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 "3.51.1"
150#define SQLITE_VERSION_NUMBER 3051001
151#define SQLITE_SOURCE_ID "2025-11-28 17:28:25 281fc0e9afc38674b9b0991943b9e9d1e64c6cbdb133d35f6f5c87ff6af3alt1"
152#define SQLITE_SCM_BRANCH "branch-3.51"
153#define SQLITE_SCM_TAGS "release version-3.51.1"
154#define SQLITE_SCM_DATETIME "2025-11-28T17:28:25.933Z"
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 use 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
1294/*
1295** CAPI3REF: Mutex Handle
1296**
1297** The mutex module within SQLite defines [sqlite3_mutex] to be an
1298** abstract type for a mutex object. The SQLite core never looks
1299** at the internal representation of an [sqlite3_mutex]. It only
1300** deals with pointers to the [sqlite3_mutex] object.
1301**
1302** Mutexes are created using [sqlite3_mutex_alloc()].
1303*/
1304typedef struct sqlite3_mutex sqlite3_mutex;
1305
1306/*
1307** CAPI3REF: Loadable Extension Thunk
1308**
1309** A pointer to the opaque sqlite3_api_routines structure is passed as
1310** the third parameter to entry points of [loadable extensions]. This
1311** structure must be typedefed in order to work around compiler warnings
1312** on some platforms.
1313*/
1314typedef struct sqlite3_api_routines sqlite3_api_routines;
1315
1316/*
1317** CAPI3REF: File Name
1318**
1319** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1320** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1321** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1322** may also be passed to special APIs such as:
1323**
1324** <ul>
1325** <li> sqlite3_filename_database()
1326** <li> sqlite3_filename_journal()
1327** <li> sqlite3_filename_wal()
1328** <li> sqlite3_uri_parameter()
1329** <li> sqlite3_uri_boolean()
1330** <li> sqlite3_uri_int64()
1331** <li> sqlite3_uri_key()
1332** </ul>
1333*/
1334typedef const char *sqlite3_filename;
1335
1336/*
1337** CAPI3REF: OS Interface Object
1338**
1339** An instance of the sqlite3_vfs object defines the interface between
1340** the SQLite core and the underlying operating system. The "vfs"
1341** in the name of the object stands for "virtual file system". See
1342** the [VFS | VFS documentation] for further information.
1343**
1344** The VFS interface is sometimes extended by adding new methods onto
1345** the end. Each time such an extension occurs, the iVersion field
1346** is incremented. The iVersion value started out as 1 in
1347** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1348** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1349** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1350** may be appended to the sqlite3_vfs object and the iVersion value
1351** may increase again in future versions of SQLite.
1352** Note that due to an oversight, the structure
1353** of the sqlite3_vfs object changed in the transition from
1354** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1355** and yet the iVersion field was not increased.
1356**
1357** The szOsFile field is the size of the subclassed [sqlite3_file]
1358** structure used by this VFS. mxPathname is the maximum length of
1359** a pathname in this VFS.
1360**
1361** Registered sqlite3_vfs objects are kept on a linked list formed by
1362** the pNext pointer. The [sqlite3_vfs_register()]
1363** and [sqlite3_vfs_unregister()] interfaces manage this list
1364** in a thread-safe way. The [sqlite3_vfs_find()] interface
1365** searches the list. Neither the application code nor the VFS
1366** implementation should use the pNext pointer.
1367**
1368** The pNext field is the only field in the sqlite3_vfs
1369** structure that SQLite will ever modify. SQLite will only access
1370** or modify this field while holding a particular static mutex.
1371** The application should never modify anything within the sqlite3_vfs
1372** object once the object has been registered.
1373**
1374** The zName field holds the name of the VFS module. The name must
1375** be unique across all VFS modules.
1376**
1377** [[sqlite3_vfs.xOpen]]
1378** ^SQLite guarantees that the zFilename parameter to xOpen
1379** is either a NULL pointer or string obtained
1380** from xFullPathname() with an optional suffix added.
1381** ^If a suffix is added to the zFilename parameter, it will
1382** consist of a single "-" character followed by no more than
1383** 11 alphanumeric and/or "-" characters.
1384** ^SQLite further guarantees that
1385** the string will be valid and unchanged until xClose() is
1386** called. Because of the previous sentence,
1387** the [sqlite3_file] can safely store a pointer to the
1388** filename if it needs to remember the filename for some reason.
1389** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1390** must invent its own temporary name for the file. ^Whenever the
1391** xFilename parameter is NULL it will also be the case that the
1392** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1393**
1394** The flags argument to xOpen() includes all bits set in
1395** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1396** or [sqlite3_open16()] is used, then flags includes at least
1397** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1398** If xOpen() opens a file read-only then it sets *pOutFlags to
1399** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1400**
1401** ^(SQLite will also add one of the following flags to the xOpen()
1402** call, depending on the object being opened:
1403**
1404** <ul>
1405** <li> [SQLITE_OPEN_MAIN_DB]
1406** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1407** <li> [SQLITE_OPEN_TEMP_DB]
1408** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1409** <li> [SQLITE_OPEN_TRANSIENT_DB]
1410** <li> [SQLITE_OPEN_SUBJOURNAL]
1411** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1412** <li> [SQLITE_OPEN_WAL]
1413** </ul>)^
1414**
1415** The file I/O implementation can use the object type flags to
1416** change the way it deals with files. For example, an application
1417** that does not care about crash recovery or rollback might make
1418** the open of a journal file a no-op. Writes to this journal would
1419** also be no-ops, and any attempt to read the journal would return
1420** SQLITE_IOERR. Or the implementation might recognize that a database
1421** file will be doing page-aligned sector reads and writes in a random
1422** order and set up its I/O subsystem accordingly.
1423**
1424** SQLite might also add one of the following flags to the xOpen method:
1425**
1426** <ul>
1427** <li> [SQLITE_OPEN_DELETEONCLOSE]
1428** <li> [SQLITE_OPEN_EXCLUSIVE]
1429** </ul>
1430**
1431** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1432** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1433** will be set for TEMP databases and their journals, transient
1434** databases, and subjournals.
1435**
1436** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1437** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1438** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1439** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1440** SQLITE_OPEN_CREATE, is used to indicate that file should always
1441** be created, and that it is an error if it already exists.
1442** It is <i>not</i> used to indicate the file should be opened
1443** for exclusive access.
1444**
1445** ^At least szOsFile bytes of memory are allocated by SQLite
1446** to hold the [sqlite3_file] structure passed as the third
1447** argument to xOpen. The xOpen method does not have to
1448** allocate the structure; it should just fill it in. Note that
1449** the xOpen method must set the sqlite3_file.pMethods to either
1450** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1451** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1452** element will be valid after xOpen returns regardless of the success
1453** or failure of the xOpen call.
1454**
1455** [[sqlite3_vfs.xAccess]]
1456** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1457** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1458** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1459** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1460** flag is never actually used and is not implemented in the built-in
1461** VFSes of SQLite. The file is named by the second argument and can be a
1462** directory. The xAccess method returns [SQLITE_OK] on success or some
1463** non-zero error code if there is an I/O error or if the name of
1464** the file given in the second argument is illegal. If SQLITE_OK
1465** is returned, then non-zero or zero is written into *pResOut to indicate
1466** whether or not the file is accessible.
