int sqlite3_stmt_scanstatus(
10738 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10739 int idx, /* Index of loop to report on */
10740 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10741 void *pOut /* Result written here */
10742);
10743SQLITE_API int sqlite3_stmt_scanstatus_v2(
10744 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10745 int idx, /* Index of loop to report on */
10746 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10747 int flags, /* Mask of flags defined below */
10748 void *pOut /* Result written here */
10749);
10750
10751/*
10752** CAPI3REF: Prepared Statement Scan Status
10753** KEYWORDS: {scan status flags}
10754*/
10755#define SQLITE_SCANSTAT_COMPLEX 0x0001
10756
10757/*
10758** CAPI3REF: Zero Scan-Status Counters
10759** METHOD: sqlite3_stmt
10760**
10761** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10762**
10763** This API is only available if the library is built with pre-processor
10764** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10765*/
10766SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10767
10768/*
10769** CAPI3REF: Flush caches to disk mid-transaction
10770** METHOD: sqlite3
10771**
10772** ^If a write-transaction is open on [database connection] D when the
10773** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
10774** pages in the pager-cache that are not currently in use are written out
10775** to disk. A dirty page may be in use if a database cursor created by an
10776** active SQL statement is reading from it, or if it is page 1 of a database
10777** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10778** interface flushes caches for all schemas - "main", "temp", and
10779** any [attached] databases.
10780**
10781** ^If this function needs to obtain extra database locks before dirty pages
10782** can be flushed to disk, it does so. ^If those locks cannot be obtained
10783** immediately and there is a busy-handler callback configured, it is invoked
10784** in the usual manner. ^If the required lock still cannot be obtained, then
10785** the database is skipped and an attempt made to flush any dirty pages
10786** belonging to the next (if any) database. ^If any databases are skipped
10787** because locks cannot be obtained, but no other error occurs, this
10788** function returns SQLITE_BUSY.
10789**
10790** ^If any other error occurs while flushing dirty pages to disk (for
10791** example an IO error or out-of-memory condition), then processing is
10792** abandoned and an SQLite [error code] is returned to the caller immediately.
10793**
10794** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10795**
10796** ^This function does not set the database handle error code or message
10797** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10798*/
10799SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10800
10801/*
10802** CAPI3REF: The pre-update hook.
10803** METHOD: sqlite3
10804**
10805** ^These interfaces are only available if SQLite is compiled using the
10806** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10807**
10808** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10809** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10810** on a database table.
10811** ^At most one preupdate hook may be registered at a time on a single
10812** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10813** the previous setting.
10814** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10815** with a NULL pointer as the second parameter.
10816** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10817** the first parameter to callbacks.
10818**
10819** ^The preupdate hook only fires for changes to real database tables; the
10820** preupdate hook is not invoked for changes to [virtual tables] or to
10821** system tables like sqlite_sequence or sqlite_stat1.
10822**
10823** ^The second parameter to the preupdate callback is a pointer to
10824** the [database connection] that registered the preupdate hook.
10825** ^The third parameter to the preupdate callback is one of the constants
10826** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10827** kind of update operation that is about to occur.
10828** ^(The fourth parameter to the preupdate callback is the name of the
10829** database within the database connection that is being modified. This
10830** will be "main" for the main database or "temp" for TEMP tables or
10831** the name given after the AS keyword in the [ATTACH] statement for attached
10832** databases.)^
10833** ^The fifth parameter to the preupdate callback is the name of the
10834** table that is being modified.
10835**
10836** For an UPDATE or DELETE operation on a [rowid table], the sixth
10837** parameter passed to the preupdate callback is the initial [rowid] of the
10838** row being modified or deleted. For an INSERT operation on a rowid table,
10839** or any operation on a WITHOUT ROWID table, the value of the sixth
10840** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10841** seventh parameter is the final rowid value of the row being inserted
10842** or updated. The value of the seventh parameter passed to the callback
10843** function is not defined for operations on WITHOUT ROWID tables, or for
10844** DELETE operations on rowid tables.
10845**
10846** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10847** the previous call on the same [database connection] D, or NULL for
10848** the first call on D.
10849**
10850** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10851** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10852** provide additional information about a preupdate event. These routines
10853** may only be called from within a preupdate callback. Invoking any of
10854** these routines from outside of a preupdate callback or with a
10855** [database connection] pointer that is different from the one supplied
10856** to the preupdate callback results in undefined and probably undesirable
10857** behavior.
10858**
10859** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10860** in the row that is being inserted, updated, or deleted.
10861**
10862** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10863** a [protected sqlite3_value] that contains the value of the Nth column of
10864** the table row before it is updated. The N parameter must be between 0
10865** and one less than the number of columns or the behavior will be
10866** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10867** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10868** behavior is undefined. The [sqlite3_value] that P points to
10869** will be destroyed when the preupdate callback returns.
10870**
10871** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10872** a [protected sqlite3_value] that contains the value of the Nth column of
10873** the table row after it is updated. The N parameter must be between 0
10874** and one less than the number of columns or the behavior will be
10875** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10876** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10877** behavior is undefined. The [sqlite3_value] that P points to
10878** will be destroyed when the preupdate callback returns.
10879**
10880** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10881** callback was invoked as a result of a direct insert, update, or delete
10882** operation; or 1 for inserts, updates, or deletes invoked by top-level
10883** triggers; or 2 for changes resulting from triggers called by top-level
10884** triggers; and so forth.
10885**
10886** When the [sqlite3_blob_write()] API is used to update a blob column,
10887** the pre-update hook is invoked with SQLITE_DELETE, because
10888** the new values are not yet available. In this case, when a
10889** callback made with op==SQLITE_DELETE is actually a write using the
10890** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10891** the index of the column being written. In other cases, where the
10892** pre-update hook is being invoked for some other reason, including a
10893** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10894**
10895** See also: [sqlite3_update_hook()]
10896*/
10897#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10898SQLITE_API void *sqlite3_preupdate_hook(
10899 sqlite3 *db,
10900 void(*xPreUpdate)(
10901 void *pCtx, /* Copy of third arg to preupdate_hook() */
10902 sqlite3 *db, /* Database handle */
10903 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10904 char const *zDb, /* Database name */
10905 char const *zName, /* Table name */
10906 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10907 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10908 ),
10909 void*
10910);
10911SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10912SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10913SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10914SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10915SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10916#endif
10917
10918/*
10919** CAPI3REF: Low-level system error code
10920** METHOD: sqlite3
10921**
10922** ^Attempt to return the underlying operating system error code or error
10923** number that caused the most recent I/O error or failure to open a file.
10924** The return value is OS-dependent. For example, on unix systems, after
10925** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10926** called to get back the underlying "errno" that caused the problem, such
10927** as ENOSPC, EAUTH, EISDIR, and so forth.
10928*/
10929SQLITE_API int sqlite3_system_errno(sqlite3*);
10930
10931/*
10932** CAPI3REF: Database Snapshot
10933** KEYWORDS: {snapshot} {sqlite3_snapshot}
10934**
10935** An instance of the snapshot object records the state of a [WAL mode]
10936** database for some specific point in history.
10937**
10938** In [WAL mode], multiple [database connections] that are open on the
10939** same database file can each be reading a different historical version
10940** of the database file. When a [database connection] begins a read
10941** transaction, that connection sees an unchanging copy of the database
10942** as it existed for the point in time when the transaction first started.
10943** Subsequent changes to the database from other connections are not seen
10944** by the reader until a new read transaction is started.
10945**
10946** The sqlite3_snapshot object records state information about an historical
10947** version of the database file so that it is possible to later open a new read
10948** transaction that sees that historical version of the database rather than
10949** the most recent version.
10950*/
10951typedef struct sqlite3_snapshot {
10952 unsigned char hidden[48];
10953} sqlite3_snapshot;
10954
10955/*
10956** CAPI3REF: Record A Database Snapshot
10957** CONSTRUCTOR: sqlite3_snapshot
10958**
10959** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10960** new [sqlite3_snapshot] object that records the current state of
10961** schema S in database connection D. ^On success, the
10962** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10963** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10964** If there is not already a read-transaction open on schema S when
10965** this function is called, one is opened automatically.
10966**
10967** If a read-transaction is opened by this function, then it is guaranteed
10968** that the returned snapshot object may not be invalidated by a database
10969** writer or checkpointer until after the read-transaction is closed. This
10970** is not guaranteed if a read-transaction is already open when this
10971** function is called. In that case, any subsequent write or checkpoint
10972** operation on the database may invalidate the returned snapshot handle,
10973** even while the read-transaction remains open.
10974**
10975** The following must be true for this function to succeed. If any of
10976** the following statements are false when sqlite3_snapshot_get() is
10977** called, SQLITE_ERROR is returned. The final value of *P is undefined
10978** in this case.
10979**
10980** <ul>
10981** <li> The database handle must not be in [autocommit mode].
10982**
10983** <li> Schema S of [database connection] D must be a [WAL mode] database.
10984**
10985** <li> There must not be a write transaction open on schema S of database
10986** connection D.
10987**
10988** <li> One or more transactions must have been written to the current wal
10989** file since it was created on disk (by any connection). This means
10990** that a snapshot cannot be taken on a wal mode database with no wal
10991** file immediately after it is first opened. At least one transaction
10992** must be written to it first.
10993** </ul>
10994**
10995** This function may also return SQLITE_NOMEM. If it is called with the
10996** database handle in autocommit mode but fails for some other reason,
10997** whether or not a read transaction is opened on schema S is undefined.
10998**
10999** The [sqlite3_snapshot] object returned from a successful call to
11000** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
11001** to avoid a memory leak.
11002**
11003** The [sqlite3_snapshot_get()] interface is only available when the
11004** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
11005*/
11006SQLITE_API int sqlite3_snapshot_get(
11007 sqlite3 *db,
11008 const char *zSchema,
11009 sqlite3_snapshot **ppSnapshot
11010);
11011
11012/*
11013** CAPI3REF: Start a read transaction on an historical snapshot
11014** METHOD: sqlite3_snapshot
11015**
11016** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
11017** transaction or upgrades an existing one for schema S of
11018** [database connection] D such that the read transaction refers to
11019** historical [snapshot] P, rather than the most recent change to the
11020** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
11021** on success or an appropriate [error code] if it fails.
11022**
11023** ^In order to succeed, the database connection must not be in
11024** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
11025** is already a read transaction open on schema S, then the database handle
11026** must have no active statements (SELECT statements that have been passed
11027** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
11028** SQLITE_ERROR is returned if either of these conditions is violated, or
11029** if schema S does not exist, or if the snapshot object is invalid.
11030**
11031** ^A call to sqlite3_snapshot_open() will fail to open if the specified
11032** snapshot has been overwritten by a [checkpoint]. In this case
11033** SQLITE_ERROR_SNAPSHOT is returned.
11034**
11035** If there is already a read transaction open when this function is
11036** invoked, then the same read transaction remains open (on the same
11037** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
11038** is returned. If another error code - for example SQLITE_PROTOCOL or an
11039** SQLITE_IOERR error code - is returned, then the final state of the
11040** read transaction is undefined. If SQLITE_OK is returned, then the
11041** read transaction is now open on database snapshot P.
11042**
11043** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
11044** database connection D does not know that the database file for
11045** schema S is in [WAL mode]. A database connection might not know
11046** that the database file is in [WAL mode] if there has been no prior
11047** I/O on that database connection, or if the database entered [WAL mode]
11048** after the most recent I/O on the database connection.)^
11049** (Hint: Run "[PRAGMA application_id]" against a newly opened
11050** database connection in order to make it ready to use snapshots.)
11051**
11052** The [sqlite3_snapshot_open()] interface is only available when the
11053** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
11054*/
11055SQLITE_API int sqlite3_snapshot_open(
11056 sqlite3 *db,
11057 const char *zSchema,
11058 sqlite3_snapshot *pSnapshot
11059);
11060
11061/*
11062** CAPI3REF: Destroy a snapshot
11063** DESTRUCTOR: sqlite3_snapshot
11064**
11065** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
11066** The application must eventually free every [sqlite3_snapshot] object
11067** using this routine to avoid a memory leak.
11068**
11069** The [sqlite3_snapshot_free()] interface is only available when the
11070** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
11071*/
11072SQLITE_API void sqlite3_snapshot_free(sqlite3_snapshot*);
11073
11074/*
11075** CAPI3REF: Compare the ages of two snapshot handles.
11076** METHOD: sqlite3_snapshot
11077**
11078** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
11079** of two valid snapshot handles.
11080**
11081** If the two snapshot handles are not associated with the same database
11082** file, the result of the comparison is undefined.
11083**
11084** Additionally, the result of the comparison is only valid if both of the
11085** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
11086** last time the wal file was deleted. The wal file is deleted when the
11087** database is changed back to rollback mode or when the number of database
11088** clients drops to zero. If either snapshot handle was obtained before the
11089** wal file was last deleted, the value returned by this function
11090** is undefined.
11091**
11092** Otherwise, this API returns a negative value if P1 refers to an older
11093** snapshot than P2, zero if the two handles refer to the same database
11094** snapshot, and a positive value if P1 is a newer snapshot than P2.
11095**
11096** This interface is only available if SQLite is compiled with the
11097** [SQLITE_ENABLE_SNAPSHOT] option.
11098*/
11099SQLITE_API int sqlite3_snapshot_cmp(
11100 sqlite3_snapshot *p1,
11101 sqlite3_snapshot *p2
11102);
11103
11104/*
11105** CAPI3REF: Recover snapshots from a wal file
11106** METHOD: sqlite3_snapshot
11107**
11108** If a [WAL file] remains on disk after all database connections close
11109** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
11110** or because the last process to have the database opened exited without
11111** calling [sqlite3_close()]) and a new connection is subsequently opened
11112** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
11113** will only be able to open the last transaction added to the WAL file
11114** even though the WAL file contains other valid transactions.
11115**
11116** This function attempts to scan the WAL file associated with database zDb
11117** of database handle db and make all valid snapshots available to
11118** sqlite3_snapshot_open(). It is an error if there is already a read
11119** transaction open on the database, or if the database is not a WAL mode
11120** database.
11121**
11122** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
11123**
11124** This interface is only available if SQLite is compiled with the
11125** [SQLITE_ENABLE_SNAPSHOT] option.
11126*/
11127SQLITE_API int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
11128
11129/*
11130** CAPI3REF: Serialize a database
11131**
11132** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
11133** memory that is a serialization of the S database on
11134** [database connection] D. If S is a NULL pointer, the main database is used.
11135** If P is not a NULL pointer, then the size of the database in bytes
11136** is written into *P.
11137**
11138** For an ordinary on-disk database file, the serialization is just a
11139** copy of the disk file. For an in-memory database or a "TEMP" database,
11140** the serialization is the same sequence of bytes which would be written
11141** to disk if that database were backed up to disk.
11142**
11143** The usual case is that sqlite3_serialize() copies the serialization of
11144** the database into memory obtained from [sqlite3_malloc64()] and returns
11145** a pointer to that memory. The caller is responsible for freeing the
11146** returned value to avoid a memory leak. However, if the F argument
11147** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
11148** are made, and the sqlite3_serialize() function will return a pointer
11149** to the contiguous memory representation of the database that SQLite
11150** is currently using for that database, or NULL if no such contiguous
11151** memory representation of the database exists. A contiguous memory
11152** representation of the database will usually only exist if there has
11153** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
11154** values of D and S.
11155** The size of the database is written into *P even if the
11156** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
11157** of the database exists.
11158**
11159** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
11160** the returned buffer content will remain accessible and unchanged
11161** until either the next write operation on the connection or when
11162** the connection is closed, and applications must not modify the
11163** buffer. If the bit had been clear, the returned buffer will not
11164** be accessed by SQLite after the call.
11165**
11166** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
11167** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
11168** allocation error occurs.
11169**
11170** This interface is omitted if SQLite is compiled with the
11171** [SQLITE_OMIT_DESERIALIZE] option.
11172*/
11173SQLITE_API unsigned char *sqlite3_serialize(
11174 sqlite3 *db, /* The database connection */
11175 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
11176 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
11177 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
11178);
11179
11180/*
11181** CAPI3REF: Flags for sqlite3_serialize
11182**
11183** Zero or more of the following constants can be OR-ed together for
11184** the F argument to [sqlite3_serialize(D,S,P,F)].
11185**
11186** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
11187** a pointer to contiguous in-memory database that it is currently using,
11188** without making a copy of the database. If SQLite is not currently using
11189** a contiguous in-memory database, then this option causes
11190** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
11191** using a contiguous in-memory database if it has been initialized by a
11192** prior call to [sqlite3_deserialize()].
11193*/
11194#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
11195
11196/*
11197** CAPI3REF: Deserialize a database
11198**
11199** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
11200** [database connection] D to disconnect from database S and then
11201** reopen S as an in-memory database based on the serialization
11202** contained in P. If S is a NULL pointer, the main database is
11203** used. The serialized database P is N bytes in size. M is the size
11204** of the buffer P, which might be larger than N. If M is larger than
11205** N, and the SQLITE_DESERIALIZE_READONLY bit is not set in F, then
11206** SQLite is permitted to add content to the in-memory database as
11207** long as the total size does not exceed M bytes.