1467**
1468** ^SQLite will always allocate at least mxPathname+1 bytes for the
1469** output buffer xFullPathname. The exact size of the output buffer
1470** is also passed as a parameter to both methods. If the output buffer
1471** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1472** handled as a fatal error by SQLite, vfs implementations should endeavor
1473** to prevent this by setting mxPathname to a sufficiently large value.
1474**
1475** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1476** interfaces are not strictly a part of the filesystem, but they are
1477** included in the VFS structure for completeness.
1478** The xRandomness() function attempts to return nBytes bytes
1479** of good-quality randomness into zOut. The return value is
1480** the actual number of bytes of randomness obtained.
1481** The xSleep() method causes the calling thread to sleep for at
1482** least the number of microseconds given. ^The xCurrentTime()
1483** method returns a Julian Day Number for the current date and time as
1484** a floating point value.
1485** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1486** Day Number multiplied by 86400000 (the number of milliseconds in
1487** a 24-hour day).
1488** ^SQLite will use the xCurrentTimeInt64() method to get the current
1489** date and time if that method is available (if iVersion is 2 or
1490** greater and the function pointer is not NULL) and will fall back
1491** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1492**
1493** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1494** are not used by the SQLite core. These optional interfaces are provided
1495** by some VFSes to facilitate testing of the VFS code. By overriding
1496** system calls with functions under its control, a test program can
1497** simulate faults and error conditions that would otherwise be difficult
1498** or impossible to induce. The set of system calls that can be overridden
1499** varies from one VFS to another, and from one version of the same VFS to the
1500** next. Applications that use these interfaces must be prepared for any
1501** or all of these interfaces to be NULL or for their behavior to change
1502** from one release to the next. Applications must not attempt to access
1503** any of these methods if the iVersion of the VFS is less than 3.
1504*/
1505typedef struct sqlite3_vfs sqlite3_vfs;
1506typedef void (*sqlite3_syscall_ptr)(void);
1507struct sqlite3_vfs {
1508 int iVersion; /* Structure version number (currently 3) */
1509 int szOsFile; /* Size of subclassed sqlite3_file */
1510 int mxPathname; /* Maximum file pathname length */
1511 sqlite3_vfs *pNext; /* Next registered VFS */
1512 const char *zName; /* Name of this virtual file system */
1513 void *pAppData; /* Pointer to application-specific data */
1514 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1515 int flags, int *pOutFlags);
1516 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1517 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1518 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1519 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1520 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1521 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1522 void (*xDlClose)(sqlite3_vfs*, void*);
1523 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1524 int (*xSleep)(sqlite3_vfs*, int microseconds);
1525 int (*xCurrentTime)(sqlite3_vfs*, double*);
1526 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1527 /*
1528 ** The methods above are in version 1 of the sqlite_vfs object
1529 ** definition. Those that follow are added in version 2 or later
1530 */
1531 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1532 /*
1533 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1534 ** Those below are for version 3 and greater.
1535 */
1536 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1537 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1538 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1539 /*
1540 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1541 ** New fields may be appended in future versions. The iVersion
1542 ** value will increment whenever this happens.
1543 */
1544};
1545
1546/*
1547** CAPI3REF: Flags for the xAccess VFS method
1548**
1549** These integer constants can be used as the third parameter to
1550** the xAccess method of an [sqlite3_vfs] object. They determine
1551** what kind of permissions the xAccess method is looking for.
1552** With SQLITE_ACCESS_EXISTS, the xAccess method
1553** simply checks whether the file exists.
1554** With SQLITE_ACCESS_READWRITE, the xAccess method
1555** checks whether the named directory is both readable and writable
1556** (in other words, if files can be added, removed, and renamed within
1557** the directory).
1558** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1559** [temp_store_directory pragma], though this could change in a future
1560** release of SQLite.
1561** With SQLITE_ACCESS_READ, the xAccess method
1562** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1563** currently unused, though it might be used in a future release of
1564** SQLite.
1565*/
1566#define SQLITE_ACCESS_EXISTS 0
1567#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1568#define SQLITE_ACCESS_READ 2 /* Unused */
1569
1570/*
1571** CAPI3REF: Flags for the xShmLock VFS method
1572**
1573** These integer constants define the various locking operations
1574** allowed by the xShmLock method of [sqlite3_io_methods]. The
1575** following are the only legal combinations of flags to the
1576** xShmLock method:
1577**
1578** <ul>
1579** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1580** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1581** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1582** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1583** </ul>
1584**
1585** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1586** was given on the corresponding lock.
1587**
1588** The xShmLock method can transition between unlocked and SHARED or
1589** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1590** and EXCLUSIVE.
1591*/
1592#define SQLITE_SHM_UNLOCK 1
1593#define SQLITE_SHM_LOCK 2
1594#define SQLITE_SHM_SHARED 4
1595#define SQLITE_SHM_EXCLUSIVE 8
1596
1597/*
1598** CAPI3REF: Maximum xShmLock index
1599**
1600** The xShmLock method on [sqlite3_io_methods] may use values
1601** between 0 and this upper bound as its "offset" argument.
1602** The SQLite core will never attempt to acquire or release a
1603** lock outside of this range
1604*/
1605#define SQLITE_SHM_NLOCK 8
1606
1607
1608/*
1609** CAPI3REF: Initialize The SQLite Library
1610**
1611** ^The sqlite3_initialize() routine initializes the
1612** SQLite library. ^The sqlite3_shutdown() routine
1613** deallocates any resources that were allocated by sqlite3_initialize().
1614** These routines are designed to aid in process initialization and
1615** shutdown on embedded systems. Workstation applications using
1616** SQLite normally do not need to invoke either of these routines.
1617**
1618** A call to sqlite3_initialize() is an "effective" call if it is
1619** the first time sqlite3_initialize() is invoked during the lifetime of
1620** the process, or if it is the first time sqlite3_initialize() is invoked
1621** following a call to sqlite3_shutdown(). ^(Only an effective call
1622** of sqlite3_initialize() does any initialization. All other calls
1623** are harmless no-ops.)^
1624**
1625** A call to sqlite3_shutdown() is an "effective" call if it is the first
1626** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1627** an effective call to sqlite3_shutdown() does any deinitialization.
1628** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1629**
1630** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1631** is not. The sqlite3_shutdown() interface must only be called from a
1632** single thread. All open [database connections] must be closed and all
1633** other SQLite resources must be deallocated prior to invoking
1634** sqlite3_shutdown().
1635**
1636** Among other things, ^sqlite3_initialize() will invoke
1637** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1638** will invoke sqlite3_os_end().
1639**
1640** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1641** ^If for some reason, sqlite3_initialize() is unable to initialize
1642** the library (perhaps it is unable to allocate a needed resource such
1643** as a mutex) it returns an [error code] other than [SQLITE_OK].
1644**
1645** ^The sqlite3_initialize() routine is called internally by many other
1646** SQLite interfaces so that an application usually does not need to
1647** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1648** calls sqlite3_initialize() so the SQLite library will be automatically
1649** initialized when [sqlite3_open()] is called if it has not been initialized
1650** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1651** compile-time option, then the automatic calls to sqlite3_initialize()
1652** are omitted and the application must call sqlite3_initialize() directly
1653** prior to using any other SQLite interface. For maximum portability,
1654** it is recommended that applications always invoke sqlite3_initialize()
1655** directly prior to using any other SQLite interface. Future releases
1656** of SQLite may require this. In other words, the behavior exhibited
1657** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1658** default behavior in some future release of SQLite.
1659**
1660** The sqlite3_os_init() routine does operating-system specific
1661** initialization of the SQLite library. The sqlite3_os_end()
1662** routine undoes the effect of sqlite3_os_init(). Typical tasks
1663** performed by these routines include allocation or deallocation
1664** of static resources, initialization of global variables,
1665** setting up a default [sqlite3_vfs] module, or setting up
1666** a default configuration using [sqlite3_config()].
1667**
1668** The application should never invoke either sqlite3_os_init()
1669** or sqlite3_os_end() directly. The application should only invoke
1670** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1671** interface is called automatically by sqlite3_initialize() and
1672** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1673** implementations for sqlite3_os_init() and sqlite3_os_end()
1674** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1675** When [custom builds | built for other platforms]
1676** (using the [SQLITE_OS_OTHER=1] compile-time
1677** option) the application must supply a suitable implementation for
1678** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1679** implementation of sqlite3_os_init() or sqlite3_os_end()
1680** must return [SQLITE_OK] on success and some other [error code] upon
1681** failure.
1682*/
1683SQLITE_API int sqlite3_initialize(void);
1684SQLITE_API int sqlite3_shutdown(void);
1685SQLITE_API int sqlite3_os_init(void);
1686SQLITE_API int sqlite3_os_end(void);
1687
1688/*
1689** CAPI3REF: Configuring The SQLite Library
1690**
1691** The sqlite3_config() interface is used to make global configuration
1692** changes to SQLite in order to tune SQLite to the specific needs of
1693** the application. The default configuration is recommended for most
1694** applications and so this routine is usually not necessary. It is
1695** provided to support rare applications with unusual needs.
1696**
1697** <b>The sqlite3_config() interface is not threadsafe. The application
1698** must ensure that no other SQLite interfaces are invoked by other
1699** threads while sqlite3_config() is running.</b>
1700**
1701** The first argument to sqlite3_config() is an integer
1702** [configuration option] that determines
1703** what property of SQLite is to be configured. Subsequent arguments
1704** vary depending on the [configuration option]
1705** in the first argument.
1706**
1707** For most configuration options, the sqlite3_config() interface
1708** may only be invoked prior to library initialization using
1709** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1710** The exceptional configuration options that may be invoked at any time
1711** are called "anytime configuration options".
1712** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1713** [sqlite3_shutdown()] with a first argument that is not an anytime
1714** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1715** Note, however, that ^sqlite3_config() can be called as part of the
1716** implementation of an application-defined [sqlite3_os_init()].
1717**
1718** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1719** ^If the option is unknown or SQLite is unable to set the option
1720** then this routine returns a non-zero [error code].
1721*/
1722SQLITE_API int sqlite3_config(int, ...);
1723
1724/*
1725** CAPI3REF: Configure database connections
1726** METHOD: sqlite3
1727**
1728** The sqlite3_db_config() interface is used to make configuration
1729** changes to a [database connection]. The interface is similar to
1730** [sqlite3_config()] except that the changes apply to a single
1731** [database connection] (specified in the first argument).
1732**
1733** The second argument to sqlite3_db_config(D,V,...) is the
1734** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1735** that indicates what aspect of the [database connection] is being configured.
1736** Subsequent arguments vary depending on the configuration verb.
1737**
1738** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1739** the call is considered successful.
1740*/
1741SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1742
1743/*
1744** CAPI3REF: Memory Allocation Routines
1745**
1746** An instance of this object defines the interface between SQLite
1747** and low-level memory allocation routines.
1748**
1749** This object is used in only one place in the SQLite interface.
1750** A pointer to an instance of this object is the argument to
1751** [sqlite3_config()] when the configuration option is
1752** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1753** By creating an instance of this object
1754** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1755** during configuration, an application can specify an alternative
1756** memory allocation subsystem for SQLite to use for all of its
1757** dynamic memory needs.
1758**
1759** Note that SQLite comes with several [built-in memory allocators]
1760** that are perfectly adequate for the overwhelming majority of applications
1761** and that this object is only useful to a tiny minority of applications
1762** with specialized memory allocation requirements. This object is
1763** also used during testing of SQLite in order to specify an alternative
1764** memory allocator that simulates memory out-of-memory conditions in
1765** order to verify that SQLite recovers gracefully from such
1766** conditions.
1767**
1768** The xMalloc, xRealloc, and xFree methods must work like the
1769** malloc(), realloc() and free() functions from the standard C library.
1770** ^SQLite guarantees that the second argument to
1771** xRealloc is always a value returned by a prior call to xRoundup.
1772**
1773** xSize should return the allocated size of a memory allocation
1774** previously obtained from xMalloc or xRealloc. The allocated size
1775** is always at least as big as the requested size but may be larger.
1776**
1777** The xRoundup method returns what would be the allocated size of
1778** a memory allocation given a particular requested size. Most memory
1779** allocators round up memory allocations at least to the next multiple
1780** of 8. Some allocators round up to a larger multiple or to a power of 2.
1781** Every memory allocation request coming in through [sqlite3_malloc()]
1782** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1783** that causes the corresponding memory allocation to fail.
1784**
1785** The xInit method initializes the memory allocator. For example,
1786** it might allocate any required mutexes or initialize internal data
1787** structures. The xShutdown method is invoked (indirectly) by
1788** [sqlite3_shutdown()] and should deallocate any resources acquired
1789** by xInit. The pAppData pointer is used as the only parameter to
1790** xInit and xShutdown.
1791**
1792** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1793** the xInit method, so the xInit method need not be threadsafe. The
1794** xShutdown method is only called from [sqlite3_shutdown()] so it does
1795** not need to be threadsafe either. For all other methods, SQLite
1796** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1797** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1798** it is by default) and so the methods are automatically serialized.
1799** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1800** methods must be threadsafe or else make their own arrangements for
1801** serialization.
1802**
1803** SQLite will never invoke xInit() more than once without an intervening
1804** call to xShutdown().
1805*/
1806typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1807struct sqlite3_mem_methods {
1808 void *(*xMalloc)(int); /* Memory allocation function */
1809 void (*xFree)(void*); /* Free a prior allocation */
1810 void *(*xRealloc)(void*,int); /* Resize an allocation */
1811 int (*xSize)(void*); /* Return the size of an allocation */
1812 int (*xRoundup)(int); /* Round up request size to allocation size */
1813 int (*xInit)(void*); /* Initialize the memory allocator */
1814 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1815 void *pAppData; /* Argument to xInit() and xShutdown() */
1816};
1817
1818/*
1819** CAPI3REF: Configuration Options
1820** KEYWORDS: {configuration option}
1821**
1822** These constants are the available integer configuration options that
1823** can be passed as the first argument to the [sqlite3_config()] interface.
1824**
1825** Most of the configuration options for sqlite3_config()
1826** will only work if invoked prior to [sqlite3_initialize()] or after
1827** [sqlite3_shutdown()]. The few exceptions to this rule are called
1828** "anytime configuration options".
1829** ^Calling [sqlite3_config()] with a first argument that is not an
1830** anytime configuration option in between calls to [sqlite3_initialize()] and
1831** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1832**
1833** The set of anytime configuration options can change (by insertions
1834** and/or deletions) from one release of SQLite to the next.