11208**
11209** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
11210** invoke sqlite3_free() on the serialization buffer when the database
11211** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
11212** SQLite will try to increase the buffer size using sqlite3_realloc64()
11213** if writes on the database cause it to grow larger than M bytes.
11214**
11215** Applications must not modify the buffer P or invalidate it before
11216** the database connection D is closed.
11217**
11218** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
11219** database is currently in a read transaction or is involved in a backup
11220** operation.
11221**
11222** It is not possible to deserialize into the TEMP database. If the
11223** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
11224** function returns SQLITE_ERROR.
11225**
11226** The deserialized database should not be in [WAL mode]. If the database
11227** is in WAL mode, then any attempt to use the database file will result
11228** in an [SQLITE_CANTOPEN] error. The application can set the
11229** [file format version numbers] (bytes 18 and 19) of the input database P
11230** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
11231** database file into rollback mode and work around this limitation.
11232**
11233** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
11234** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
11235** [sqlite3_free()] is invoked on argument P prior to returning.
11236**
11237** This interface is omitted if SQLite is compiled with the
11238** [SQLITE_OMIT_DESERIALIZE] option.
11239*/
11240SQLITE_API int sqlite3_deserialize(
11241 sqlite3 *db, /* The database connection */
11242 const char *zSchema, /* Which DB to reopen with the deserialization */
11243 unsigned char *pData, /* The serialized database content */
11244 sqlite3_int64 szDb, /* Number of bytes in the deserialization */
11245 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
11246 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
11247);
11248
11249/*
11250** CAPI3REF: Flags for sqlite3_deserialize()
11251**
11252** The following are allowed values for the 6th argument (the F argument) to
11253** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
11254**
11255** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
11256** in the P argument is held in memory obtained from [sqlite3_malloc64()]
11257** and that SQLite should take ownership of this memory and automatically
11258** free it when it has finished using it. Without this flag, the caller
11259** is responsible for freeing any dynamically allocated memory.
11260**
11261** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
11262** grow the size of the database using calls to [sqlite3_realloc64()]. This
11263** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
11264** Without this flag, the deserialized database cannot increase in size beyond
11265** the number of bytes specified by the M parameter.
11266**
11267** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
11268** should be treated as read-only.
11269*/
11270#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
11271#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
11272#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
11273
11274/*
11275** CAPI3REF: Bind array values to the CARRAY table-valued function
11276**
11277** The sqlite3_carray_bind_v2(S,I,P,N,F,X,D) interface binds an array value to
11278** parameter that is the first argument of the [carray() table-valued function].
11279** The S parameter is a pointer to the [prepared statement] that uses the
11280** carray() functions. I is the parameter index to be bound. I must be the
11281** index of the parameter that is the first argument to the carray()
11282** table-valued function. P is a pointer to the array to be bound, and N
11283** is the number of elements in the array. The F argument is one of
11284** constants [SQLITE_CARRAY_INT32], [SQLITE_CARRAY_INT64],
11285** [SQLITE_CARRAY_DOUBLE], [SQLITE_CARRAY_TEXT],
11286** or [SQLITE_CARRAY_BLOB] to indicate the datatype of the array P.
11287**
11288** If the X argument is not a NULL pointer or one of the special
11289** values [SQLITE_STATIC] or [SQLITE_TRANSIENT], then SQLite will invoke
11290** the function X with argument D when it is finished using the data in P.
11291** The call to X(D) is a destructor for the array P. The destructor X(D)
11292** is invoked even if the call to sqlite3_carray_bind_v2() fails. If the X
11293** parameter is the special-case value [SQLITE_STATIC], then SQLite assumes
11294** that the data static and the destructor is never invoked. If the X
11295** parameter is the special-case value [SQLITE_TRANSIENT], then
11296** sqlite3_carray_bind_v2() makes its own private copy of the data prior
11297** to returning and never invokes the destructor X.
11298**
11299** The sqlite3_carray_bind() function works the same as sqlite3_carray_bind_v2()
11300** with a D parameter set to P. In other words,
11301** sqlite3_carray_bind(S,I,P,N,F,X) is same as
11302** sqlite3_carray_bind_v2(S,I,P,N,F,X,P).
11303*/
11304SQLITE_API int sqlite3_carray_bind_v2(
11305 sqlite3_stmt *pStmt, /* Statement to be bound */
11306 int i, /* Parameter index */
11307 void *aData, /* Pointer to array data */
11308 int nData, /* Number of data elements */
11309 int mFlags, /* CARRAY flags */
11310 void (*xDel)(void*), /* Destructor for aData */
11311 void *pDel /* Optional argument to xDel() */
11312);
11313SQLITE_API int sqlite3_carray_bind(
11314 sqlite3_stmt *pStmt, /* Statement to be bound */
11315 int i, /* Parameter index */
11316 void *aData, /* Pointer to array data */
11317 int nData, /* Number of data elements */
11318 int mFlags, /* CARRAY flags */
11319 void (*xDel)(void*) /* Destructor for aData */
11320);
11321
11322/*
11323** CAPI3REF: Datatypes for the CARRAY table-valued function
11324**
11325** The fifth argument to the [sqlite3_carray_bind()] interface musts be
11326** one of the following constants, to specify the datatype of the array
11327** that is being bound into the [carray table-valued function].
11328*/
11329#define SQLITE_CARRAY_INT32 0 /* Data is 32-bit signed integers */
11330#define SQLITE_CARRAY_INT64 1 /* Data is 64-bit signed integers */
11331#define SQLITE_CARRAY_DOUBLE 2 /* Data is doubles */
11332#define SQLITE_CARRAY_TEXT 3 /* Data is char* */
11333#define SQLITE_CARRAY_BLOB 4 /* Data is struct iovec */
11334
11335/*
11336** Versions of the above #defines that omit the initial SQLITE_, for
11337** legacy compatibility.
11338*/
11339#define CARRAY_INT32 0 /* Data is 32-bit signed integers */
11340#define CARRAY_INT64 1 /* Data is 64-bit signed integers */
11341#define CARRAY_DOUBLE 2 /* Data is doubles */
11342#define CARRAY_TEXT 3 /* Data is char* */
11343#define CARRAY_BLOB 4 /* Data is struct iovec */
11344
11345/*
11346** Undo the hack that converts floating point types to integer for
11347** builds on processors without floating point support.
11348*/
11349#ifdef SQLITE_OMIT_FLOATING_POINT
11350# undef double
11351#endif
11352
11353#if defined(__wasi__)
11354# undef SQLITE_WASI
11355# define SQLITE_WASI 1
11356# ifndef SQLITE_OMIT_LOAD_EXTENSION
11357# define SQLITE_OMIT_LOAD_EXTENSION
11358# endif
11359# ifndef SQLITE_THREADSAFE
11360# define SQLITE_THREADSAFE 0
11361# endif
11362#endif
11363
11364#ifdef __cplusplus
11365} /* End of the 'extern "C"' block */
11366#endif
11367/* #endif for SQLITE3_H will be added by mksqlite3.tcl */
11368
11369/******** Begin file sqlite3rtree.h *********/
11370/*
11371** 2010 August 30
11372**
11373** The author disclaims copyright to this source code. In place of
11374** a legal notice, here is a blessing:
11375**
11376** May you do good and not evil.
11377** May you find forgiveness for yourself and forgive others.
11378** May you share freely, never taking more than you give.
11379**
11380*************************************************************************
11381*/
11382
11383#ifndef _SQLITE3RTREE_H_
11384#define _SQLITE3RTREE_H_
11385
11386
11387#ifdef __cplusplus
11388extern "C" {
11389#endif
11390
11391typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
11392typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
11393
11394/* The double-precision datatype used by RTree depends on the
11395** SQLITE_RTREE_INT_ONLY compile-time option.
11396*/
11397#ifdef SQLITE_RTREE_INT_ONLY
11398 typedef sqlite3_int64 sqlite3_rtree_dbl;
11399#else
11400 typedef double sqlite3_rtree_dbl;
11401#endif
11402
11403/*
11404** Register a geometry callback named zGeom that can be used as part of an
11405** R-Tree geometry query as follows:
11406**
11407** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
11408*/
11409SQLITE_API int sqlite3_rtree_geometry_callback(
11410 sqlite3 *db,
11411 const char *zGeom,
11412 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
11413 void *pContext
11414);
11415
11416
11417/*
11418** A pointer to a structure of the following type is passed as the first
11419** argument to callbacks registered using rtree_geometry_callback().
11420*/
11421struct sqlite3_rtree_geometry {
11422 void *pContext; /* Copy of pContext passed to s_r_g_c() */
11423 int nParam; /* Size of array aParam[] */
11424 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
11425 void *pUser; /* Callback implementation user data */
11426 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
11427};
11428
11429/*
11430** Register a 2nd-generation geometry callback named zScore that can be
11431** used as part of an R-Tree geometry query as follows:
11432**
11433** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
11434*/
11435SQLITE_API int sqlite3_rtree_query_callback(
11436 sqlite3 *db,
11437 const char *zQueryFunc,
11438 int (*xQueryFunc)(sqlite3_rtree_query_info*),
11439 void *pContext,
11440 void (*xDestructor)(void*)
11441);
11442
11443
11444/*
11445** A pointer to a structure of the following type is passed as the
11446** argument to scored geometry callback registered using
11447** sqlite3_rtree_query_callback().
11448**
11449** Note that the first 5 fields of this structure are identical to
11450** sqlite3_rtree_geometry. This structure is a subclass of
11451** sqlite3_rtree_geometry.
11452*/
11453struct sqlite3_rtree_query_info {
11454 void *pContext; /* pContext from when function registered */
11455 int nParam; /* Number of function parameters */
11456 sqlite3_rtree_dbl *aParam; /* value of function parameters */
11457 void *pUser; /* callback can use this, if desired */
11458 void (*xDelUser)(void*); /* function to free pUser */
11459 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
11460 unsigned int *anQueue; /* Number of pending entries in the queue */
11461 int nCoord; /* Number of coordinates */
11462 int iLevel; /* Level of current node or entry */
11463 int mxLevel; /* The largest iLevel value in the tree */
11464 sqlite3_int64 iRowid; /* Rowid for current entry */
11465 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
11466 int eParentWithin; /* Visibility of parent node */
11467 int eWithin; /* OUT: Visibility */
11468 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
11469 /* The following fields are only available in 3.8.11 and later */
11470 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
11471};
11472
11473/*
11474** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
11475*/
11476#define NOT_WITHIN 0 /* Object completely outside of query region */
11477#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
11478#define FULLY_WITHIN 2 /* Object fully contained within query region */
11479
11480
11481#ifdef __cplusplus
11482} /* end of the 'extern "C"' block */
11483#endif
11484
11485#endif /* ifndef _SQLITE3RTREE_H_ */
11486
11487/******** End of sqlite3rtree.h *********/
11488/******** Begin file sqlite3session.h *********/
11489
11490#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
11491#define __SQLITESESSION_H_ 1
11492
11493/*
11494** Make sure we can call this stuff from C++.
11495*/
11496#ifdef __cplusplus
11497extern "C" {
11498#endif
11499
11500
11501/*
11502** CAPI3REF: Session Object Handle
11503**
11504** An instance of this object is a [session] that can be used to
11505** record changes to a database.
11506*/
11507typedef struct sqlite3_session sqlite3_session;
11508
11509/*
11510** CAPI3REF: Changeset Iterator Handle
11511**
11512** An instance of this object acts as a cursor for iterating
11513** over the elements of a [changeset] or [patchset].
11514*/
11515typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
11516
11517/*
11518** CAPI3REF: Create A New Session Object
11519** CONSTRUCTOR: sqlite3_session
11520**
11521** Create a new session object attached to database handle db. If successful,
11522** a pointer to the new object is written to *ppSession and SQLITE_OK is
11523** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11524** error code (e.g. SQLITE_NOMEM) is returned.
11525**
11526** It is possible to create multiple session objects attached to a single
11527** database handle.
11528**
11529** Session objects created using this function should be deleted using the
11530** [sqlite3session_delete()] function before the database handle that they
11531** are attached to is itself closed. If the database handle is closed before
11532** the session object is deleted, then the results of calling any session
11533** module function, including [sqlite3session_delete()] on the session object
11534** are undefined.
11535**
11536** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11537** is not possible for an application to register a pre-update hook on a
11538** database handle that has one or more session objects attached. Nor is
11539** it possible to create a session object attached to a database handle for
11540** which a pre-update hook is already defined. The results of attempting
11541** either of these things are undefined.
11542**
11543** The session object will be used to create changesets for tables in
11544** database zDb, where zDb is either "main", or "temp", or the name of an
11545** attached database. It is not an error if database zDb is not attached
11546** to the database when the session object is created.
11547*/
11548SQLITE_API int sqlite3session_create(
11549 sqlite3 *db, /* Database handle */
11550 const char *zDb, /* Name of db (e.g. "main") */
11551 sqlite3_session **ppSession /* OUT: New session object */
11552);
11553
11554/*
11555** CAPI3REF: Delete A Session Object
11556** DESTRUCTOR: sqlite3_session
11557**
11558** Delete a session object previously allocated using
11559** [sqlite3session_create()]. Once a session object has been deleted, the
11560** results of attempting to use pSession with any other session module
11561** function are undefined.
11562**
11563** Session objects must be deleted before the database handle to which they
11564** are attached is closed. Refer to the documentation for
11565** [sqlite3session_create()] for details.
11566*/
11567SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11568
11569/*
11570** CAPI3REF: Configure a Session Object
11571** METHOD: sqlite3_session
11572**
11573** This method is used to configure a session object after it has been
11574** created. At present the only valid values for the second parameter are
11575** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11576**
11577*/
11578SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11579
11580/*
11581** CAPI3REF: Options for sqlite3session_object_config
11582**
11583** The following values may passed as the the 2nd parameter to
11584** sqlite3session_object_config().
11585**
11586** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11587** This option is used to set, clear or query the flag that enables
11588** the [sqlite3session_changeset_size()] API. Because it imposes some
11589** computational overhead, this API is disabled by default. Argument
11590** pArg must point to a value of type (int). If the value is initially
11591** 0, then the sqlite3session_changeset_size() API is disabled. If it
11592** is greater than 0, then the same API is enabled. Or, if the initial
11593** value is less than zero, no change is made. In all cases the (int)
11594** variable is set to 1 if the sqlite3session_changeset_size() API is
11595** enabled following the current call, or 0 otherwise.
11596**
11597** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11598** the first table has been attached to the session object.
11599**
11600** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11601** This option is used to set, clear or query the flag that enables
11602** collection of data for tables with no explicit PRIMARY KEY.
11603**
11604** Normally, tables with no explicit PRIMARY KEY are simply ignored
11605** by the sessions module. However, if this flag is set, it behaves
11606** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11607** as their leftmost columns.
11608**
11609** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11610** the first table has been attached to the session object.
11611*/
11612#define SQLITE_SESSION_OBJCONFIG_SIZE 1
11613#define SQLITE_SESSION_OBJCONFIG_ROWID 2
11614
11615/*
11616** CAPI3REF: Enable Or Disable A Session Object
11617** METHOD: sqlite3_session
11618**
11619** Enable or disable the recording of changes by a session object. When
11620** enabled, a session object records changes made to the database. When
11621** disabled - it does not. A newly created session object is enabled.
11622** Refer to the documentation for [sqlite3session_changeset()] for further
11623** details regarding how enabling and disabling a session object affects
11624** the eventual changesets.
11625**
11626** Passing zero to this function disables the session. Passing a value
11627** greater than zero enables it. Passing a value less than zero is a
11628** no-op, and may be used to query the current state of the session.
11629**
11630** The return value indicates the final state of the session object: 0 if
11631** the session is disabled, or 1 if it is enabled.
11632*/
11633SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11634
11635/*
11636** CAPI3REF: Set Or Clear the Indirect Change Flag
11637** METHOD: sqlite3_session
11638**
11639** Each change recorded by a session object is marked as either direct or
11640** indirect. A change is marked as indirect if either:
11641**
11642** <ul>
11643** <li> The session object "indirect" flag is set when the change is
11644** made, or
11645** <li> The change is made by an SQL trigger or foreign key action
11646** instead of directly as a result of a users SQL statement.
11647** </ul>
11648**
11649** If a single row is affected by more than one operation within a session,
11650** then the change is considered indirect if all operations meet the criteria
11651** for an indirect change above, or direct otherwise.
11652**
11653** This function is used to set, clear or query the session object indirect
11654** flag. If the second argument passed to this function is zero, then the
11655** indirect flag is cleared. If it is greater than zero, the indirect flag
11656** is set. Passing a value less than zero does not modify the current value
11657** of the indirect flag, and may be used to query the current state of the
11658** indirect flag for the specified session object.
11659**
11660** The return value indicates the final state of the indirect flag: 0 if
11661** it is clear, or 1 if it is set.
11662*/
11663SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11664
11665/*
11666** CAPI3REF: Attach A Table To A Session Object
11667** METHOD: sqlite3_session
11668**
11669** If argument zTab is not NULL, then it is the name of a table to attach
11670** to the session object passed as the first argument. All subsequent changes
11671** made to the table while the session object is enabled will be recorded. See
11672** documentation for [sqlite3session_changeset()] for further details.