1835** As of SQLite version 3.42.0, the complete set of anytime configuration
1836** options is:
1837** <ul>
1838** <li> SQLITE_CONFIG_LOG
1839** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1840** </ul>
1841**
1842** New configuration options may be added in future releases of SQLite.
1843** Existing configuration options might be discontinued. Applications
1844** should check the return code from [sqlite3_config()] to make sure that
1845** the call worked. The [sqlite3_config()] interface will return a
1846** non-zero [error code] if a discontinued or unsupported configuration option
1847** is invoked.
1848**
1849** <dl>
1850** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1851** <dd>There are no arguments to this option. ^This option sets the
1852** [threading mode] to Single-thread. In other words, it disables
1853** all mutexing and puts SQLite into a mode where it can only be used
1854** by a single thread. ^If SQLite is compiled with
1855** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1856** it is not possible to change the [threading mode] from its default
1857** value of Single-thread and so [sqlite3_config()] will return
1858** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1859** configuration option.</dd>
1860**
1861** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1862** <dd>There are no arguments to this option. ^This option sets the
1863** [threading mode] to Multi-thread. In other words, it disables
1864** mutexing on [database connection] and [prepared statement] objects.
1865** The application is responsible for serializing access to
1866** [database connections] and [prepared statements]. But other mutexes
1867** are enabled so that SQLite will be safe to use in a multi-threaded
1868** environment as long as no two threads attempt to use the same
1869** [database connection] at the same time. ^If SQLite is compiled with
1870** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1871** it is not possible to set the Multi-thread [threading mode] and
1872** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1873** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1874**
1875** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1876** <dd>There are no arguments to this option. ^This option sets the
1877** [threading mode] to Serialized. In other words, this option enables
1878** all mutexes including the recursive
1879** mutexes on [database connection] and [prepared statement] objects.
1880** In this mode (which is the default when SQLite is compiled with
1881** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1882** to [database connections] and [prepared statements] so that the
1883** application is free to use the same [database connection] or the
1884** same [prepared statement] in different threads at the same time.
1885** ^If SQLite is compiled with
1886** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1887** it is not possible to set the Serialized [threading mode] and
1888** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1889** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1890**
1891** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1892** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1893** a pointer to an instance of the [sqlite3_mem_methods] structure.
1894** The argument specifies
1895** alternative low-level memory allocation routines to be used in place of
1896** the memory allocation routines built into SQLite.)^ ^SQLite makes
1897** its own private copy of the content of the [sqlite3_mem_methods] structure
1898** before the [sqlite3_config()] call returns.</dd>
1899**
1900** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1901** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1902** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1903** The [sqlite3_mem_methods]
1904** structure is filled with the currently defined memory allocation routines.)^
1905** This option can be used to overload the default memory allocation
1906** routines with a wrapper that simulates memory allocation failure or
1907** tracks memory usage, for example. </dd>
1908**
1909** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1910** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes a single argument of
1911** type int, interpreted as a boolean, which if true provides a hint to
1912** SQLite that it should avoid large memory allocations if possible.
1913** SQLite will run faster if it is free to make large memory allocations,
1914** but some applications might prefer to run slower in exchange for
1915** guarantees about memory fragmentation that are possible if large
1916** allocations are avoided. This hint is normally off.
1917** </dd>
1918**
1919** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1920** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes a single argument of type int,
1921** interpreted as a boolean, which enables or disables the collection of
1922** memory allocation statistics. ^(When memory allocation statistics are
1923** disabled, the following SQLite interfaces become non-operational:
1924** <ul>
1925** <li> [sqlite3_hard_heap_limit64()]
1926** <li> [sqlite3_memory_used()]
1927** <li> [sqlite3_memory_highwater()]
1928** <li> [sqlite3_soft_heap_limit64()]
1929** <li> [sqlite3_status64()]
1930** </ul>)^
1931** ^Memory allocation statistics are enabled by default unless SQLite is
1932** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1933** allocation statistics are disabled by default.
1934** </dd>
1935**
1936** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1937** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1938** </dd>
1939**
1940** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1941** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1942** that SQLite can use for the database page cache with the default page
1943** cache implementation.
1944** This configuration option is a no-op if an application-defined page
1945** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1946** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1947** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1948** and the number of cache lines (N).
1949** The sz argument should be the size of the largest database page
1950** (a power of two between 512 and 65536) plus some extra bytes for each
1951** page header. ^The number of extra bytes needed by the page header
1952** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1953** ^It is harmless, apart from the wasted memory,
1954** for the sz parameter to be larger than necessary. The pMem
1955** argument must be either a NULL pointer or a pointer to an 8-byte
1956** aligned block of memory of at least sz*N bytes, otherwise
1957** subsequent behavior is undefined.
1958** ^When pMem is not NULL, SQLite will strive to use the memory provided
1959** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1960** a page cache line is larger than sz bytes or if all of the pMem buffer
1961** is exhausted.
1962** ^If pMem is NULL and N is non-zero, then each database connection
1963** does an initial bulk allocation for page cache memory
1964** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1965** of -1024*N bytes if N is negative. ^If additional
1966** page cache memory is needed beyond what is provided by the initial
1967** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1968** additional cache line. </dd>
1969**
1970** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1971** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1972** that SQLite will use for all of its dynamic memory allocation needs
1973** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1974** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1975** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1976** [SQLITE_ERROR] if invoked otherwise.
1977** ^There are three arguments to SQLITE_CONFIG_HEAP:
1978** An 8-byte aligned pointer to the memory,
1979** the number of bytes in the memory buffer, and the minimum allocation size.
1980** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1981** to using its default memory allocator (the system malloc() implementation),
1982** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1983** memory pointer is not NULL then the alternative memory
1984** allocator is engaged to handle all of SQLites memory allocation needs.
1985** The first pointer (the memory pointer) must be aligned to an 8-byte
1986** boundary or subsequent behavior of SQLite will be undefined.
1987** The minimum allocation size is capped at 2**12. Reasonable values
1988** for the minimum allocation size are 2**5 through 2**8.</dd>
1989**
1990** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1991** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1992** pointer to an instance of the [sqlite3_mutex_methods] structure.
1993** The argument specifies alternative low-level mutex routines to be used
1994** in place of the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1995** the content of the [sqlite3_mutex_methods] structure before the call to
1996** [sqlite3_config()] returns. ^If SQLite is compiled with
1997** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1998** the entire mutexing subsystem is omitted from the build and hence calls to
1999** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
2000** return [SQLITE_ERROR].</dd>
2001**
2002** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
2003** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
2004** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
2005** [sqlite3_mutex_methods]
2006** structure is filled with the currently defined mutex routines.)^
2007** This option can be used to overload the default mutex allocation
2008** routines with a wrapper used to track mutex usage for performance
2009** profiling or testing, for example. ^If SQLite is compiled with
2010** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
2011** the entire mutexing subsystem is omitted from the build and hence calls to
2012** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
2013** return [SQLITE_ERROR].</dd>
2014**
2015** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
2016** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
2017** the default size of [lookaside memory] on each [database connection].
2018** The first argument is the
2019** size of each lookaside buffer slot ("sz") and the second is the number of
2020** slots allocated to each database connection ("cnt").)^
2021** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
2022** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
2023** be used to change the lookaside configuration on individual connections.)^
2024** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
2025** default lookaside configuration at compile-time.
2026** </dd>
2027**
2028** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
2029** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
2030** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
2031** the interface to a custom page cache implementation.)^
2032** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
2033**
2034** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
2035** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
2036** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies off
2037** the current page cache implementation into that object.)^ </dd>
2038**
2039** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
2040** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
2041** global [error log].
2042** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2043** function with a call signature of void(*)(void*,int,const char*),
2044** and a pointer to void. ^If the function pointer is not NULL, it is
2045** invoked by [sqlite3_log()] to process each logging event. ^If the
2046** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2047** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2048** passed through as the first parameter to the application-defined logger
2049** function whenever that function is invoked. ^The second parameter to
2050** the logger function is a copy of the first parameter to the corresponding
2051** [sqlite3_log()] call and is intended to be a [result code] or an
2052** [extended result code]. ^The third parameter passed to the logger is
2053** a log message after formatting via [sqlite3_snprintf()].
2054** The SQLite logging interface is not reentrant; the logger function
2055** supplied by the application must not invoke any SQLite interface.
2056** In a multi-threaded application, the application-defined logger
2057** function must be threadsafe. </dd>
2058**
2059** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2060** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2061** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2062** then URI handling is globally disabled.)^ ^If URI handling is globally
2063** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2064** [sqlite3_open16()] or
2065** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2066** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2067** connection is opened. ^If it is globally disabled, filenames are
2068** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2069** database connection is opened. ^(By default, URI handling is globally
2070** disabled. The default value may be changed by compiling with the
2071** [SQLITE_USE_URI] symbol defined.)^
2072**
2073** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2074** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2075** argument which is interpreted as a boolean in order to enable or disable
2076** the use of covering indices for full table scans in the query optimizer.
2077** ^The default setting is determined
2078** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2079** if that compile-time option is omitted.
2080** The ability to disable the use of covering indices for full table scans
2081** is because some incorrectly coded legacy applications might malfunction
2082** when the optimization is enabled. Providing the ability to
2083** disable the optimization allows the older, buggy application code to work
2084** without change even with newer versions of SQLite.
2085**
2086** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2087** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2088** <dd> These options are obsolete and should not be used by new code.
2089** They are retained for backwards compatibility but are now no-ops.
2090** </dd>
2091**
2092** [[SQLITE_CONFIG_SQLLOG]]
2093** <dt>SQLITE_CONFIG_SQLLOG
2094** <dd>This option is only available if sqlite is compiled with the
2095** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2096** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2097** The second should be of type (void*). The callback is invoked by the library
2098** in three separate circumstances, identified by the value passed as the
2099** fourth parameter. If the fourth parameter is 0, then the database connection
2100** passed as the second argument has just been opened. The third argument
2101** points to a buffer containing the name of the main database file. If the
2102** fourth parameter is 1, then the SQL statement that the third parameter
2103** points to has just been executed. Or, if the fourth parameter is 2, then
2104** the connection being passed as the second parameter is being closed. The
2105** third parameter is passed NULL In this case. An example of using this
2106** configuration option can be seen in the "test_sqllog.c" source file in
2107** the canonical SQLite source tree.</dd>
2108**
2109** [[SQLITE_CONFIG_MMAP_SIZE]]
2110** <dt>SQLITE_CONFIG_MMAP_SIZE
2111** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2112** that are the default mmap size limit (the default setting for
2113** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2114** ^The default setting can be overridden by each database connection using
2115** either the [PRAGMA mmap_size] command, or by using the
2116** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2117** will be silently truncated if necessary so that it does not exceed the
2118** compile-time maximum mmap size set by the
2119** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2120** ^If either argument to this option is negative, then that argument is
2121** changed to its compile-time default.
2122**
2123** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2124** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2125** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2126** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2127** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2128** that specifies the maximum size of the created heap.
2129**
2130** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2131** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2132** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2133** is a pointer to an integer and writes into that integer the number of extra
2134** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2135** The amount of extra space required can change depending on the compiler,
2136** target platform, and SQLite version.
2137**
2138** [[SQLITE_CONFIG_PMASZ]]
2139** <dt>SQLITE_CONFIG_PMASZ
2140** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2141** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2142** sorter to that integer. The default minimum PMA Size is set by the
2143** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2144** to help with sort operations when multithreaded sorting
2145** is enabled (using the [PRAGMA threads] command) and the amount of content
2146** to be sorted exceeds the page size times the minimum of the
2147** [PRAGMA cache_size] setting and this value.
2148**
2149** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2150** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2151** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2152** becomes the [statement journal] spill-to-disk threshold.
2153** [Statement journals] are held in memory until their size (in bytes)
2154** exceeds this threshold, at which point they are written to disk.
2155** Or if the threshold is -1, statement journals are always held
2156** exclusively in memory.
2157** Since many statement journals never become large, setting the spill
2158** threshold to a value such as 64KiB can greatly reduce the amount of
2159** I/O required to support statement rollback.
2160** The default value for this setting is controlled by the
2161** [SQLITE_STMTJRNL_SPILL] compile-time option.
2162**
2163** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2164** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2165** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2166** of type (int) - the new value of the sorter-reference size threshold.
2167** Usually, when SQLite uses an external sort to order records according
2168** to an ORDER BY clause, all fields required by the caller are present in the
2169** sorted records. However, if SQLite determines based on the declared type
2170** of a table column that its values are likely to be very large - larger
2171** than the configured sorter-reference size threshold - then a reference
2172** is stored in each sorted record and the required column values loaded
2173** from the database as records are returned in sorted order. The default
2174** value for this option is to never use this optimization. Specifying a
2175** negative value for this option restores the default behavior.
2176** This option is only available if SQLite is compiled with the
2177** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2178**
2179** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2180** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2181** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2182** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2183** database created using [sqlite3_deserialize()]. This default maximum
2184** size can be adjusted up or down for individual databases using the
2185** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2186** configuration setting is never used, then the default maximum is determined
2187** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2188** compile-time option is not set, then the default maximum is 1073741824.
2189**
2190** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2191** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2192** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2193** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2194** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2195** defaults to on. This configuration option queries the current setting or
2196** changes the setting to off or on. The argument is a pointer to an integer.
2197** If that integer initially holds a value of 1, then the ability for VIEWs to
2198** have ROWIDs is activated. If the integer initially holds zero, then the
2199** ability is deactivated. Any other initial value for the integer leaves the
2200** setting unchanged. After changes, if any, the integer is written with
2201** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2202** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2203** recommended case) then the integer is always filled with zero, regardless
2204** if its initial value.
2205** </dl>
2206*/
2207#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2208#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2209#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2210#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2211#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2212#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2213#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2214#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2215#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2216#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2217#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2218/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2219#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2220#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2221#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2222#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2223#define SQLITE_CONFIG_URI 17 /* int */
2224#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2225#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2226#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2227#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2228#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2229#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2230#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2231#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2232#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2233#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2234#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2235#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2236#define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2237
2238/*
2239** CAPI3REF: Database Connection Configuration Options
2240**
2241** These constants are the available integer configuration options that
2242** can be passed as the second parameter to the [sqlite3_db_config()] interface.
2243**
2244** The [sqlite3_db_config()] interface is a var-args function. It takes a
2245** variable number of parameters, though always at least two. The number of
2246** parameters passed into sqlite3_db_config() depends on which of these
2247** constants is given as the second parameter. This documentation page
2248** refers to parameters beyond the second as "arguments". Thus, when this
2249** page says "the N-th argument" it means "the N-th parameter past the
2250** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
2251**
2252** New configuration options may be added in future releases of SQLite.