11673**
11674** Or, if argument zTab is NULL, then changes are recorded for all tables
11675** in the database. If additional tables are added to the database (by
11676** executing "CREATE TABLE" statements) after this call is made, changes for
11677** the new tables are also recorded.
11678**
11679** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11680** defined as part of their CREATE TABLE statement. It does not matter if the
11681** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11682** KEY may consist of a single column, or may be a composite key.
11683**
11684** It is not an error if the named table does not exist in the database. Nor
11685** is it an error if the named table does not have a PRIMARY KEY. However,
11686** no changes will be recorded in either of these scenarios.
11687**
11688** Changes are not recorded for individual rows that have NULL values stored
11689** in one or more of their PRIMARY KEY columns.
11690**
11691** SQLITE_OK is returned if the call completes without error. Or, if an error
11692** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11693**
11694** <h3>Special sqlite_stat1 Handling</h3>
11695**
11696** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11697** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11698** <pre>
11699** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
11700** </pre>
11701**
11702** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11703** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11704** are recorded for rows for which (idx IS NULL) is true. However, for such
11705** rows a zero-length blob (SQL value X'') is stored in the changeset or
11706** patchset instead of a NULL value. This allows such changesets to be
11707** manipulated by legacy implementations of sqlite3changeset_invert(),
11708** concat() and similar.
11709**
11710** The sqlite3changeset_apply() function automatically converts the
11711** zero-length blob back to a NULL value when updating the sqlite_stat1
11712** table. However, if the application calls sqlite3changeset_new(),
11713** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11714** iterator directly (including on a changeset iterator passed to a
11715** conflict-handler callback) then the X'' value is returned. The application
11716** must translate X'' to NULL itself if required.
11717**
11718** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11719** changes made to the sqlite_stat1 table. Legacy versions of the
11720** sqlite3changeset_apply() function silently ignore any modifications to the
11721** sqlite_stat1 table that are part of a changeset or patchset.
11722*/
11723SQLITE_API int sqlite3session_attach(
11724 sqlite3_session *pSession, /* Session object */
11725 const char *zTab /* Table name */
11726);
11727
11728/*
11729** CAPI3REF: Set a table filter on a Session Object.
11730** METHOD: sqlite3_session
11731**
11732** The second argument (xFilter) is the "filter callback". For changes to rows
11733** in tables that are not attached to the Session object, the filter is called
11734** to determine whether changes to the table's rows should be tracked or not.
11735** If xFilter returns 0, changes are not tracked. Note that once a table is
11736** attached, xFilter will not be called again.
11737*/
11738SQLITE_API void sqlite3session_table_filter(
11739 sqlite3_session *pSession, /* Session object */
11740 int(*xFilter)(
11741 void *pCtx, /* Copy of third arg to _filter_table() */
11742 const char *zTab /* Table name */
11743 ),
11744 void *pCtx /* First argument passed to xFilter */
11745);
11746
11747/*
11748** CAPI3REF: Generate A Changeset From A Session Object
11749** METHOD: sqlite3_session
11750**
11751** Obtain a changeset containing changes to the tables attached to the
11752** session object passed as the first argument. If successful,
11753** set *ppChangeset to point to a buffer containing the changeset
11754** and *pnChangeset to the size of the changeset in bytes before returning
11755** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11756** zero and return an SQLite error code.
11757**
11758** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11759** each representing a change to a single row of an attached table. An INSERT
11760** change contains the values of each field of a new database row. A DELETE
11761** contains the original values of each field of a deleted database row. An
11762** UPDATE change contains the original values of each field of an updated
11763** database row along with the updated values for each updated non-primary-key
11764** column. It is not possible for an UPDATE change to represent a change that
11765** modifies the values of primary key columns. If such a change is made, it
11766** is represented in a changeset as a DELETE followed by an INSERT.
11767**
11768** Changes are not recorded for rows that have NULL values stored in one or
11769** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11770** no corresponding change is present in the changesets returned by this
11771** function. If an existing row with one or more NULL values stored in
11772** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11773** only an INSERT is appears in the changeset. Similarly, if an existing row
11774** with non-NULL PRIMARY KEY values is updated so that one or more of its
11775** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11776** DELETE change only.
11777**
11778** The contents of a changeset may be traversed using an iterator created
11779** using the [sqlite3changeset_start()] API. A changeset may be applied to
11780** a database with a compatible schema using the [sqlite3changeset_apply()]
11781** API.
11782**
11783** Within a changeset generated by this function, all changes related to a
11784** single table are grouped together. In other words, when iterating through
11785** a changeset or when applying a changeset to a database, all changes related
11786** to a single table are processed before moving on to the next table. Tables
11787** are sorted in the same order in which they were attached (or auto-attached)
11788** to the sqlite3_session object. The order in which the changes related to
11789** a single table are stored is undefined.
11790**
11791** Following a successful call to this function, it is the responsibility of
11792** the caller to eventually free the buffer that *ppChangeset points to using
11793** [sqlite3_free()].
11794**
11795** <h3>Changeset Generation</h3>
11796**
11797** Once a table has been attached to a session object, the session object
11798** records the primary key values of all new rows inserted into the table.
11799** It also records the original primary key and other column values of any
11800** deleted or updated rows. For each unique primary key value, data is only
11801** recorded once - the first time a row with said primary key is inserted,
11802** updated or deleted in the lifetime of the session.
11803**
11804** There is one exception to the previous paragraph: when a row is inserted,
11805** updated or deleted, if one or more of its primary key columns contain a
11806** NULL value, no record of the change is made.
11807**
11808** The session object therefore accumulates two types of records - those
11809** that consist of primary key values only (created when the user inserts
11810** a new record) and those that consist of the primary key values and the
11811** original values of other table columns (created when the users deletes
11812** or updates a record).
11813**
11814** When this function is called, the requested changeset is created using
11815** both the accumulated records and the current contents of the database
11816** file. Specifically:
11817**
11818** <ul>
11819** <li> For each record generated by an insert, the database is queried
11820** for a row with a matching primary key. If one is found, an INSERT
11821** change is added to the changeset. If no such row is found, no change
11822** is added to the changeset.
11823**
11824** <li> For each record generated by an update or delete, the database is
11825** queried for a row with a matching primary key. If such a row is
11826** found and one or more of the non-primary key fields have been
11827** modified from their original values, an UPDATE change is added to
11828** the changeset. Or, if no such row is found in the table, a DELETE
11829** change is added to the changeset. If there is a row with a matching
11830** primary key in the database, but all fields contain their original
11831** values, no change is added to the changeset.
11832** </ul>
11833**
11834** This means, amongst other things, that if a row is inserted and then later
11835** deleted while a session object is active, neither the insert nor the delete
11836** will be present in the changeset. Or if a row is deleted and then later a
11837** row with the same primary key values inserted while a session object is
11838** active, the resulting changeset will contain an UPDATE change instead of
11839** a DELETE and an INSERT.
11840**
11841** When a session object is disabled (see the [sqlite3session_enable()] API),
11842** it does not accumulate records when rows are inserted, updated or deleted.
11843** This may appear to have some counter-intuitive effects if a single row
11844** is written to more than once during a session. For example, if a row
11845** is inserted while a session object is enabled, then later deleted while
11846** the same session object is disabled, no INSERT record will appear in the
11847** changeset, even though the delete took place while the session was disabled.
11848** Or, if one field of a row is updated while a session is enabled, and
11849** then another field of the same row is updated while the session is disabled,
11850** the resulting changeset will contain an UPDATE change that updates both
11851** fields.
11852*/
11853SQLITE_API int sqlite3session_changeset(
11854 sqlite3_session *pSession, /* Session object */
11855 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11856 void **ppChangeset /* OUT: Buffer containing changeset */
11857);
11858
11859/*
11860** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11861** METHOD: sqlite3_session
11862**
11863** By default, this function always returns 0. For it to return
11864** a useful result, the sqlite3_session object must have been configured
11865** to enable this API using sqlite3session_object_config() with the
11866** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11867**
11868** When enabled, this function returns an upper limit, in bytes, for the size
11869** of the changeset that might be produced if sqlite3session_changeset() were
11870** called. The final changeset size might be equal to or smaller than the
11871** size in bytes returned by this function.
11872*/
11873SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11874
11875/*
11876** CAPI3REF: Load The Difference Between Tables Into A Session
11877** METHOD: sqlite3_session
11878**
11879** If it is not already attached to the session object passed as the first
11880** argument, this function attaches table zTbl in the same manner as the
11881** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11882** does not have a primary key, this function is a no-op (but does not return
11883** an error).
11884**
11885** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11886** attached to the same database handle as the session object that contains
11887** a table compatible with the table attached to the session by this function.
11888** A table is considered compatible if it:
11889**
11890** <ul>
11891** <li> Has the same name,
11892** <li> Has the same set of columns declared in the same order, and
11893** <li> Has the same PRIMARY KEY definition.
11894** </ul>
11895**
11896** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11897** are compatible but do not have any PRIMARY KEY columns, it is not an error
11898** but no changes are added to the session object. As with other session
11899** APIs, tables without PRIMARY KEYs are simply ignored.
11900**
11901** This function adds a set of changes to the session object that could be
11902** used to update the table in database zFrom (call this the "from-table")
11903** so that its content is the same as the table attached to the session
11904** object (call this the "to-table"). Specifically:
11905**
11906** <ul>
11907** <li> For each row (primary key) that exists in the to-table but not in
11908** the from-table, an INSERT record is added to the session object.
11909**
11910** <li> For each row (primary key) that exists in the to-table but not in
11911** the from-table, a DELETE record is added to the session object.
11912**
11913** <li> For each row (primary key) that exists in both tables, but features
11914** different non-PK values in each, an UPDATE record is added to the
11915** session.
11916** </ul>
11917**
11918** To clarify, if this function is called and then a changeset constructed
11919** using [sqlite3session_changeset()], then after applying that changeset to
11920** database zFrom the contents of the two compatible tables would be
11921** identical.
11922**
11923** Unless the call to this function is a no-op as described above, it is an
11924** error if database zFrom does not exist or does not contain the required
11925** compatible table.
11926**
11927** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11928** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11929** may be set to point to a buffer containing an English language error
11930** message. It is the responsibility of the caller to free this buffer using
11931** sqlite3_free().
11932*/
11933SQLITE_API int sqlite3session_diff(
11934 sqlite3_session *pSession,
11935 const char *zFromDb,
11936 const char *zTbl,
11937 char **pzErrMsg
11938);
11939
11940
11941/*
11942** CAPI3REF: Generate A Patchset From A Session Object
11943** METHOD: sqlite3_session
11944**
11945** The differences between a patchset and a changeset are that:
11946**
11947** <ul>
11948** <li> DELETE records consist of the primary key fields only. The
11949** original values of other fields are omitted.
11950** <li> The original values of any modified fields are omitted from
11951** UPDATE records.
11952** </ul>
11953**
11954** A patchset blob may be used with up to date versions of all
11955** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11956** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11957** attempting to use a patchset blob with old versions of the
11958** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11959**
11960** Because the non-primary key "old.*" fields are omitted, no
11961** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11962** is passed to the sqlite3changeset_apply() API. Other conflict types work
11963** in the same way as for changesets.
11964**
11965** Changes within a patchset are ordered in the same way as for changesets
11966** generated by the sqlite3session_changeset() function (i.e. all changes for
11967** a single table are grouped together, tables appear in the order in which
11968** they were attached to the session object).
11969*/
11970SQLITE_API int sqlite3session_patchset(
11971 sqlite3_session *pSession, /* Session object */
11972 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11973 void **ppPatchset /* OUT: Buffer containing patchset */
11974);
11975
11976/*
11977** CAPI3REF: Test if a changeset has recorded any changes.
11978**
11979** Return non-zero if no changes to attached tables have been recorded by
11980** the session object passed as the first argument. Otherwise, if one or
11981** more changes have been recorded, return zero.
11982**
11983** Even if this function returns zero, it is possible that calling
11984** [sqlite3session_changeset()] on the session handle may still return a
11985** changeset that contains no changes. This can happen when a row in
11986** an attached table is modified and then later on the original values
11987** are restored. However, if this function returns non-zero, then it is
11988** guaranteed that a call to sqlite3session_changeset() will return a
11989** changeset containing zero changes.
11990*/
11991SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11992
11993/*
11994** CAPI3REF: Query for the amount of heap memory used by a session object.
11995**
11996** This API returns the total amount of heap memory in bytes currently
11997** used by the session object passed as the only argument.
11998*/
11999SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
12000
12001/*
12002** CAPI3REF: Create An Iterator To Traverse A Changeset
12003** CONSTRUCTOR: sqlite3_changeset_iter
12004**
12005** Create an iterator used to iterate through the contents of a changeset.
12006** If successful, *pp is set to point to the iterator handle and SQLITE_OK
12007** is returned. Otherwise, if an error occurs, *pp is set to zero and an
12008** SQLite error code is returned.
12009**
12010** The following functions can be used to advance and query a changeset
12011** iterator created by this function:
12012**
12013** <ul>
12014** <li> [sqlite3changeset_next()]
12015** <li> [sqlite3changeset_op()]
12016** <li> [sqlite3changeset_new()]
12017** <li> [sqlite3changeset_old()]
12018** </ul>
12019**
12020** It is the responsibility of the caller to eventually destroy the iterator
12021** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
12022** changeset (pChangeset) must remain valid until after the iterator is
12023** destroyed.
12024**
12025** Assuming the changeset blob was created by one of the
12026** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
12027** [sqlite3changeset_invert()] functions, all changes within the changeset
12028** that apply to a single table are grouped together. This means that when
12029** an application iterates through a changeset using an iterator created by
12030** this function, all changes that relate to a single table are visited
12031** consecutively. There is no chance that the iterator will visit a change
12032** the applies to table X, then one for table Y, and then later on visit
12033** another change for table X.
12034**
12035** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
12036** may be modified by passing a combination of
12037** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
12038**
12039** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
12040** and therefore subject to change.
12041*/
12042SQLITE_API int sqlite3changeset_start(
12043 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
12044 int nChangeset, /* Size of changeset blob in bytes */
12045 void *pChangeset /* Pointer to blob containing changeset */
12046);
12047SQLITE_API int sqlite3changeset_start_v2(
12048 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
12049 int nChangeset, /* Size of changeset blob in bytes */
12050 void *pChangeset, /* Pointer to blob containing changeset */
12051 int flags /* SESSION_CHANGESETSTART_* flags */
12052);
12053
12054/*
12055** CAPI3REF: Flags for sqlite3changeset_start_v2
12056**
12057** The following flags may passed via the 4th parameter to
12058** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
12059**
12060** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
12061** Invert the changeset while iterating through it. This is equivalent to
12062** inverting a changeset using sqlite3changeset_invert() before applying it.
12063** It is an error to specify this flag with a patchset.
12064*/
12065#define SQLITE_CHANGESETSTART_INVERT 0x0002
12066
12067
12068/*
12069** CAPI3REF: Advance A Changeset Iterator
12070** METHOD: sqlite3_changeset_iter
12071**
12072** This function may only be used with iterators created by the function
12073** [sqlite3changeset_start()]. If it is called on an iterator passed to
12074** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
12075** is returned and the call has no effect.
12076**
12077** Immediately after an iterator is created by sqlite3changeset_start(), it
12078** does not point to any change in the changeset. Assuming the changeset
12079** is not empty, the first call to this function advances the iterator to
12080** point to the first change in the changeset. Each subsequent call advances
12081** the iterator to point to the next change in the changeset (if any). If
12082** no error occurs and the iterator points to a valid change after a call
12083** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
12084** Otherwise, if all changes in the changeset have already been visited,
12085** SQLITE_DONE is returned.
12086**
12087** If an error occurs, an SQLite error code is returned. Possible error
12088** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
12089** SQLITE_NOMEM.
12090*/
12091SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
12092
12093/*
12094** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
12095** METHOD: sqlite3_changeset_iter
12096**
12097** The pIter argument passed to this function may either be an iterator
12098** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12099** created by [sqlite3changeset_start()]. In the latter case, the most recent
12100** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
12101** is not the case, this function returns [SQLITE_MISUSE].
12102**
12103** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
12104** outputs are set through these pointers:
12105**
12106** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
12107** depending on the type of change that the iterator currently points to;
12108**
12109** *pnCol is set to the number of columns in the table affected by the change; and
12110**
12111** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
12112** the name of the table affected by the current change. The buffer remains
12113** valid until either sqlite3changeset_next() is called on the iterator
12114** or until the conflict-handler function returns.
12115**
12116** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
12117** is an indirect change, or false (0) otherwise. See the documentation for
12118** [sqlite3session_indirect()] for a description of direct and indirect
12119** changes.
12120**
12121** If no error occurs, SQLITE_OK is returned. If an error does occur, an
12122** SQLite error code is returned. The values of the output variables may not
12123** be trusted in this case.