2253** Existing configuration options might be discontinued. Applications
2254** should check the return code from [sqlite3_db_config()] to make sure that
2255** the call worked. ^The [sqlite3_db_config()] interface will return a
2256** non-zero [error code] if a discontinued or unsupported configuration option
2257** is invoked.
2258**
2259** <dl>
2260** [[SQLITE_DBCONFIG_LOOKASIDE]]
2261** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2262** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
2263** configuration of the [lookaside memory allocator] within a database
2264** connection.
2265** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
2266** in the [DBCONFIG arguments|usual format].
2267** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
2268** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
2269** should have a total of five parameters.
2270** <ol>
2271** <li><p>The first argument ("buf") is a
2272** pointer to a memory buffer to use for lookaside memory.
2273** The first argument may be NULL in which case SQLite will allocate the
2274** lookaside buffer itself using [sqlite3_malloc()].
2275** <li><P>The second argument ("sz") is the
2276** size of each lookaside buffer slot. Lookaside is disabled if "sz"
2277** is less than 8. The "sz" argument should be a multiple of 8 less than
2278** 65536. If "sz" does not meet this constraint, it is reduced in size until
2279** it does.
2280** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled
2281** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so
2282** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt"
2283** parameter is usually chosen so that the product of "sz" and "cnt" is less
2284** than 1,000,000.
2285** </ol>
2286** <p>If the "buf" argument is not NULL, then it must
2287** point to a memory buffer with a size that is greater than
2288** or equal to the product of "sz" and "cnt".
2289** The buffer must be aligned to an 8-byte boundary.
2290** The lookaside memory
2291** configuration for a database connection can only be changed when that
2292** connection is not currently using lookaside memory, or in other words
2293** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
2294** Any attempt to change the lookaside memory configuration when lookaside
2295** memory is in use leaves the configuration unchanged and returns
2296** [SQLITE_BUSY].
2297** If the "buf" argument is NULL and an attempt
2298** to allocate memory based on "sz" and "cnt" fails, then
2299** lookaside is silently disabled.
2300** <p>
2301** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
2302** default lookaside configuration at initialization. The
2303** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
2304** configuration at compile-time. Typical values for lookaside are 1200 for
2305** "sz" and 40 to 100 for "cnt".
2306** </dd>
2307**
2308** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2309** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2310** <dd> ^This option is used to enable or disable the enforcement of
2311** [foreign key constraints]. This is the same setting that is
2312** enabled or disabled by the [PRAGMA foreign_keys] statement.
2313** The first argument is an integer which is 0 to disable FK enforcement,
2314** positive to enable FK enforcement or negative to leave FK enforcement
2315** unchanged. The second parameter is a pointer to an integer into which
2316** is written 0 or 1 to indicate whether FK enforcement is off or on
2317** following this call. The second parameter may be a NULL pointer, in
2318** which case the FK enforcement setting is not reported back. </dd>
2319**
2320** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2321** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2322** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2323** There should be two additional arguments.
2324** The first argument is an integer which is 0 to disable triggers,
2325** positive to enable triggers or negative to leave the setting unchanged.
2326** The second parameter is a pointer to an integer into which
2327** is written 0 or 1 to indicate whether triggers are disabled or enabled
2328** following this call. The second parameter may be a NULL pointer, in
2329** which case the trigger setting is not reported back.
2330**
2331** <p>Originally this option disabled all triggers. ^(However, since
2332** SQLite version 3.35.0, TEMP triggers are still allowed even if
2333** this option is off. So, in other words, this option now only disables
2334** triggers in the main database schema or in the schemas of [ATTACH]-ed
2335** databases.)^ </dd>
2336**
2337** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2338** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2339** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2340** There must be two additional arguments.
2341** The first argument is an integer which is 0 to disable views,
2342** positive to enable views or negative to leave the setting unchanged.
2343** The second parameter is a pointer to an integer into which
2344** is written 0 or 1 to indicate whether views are disabled or enabled
2345** following this call. The second parameter may be a NULL pointer, in
2346** which case the view setting is not reported back.
2347**
2348** <p>Originally this option disabled all views. ^(However, since
2349** SQLite version 3.35.0, TEMP views are still allowed even if
2350** this option is off. So, in other words, this option now only disables
2351** views in the main database schema or in the schemas of ATTACH-ed
2352** databases.)^ </dd>
2353**
2354** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2355** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2356** <dd> ^This option is used to enable or disable using the
2357** [fts3_tokenizer()] function - part of the [FTS3] full-text search engine
2358** extension - without using bound parameters as the parameters. Doing so
2359** is disabled by default. There must be two additional arguments. The first
2360** argument is an integer. If it is passed 0, then using fts3_tokenizer()
2361** without bound parameters is disabled. If it is passed a positive value,
2362** then calling fts3_tokenizer without bound parameters is enabled. If it
2363** is passed a negative value, this setting is not modified - this can be
2364** used to query for the current setting. The second parameter is a pointer
2365** to an integer into which is written 0 or 1 to indicate the current value
2366** of this setting (after it is modified, if applicable). The second
2367** parameter may be a NULL pointer, in which case the value of the setting
2368** is not reported back. Refer to [FTS3] documentation for further details.
2369** </dd>
2370**
2371** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2372** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2373** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2374** interface independently of the [load_extension()] SQL function.
2375** The [sqlite3_enable_load_extension()] API enables or disables both the
2376** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2377** There must be two additional arguments.
2378** When the first argument to this interface is 1, then only the C-API is
2379** enabled and the SQL function remains disabled. If the first argument to
2380** this interface is 0, then both the C-API and the SQL function are disabled.
2381** If the first argument is -1, then no changes are made to the state of either
2382** the C-API or the SQL function.
2383** The second parameter is a pointer to an integer into which
2384** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2385** is disabled or enabled following this call. The second parameter may
2386** be a NULL pointer, in which case the new setting is not reported back.
2387** </dd>
2388**
2389** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2390** <dd> ^This option is used to change the name of the "main" database
2391** schema. This option does not follow the
2392** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
2393** This option takes exactly one additional argument so that the
2394** [sqlite3_db_config()] call has a total of three parameters. The
2395** extra argument must be a pointer to a constant UTF8 string which
2396** will become the new schema name in place of "main". ^SQLite does
2397** not make a copy of the new main schema name string, so the application
2398** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
2399** is unchanged until after the database connection closes.
2400** </dd>
2401**
2402** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2403** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2404** <dd> Usually, when a database in [WAL mode] is closed or detached from a
2405** database handle, SQLite checks if if there are other connections to the
2406** same database, and if there are no other database connection (if the
2407** connection being closed is the last open connection to the database),
2408** then SQLite performs a [checkpoint] before closing the connection and
2409** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
2410** be used to override that behavior. The first argument passed to this
2411** operation (the third parameter to [sqlite3_db_config()]) is an integer
2412** which is positive to disable checkpoints-on-close, or zero (the default)
2413** to enable them, and negative to leave the setting unchanged.
2414** The second argument (the fourth parameter) is a pointer to an integer
2415** into which is written 0 or 1 to indicate whether checkpoints-on-close
2416** have been disabled - 0 if they are not disabled, 1 if they are.
2417** </dd>
2418**
2419** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2420** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2421** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2422** a single SQL query statement will always use the same algorithm regardless
2423** of values of [bound parameters].)^ The QPSG disables some query optimizations
2424** that look at the values of bound parameters, which can make some queries
2425** slower. But the QPSG has the advantage of more predictable behavior. With
2426** the QPSG active, SQLite will always use the same query plan in the field as
2427** was used during testing in the lab.
2428** The first argument to this setting is an integer which is 0 to disable
2429** the QPSG, positive to enable QPSG, or negative to leave the setting
2430** unchanged. The second parameter is a pointer to an integer into which
2431** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2432** following this call.
2433** </dd>
2434**
2435** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2436** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2437** include output for any operations performed by trigger programs. This
2438** option is used to set or clear (the default) a flag that governs this
2439** behavior. The first parameter passed to this operation is an integer -
2440** positive to enable output for trigger programs, or zero to disable it,
2441** or negative to leave the setting unchanged.
2442** The second parameter is a pointer to an integer into which is written
2443** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2444** it is not disabled, 1 if it is.
2445** </dd>
2446**
2447** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2448** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2449** [VACUUM] in order to reset a database back to an empty database
2450** with no schema and no content. The following process works even for
2451** a badly corrupted database file:
2452** <ol>
2453** <li> If the database connection is newly opened, make sure it has read the
2454** database schema by preparing then discarding some query against the
2455** database, or calling sqlite3_table_column_metadata(), ignoring any
2456** errors. This step is only necessary if the application desires to keep
2457** the database in WAL mode after the reset if it was in WAL mode before
2458** the reset.
2459** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2460** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2461** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2462** </ol>
2463** Because resetting a database is destructive and irreversible, the
2464** process requires the use of this obscure API and multiple steps to
2465** help ensure that it does not happen by accident. Because this
2466** feature must be capable of resetting corrupt databases, and
2467** shutting down virtual tables may require access to that corrupt
2468** storage, the library must abandon any installed virtual tables
2469** without calling their xDestroy() methods.
2470**
2471** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2472** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2473** "defensive" flag for a database connection. When the defensive
2474** flag is enabled, language features that allow ordinary SQL to
2475** deliberately corrupt the database file are disabled. The disabled
2476** features include but are not limited to the following:
2477** <ul>
2478** <li> The [PRAGMA writable_schema=ON] statement.
2479** <li> The [PRAGMA journal_mode=OFF] statement.
2480** <li> The [PRAGMA schema_version=N] statement.
2481** <li> Writes to the [sqlite_dbpage] virtual table.
2482** <li> Direct writes to [shadow tables].
2483** </ul>
2484** </dd>
2485**
2486** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2487** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2488** "writable_schema" flag. This has the same effect and is logically equivalent
2489** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2490** The first argument to this setting is an integer which is 0 to disable
2491** the writable_schema, positive to enable writable_schema, or negative to
2492** leave the setting unchanged. The second parameter is a pointer to an
2493** integer into which is written 0 or 1 to indicate whether the writable_schema
2494** is enabled or disabled following this call.
2495** </dd>
2496**
2497** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2498** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2499** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2500** the legacy behavior of the [ALTER TABLE RENAME] command such that it
2501** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2502** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2503** additional information. This feature can also be turned on and off
2504** using the [PRAGMA legacy_alter_table] statement.
2505** </dd>
2506**
2507** [[SQLITE_DBCONFIG_DQS_DML]]
2508** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2509** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2510** the legacy [double-quoted string literal] misfeature for DML statements
2511** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2512** default value of this setting is determined by the [-DSQLITE_DQS]
2513** compile-time option.
2514** </dd>
2515**
2516** [[SQLITE_DBCONFIG_DQS_DDL]]
2517** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2518** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2519** the legacy [double-quoted string literal] misfeature for DDL statements,
2520** such as CREATE TABLE and CREATE INDEX. The
2521** default value of this setting is determined by the [-DSQLITE_DQS]
2522** compile-time option.
2523** </dd>
2524**
2525** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2526** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2527** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2528** assume that database schemas are untainted by malicious content.
2529** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2530** takes additional defensive steps to protect the application from harm
2531** including:
2532** <ul>
2533** <li> Prohibit the use of SQL functions inside triggers, views,
2534** CHECK constraints, DEFAULT clauses, expression indexes,
2535** partial indexes, or generated columns
2536** unless those functions are tagged with [SQLITE_INNOCUOUS].
2537** <li> Prohibit the use of virtual tables inside of triggers or views
2538** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2539** </ul>
2540** This setting defaults to "on" for legacy compatibility, however
2541** all applications are advised to turn it off if possible. This setting
2542** can also be controlled using the [PRAGMA trusted_schema] statement.
2543** </dd>
2544**
2545** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2546** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2547** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2548** the legacy file format flag. When activated, this flag causes all newly
2549** created database files to have a schema format version number (the 4-byte
2550** integer found at offset 44 into the database header) of 1. This in turn
2551** means that the resulting database file will be readable and writable by
2552** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2553** newly created databases are generally not understandable by SQLite versions
2554** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2555** is now scarcely any need to generate database files that are compatible
2556** all the way back to version 3.0.0, and so this setting is of little
2557** practical use, but is provided so that SQLite can continue to claim the
2558** ability to generate new database files that are compatible with version
2559** 3.0.0.
2560** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2561** the [VACUUM] command will fail with an obscure error when attempting to
2562** process a table with generated columns and a descending index. This is
2563** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2564** either generated columns or descending indexes.
2565** </dd>
2566**
2567** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2568** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2569** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2570** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2571** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2572** statistics. For statistics to be collected, the flag must be set on
2573** the database handle both when the SQL statement is prepared and when it
2574** is stepped. The flag is set (collection of statistics is enabled)
2575** by default. <p>This option takes two arguments: an integer and a pointer to
2576** an integer. The first argument is 1, 0, or -1 to enable, disable, or
2577** leave unchanged the statement scanstatus option. If the second argument
2578** is not NULL, then the value of the statement scanstatus setting after
2579** processing the first argument is written into the integer that the second
2580** argument points to.
2581** </dd>
2582**
2583** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2584** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2585** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2586** in which tables and indexes are scanned so that the scans start at the end
2587** and work toward the beginning rather than starting at the beginning and
2588** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2589** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2590** two arguments which are an integer and a pointer to an integer. The first
2591** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2592** reverse scan order flag, respectively. If the second argument is not NULL,
2593** then 0 or 1 is written into the integer that the second argument points to
2594** depending on if the reverse scan order flag is set after processing the
2595** first argument.
2596** </dd>
2597**
2598** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2599** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2600** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2601** the ability of the [ATTACH DATABASE] SQL command to create a new database
2602** file if the database filed named in the ATTACH command does not already
2603** exist. This ability of ATTACH to create a new database is enabled by
2604** default. Applications can disable or reenable the ability for ATTACH to
2605** create new database files using this DBCONFIG option.<p>
2606** This option takes two arguments which are an integer and a pointer
2607** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2608** leave unchanged the attach-create flag, respectively. If the second
2609** argument is not NULL, then 0 or 1 is written into the integer that the
2610** second argument points to depending on if the attach-create flag is set
2611** after processing the first argument.