12124*/
12125SQLITE_API int sqlite3changeset_op(
12126 sqlite3_changeset_iter *pIter, /* Iterator object */
12127 const char **pzTab, /* OUT: Pointer to table name */
12128 int *pnCol, /* OUT: Number of columns in table */
12129 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
12130 int *pbIndirect /* OUT: True for an 'indirect' change */
12131);
12132
12133/*
12134** CAPI3REF: Obtain The Primary Key Definition Of A Table
12135** METHOD: sqlite3_changeset_iter
12136**
12137** For each modified table, a changeset includes the following:
12138**
12139** <ul>
12140** <li> The number of columns in the table, and
12141** <li> Which of those columns make up the tables PRIMARY KEY.
12142** </ul>
12143**
12144** This function is used to find which columns comprise the PRIMARY KEY of
12145** the table modified by the change that iterator pIter currently points to.
12146** If successful, *pabPK is set to point to an array of nCol entries, where
12147** nCol is the number of columns in the table. Elements of *pabPK are set to
12148** 0x01 if the corresponding column is part of the tables primary key, or
12149** 0x00 if it is not.
12150**
12151** If argument pnCol is not NULL, then *pnCol is set to the number of columns
12152** in the table.
12153**
12154** If this function is called when the iterator does not point to a valid
12155** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
12156** SQLITE_OK is returned and the output variables populated as described
12157** above.
12158*/
12159SQLITE_API int sqlite3changeset_pk(
12160 sqlite3_changeset_iter *pIter, /* Iterator object */
12161 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
12162 int *pnCol /* OUT: Number of entries in output array */
12163);
12164
12165/*
12166** CAPI3REF: Obtain old.* Values From A Changeset Iterator
12167** METHOD: sqlite3_changeset_iter
12168**
12169** The pIter argument passed to this function may either be an iterator
12170** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12171** created by [sqlite3changeset_start()]. In the latter case, the most recent
12172** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12173** Furthermore, it may only be called if the type of change that the iterator
12174** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
12175** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12176**
12177** Argument iVal must be greater than or equal to 0, and less than the number
12178** of columns in the table affected by the current change. Otherwise,
12179** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12180**
12181** If successful, this function sets *ppValue to point to a protected
12182** sqlite3_value object containing the iVal'th value from the vector of
12183** original row values stored as part of the UPDATE or DELETE change and
12184** returns SQLITE_OK. The name of the function comes from the fact that this
12185** is similar to the "old.*" columns available to update or delete triggers.
12186**
12187** If some other error occurs (e.g. an OOM condition), an SQLite error code
12188** is returned and *ppValue is set to NULL.
12189*/
12190SQLITE_API int sqlite3changeset_old(
12191 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12192 int iVal, /* Column number */
12193 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
12194);
12195
12196/*
12197** CAPI3REF: Obtain new.* Values From A Changeset Iterator
12198** METHOD: sqlite3_changeset_iter
12199**
12200** The pIter argument passed to this function may either be an iterator
12201** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12202** created by [sqlite3changeset_start()]. In the latter case, the most recent
12203** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12204** Furthermore, it may only be called if the type of change that the iterator
12205** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
12206** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12207**
12208** Argument iVal must be greater than or equal to 0, and less than the number
12209** of columns in the table affected by the current change. Otherwise,
12210** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12211**
12212** If successful, this function sets *ppValue to point to a protected
12213** sqlite3_value object containing the iVal'th value from the vector of
12214** new row values stored as part of the UPDATE or INSERT change and
12215** returns SQLITE_OK. If the change is an UPDATE and does not include
12216** a new value for the requested column, *ppValue is set to NULL and
12217** SQLITE_OK returned. The name of the function comes from the fact that
12218** this is similar to the "new.*" columns available to update or delete
12219** triggers.
12220**
12221** If some other error occurs (e.g. an OOM condition), an SQLite error code
12222** is returned and *ppValue is set to NULL.
12223*/
12224SQLITE_API int sqlite3changeset_new(
12225 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12226 int iVal, /* Column number */
12227 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
12228);
12229
12230/*
12231** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
12232** METHOD: sqlite3_changeset_iter
12233**
12234** This function should only be used with iterator objects passed to a
12235** conflict-handler callback by [sqlite3changeset_apply()] with either
12236** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
12237** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
12238** is set to NULL.
12239**
12240** Argument iVal must be greater than or equal to 0, and less than the number
12241** of columns in the table affected by the current change. Otherwise,
12242** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12243**
12244** If successful, this function sets *ppValue to point to a protected
12245** sqlite3_value object containing the iVal'th value from the
12246** "conflicting row" associated with the current conflict-handler callback
12247** and returns SQLITE_OK.
12248**
12249** If some other error occurs (e.g. an OOM condition), an SQLite error code
12250** is returned and *ppValue is set to NULL.
12251*/
12252SQLITE_API int sqlite3changeset_conflict(
12253 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12254 int iVal, /* Column number */
12255 sqlite3_value **ppValue /* OUT: Value from conflicting row */
12256);
12257
12258/*
12259** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
12260** METHOD: sqlite3_changeset_iter
12261**
12262** This function may only be called with an iterator passed to an
12263** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
12264** it sets the output variable to the total number of known foreign key
12265** violations in the destination database and returns SQLITE_OK.
12266**
12267** In all other cases this function returns SQLITE_MISUSE.
12268*/
12269SQLITE_API int sqlite3changeset_fk_conflicts(
12270 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12271 int *pnOut /* OUT: Number of FK violations */
12272);
12273
12274
12275/*
12276** CAPI3REF: Finalize A Changeset Iterator
12277** METHOD: sqlite3_changeset_iter
12278**
12279** This function is used to finalize an iterator allocated with
12280** [sqlite3changeset_start()].
12281**
12282** This function should only be called on iterators created using the
12283** [sqlite3changeset_start()] function. If an application calls this
12284** function with an iterator passed to a conflict-handler by
12285** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
12286** call has no effect.
12287**
12288** If an error was encountered within a call to an sqlite3changeset_xxx()
12289** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
12290** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
12291** to that error is returned by this function. Otherwise, SQLITE_OK is
12292** returned. This is to allow the following pattern (pseudo-code):
12293**
12294** <pre>
12295** sqlite3changeset_start();
12296** while( SQLITE_ROW==sqlite3changeset_next() ){
12297** // Do something with change.
12298** }
12299** rc = sqlite3changeset_finalize();
12300** if( rc!=SQLITE_OK ){
12301** // An error has occurred
12302** }
12303** </pre>
12304*/
12305SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
12306
12307/*
12308** CAPI3REF: Invert A Changeset
12309**
12310** This function is used to "invert" a changeset object. Applying an inverted
12311** changeset to a database reverses the effects of applying the uninverted
12312** changeset. Specifically:
12313**
12314** <ul>
12315** <li> Each DELETE change is changed to an INSERT, and
12316** <li> Each INSERT change is changed to a DELETE, and
12317** <li> For each UPDATE change, the old.* and new.* values are exchanged.
12318** </ul>
12319**
12320** This function does not change the order in which changes appear within
12321** the changeset. It merely reverses the sense of each individual change.
12322**
12323** If successful, a pointer to a buffer containing the inverted changeset
12324** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
12325** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
12326** zeroed and an SQLite error code returned.
12327**
12328** It is the responsibility of the caller to eventually call sqlite3_free()
12329** on the *ppOut pointer to free the buffer allocation following a successful
12330** call to this function.
12331**
12332** WARNING/TODO: This function currently assumes that the input is a valid
12333** changeset. If it is not, the results are undefined.
12334*/
12335SQLITE_API int sqlite3changeset_invert(
12336 int nIn, const void *pIn, /* Input changeset */
12337 int *pnOut, void **ppOut /* OUT: Inverse of input */
12338);
12339
12340/*
12341** CAPI3REF: Concatenate Two Changeset Objects
12342**
12343** This function is used to concatenate two changesets, A and B, into a
12344** single changeset. The result is a changeset equivalent to applying
12345** changeset A followed by changeset B.
12346**
12347** This function combines the two input changesets using an
12348** sqlite3_changegroup object. Calling it produces similar results as the
12349** following code fragment:
12350**
12351** <pre>
12352** sqlite3_changegroup *pGrp;
12353** rc = sqlite3_changegroup_new(&pGrp);
12354** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
12355** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
12356** if( rc==SQLITE_OK ){
12357** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
12358** }else{
12359** *ppOut = 0;
12360** *pnOut = 0;
12361** }
12362** </pre>
12363**
12364** Refer to the sqlite3_changegroup documentation below for details.
12365*/
12366SQLITE_API int sqlite3changeset_concat(
12367 int nA, /* Number of bytes in buffer pA */
12368 void *pA, /* Pointer to buffer containing changeset A */
12369 int nB, /* Number of bytes in buffer pB */
12370 void *pB, /* Pointer to buffer containing changeset B */
12371 int *pnOut, /* OUT: Number of bytes in output changeset */
12372 void **ppOut /* OUT: Buffer containing output changeset */
12373);
12374
12375/*
12376** CAPI3REF: Changegroup Handle
12377**
12378** A changegroup is an object used to combine two or more
12379** [changesets] or [patchsets]
12380*/
12381typedef struct sqlite3_changegroup sqlite3_changegroup;
12382
12383/*
12384** CAPI3REF: Create A New Changegroup Object
12385** CONSTRUCTOR: sqlite3_changegroup
12386**
12387** An sqlite3_changegroup object is used to combine two or more changesets
12388** (or patchsets) into a single changeset (or patchset). A single changegroup
12389** object may combine changesets or patchsets, but not both. The output is
12390** always in the same format as the input.
12391**
12392** If successful, this function returns SQLITE_OK and populates (*pp) with
12393** a pointer to a new sqlite3_changegroup object before returning. The caller
12394** should eventually free the returned object using a call to
12395** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
12396** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
12397**
12398** The usual usage pattern for an sqlite3_changegroup object is as follows:
12399**
12400** <ul>
12401** <li> It is created using a call to sqlite3changegroup_new().
12402**
12403** <li> Zero or more changesets (or patchsets) are added to the object
12404** by calling sqlite3changegroup_add().
12405**
12406** <li> The result of combining all input changesets together is obtained
12407** by the application via a call to sqlite3changegroup_output().
12408**
12409** <li> The object is deleted using a call to sqlite3changegroup_delete().
12410** </ul>
12411**
12412** Any number of calls to add() and output() may be made between the calls to
12413** new() and delete(), and in any order.
12414**
12415** As well as the regular sqlite3changegroup_add() and
12416** sqlite3changegroup_output() functions, also available are the streaming
12417** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
12418*/
12419SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
12420
12421/*
12422** CAPI3REF: Add a Schema to a Changegroup
12423** METHOD: sqlite3_changegroup_schema
12424**
12425** This method may be used to optionally enforce the rule that the changesets
12426** added to the changegroup handle must match the schema of database zDb
12427** ("main", "temp", or the name of an attached database). If
12428** sqlite3changegroup_add() is called to add a changeset that is not compatible
12429** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
12430** object is left in an undefined state.
12431**
12432** A changeset schema is considered compatible with the database schema in
12433** the same way as for sqlite3changeset_apply(). Specifically, for each
12434** table in the changeset, there exists a database table with:
12435**
12436** <ul>
12437** <li> The name identified by the changeset, and
12438** <li> at least as many columns as recorded in the changeset, and
12439** <li> the primary key columns in the same position as recorded in
12440** the changeset.
12441** </ul>
12442**
12443** The output of the changegroup object always has the same schema as the
12444** database nominated using this function. In cases where changesets passed
12445** to sqlite3changegroup_add() have fewer columns than the corresponding table
12446** in the database schema, these are filled in using the default column
12447** values from the database schema. This makes it possible to combined
12448** changesets that have different numbers of columns for a single table
12449** within a changegroup, provided that they are otherwise compatible.
12450*/
12451SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
12452
12453/*
12454** CAPI3REF: Add A Changeset To A Changegroup
12455** METHOD: sqlite3_changegroup
12456**
12457** Add all changes within the changeset (or patchset) in buffer pData (size
12458** nData bytes) to the changegroup.
12459**
12460** If the buffer contains a patchset, then all prior calls to this function
12461** on the same changegroup object must also have specified patchsets. Or, if
12462** the buffer contains a changeset, so must have the earlier calls to this
12463** function. Otherwise, SQLITE_ERROR is returned and no changes are added
12464** to the changegroup.
12465**
12466** Rows within the changeset and changegroup are identified by the values in
12467** their PRIMARY KEY columns. A change in the changeset is considered to
12468** apply to the same row as a change already present in the changegroup if
12469** the two rows have the same primary key.
12470**
12471** Changes to rows that do not already appear in the changegroup are
12472** simply copied into it. Or, if both the new changeset and the changegroup
12473** contain changes that apply to a single row, the final contents of the
12474** changegroup depends on the type of each change, as follows:
12475**
12476** <table border=1 style="margin-left:8ex;margin-right:8ex">
12477** <tr><th style="white-space:pre">Existing Change </th>
12478** <th style="white-space:pre">New Change </th>
12479** <th>Output Change
12480** <tr><td>INSERT <td>INSERT <td>
12481** The new change is ignored. This case does not occur if the new
12482** changeset was recorded immediately after the changesets already
12483** added to the changegroup.
12484** <tr><td>INSERT <td>UPDATE <td>
12485** The INSERT change remains in the changegroup. The values in the
12486** INSERT change are modified as if the row was inserted by the
12487** existing change and then updated according to the new change.
12488** <tr><td>INSERT <td>DELETE <td>
12489** The existing INSERT is removed from the changegroup. The DELETE is
12490** not added.
12491** <tr><td>UPDATE <td>INSERT <td>
12492** The new change is ignored. This case does not occur if the new
12493** changeset was recorded immediately after the changesets already
12494** added to the changegroup.
12495** <tr><td>UPDATE <td>UPDATE <td>
12496** The existing UPDATE remains within the changegroup. It is amended
12497** so that the accompanying values are as if the row was updated once
12498** by the existing change and then again by the new change.
12499** <tr><td>UPDATE <td>DELETE <td>
12500** The existing UPDATE is replaced by the new DELETE within the
12501** changegroup.
12502** <tr><td>DELETE <td>INSERT <td>
12503** If one or more of the column values in the row inserted by the
12504** new change differ from those in the row deleted by the existing
12505** change, the existing DELETE is replaced by an UPDATE within the
12506** changegroup. Otherwise, if the inserted row is exactly the same
12507** as the deleted row, the existing DELETE is simply discarded.
12508** <tr><td>DELETE <td>UPDATE <td>
12509** The new change is ignored. This case does not occur if the new
12510** changeset was recorded immediately after the changesets already
12511** added to the changegroup.
12512** <tr><td>DELETE <td>DELETE <td>
12513** The new change is ignored. This case does not occur if the new
12514** changeset was recorded immediately after the changesets already
12515** added to the changegroup.
12516** </table>
12517**
12518** If the new changeset contains changes to a table that is already present
12519** in the changegroup, then the number of columns and the position of the
12520** primary key columns for the table must be consistent. If this is not the
12521** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12522** object has been configured with a database schema using the
12523** sqlite3changegroup_schema() API, then it is possible to combine changesets
12524** with different numbers of columns for a single table, provided that
12525** they are otherwise compatible.
12526**
12527** If the input changeset appears to be corrupt and the corruption is
12528** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12529** occurs during processing, this function returns SQLITE_NOMEM.
12530**
12531** In all cases, if an error occurs the state of the final contents of the
12532** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12533*/
12534SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12535
12536/*
12537** CAPI3REF: Add A Single Change To A Changegroup
12538** METHOD: sqlite3_changegroup
12539**
12540** This function adds the single change currently indicated by the iterator
12541** passed as the second argument to the changegroup object. The rules for
12542** adding the change are just as described for [sqlite3changegroup_add()].
12543**
12544** If the change is successfully added to the changegroup, SQLITE_OK is
12545** returned. Otherwise, an SQLite error code is returned.
12546**
12547** The iterator must point to a valid entry when this function is called.
12548** If it does not, SQLITE_ERROR is returned and no change is added to the
12549** changegroup. Additionally, the iterator must not have been opened with
12550** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12551** returned.
12552*/
12553SQLITE_API int sqlite3changegroup_add_change(
12554 sqlite3_changegroup*,
12555 sqlite3_changeset_iter*
12556);
12557
12558
12559
12560/*
12561** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12562** METHOD: sqlite3_changegroup
12563**
12564** Obtain a buffer containing a changeset (or patchset) representing the
12565** current contents of the changegroup. If the inputs to the changegroup
12566** were themselves changesets, the output is a changeset. Or, if the
12567** inputs were patchsets, the output is also a patchset.
12568**
12569** As with the output of the sqlite3session_changeset() and
12570** sqlite3session_patchset() functions, all changes related to a single
12571** table are grouped together in the output of this function. Tables appear
12572** in the same order as for the very first changeset added to the changegroup.
12573** If the second or subsequent changesets added to the changegroup contain
12574** changes for tables that do not appear in the first changeset, they are
12575** appended onto the end of the output changeset, again in the order in
12576** which they are first encountered.
12577**
12578** If an error occurs, an SQLite error code is returned and the output
12579** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12580** is returned and the output variables are set to the size of and a
12581** pointer to the output buffer, respectively. In this case it is the
12582** responsibility of the caller to eventually free the buffer using a
12583** call to sqlite3_free().
12584*/
12585SQLITE_API int sqlite3changegroup_output(
12586 sqlite3_changegroup*,
12587 int *pnData, /* OUT: Size of output buffer in bytes */
12588 void **ppData /* OUT: Pointer to output buffer */
12589);
12590
12591/*
12592** CAPI3REF: Delete A Changegroup Object
12593** DESTRUCTOR: sqlite3_changegroup
12594*/
12595SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12596
12597/*
12598** CAPI3REF: Apply A Changeset To A Database
12599**
12600** Apply a changeset or patchset to a database. These functions attempt to
12601** update the "main" database attached to handle db with the changes found in
12602** the changeset passed via the second and third arguments.
12603**
12604** All changes made by these functions are enclosed in a savepoint transaction.
12605** If any other error (aside from a constraint failure when attempting to
12606** write to the target database) occurs, then the savepoint transaction is
12607** rolled back, restoring the target database to its original state, and an
12608** SQLite error code returned. Additionally, starting with version 3.51.0,
12609** an error code and error message that may be accessed using the
12610** [sqlite3_errcode()] and [sqlite3_errmsg()] APIs are left in the database
12611** handle.
12612**
12613** The fourth argument (xFilter) passed to these functions is the "filter
12614** callback". This may be passed NULL, in which case all changes in the
12615** changeset are applied to the database. For sqlite3changeset_apply() and
12616** sqlite3_changeset_apply_v2(), if it is not NULL, then it is invoked once
12617** for each table affected by at least one change in the changeset. In this
12618** case the table name is passed as the second argument, and a copy of
12619** the context pointer passed as the sixth argument to apply() or apply_v2()
12620** as the first. If the "filter callback" returns zero, then no attempt is
12621** made to apply any changes to the table. Otherwise, if the return value is
12622** non-zero, all changes related to the table are attempted.
12623**
12624** For sqlite3_changeset_apply_v3(), the xFilter callback is invoked once
12625** per change. The second argument in this case is an sqlite3_changeset_iter
12626** that may be queried using the usual APIs for the details of the current
12627** change. If the "filter callback" returns zero in this case, then no attempt
12628** is made to apply the current change. If it returns non-zero, the change
12629** is applied.
12630**
12631** For each table that is not excluded by the filter callback, this function
12632** tests that the target database contains a compatible table. A table is
12633** considered compatible if all of the following are true:
12634**
12635** <ul>
12636** <li> The table has the same name as the name recorded in the
12637** changeset, and
12638** <li> The table has at least as many columns as recorded in the
12639** changeset, and
12640** <li> The table has primary key columns in the same position as
12641** recorded in the changeset.
12642** </ul>
12643**
12644** If there is no compatible table, it is not an error, but none of the
12645** changes associated with the table are applied. A warning message is issued
12646** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12647** one such warning is issued for each table in the changeset.
12648**
12649** For each change for which there is a compatible table, an attempt is made
12650** to modify the table contents according to each UPDATE, INSERT or DELETE
12651** change that is not excluded by a filter callback. If a change cannot be
12652** applied cleanly, the conflict handler function passed as the fifth argument
12653** to sqlite3changeset_apply() may be invoked. A description of exactly when
12654** the conflict handler is invoked for each type of change is below.
12655**
12656** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12657** of passing anything other than a valid function pointer as the xConflict
12658** argument are undefined.
12659**
12660** Each time the conflict handler function is invoked, it must return one
12661** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12662** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12663** if the second argument passed to the conflict handler is either
12664** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12665** returns an illegal value, any changes already made are rolled back and
12666** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12667** actions are taken by sqlite3changeset_apply() depending on the value
12668** returned by each invocation of the conflict-handler function. Refer to
12669** the documentation for the three
12670** [SQLITE_CHANGESET_OMIT|available return values] for details.
12671**
12672** <dl>
12673** <dt>DELETE Changes<dd>
12674** For each DELETE change, the function checks if the target database
12675** contains a row with the same primary key value (or values) as the
12676** original row values stored in the changeset. If it does, and the values
12677** stored in all non-primary key columns also match the values stored in
12678** the changeset the row is deleted from the target database.
12679**
12680** If a row with matching primary key values is found, but one or more of
12681** the non-primary key fields contains a value different from the original
12682** row value stored in the changeset, the conflict-handler function is
12683** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12684** database table has more columns than are recorded in the changeset,
12685** only the values of those non-primary key fields are compared against
12686** the current database contents - any trailing database table columns
12687** are ignored.
12688**
12689** If no row with matching primary key values is found in the database,
12690** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12691** passed as the second argument.
12692**
12693** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12694** (which can only happen if a foreign key constraint is violated), the
12695** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12696** passed as the second argument. This includes the case where the DELETE
12697** operation is attempted because an earlier call to the conflict handler
12698** function returned [SQLITE_CHANGESET_REPLACE].
12699**
12700** <dt>INSERT Changes<dd>
12701** For each INSERT change, an attempt is made to insert the new row into
12702** the database. If the changeset row contains fewer fields than the
12703** database table, the trailing fields are populated with their default
12704** values.
12705**
12706** If the attempt to insert the row fails because the database already
12707** contains a row with the same primary key values, the conflict handler
12708** function is invoked with the second argument set to
12709** [SQLITE_CHANGESET_CONFLICT].
12710**
12711** If the attempt to insert the row fails because of some other constraint
12712** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12713** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12714** This includes the case where the INSERT operation is re-attempted because
12715** an earlier call to the conflict handler function returned
12716** [SQLITE_CHANGESET_REPLACE].
12717**
12718** <dt>UPDATE Changes<dd>
12719** For each UPDATE change, the function checks if the target database
12720** contains a row with the same primary key value (or values) as the
12721** original row values stored in the changeset. If it does, and the values
12722** stored in all modified non-primary key columns also match the values
12723** stored in the changeset the row is updated within the target database.
12724**
12725** If a row with matching primary key values is found, but one or more of
12726** the modified non-primary key fields contains a value different from an
12727** original row value stored in the changeset, the conflict-handler function
12728** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12729** UPDATE changes only contain values for non-primary key fields that are
12730** to be modified, only those fields need to match the original values to
12731** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12732**
12733** If no row with matching primary key values is found in the database,
12734** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12735** passed as the second argument.
12736**
12737** If the UPDATE operation is attempted, but SQLite returns
12738** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12739** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12740** This includes the case where the UPDATE operation is attempted after
12741** an earlier call to the conflict handler function returned
12742** [SQLITE_CHANGESET_REPLACE].
12743** </dl>
12744**
12745** It is safe to execute SQL statements, including those that write to the
12746** table that the callback related to, from within the xConflict callback.
12747** This can be used to further customize the application's conflict
12748** resolution strategy.
12749**
12750** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12751** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12752** may set (*ppRebase) to point to a "rebase" that may be used with the
12753** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12754** is set to the size of the buffer in bytes. It is the responsibility of the
12755** caller to eventually free any such buffer using sqlite3_free(). The buffer
12756** is only allocated and populated if one or more conflicts were encountered
12757** while applying the patchset. See comments surrounding the sqlite3_rebaser
12758** APIs for further details.
12759**
12760** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12761** may be modified by passing a combination of
12762** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12763**
12764** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12765** and therefore subject to change.
12766*/
12767SQLITE_API int sqlite3changeset_apply(
12768 sqlite3 *db, /* Apply change to "main" db of this handle */
12769 int nChangeset, /* Size of changeset in bytes */
12770 void *pChangeset, /* Changeset blob */
12771 int(*xFilter)(
12772 void *pCtx, /* Copy of sixth arg to _apply() */
12773 const char *zTab /* Table name */
12774 ),
12775 int(*xConflict)(
12776 void *pCtx, /* Copy of sixth arg to _apply() */
12777 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12778 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12779 ),
12780 void *pCtx /* First argument passed to xConflict */
12781);
12782SQLITE_API int sqlite3changeset_apply_v2(
12783 sqlite3 *db, /* Apply change to "main" db of this handle */
12784 int nChangeset, /* Size of changeset in bytes */
12785 void *pChangeset, /* Changeset blob */
12786 int(*xFilter)(
12787 void *pCtx, /* Copy of sixth arg to _apply() */
12788 const char *zTab /* Table name */
12789 ),
12790 int(*xConflict)(
12791 void *pCtx, /* Copy of sixth arg to _apply() */
12792 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12793 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12794 ),
12795 void *pCtx, /* First argument passed to xConflict */
12796 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12797 int flags /* SESSION_CHANGESETAPPLY_* flags */
12798);
12799SQLITE_API int sqlite3changeset_apply_v3(
12800 sqlite3 *db, /* Apply change to "main" db of this handle */
12801 int nChangeset, /* Size of changeset in bytes */
12802 void *pChangeset, /* Changeset blob */
12803 int(*xFilter)(
12804 void *pCtx, /* Copy of sixth arg to _apply() */
12805 sqlite3_changeset_iter *p /* Handle describing change */
12806 ),
12807 int(*xConflict)(
12808 void *pCtx, /* Copy of sixth arg to _apply() */
12809 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12810 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12811 ),
12812 void *pCtx, /* First argument passed to xConflict */
12813 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12814 int flags /* SESSION_CHANGESETAPPLY_* flags */
12815);
12816
12817/*
12818** CAPI3REF: Flags for sqlite3changeset_apply_v2
12819**
12820** The following flags may passed via the 9th parameter to
12821** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12822**
12823** <dl>
12824** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12825** Usually, the sessions module encloses all operations performed by
12826** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12827** SAVEPOINT is committed if the changeset or patchset is successfully
12828** applied, or rolled back if an error occurs. Specifying this flag
12829** causes the sessions module to omit this savepoint. In this case, if the
12830** caller has an open transaction or savepoint when apply_v2() is called,
12831** it may revert the partially applied changeset by rolling it back.
12832**
12833** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12834** Invert the changeset before applying it. This is equivalent to inverting
12835** a changeset using sqlite3changeset_invert() before applying it. It is
12836** an error to specify this flag with a patchset.
12837**
12838** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12839** Do not invoke the conflict handler callback for any changes that
12840** would not actually modify the database even if they were applied.
12841** Specifically, this means that the conflict handler is not invoked
12842** for:
12843** <ul>
12844** <li>a delete change if the row being deleted cannot be found,
12845** <li>an update change if the modified fields are already set to
12846** their new values in the conflicting row, or
12847** <li>an insert change if all fields of the conflicting row match
12848** the row being inserted.
12849** </ul>
12850**
12851** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12852** If this flag it set, then all foreign key constraints in the target
12853** database behave as if they were declared with "ON UPDATE NO ACTION ON
12854** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12855** or SET DEFAULT.
12856*/
12857#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12858#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12859#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12860#define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12861
12862/*
12863** CAPI3REF: Constants Passed To The Conflict Handler
12864**
12865** Values that may be passed as the second argument to a conflict-handler.
12866**
12867** <dl>
12868** <dt>SQLITE_CHANGESET_DATA<dd>
12869** The conflict handler is invoked with CHANGESET_DATA as the second argument
12870** when processing a DELETE or UPDATE change if a row with the required
12871** PRIMARY KEY fields is present in the database, but one or more other
12872** (non primary-key) fields modified by the update do not contain the
12873** expected "before" values.
12874**
12875** The conflicting row, in this case, is the database row with the matching
12876** primary key.
12877**
12878** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12879** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12880** argument when processing a DELETE or UPDATE change if a row with the
12881** required PRIMARY KEY fields is not present in the database.
12882**
12883** There is no conflicting row in this case. The results of invoking the
12884** sqlite3changeset_conflict() API are undefined.
12885**
12886** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12887** CHANGESET_CONFLICT is passed as the second argument to the conflict
12888** handler while processing an INSERT change if the operation would result
12889** in duplicate primary key values.
12890**
12891** The conflicting row in this case is the database row with the matching
12892** primary key.
12893**
12894** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12895** If foreign key handling is enabled, and applying a changeset leaves the
12896** database in a state containing foreign key violations, the conflict
12897** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12898** exactly once before the changeset is committed. If the conflict handler
12899** returns CHANGESET_OMIT, the changes, including those that caused the
12900** foreign key constraint violation, are committed. Or, if it returns
12901** CHANGESET_ABORT, the changeset is rolled back.
12902**
12903** No current or conflicting row information is provided. The only function
12904** it is possible to call on the supplied sqlite3_changeset_iter handle
12905** is sqlite3changeset_fk_conflicts().
12906**
12907** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12908** If any other constraint violation occurs while applying a change (i.e.
12909** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12910** invoked with CHANGESET_CONSTRAINT as the second argument.
12911**
12912** There is no conflicting row in this case. The results of invoking the
12913** sqlite3changeset_conflict() API are undefined.
12914**
12915** </dl>
12916*/
12917#define SQLITE_CHANGESET_DATA 1
12918#define SQLITE_CHANGESET_NOTFOUND 2
12919#define SQLITE_CHANGESET_CONFLICT 3
12920#define SQLITE_CHANGESET_CONSTRAINT 4
12921#define SQLITE_CHANGESET_FOREIGN_KEY 5
12922
12923/*
12924** CAPI3REF: Constants Returned By The Conflict Handler
12925**
12926** A conflict handler callback must return one of the following three values.
12927**
12928** <dl>
12929** <dt>SQLITE_CHANGESET_OMIT<dd>
12930** If a conflict handler returns this value no special action is taken. The
12931** change that caused the conflict is not applied. The session module
12932** continues to the next change in the changeset.
12933**
12934** <dt>SQLITE_CHANGESET_REPLACE<dd>
12935** This value may only be returned if the second argument to the conflict
12936** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12937** is not the case, any changes applied so far are rolled back and the
12938** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12939**
12940** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12941** handler, then the conflicting row is either updated or deleted, depending
12942** on the type of change.
12943**
12944** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12945** handler, then the conflicting row is removed from the database and a
12946** second attempt to apply the change is made. If this second attempt fails,
12947** the original row is restored to the database before continuing.
12948**
12949** <dt>SQLITE_CHANGESET_ABORT<dd>
12950** If this value is returned, any changes applied so far are rolled back
12951** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12952** </dl>
12953*/
12954#define SQLITE_CHANGESET_OMIT 0
12955#define SQLITE_CHANGESET_REPLACE 1
12956#define SQLITE_CHANGESET_ABORT 2
12957
12958/*
12959** CAPI3REF: Rebasing changesets
12960** EXPERIMENTAL
12961**
12962** Suppose there is a site hosting a database in state S0. And that
12963** modifications are made that move that database to state S1 and a
12964** changeset recorded (the "local" changeset). Then, a changeset based
12965** on S0 is received from another site (the "remote" changeset) and
12966** applied to the database. The database is then in state
12967** (S1+"remote"), where the exact state depends on any conflict
12968** resolution decisions (OMIT or REPLACE) made while applying "remote".
12969** Rebasing a changeset is to update it to take those conflict
12970** resolution decisions into account, so that the same conflicts
12971** do not have to be resolved elsewhere in the network.
12972**
12973** For example, if both the local and remote changesets contain an
12974** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12975**
12976** local: INSERT INTO t1 VALUES(1, 'v1');
12977** remote: INSERT INTO t1 VALUES(1, 'v2');
12978**
12979** and the conflict resolution is REPLACE, then the INSERT change is
12980** removed from the local changeset (it was overridden). Or, if the
12981** conflict resolution was "OMIT", then the local changeset is modified
12982** to instead contain:
12983**
12984** UPDATE t1 SET b = 'v2' WHERE a=1;
12985**
12986** Changes within the local changeset are rebased as follows:
12987**
12988** <dl>
12989** <dt>Local INSERT<dd>
12990** This may only conflict with a remote INSERT. If the conflict
12991** resolution was OMIT, then add an UPDATE change to the rebased
12992** changeset. Or, if the conflict resolution was REPLACE, add
12993** nothing to the rebased changeset.
12994**
12995** <dt>Local DELETE<dd>
12996** This may conflict with a remote UPDATE or DELETE. In both cases the
12997** only possible resolution is OMIT. If the remote operation was a
12998** DELETE, then add no change to the rebased changeset. If the remote
12999** operation was an UPDATE, then the old.* fields of change are updated
13000** to reflect the new.* values in the UPDATE.
13001**
13002** <dt>Local UPDATE<dd>
13003** This may conflict with a remote UPDATE or DELETE. If it conflicts
13004** with a DELETE, and the conflict resolution was OMIT, then the update
13005** is changed into an INSERT. Any undefined values in the new.* record
13006** from the update change are filled in using the old.* values from
13007** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
13008** the UPDATE change is simply omitted from the rebased changeset.
13009**
13010** If conflict is with a remote UPDATE and the resolution is OMIT, then
13011** the old.* values are rebased using the new.* values in the remote
13012** change. Or, if the resolution is REPLACE, then the change is copied
13013** into the rebased changeset with updates to columns also updated by
13014** the conflicting remote UPDATE removed. If this means no columns would
13015** be updated, the change is omitted.
13016** </dl>
13017**
13018** A local change may be rebased against multiple remote changes
13019** simultaneously. If a single key is modified by multiple remote
13020** changesets, they are combined as follows before the local changeset
13021** is rebased:
13022**
13023** <ul>
13024** <li> If there has been one or more REPLACE resolutions on a
13025** key, it is rebased according to a REPLACE.
13026**
13027** <li> If there have been no REPLACE resolutions on a key, then
13028** the local changeset is rebased according to the most recent
13029** of the OMIT resolutions.
13030** </ul>
13031**
13032** Note that conflict resolutions from multiple remote changesets are
13033** combined on a per-field basis, not per-row. This means that in the
13034** case of multiple remote UPDATE operations, some fields of a single
13035** local change may be rebased for REPLACE while others are rebased for
13036** OMIT.
13037**
13038** In order to rebase a local changeset, the remote changeset must first
13039** be applied to the local database using sqlite3changeset_apply_v2() and
13040** the buffer of rebase information captured. Then:
13041**
13042** <ol>
13043** <li> An sqlite3_rebaser object is created by calling
13044** sqlite3rebaser_create().
13045** <li> The new object is configured with the rebase buffer obtained from
13046** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
13047** If the local changeset is to be rebased against multiple remote
13048** changesets, then sqlite3rebaser_configure() should be called
13049** multiple times, in the same order that the multiple
13050** sqlite3changeset_apply_v2() calls were made.
13051** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
13052** <li> The sqlite3_rebaser object is deleted by calling
13053** sqlite3rebaser_delete().
13054** </ol>
13055*/
13056typedef struct sqlite3_rebaser sqlite3_rebaser;
13057
13058/*
13059** CAPI3REF: Create a changeset rebaser object.
13060** EXPERIMENTAL
13061**
13062** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
13063** point to the new object and return SQLITE_OK. Otherwise, if an error
13064** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
13065** to NULL.
13066*/
13067SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
13068
13069/*
13070** CAPI3REF: Configure a changeset rebaser object.
13071** EXPERIMENTAL
13072**
13073** Configure the changeset rebaser object to rebase changesets according
13074** to the conflict resolutions described by buffer pRebase (size nRebase
13075** bytes), which must have been obtained from a previous call to
13076** sqlite3changeset_apply_v2().
13077*/
13078SQLITE_API int sqlite3rebaser_configure(
13079 sqlite3_rebaser*,
13080 int nRebase, const void *pRebase
13081);
13082
13083/*
13084** CAPI3REF: Rebase a changeset
13085** EXPERIMENTAL
13086**
13087** Argument pIn must point to a buffer containing a changeset nIn bytes
13088** in size. This function allocates and populates a buffer with a copy
13089** of the changeset rebased according to the configuration of the
13090** rebaser object passed as the first argument. If successful, (*ppOut)
13091** is set to point to the new buffer containing the rebased changeset and
13092** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
13093** responsibility of the caller to eventually free the new buffer using
13094** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
13095** are set to zero and an SQLite error code returned.
13096*/
13097SQLITE_API int sqlite3rebaser_rebase(
13098 sqlite3_rebaser*,
13099 int nIn, const void *pIn,
13100 int *pnOut, void **ppOut
13101);
13102
13103/*
13104** CAPI3REF: Delete a changeset rebaser object.
13105** EXPERIMENTAL
13106**
13107** Delete the changeset rebaser object and all associated resources. There
13108** should be one call to this function for each successful invocation
13109** of sqlite3rebaser_create().
13110*/
13111SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
13112
13113/*
13114** CAPI3REF: Streaming Versions of API functions.
13115**
13116** The six streaming API xxx_strm() functions serve similar purposes to the
13117** corresponding non-streaming API functions:
13118**
13119** <table border=1 style="margin-left:8ex;margin-right:8ex">
13120** <tr><th>Streaming function<th>Non-streaming equivalent</th>
13121** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
13122** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
13123** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
13124** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
13125** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
13126** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
13127** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
13128** </table>
13129**
13130** Non-streaming functions that accept changesets (or patchsets) as input
13131** require that the entire changeset be stored in a single buffer in memory.
13132** Similarly, those that return a changeset or patchset do so by returning
13133** a pointer to a single large buffer allocated using sqlite3_malloc().
13134** Normally this is convenient. However, if an application running in a
13135** low-memory environment is required to handle very large changesets, the
13136** large contiguous memory allocations required can become onerous.
13137**
13138** In order to avoid this problem, instead of a single large buffer, input
13139** is passed to a streaming API functions by way of a callback function that
13140** the sessions module invokes to incrementally request input data as it is
13141** required. In all cases, a pair of API function parameters such as
13142**
13143** <pre>
13144** &nbsp; int nChangeset,
13145** &nbsp; void *pChangeset,
13146** </pre>
13147**
13148** Is replaced by:
13149**
13150** <pre>
13151** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
13152** &nbsp; void *pIn,
13153** </pre>
13154**
13155** Each time the xInput callback is invoked by the sessions module, the first
13156** argument passed is a copy of the supplied pIn context pointer. The second
13157** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
13158** error occurs the xInput method should copy up to (*pnData) bytes of data
13159** into the buffer and set (*pnData) to the actual number of bytes copied
13160** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
13161** should be set to zero to indicate this. Or, if an error occurs, an SQLite
13162** error code should be returned. In all cases, if an xInput callback returns
13163** an error, all processing is abandoned and the streaming API function
13164** returns a copy of the error code to the caller.
13165**
13166** In the case of sqlite3changeset_start_strm(), the xInput callback may be
13167** invoked by the sessions module at any point during the lifetime of the
13168** iterator. If such an xInput callback returns an error, the iterator enters
13169** an error state, whereby all subsequent calls to iterator functions
13170** immediately fail with the same error code as returned by xInput.
13171**
13172** Similarly, streaming API functions that return changesets (or patchsets)
13173** return them in chunks by way of a callback function instead of via a
13174** pointer to a single large buffer. In this case, a pair of parameters such
13175** as:
13176**
13177** <pre>
13178** &nbsp; int *pnChangeset,
13179** &nbsp; void **ppChangeset,
13180** </pre>
13181**
13182** Is replaced by:
13183**
13184** <pre>
13185** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
13186** &nbsp; void *pOut
13187** </pre>
13188**
13189** The xOutput callback is invoked zero or more times to return data to
13190** the application. The first parameter passed to each call is a copy of the
13191** pOut pointer supplied by the application. The second parameter, pData,
13192** points to a buffer nData bytes in size containing the chunk of output
13193** data being returned. If the xOutput callback successfully processes the
13194** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
13195** it should return some other SQLite error code. In this case processing
13196** is immediately abandoned and the streaming API function returns a copy
13197** of the xOutput error code to the application.
13198**
13199** The sessions module never invokes an xOutput callback with the third
13200** parameter set to a value less than or equal to zero. Other than this,
13201** no guarantees are made as to the size of the chunks of data returned.
13202*/
13203SQLITE_API int sqlite3changeset_apply_strm(
13204 sqlite3 *db, /* Apply change to "main" db of this handle */
13205 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13206 void *pIn, /* First arg for xInput */
13207 int(*xFilter)(
13208 void *pCtx, /* Copy of sixth arg to _apply() */
13209 const char *zTab /* Table name */
13210 ),
13211 int(*xConflict)(
13212 void *pCtx, /* Copy of sixth arg to _apply() */
13213 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13214 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13215 ),
13216 void *pCtx /* First argument passed to xConflict */
13217);
13218SQLITE_API int sqlite3changeset_apply_v2_strm(
13219 sqlite3 *db, /* Apply change to "main" db of this handle */
13220 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13221 void *pIn, /* First arg for xInput */
13222 int(*xFilter)(
13223 void *pCtx, /* Copy of sixth arg to _apply() */
13224 const char *zTab /* Table name */
13225 ),
13226 int(*xConflict)(
13227 void *pCtx, /* Copy of sixth arg to _apply() */
13228 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13229 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13230 ),
13231 void *pCtx, /* First argument passed to xConflict */
13232 void **ppRebase, int *pnRebase,
13233 int flags
13234);
13235SQLITE_API int sqlite3changeset_apply_v3_strm(
13236 sqlite3 *db, /* Apply change to "main" db of this handle */
13237 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13238 void *pIn, /* First arg for xInput */
13239 int(*xFilter)(
13240 void *pCtx, /* Copy of sixth arg to _apply() */
13241 sqlite3_changeset_iter *p
13242 ),
13243 int(*xConflict)(
13244 void *pCtx, /* Copy of sixth arg to _apply() */
13245 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13246 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13247 ),
13248 void *pCtx, /* First argument passed to xConflict */
13249 void **ppRebase, int *pnRebase,
13250 int flags
13251);
13252SQLITE_API int sqlite3changeset_concat_strm(
13253 int (*xInputA)(void *pIn, void *pData, int *pnData),
13254 void *pInA,
13255 int (*xInputB)(void *pIn, void *pData, int *pnData),
13256 void *pInB,
13257 int (*xOutput)(void *pOut, const void *pData, int nData),
13258 void *pOut
13259);
13260SQLITE_API int sqlite3changeset_invert_strm(
13261 int (*xInput)(void *pIn, void *pData, int *pnData),
13262 void *pIn,
13263 int (*xOutput)(void *pOut, const void *pData, int nData),
13264 void *pOut
13265);
13266SQLITE_API int sqlite3changeset_start_strm(
13267 sqlite3_changeset_iter **pp,
13268 int (*xInput)(void *pIn, void *pData, int *pnData),
13269 void *pIn
13270);
13271SQLITE_API int sqlite3changeset_start_v2_strm(
13272 sqlite3_changeset_iter **pp,
13273 int (*xInput)(void *pIn, void *pData, int *pnData),
13274 void *pIn,
13275 int flags
13276);
13277SQLITE_API int sqlite3session_changeset_strm(
13278 sqlite3_session *pSession,
13279 int (*xOutput)(void *pOut, const void *pData, int nData),
13280 void *pOut
13281);
13282SQLITE_API int sqlite3session_patchset_strm(
13283 sqlite3_session *pSession,
13284 int (*xOutput)(void *pOut, const void *pData, int nData),
13285 void *pOut
13286);
13287SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
13288 int (*xInput)(void *pIn, void *pData, int *pnData),
13289 void *pIn
13290);
13291SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
13292 int (*xOutput)(void *pOut, const void *pData, int nData),
13293 void *pOut
13294);
13295SQLITE_API int sqlite3rebaser_rebase_strm(
13296 sqlite3_rebaser *pRebaser,
13297 int (*xInput)(void *pIn, void *pData, int *pnData),
13298 void *pIn,
13299 int (*xOutput)(void *pOut, const void *pData, int nData),
13300 void *pOut
13301);
13302
13303/*
13304** CAPI3REF: Configure global parameters
13305**
13306** The sqlite3session_config() interface is used to make global configuration
13307** changes to the sessions module in order to tune it to the specific needs
13308** of the application.
13309**
13310** The sqlite3session_config() interface is not threadsafe. If it is invoked
13311** while any other thread is inside any other sessions method then the
13312** results are undefined. Furthermore, if it is invoked after any sessions
13313** related objects have been created, the results are also undefined.
13314**
13315** The first argument to the sqlite3session_config() function must be one
13316** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
13317** interpretation of the (void*) value passed as the second parameter and
13318** the effect of calling this function depends on the value of the first
13319** parameter.
13320**
13321** <dl>
13322** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
13323** By default, the sessions module streaming interfaces attempt to input
13324** and output data in approximately 1 KiB chunks. This operand may be used
13325** to set and query the value of this configuration setting. The pointer
13326** passed as the second argument must point to a value of type (int).
13327** If this value is greater than 0, it is used as the new streaming data
13328** chunk size for both input and output. Before returning, the (int) value
13329** pointed to by pArg is set to the final value of the streaming interface
13330** chunk size.
13331** </dl>
13332**
13333** This function returns SQLITE_OK if successful, or an SQLite error code
13334** otherwise.
13335*/
13336SQLITE_API int sqlite3session_config(int op, void *pArg);
13337
13338/*
13339** CAPI3REF: Values for sqlite3session_config().
13340*/
13341#define SQLITE_SESSION_CONFIG_STRMSIZE 1
13342
13343/*
13344** CAPI3REF: Configure a changegroup object
13345**
13346** Configure the changegroup object passed as the first argument.
13347** At present the only valid value for the second parameter is
13348** [SQLITE_CHANGEGROUP_CONFIG_PATCHSET].
13349*/
13350SQLITE_API int sqlite3changegroup_config(sqlite3_changegroup*, int, void *pArg);
13351
13352/*
13353** CAPI3REF: Options for sqlite3changegroup_config().
13354**
13355** The following values may be passed as the 2nd parameter to
13356** sqlite3changegroup_config().
13357**
13358** <dt>SQLITE_CHANGEGROUP_CONFIG_PATCHSET <dd>
13359** A changegroup object generates either a changeset or patchset. Usually,
13360** this is determined by whether the first call to sqlite3changegroup_add()
13361** is passed a changeset or a patchset. Or, if the first changes are added
13362** to the changegroup object using the sqlite3changegroup_change_xxx()
13363** APIs, then this option may be used to configure whether the changegroup
13364** object generates a changeset or patchset.
13365**
13366** When this option is invoked, parameter pArg must point to a value of
13367** type int. If the changegroup currently contains zero changes, and the
13368** value of the int variable is zero or greater than zero, then the
13369** changegroup is configured to generate a changeset or patchset,
13370** respectively. It is a no-op, not an error, if the changegroup is not
13371** configured because it has already started accumulating changes.
13372**
13373** Before returning, the int variable is set to 0 if the changegroup is
13374** configured to generate a changeset, or 1 if it is configured to generate
13375** a patchset.
13376*/
13377#define SQLITE_CHANGEGROUP_CONFIG_PATCHSET 1
13378
13379
13380/*
13381** CAPI3REF: Begin adding a change to a changegroup
13382**
13383** This API is used, in concert with other sqlite3changegroup_change_xxx()
13384** APIs, to add changes to a changegroup object one at a time. To add a
13385** single change, the caller must:
13386**
13387** 1. Invoke sqlite3changegroup_change_begin() to indicate the type of
13388** change (INSERT, UPDATE or DELETE), the affected table and whether
13389** or not the change should be marked as indirect.
13390**
13391** 2. Invoke sqlite3changegroup_change_int64() or one of the other four
13392** value functions - _null(), _double(), _text() or _blob() - one or
13393** more times to specify old.* and new.* values for the change being
13394** constructed.
13395**
13396** 3. Invoke sqlite3changegroup_change_finish() to either finish adding
13397** the change to the group, or to discard the change altogether.
13398**
13399** The first argument to this function must be a pointer to the existing
13400** changegroup object that the change will be added to. The second argument
13401** must be SQLITE_INSERT, SQLITE_UPDATE or SQLITE_DELETE. The third is the
13402** name of the table that the change affects, and the fourth is a boolean
13403** flag specifying whether the change should be marked as "indirect" (if
13404** bIndirect is non-zero) or not indirect (if bIndirect is zero).
13405**
13406** Following a successful call to this function, this function may not be
13407** called again on the same changegroup object until after
13408** sqlite3changegroup_change_finish() has been called. Doing so is an
13409** SQLITE_MISUSE error.
13410**
13411** The changegroup object passed as the first argument must be already
13412** configured with schema data for the specified table. It may be configured
13413** either by calling sqlite3changegroup_schema() with a database that contains
13414** the table, or sqlite3changegroup_add() with a changeset that contains the
13415** table. If the changegroup object has not been configured with a schema for
13416** the specified table when this function is called, SQLITE_ERROR is returned.
13417**
13418** If successful, SQLITE_OK is returned. Otherwise, if an error occurs, an
13419** SQLite error code is returned. In this case, if argument pzErr is non-NULL,
13420** then (*pzErr) may be set to point to a buffer containing a utf-8 formated,
13421** nul-terminated, English language error message. It is the responsibility
13422** of the caller to eventually free this buffer using sqlite3_free().
13423*/
13424SQLITE_API int sqlite3changegroup_change_begin(
13425 sqlite3_changegroup*,
13426 int eOp,
13427 const char *zTab,
13428 int bIndirect,
13429 char **pzErr
13430);
13431
13432/*
13433** CAPI3REF: Add a 64-bit integer to a changegroup
13434**
13435** This function may only be called between a successful call to
13436** sqlite3changegroup_change_begin() and its matching
13437** sqlite3changegroup_change_finish() call. If it is called at any
13438** other time, it is an SQLITE_MISUSE error. Calling this function
13439** specifies a 64-bit integer value to be used in the change currently being
13440** added to the changegroup object passed as the first argument.
13441**
13442** The second parameter, bNew, specifies whether the value is to be part of
13443** the new.* (if bNew is non-zero) or old.* (if bNew is zero) record of
13444** the change under construction. If this does not match the type of change
13445** specified by the preceding call to sqlite3changegroup_change_begin() (i.e.
13446** an old.* value for an SQLITE_INSERT change, or a new.* value for an
13447** SQLITE_DELETE), then SQLITE_ERROR is returned.
13448**
13449** The third parameter specifies the column of the old.* or new.* record that
13450** the value will be a part of. If the specified table has an explicit primary
13451** key, then this is the index of the table column, numbered from 0 in the order
13452** specified within the CREATE TABLE statement. Or, if the table uses an
13453** implicit rowid key, then the column 0 is the rowid and the explicit columns
13454** are numbered starting from 1. If the iCol parameter is less than 0 or greater
13455** than the index of the last column in the table, SQLITE_RANGE is returned.
13456**
13457** The fourth parameter is the integer value to use as part of the old.* or
13458** new.* record.
13459**
13460** If this call is successful, SQLITE_OK is returned. Otherwise, if an
13461** error occurs, an SQLite error code is returned.
13462*/
13463SQLITE_API int sqlite3changegroup_change_int64(
13464 sqlite3_changegroup*,
13465 int bNew,
13466 int iCol,
13467 sqlite3_int64 iVal
13468);
13469
13470/*
13471** CAPI3REF: Add a NULL to a changegroup
13472**
13473** This function is similar to sqlite3changegroup_change_int64(). Except that
13474** it configures the change currently under construction with a NULL value
13475** instead of a 64-bit integer.
13476*/
13477SQLITE_API int sqlite3changegroup_change_null(sqlite3_changegroup*, int, int);
13478
13479/*
13480** CAPI3REF: Add an double to a changegroup
13481**
13482** This function is similar to sqlite3changegroup_change_int64(). Except that
13483** it configures the change currently being constructed with a real value
13484** instead of a 64-bit integer.
13485*/
13486SQLITE_API int sqlite3changegroup_change_double(sqlite3_changegroup*, int, int, double);
13487
13488/*
13489** CAPI3REF: Add a text value to a changegroup
13490**
13491** This function is similar to sqlite3changegroup_change_int64(). It configures
13492** the currently accumulated change with a text value instead of a 64-bit
13493** integer. Parameter pVal points to a buffer containing the text encoded using
13494** utf-8. Parameter nVal may either be the size of the text value in bytes, or
13495** else a negative value, in which case the buffer pVal points to is assumed to
13496** be nul-terminated.
13497*/
13498SQLITE_API int sqlite3changegroup_change_text(
13499 sqlite3_changegroup*, int, int, const char *pVal, int nVal
13500);
13501
13502/*
13503** CAPI3REF: Add a blob to a changegroup
13504**
13505** This function is similar to sqlite3changegroup_change_int64(). It configures
13506** the currently accumulated change with a blob value instead of a 64-bit
13507** integer. Parameter pVal points to a buffer containing the blob. Parameter
13508** nVal is the size of the blob in bytes.
13509*/
13510SQLITE_API int sqlite3changegroup_change_blob(
13511 sqlite3_changegroup*, int, int, const void *pVal, int nVal
13512);
13513
13514/*
13515** CAPI3REF: Finish adding one-at-at-time changes to a changegroup
13516**
13517** This function may only be called following a successful call to
13518** sqlite3changegroup_change_begin(). Otherwise, it is an SQLITE_MISUSE error.
13519**
13520** If parameter bDiscard is non-zero, then the current change is simply
13521** discarded. In this case this function is always successful and SQLITE_OK
13522** returned.
13523**
13524** If parameter bDiscard is zero, then an attempt is made to add the current
13525** change to the changegroup. Assuming the changegroup is configured to
13526** produce a changeset (not a patchset), this requires that:
13527**
13528** * If the change is an INSERT or DELETE, then a value must be specified
13529** for all columns of the new.* or old.* record, respectively.
13530**
13531** * If the change is an UPDATE record, then values must be provided for
13532** the PRIMARY KEY columns of the old.* record, but must not be provided
13533** for PRIMARY KEY columns of the new.* record.
13534**
13535** * If the change is an UPDATE record, then for each non-PRIMARY KEY
13536** column in the old.* record for which a value has been provided, a
13537** value must also be provided for the same column in the new.* record.
13538** Similarly, for each non-PK column in the old.* record for which
13539** a value is not provided, a value must not be provided for the same
13540** column in the new.* record.
13541**
13542** * All values specified for PRIMARY KEY columns must be non-NULL.
13543**
13544** Otherwise, it is an error.
13545**
13546** If the changegroup already contains a change for the same row (identified
13547** by PRIMARY KEY columns), then the current change is combined with the
13548** existing change in the same way as for sqlite3changegroup_add().
13549**
13550** For a patchset, all of the above rules apply except that it doesn't matter
13551** whether or not values are provided for the non-PK old.* record columns
13552** for an UPDATE or DELETE change. This means that code used to produce
13553** a changeset using the sqlite3changegroup_change_xxx() APIs may also
13554** be used to produce patchsets.
13555**
13556** If the call is successful, SQLITE_OK is returned. Otherwise, if an error
13557** occurs, an SQLite error code is returned. If an error is returned and
13558** parameter pzErr is not NULL, then (*pzErr) may be set to point to a buffer
13559** containing a nul-terminated, utf-8 encoded, English language error message.
13560** It is the responsibility of the caller to eventually free any such error
13561** message buffer using sqlite3_free().
13562*/
13563SQLITE_API int sqlite3changegroup_change_finish(
13564 sqlite3_changegroup*,
13565 int bDiscard,
13566 char **pzErr
13567);
13568
13569/*
13570** Make sure we can call this stuff from C++.
13571*/
13572#ifdef __cplusplus
13573}
13574#endif
13575
13576#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
13577
13578/******** End of sqlite3session.h *********/
13579/******** Begin file fts5.h *********/
13580/*
13581** 2014 May 31
13582**
13583** The author disclaims copyright to this source code. In place of
13584** a legal notice, here is a blessing:
13585**
13586** May you do good and not evil.
13587** May you find forgiveness for yourself and forgive others.
13588** May you share freely, never taking more than you give.
13589**
13590******************************************************************************
13591**
13592** Interfaces to extend FTS5. Using the interfaces defined in this file,
13593** FTS5 may be extended with:
13594**
13595** * custom tokenizers, and
13596** * custom auxiliary functions.
13597*/
13598
13599
13600#ifndef _FTS5_H
13601#define _FTS5_H
13602
13603
13604#ifdef __cplusplus
13605extern "C" {
13606#endif
13607
13608/*************************************************************************
13609** CUSTOM AUXILIARY FUNCTIONS
13610**
13611** Virtual table implementations may overload SQL functions by implementing
13612** the sqlite3_module.xFindFunction() method.
13613*/
13614
13615typedef struct Fts5ExtensionApi Fts5ExtensionApi;
13616typedef struct Fts5Context Fts5Context;
13617typedef struct Fts5PhraseIter Fts5PhraseIter;
13618
13619typedef void (*fts5_extension_function)(
13620 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
13621 Fts5Context *pFts, /* First arg to pass to pApi functions */
13622 sqlite3_context *pCtx, /* Context for returning result/error */
13623 int nVal, /* Number of values in apVal[] array */
13624 sqlite3_value **apVal /* Array of trailing arguments */
13625);
13626
13627struct Fts5PhraseIter {
13628 const unsigned char *a;
13629 const unsigned char *b;
13630};
13631
13632/*
13633** EXTENSION API FUNCTIONS
13634**
13635** xUserData(pFts):
13636** Return a copy of the pUserData pointer passed to the xCreateFunction()
13637** API when the extension function was registered.
13638**
13639** xColumnTotalSize(pFts, iCol, pnToken):
13640** If parameter iCol is less than zero, set output variable *pnToken
13641** to the total number of tokens in the FTS5 table. Or, if iCol is
13642** non-negative but less than the number of columns in the table, return
13643** the total number of tokens in column iCol, considering all rows in
13644** the FTS5 table.
13645**
13646** If parameter iCol is greater than or equal to the number of columns
13647** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13648** an OOM condition or IO error), an appropriate SQLite error code is
13649** returned.
13650**
13651** xColumnCount(pFts):
13652** Return the number of columns in the table.
13653**
13654** xColumnSize(pFts, iCol, pnToken):
13655** If parameter iCol is less than zero, set output variable *pnToken
13656** to the total number of tokens in the current row. Or, if iCol is
13657** non-negative but less than the number of columns in the table, set
13658** *pnToken to the number of tokens in column iCol of the current row.
13659**
13660** If parameter iCol is greater than or equal to the number of columns
13661** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13662** an OOM condition or IO error), an appropriate SQLite error code is
13663** returned.
13664**
13665** This function may be quite inefficient if used with an FTS5 table
13666** created with the "columnsize=0" option.
13667**
13668** xColumnText:
13669** If parameter iCol is less than zero, or greater than or equal to the
13670** number of columns in the table, SQLITE_RANGE is returned.
13671**
13672** Otherwise, this function attempts to retrieve the text of column iCol of
13673** the current document. If successful, (*pz) is set to point to a buffer
13674** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
13675** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
13676** if an error occurs, an SQLite error code is returned and the final values
13677** of (*pz) and (*pn) are undefined.
13678**
13679** xPhraseCount:
13680** Returns the number of phrases in the current query expression.
13681**
13682** xPhraseSize:
13683** If parameter iCol is less than zero, or greater than or equal to the
13684** number of phrases in the current query, as returned by xPhraseCount,
13685** 0 is returned. Otherwise, this function returns the number of tokens in
13686** phrase iPhrase of the query. Phrases are numbered starting from zero.
13687**
13688** xInstCount:
13689** Set *pnInst to the total number of occurrences of all phrases within
13690** the query within the current row. Return SQLITE_OK if successful, or
13691** an error code (i.e. SQLITE_NOMEM) if an error occurs.
13692**
13693** This API can be quite slow if used with an FTS5 table created with the
13694** "detail=none" or "detail=column" option. If the FTS5 table is created
13695** with either "detail=none" or "detail=column" and "content=" option
13696** (i.e. if it is a contentless table), then this API always returns 0.
13697**
13698** xInst:
13699** Query for the details of phrase match iIdx within the current row.
13700** Phrase matches are numbered starting from zero, so the iIdx argument
13701** should be greater than or equal to zero and smaller than the value
13702** output by xInstCount(). If iIdx is less than zero or greater than
13703** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
13704**
13705** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
13706** to the column in which it occurs and *piOff the token offset of the
13707** first token of the phrase. SQLITE_OK is returned if successful, or an
13708** error code (i.e. SQLITE_NOMEM) if an error occurs.
13709**
13710** This API can be quite slow if used with an FTS5 table created with the
13711** "detail=none" or "detail=column" option.
13712**
13713** xRowid:
13714** Returns the rowid of the current row.
13715**
13716** xTokenize:
13717** Tokenize text using the tokenizer belonging to the FTS5 table.
13718**
13719** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
13720** This API function is used to query the FTS table for phrase iPhrase
13721** of the current query. Specifically, a query equivalent to:
13722**
13723** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
13724**
13725** with $p set to a phrase equivalent to the phrase iPhrase of the
13726** current query is executed. Any column filter that applies to
13727** phrase iPhrase of the current query is included in $p. For each
13728** row visited, the callback function passed as the fourth argument
13729** is invoked. The context and API objects passed to the callback
13730** function may be used to access the properties of each matched row.
13731** Invoking Api.xUserData() returns a copy of the pointer passed as
13732** the third argument to pUserData.
13733**
13734** If parameter iPhrase is less than zero, or greater than or equal to
13735** the number of phrases in the query, as returned by xPhraseCount(),
13736** this function returns SQLITE_RANGE.
13737**
13738** If the callback function returns any value other than SQLITE_OK, the
13739** query is abandoned and the xQueryPhrase function returns immediately.
13740** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
13741** Otherwise, the error code is propagated upwards.
13742**
13743** If the query runs to completion without incident, SQLITE_OK is returned.
13744** Or, if some error occurs before the query completes or is aborted by
13745** the callback, an SQLite error code is returned.
13746**
13747**
13748** xSetAuxdata(pFts5, pAux, xDelete)
13749**
13750** Save the pointer passed as the second argument as the extension function's
13751** "auxiliary data". The pointer may then be retrieved by the current or any
13752** future invocation of the same fts5 extension function made as part of
13753** the same MATCH query using the xGetAuxdata() API.
13754**
13755** Each extension function is allocated a single auxiliary data slot for
13756** each FTS query (MATCH expression). If the extension function is invoked
13757** more than once for a single FTS query, then all invocations share a
13758** single auxiliary data context.
13759**
13760** If there is already an auxiliary data pointer when this function is
13761** invoked, then it is replaced by the new pointer. If an xDelete callback
13762** was specified along with the original pointer, it is invoked at this
13763** point.
13764**
13765** The xDelete callback, if one is specified, is also invoked on the
13766** auxiliary data pointer after the FTS5 query has finished.
13767**
13768** If an error (e.g. an OOM condition) occurs within this function,
13769** the auxiliary data is set to NULL and an error code returned. If the
13770** xDelete parameter was not NULL, it is invoked on the auxiliary data
13771** pointer before returning.
13772**
13773**
13774** xGetAuxdata(pFts5, bClear)
13775**
13776** Returns the current auxiliary data pointer for the fts5 extension
13777** function. See the xSetAuxdata() method for details.
13778**
13779** If the bClear argument is non-zero, then the auxiliary data is cleared
13780** (set to NULL) before this function returns. In this case the xDelete,
13781** if any, is not invoked.
13782**
13783**
13784** xRowCount(pFts5, pnRow)
13785**
13786** This function is used to retrieve the total number of rows in the table.
13787** In other words, the same value that would be returned by:
13788**
13789** SELECT count(*) FROM ftstable;
13790**
13791** xPhraseFirst()
13792** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13793** method, to iterate through all instances of a single query phrase within
13794** the current row. This is the same information as is accessible via the
13795** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13796** to use, this API may be faster under some circumstances. To iterate
13797** through instances of phrase iPhrase, use the following code:
13798**
13799** Fts5PhraseIter iter;
13800** int iCol, iOff;
13801** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13802** iCol>=0;
13803** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13804** ){
13805** // An instance of phrase iPhrase at offset iOff of column iCol
13806** }
13807**
13808** The Fts5PhraseIter structure is defined above. Applications should not
13809** modify this structure directly - it should only be used as shown above
13810** with the xPhraseFirst() and xPhraseNext() API methods (and by
13811** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13812**
13813** This API can be quite slow if used with an FTS5 table created with the
13814** "detail=none" or "detail=column" option. If the FTS5 table is created
13815** with either "detail=none" or "detail=column" and "content=" option
13816** (i.e. if it is a contentless table), then this API always iterates
13817** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13818**
13819** In all cases, matches are visited in (column ASC, offset ASC) order.
13820** i.e. all those in column 0, sorted by offset, followed by those in
13821** column 1, etc.
13822**
13823** xPhraseNext()
13824** See xPhraseFirst above.
13825**
13826** xPhraseFirstColumn()
13827** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13828** and xPhraseNext() APIs described above. The difference is that instead
13829** of iterating through all instances of a phrase in the current row, these
13830** APIs are used to iterate through the set of columns in the current row
13831** that contain one or more instances of a specified phrase. For example:
13832**
13833** Fts5PhraseIter iter;
13834** int iCol;
13835** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13836** iCol>=0;
13837** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13838** ){
13839** // Column iCol contains at least one instance of phrase iPhrase
13840** }
13841**
13842** This API can be quite slow if used with an FTS5 table created with the
13843** "detail=none" option. If the FTS5 table is created with either
13844** "detail=none" "content=" option (i.e. if it is a contentless table),
13845** then this API always iterates through an empty set (all calls to
13846** xPhraseFirstColumn() set iCol to -1).
13847**
13848** The information accessed using this API and its companion
13849** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13850** (or xInst/xInstCount). The chief advantage of this API is that it is
13851** significantly more efficient than those alternatives when used with
13852** "detail=column" tables.
13853**
13854** xPhraseNextColumn()
13855** See xPhraseFirstColumn above.
13856**
13857** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13858** This is used to access token iToken of phrase iPhrase of the current
13859** query. Before returning, output parameter *ppToken is set to point
13860** to a buffer containing the requested token, and *pnToken to the
13861** size of this buffer in bytes.
13862**
13863** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13864** or equal to the number of phrases in the query as reported by
13865** xPhraseCount(), or if iToken is equal to or greater than the number of
13866** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13867 are both zeroed.
13868**
13869** The output text is not a copy of the query text that specified the
13870** token. It is the output of the tokenizer module. For tokendata=1
13871** tables, this includes any embedded 0x00 and trailing data.
13872**
13873** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13874** This is used to access token iToken of phrase hit iIdx within the
13875** current row. If iIdx is less than zero or greater than or equal to the
13876** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13877** output variable (*ppToken) is set to point to a buffer containing the
13878** matching document token, and (*pnToken) to the size of that buffer in
13879** bytes.
13880**
13881** The output text is not a copy of the document text that was tokenized.
13882** It is the output of the tokenizer module. For tokendata=1 tables, this
13883** includes any embedded 0x00 and trailing data.
13884**
13885** This API may be slow in some cases if the token identified by parameters
13886** iIdx and iToken matched a prefix token in the query. In most cases, the
13887** first call to this API for each prefix token in the query is forced
13888** to scan the portion of the full-text index that matches the prefix
13889** token to collect the extra data required by this API. If the prefix
13890** token matches a large number of token instances in the document set,
13891** this may be a performance problem.
13892**
13893** If the user knows in advance that a query may use this API for a
13894** prefix token, FTS5 may be configured to collect all required data as part
13895** of the initial querying of the full-text index, avoiding the second scan
13896** entirely. This also causes prefix queries that do not use this API to
13897** run more slowly and use more memory. FTS5 may be configured in this way
13898** either on a per-table basis using the [FTS5 insttoken | 'insttoken']
13899** option, or on a per-query basis using the
13900** [fts5_insttoken | fts5_insttoken()] user function.
13901**
13902** This API can be quite slow if used with an FTS5 table created with the
13903** "detail=none" or "detail=column" option.
13904**
13905** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
13906** If parameter iCol is less than zero, or greater than or equal to the
13907** number of columns in the table, SQLITE_RANGE is returned.
13908**
13909** Otherwise, this function attempts to retrieve the locale associated
13910** with column iCol of the current row. Usually, there is no associated
13911** locale, and output parameters (*pzLocale) and (*pnLocale) are set
13912** to NULL and 0, respectively. However, if the fts5_locale() function
13913** was used to associate a locale with the value when it was inserted
13914** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
13915** buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
13916** is set to the size in bytes of the buffer, not including the
13917** nul-terminator.
13918**
13919** If successful, SQLITE_OK is returned. Or, if an error occurs, an
13920** SQLite error code is returned. The final value of the output parameters
13921** is undefined in this case.
13922**
13923** xTokenize_v2:
13924** Tokenize text using the tokenizer belonging to the FTS5 table. This
13925** API is the same as the xTokenize() API, except that it allows a tokenizer
13926** locale to be specified.
13927*/
13928struct Fts5ExtensionApi {
13929 int iVersion; /* Currently always set to 4 */
13930
13931 void *(*xUserData)(Fts5Context*);
13932
13933 int (*xColumnCount)(Fts5Context*);
13934 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13935 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13936
13937 int (*xTokenize)(Fts5Context*,
13938 const char *pText, int nText, /* Text to tokenize */
13939 void *pCtx, /* Context passed to xToken() */
13940 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13941 );
13942
13943 int (*xPhraseCount)(Fts5Context*);
13944 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13945
13946 int (*xInstCount)(Fts5Context*, int *pnInst);
13947 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13948
13949 sqlite3_int64 (*xRowid)(Fts5Context*);
13950 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13951 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13952
13953 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13954 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13955 );
13956 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13957 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13958
13959 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13960 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13961
13962 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13963 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13964
13965 /* Below this point are iVersion>=3 only */
13966 int (*xQueryToken)(Fts5Context*,
13967 int iPhrase, int iToken,
13968 const char **ppToken, int *pnToken
13969 );
13970 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13971
13972 /* Below this point are iVersion>=4 only */
13973 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
13974 int (*xTokenize_v2)(Fts5Context*,
13975 const char *pText, int nText, /* Text to tokenize */
13976 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */
13977 void *pCtx, /* Context passed to xToken() */
13978 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13979 );
13980};
13981
13982/*
13983** CUSTOM AUXILIARY FUNCTIONS
13984*************************************************************************/
13985
13986/*************************************************************************
13987** CUSTOM TOKENIZERS
13988**
13989** Applications may also register custom tokenizer types. A tokenizer
13990** is registered by providing fts5 with a populated instance of the
13991** following structure. All structure methods must be defined, setting
13992** any member of the fts5_tokenizer struct to NULL leads to undefined
13993** behaviour. The structure methods are expected to function as follows:
13994**
13995** xCreate:
13996** This function is used to allocate and initialize a tokenizer instance.
13997** A tokenizer instance is required to actually tokenize text.
13998**
13999** The first argument passed to this function is a copy of the (void*)
14000** pointer provided by the application when the fts5_tokenizer_v2 object
14001** was registered with FTS5 (the third argument to xCreateTokenizer()).
14002** The second and third arguments are an array of nul-terminated strings
14003** containing the tokenizer arguments, if any, specified following the
14004** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
14005** to create the FTS5 table.
14006**
14007** The final argument is an output variable. If successful, (*ppOut)
14008** should be set to point to the new tokenizer handle and SQLITE_OK
14009** returned. If an error occurs, some value other than SQLITE_OK should
14010** be returned. In this case, fts5 assumes that the final value of *ppOut
14011** is undefined.
14012**
14013** xDelete:
14014** This function is invoked to delete a tokenizer handle previously
14015** allocated using xCreate(). Fts5 guarantees that this function will
14016** be invoked exactly once for each successful call to xCreate().
14017**
14018** xTokenize:
14019** This function is expected to tokenize the nText byte string indicated
14020** by argument pText. pText may or may not be nul-terminated. The first
14021** argument passed to this function is a pointer to an Fts5Tokenizer object
14022** returned by an earlier call to xCreate().
14023**
14024** The third argument indicates the reason that FTS5 is requesting
14025** tokenization of the supplied text. This is always one of the following
14026** four values:
14027**
14028** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
14029** or removed from the FTS table. The tokenizer is being invoked to
14030** determine the set of tokens to add to (or delete from) the
14031** FTS index.
14032**
14033** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
14034** against the FTS index. The tokenizer is being called to tokenize
14035** a bareword or quoted string specified as part of the query.
14036**
14037** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
14038** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
14039** followed by a "*" character, indicating that the last token
14040** returned by the tokenizer will be treated as a token prefix.
14041**
14042** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
14043** satisfy an fts5_api.xTokenize() request made by an auxiliary
14044** function. Or an fts5_api.xColumnSize() request made by the same
14045** on a columnsize=0 database.
14046** </ul>
14047**
14048** The sixth and seventh arguments passed to xTokenize() - pLocale and
14049** nLocale - are a pointer to a buffer containing the locale to use for
14050** tokenization (e.g. "en_US") and its size in bytes, respectively. The
14051** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
14052** which case nLocale is always 0) to indicate that the tokenizer should
14053** use its default locale.
14054**
14055** For each token in the input string, the supplied callback xToken() must
14056** be invoked. The first argument to it should be a copy of the pointer
14057** passed as the second argument to xTokenize(). The third and fourth
14058** arguments are a pointer to a buffer containing the token text, and the
14059** size of the token in bytes. The 4th and 5th arguments are the byte offsets
14060** of the first byte of and first byte immediately following the text from
14061** which the token is derived within the input.
14062**
14063** The second argument passed to the xToken() callback ("tflags") should
14064** normally be set to 0. The exception is if the tokenizer supports
14065** synonyms. In this case see the discussion below for details.
14066**
14067** FTS5 assumes the xToken() callback is invoked for each token in the
14068** order that they occur within the input text.
14069**
14070** If an xToken() callback returns any value other than SQLITE_OK, then
14071** the tokenization should be abandoned and the xTokenize() method should
14072** immediately return a copy of the xToken() return value. Or, if the
14073** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
14074** if an error occurs with the xTokenize() implementation itself, it
14075** may abandon the tokenization and return any error code other than
14076** SQLITE_OK or SQLITE_DONE.
14077**
14078** If the tokenizer is registered using an fts5_tokenizer_v2 object,
14079** then the xTokenize() method has two additional arguments - pLocale
14080** and nLocale. These specify the locale that the tokenizer should use
14081** for the current request. If pLocale and nLocale are both 0, then the
14082** tokenizer should use its default locale. Otherwise, pLocale points to
14083** an nLocale byte buffer containing the name of the locale to use as utf-8
14084** text. pLocale is not nul-terminated.
14085**
14086** FTS5_TOKENIZER
14087**
14088** There is also an fts5_tokenizer object. This is an older, deprecated,
14089** version of fts5_tokenizer_v2. It is similar except that:
14090**
14091** <ul>
14092** <li> There is no "iVersion" field, and
14093** <li> The xTokenize() method does not take a locale argument.
14094** </ul>
14095**
14096** Legacy fts5_tokenizer tokenizers must be registered using the
14097** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
14098**
14099** Tokenizer implementations registered using either API may be retrieved
14100** using both xFindTokenizer() and xFindTokenizer_v2().
14101**
14102** SYNONYM SUPPORT
14103**
14104** Custom tokenizers may also support synonyms. Consider a case in which a
14105** user wishes to query for a phrase such as "first place". Using the
14106** built-in tokenizers, the FTS5 query 'first + place' will match instances
14107** of "first place" within the document set, but not alternative forms
14108** such as "1st place". In some applications, it would be better to match
14109** all instances of "first place" or "1st place" regardless of which form
14110** the user specified in the MATCH query text.
14111**
14112** There are several ways to approach this in FTS5:
14113**
14114** <ol><li> By mapping all synonyms to a single token. In this case, using
14115** the above example, this means that the tokenizer returns the
14116** same token for inputs "first" and "1st". Say that token is in
14117** fact "first", so that when the user inserts the document "I won
14118** 1st place" entries are added to the index for tokens "i", "won",
14119** "first" and "place". If the user then queries for '1st + place',
14120** the tokenizer substitutes "first" for "1st" and the query works
14121** as expected.
14122**
14123** <li> By querying the index for all synonyms of each query term
14124** separately. In this case, when tokenizing query text, the
14125** tokenizer may provide multiple synonyms for a single term
14126** within the document. FTS5 then queries the index for each
14127** synonym individually. For example, faced with the query:
14128**
14129** <codeblock>
14130** ... MATCH 'first place'</codeblock>
14131**
14132** the tokenizer offers both "1st" and "first" as synonyms for the
14133** first token in the MATCH query and FTS5 effectively runs a query
14134** similar to:
14135**
14136** <codeblock>
14137** ... MATCH '(first OR 1st) place'</codeblock>
14138**
14139** except that, for the purposes of auxiliary functions, the query
14140** still appears to contain just two phrases - "(first OR 1st)"
14141** being treated as a single phrase.
14142**
14143** <li> By adding multiple synonyms for a single term to the FTS index.
14144** Using this method, when tokenizing document text, the tokenizer
14145** provides multiple synonyms for each token. So that when a
14146** document such as "I won first place" is tokenized, entries are
14147** added to the FTS index for "i", "won", "first", "1st" and
14148** "place".
14149**
14150** This way, even if the tokenizer does not provide synonyms
14151** when tokenizing query text (it should not - to do so would be
14152** inefficient), it doesn't matter if the user queries for
14153** 'first + place' or '1st + place', as there are entries in the
14154** FTS index corresponding to both forms of the first token.
14155** </ol>
14156**
14157** Whether it is parsing document or query text, any call to xToken that
14158** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
14159** is considered to supply a synonym for the previous token. For example,
14160** when parsing the document "I won first place", a tokenizer that supports
14161** synonyms would call xToken() 5 times, as follows:
14162**
14163** <codeblock>
14164** xToken(pCtx, 0, "i", 1, 0, 1);
14165** xToken(pCtx, 0, "won", 3, 2, 5);
14166** xToken(pCtx, 0, "first", 5, 6, 11);
14167** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
14168** xToken(pCtx, 0, "place", 5, 12, 17);
14169**</codeblock>
14170**
14171** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
14172** xToken() is called. Multiple synonyms may be specified for a single token
14173** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
14174** There is no limit to the number of synonyms that may be provided for a
14175** single token.
14176**
14177** In many cases, method (1) above is the best approach. It does not add
14178** extra data to the FTS index or require FTS5 to query for multiple terms,
14179** so it is efficient in terms of disk space and query speed. However, it
14180** does not support prefix queries very well. If, as suggested above, the
14181** token "first" is substituted for "1st" by the tokenizer, then the query:
14182**
14183** <codeblock>
14184** ... MATCH '1s*'</codeblock>
14185**
14186** will not match documents that contain the token "1st" (as the tokenizer
14187** will probably not map "1s" to any prefix of "first").
14188**
14189** For full prefix support, method (3) may be preferred. In this case,
14190** because the index contains entries for both "first" and "1st", prefix
14191** queries such as 'fi*' or '1s*' will match correctly. However, because
14192** extra entries are added to the FTS index, this method uses more space
14193** within the database.
14194**
14195** Method (2) offers a midpoint between (1) and (3). Using this method,
14196** a query such as '1s*' will match documents that contain the literal
14197** token "1st", but not "first" (assuming the tokenizer is not able to
14198** provide synonyms for prefixes). However, a non-prefix query like '1st'
14199** will match against "1st" and "first". This method does not require
14200** extra disk space, as no extra entries are added to the FTS index.
14201** On the other hand, it may require more CPU cycles to run MATCH queries,
14202** as separate queries of the FTS index are required for each synonym.
14203**
14204** When using methods (2) or (3), it is important that the tokenizer only
14205** provide synonyms when tokenizing document text (method (3)) or query
14206** text (method (2)), not both. Doing so will not cause any errors, but is
14207** inefficient.
14208*/
14209typedef struct Fts5Tokenizer Fts5Tokenizer;
14210typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
14211struct fts5_tokenizer_v2 {
14212 int iVersion; /* Currently always 2 */
14213
14214 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
14215 void (*xDelete)(Fts5Tokenizer*);
14216 int (*xTokenize)(Fts5Tokenizer*,
14217 void *pCtx,
14218 int flags, /* Mask of FTS5_TOKENIZE_* flags */
14219 const char *pText, int nText,
14220 const char *pLocale, int nLocale,
14221 int (*xToken)(
14222 void *pCtx, /* Copy of 2nd argument to xTokenize() */
14223 int tflags, /* Mask of FTS5_TOKEN_* flags */
14224 const char *pToken, /* Pointer to buffer containing token */
14225 int nToken, /* Size of token in bytes */
14226 int iStart, /* Byte offset of token within input text */
14227 int iEnd /* Byte offset of end of token within input text */
14228 )
14229 );
14230};
14231
14232/*
14233** New code should use the fts5_tokenizer_v2 type to define tokenizer
14234** implementations. The following type is included for legacy applications
14235** that still use it.
14236*/
14237typedef struct fts5_tokenizer fts5_tokenizer;
14238struct fts5_tokenizer {
14239 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
14240 void (*xDelete)(Fts5Tokenizer*);
14241 int (*xTokenize)(Fts5Tokenizer*,
14242 void *pCtx,
14243 int flags, /* Mask of FTS5_TOKENIZE_* flags */
14244 const char *pText, int nText,
14245 int (*xToken)(
14246 void *pCtx, /* Copy of 2nd argument to xTokenize() */
14247 int tflags, /* Mask of FTS5_TOKEN_* flags */
14248 const char *pToken, /* Pointer to buffer containing token */
14249 int nToken, /* Size of token in bytes */
14250 int iStart, /* Byte offset of token within input text */
14251 int iEnd /* Byte offset of end of token within input text */
14252 )
14253 );
14254};
14255
14256
14257/* Flags that may be passed as the third argument to xTokenize() */
14258#define FTS5_TOKENIZE_QUERY 0x0001
14259#define FTS5_TOKENIZE_PREFIX 0x0002
14260#define FTS5_TOKENIZE_DOCUMENT 0x0004
14261#define FTS5_TOKENIZE_AUX 0x0008
14262
14263/* Flags that may be passed by the tokenizer implementation back to FTS5
14264** as the third argument to the supplied xToken callback. */
14265#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
14266
14267/*
14268** END OF CUSTOM TOKENIZERS
14269*************************************************************************/
14270
14271/*************************************************************************
14272** FTS5 EXTENSION REGISTRATION API
14273*/
14274typedef struct fts5_api fts5_api;
14275struct fts5_api {
14276 int iVersion; /* Currently always set to 3 */
14277
14278 /* Create a new tokenizer */
14279 int (*xCreateTokenizer)(
14280 fts5_api *pApi,
14281 const char *zName,
14282 void *pUserData,
14283 fts5_tokenizer *pTokenizer,
14284 void (*xDestroy)(void*)
14285 );
14286
14287 /* Find an existing tokenizer */
14288 int (*xFindTokenizer)(
14289 fts5_api *pApi,
14290 const char *zName,
14291 void **ppUserData,
14292 fts5_tokenizer *pTokenizer
14293 );
14294
14295 /* Create a new auxiliary function */
14296 int (*xCreateFunction)(
14297 fts5_api *pApi,
14298 const char *zName,
14299 void *pUserData,
14300 fts5_extension_function xFunction,
14301 void (*xDestroy)(void*)
14302 );
14303
14304 /* APIs below this point are only available if iVersion>=3 */
14305
14306 /* Create a new tokenizer */
14307 int (*xCreateTokenizer_v2)(
14308 fts5_api *pApi,
14309 const char *zName,
14310 void *pUserData,
14311 fts5_tokenizer_v2 *pTokenizer,
14312 void (*xDestroy)(void*)
14313 );
14314
14315 /* Find an existing tokenizer */
14316 int (*xFindTokenizer_v2)(
14317 fts5_api *pApi,
14318 const char *zName,
14319 void **ppUserData,
14320 fts5_tokenizer_v2 **ppTokenizer
14321 );
14322};
14323
14324/*
14325** END OF REGISTRATION API
14326*************************************************************************/
14327
14328#ifdef __cplusplus
14329} /* end of the 'extern "C"' block */
14330#endif
14331
14332#endif /* _FTS5_H */
14333
14334/******** End of fts5.h *********/
14335#endif /* SQLITE3_H */
14336