2612** </dd>
2613**
2614** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2615** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2616** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2617** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2618** This capability is enabled by default. Applications can disable or
2619** reenable this capability using the current DBCONFIG option. If
2620** this capability is disabled, the [ATTACH] command will still work,
2621** but the database will be opened read-only. If this option is disabled,
2622** then the ability to create a new database using [ATTACH] is also disabled,
2623** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2624** option.<p>
2625** This option takes two arguments which are an integer and a pointer
2626** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2627** leave unchanged the ability to ATTACH another database for writing,
2628** respectively. If the second argument is not NULL, then 0 or 1 is written
2629** into the integer to which the second argument points, depending on whether
2630** the ability to ATTACH a read/write database is enabled or disabled
2631** after processing the first argument.
2632** </dd>
2633**
2634** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2635** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2636** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2637** ability to include comments in SQL text. Comments are enabled by default.
2638** An application can disable or reenable comments in SQL text using this
2639** DBCONFIG option.<p>
2640** This option takes two arguments which are an integer and a pointer
2641** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2642** leave unchanged the ability to use comments in SQL text,
2643** respectively. If the second argument is not NULL, then 0 or 1 is written
2644** into the integer that the second argument points to depending on if
2645** comments are allowed in SQL text after processing the first argument.
2646** </dd>
2647**
2648** </dl>
2649**
2650** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2651**
2652** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2653** overall call to [sqlite3_db_config()] has a total of four parameters.
2654** The first argument (the third parameter to sqlite3_db_config()) is an integer.
2655** The second argument is a pointer to an integer. If the first argument is 1,
2656** then the option becomes enabled. If the first integer argument is 0, then the
2657** option is disabled. If the first argument is -1, then the option setting
2658** is unchanged. The second argument, the pointer to an integer, may be NULL.
2659** If the second argument is not NULL, then a value of 0 or 1 is written into
2660** the integer to which the second argument points, depending on whether the
2661** setting is disabled or enabled after applying any changes specified by
2662** the first argument.
2663**
2664** <p>While most SQLITE_DBCONFIG options use the argument format
2665** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME]
2666** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the
2667** documentation of those exceptional options for details.
2668*/
2669#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2670#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2671#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2672#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2673#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2674#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2675#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2676#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2677#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2678#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2679#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2680#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2681#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2682#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2683#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2684#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2685#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2686#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2687#define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2688#define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2689#define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2690#define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2691#define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2692#define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */
2693
2694/*
2695** CAPI3REF: Enable Or Disable Extended Result Codes
2696** METHOD: sqlite3
2697**
2698** ^The sqlite3_extended_result_codes() routine enables or disables the
2699** [extended result codes] feature of SQLite. ^The extended result
2700** codes are disabled by default for historical compatibility.
2701*/
2702SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2703
2704/*
2705** CAPI3REF: Last Insert Rowid
2706** METHOD: sqlite3
2707**
2708** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2709** has a unique 64-bit signed
2710** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2711** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2712** names are not also used by explicitly declared columns. ^If
2713** the table has a column of type [INTEGER PRIMARY KEY] then that column
2714** is another alias for the rowid.
2715**
2716** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2717** the most recent successful [INSERT] into a rowid table or [virtual table]
2718** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2719** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2720** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2721** zero.
2722**
2723** As well as being set automatically as rows are inserted into database
2724** tables, the value returned by this function may be set explicitly by
2725** [sqlite3_set_last_insert_rowid()]
2726**
2727** Some virtual table implementations may INSERT rows into rowid tables as
2728** part of committing a transaction (e.g. to flush data accumulated in memory
2729** to disk). In this case subsequent calls to this function return the rowid
2730** associated with these internal INSERT operations, which leads to
2731** unintuitive results. Virtual table implementations that do write to rowid
2732** tables in this way can avoid this problem by restoring the original
2733** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2734** control to the user.
2735**
2736** ^(If an [INSERT] occurs within a trigger then this routine will
2737** return the [rowid] of the inserted row as long as the trigger is
2738** running. Once the trigger program ends, the value returned
2739** by this routine reverts to what it was before the trigger was fired.)^
2740**
2741** ^An [INSERT] that fails due to a constraint violation is not a
2742** successful [INSERT] and does not change the value returned by this
2743** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2744** and INSERT OR ABORT make no changes to the return value of this
2745** routine when their insertion fails. ^(When INSERT OR REPLACE
2746** encounters a constraint violation, it does not fail. The
2747** INSERT continues to completion after deleting rows that caused
2748** the constraint problem so INSERT OR REPLACE will always change
2749** the return value of this interface.)^
2750**
2751** ^For the purposes of this routine, an [INSERT] is considered to
2752** be successful even if it is subsequently rolled back.
2753**
2754** This function is accessible to SQL statements via the
2755** [last_insert_rowid() SQL function].
2756**
2757** If a separate thread performs a new [INSERT] on the same
2758** database connection while the [sqlite3_last_insert_rowid()]
2759** function is running and thus changes the last insert [rowid],
2760** then the value returned by [sqlite3_last_insert_rowid()] is
2761** unpredictable and might not equal either the old or the new
2762** last insert [rowid].
2763*/
2764SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2765
2766/*
2767** CAPI3REF: Set the Last Insert Rowid value.
2768** METHOD: sqlite3
2769**
2770** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2771** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2772** without inserting a row into the database.
2773*/
2774SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2775
2776/*
2777** CAPI3REF: Count The Number Of Rows Modified
2778** METHOD: sqlite3
2779**
2780** ^These functions return the number of rows modified, inserted or
2781** deleted by the most recently completed INSERT, UPDATE or DELETE
2782** statement on the database connection specified by the only parameter.
2783** The two functions are identical except for the type of the return value
2784** and that if the number of rows modified by the most recent INSERT, UPDATE,
2785** or DELETE is greater than the maximum value supported by type "int", then
2786** the return value of sqlite3_changes() is undefined. ^Executing any other
2787** type of SQL statement does not modify the value returned by these functions.
2788** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2789** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2790** added to the new table by the CREATE TABLE AS SELECT statement are not
2791** counted.
2792**
2793** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2794** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2795** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2796**
2797** Changes to a view that are intercepted by
2798** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2799** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2800** DELETE statement run on a view is always zero. Only changes made to real
2801** tables are counted.
2802**
2803** Things are more complicated if the sqlite3_changes() function is
2804** executed while a trigger program is running. This may happen if the
2805** program uses the [changes() SQL function], or if some other callback
2806** function invokes sqlite3_changes() directly. Essentially:
2807**
2808** <ul>
2809** <li> ^(Before entering a trigger program the value returned by
2810** sqlite3_changes() function is saved. After the trigger program
2811** has finished, the original value is restored.)^
2812**
2813** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2814** statement sets the value returned by sqlite3_changes()
2815** upon completion as normal. Of course, this value will not include
2816** any changes performed by sub-triggers, as the sqlite3_changes()
2817** value will be saved and restored after each sub-trigger has run.)^
2818** </ul>
2819**
2820** ^This means that if the changes() SQL function (or similar) is used
2821** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2822** returns the value as set when the calling statement began executing.
2823** ^If it is used by the second or subsequent such statement within a trigger
2824** program, the value returned reflects the number of rows modified by the
2825** previous INSERT, UPDATE or DELETE statement within the same trigger.
2826**
2827** If a separate thread makes changes on the same database connection
2828** while [sqlite3_changes()] is running then the value returned
2829** is unpredictable and not meaningful.
2830**
2831** See also:
2832** <ul>
2833** <li> the [sqlite3_total_changes()] interface
2834** <li> the [count_changes pragma]
2835** <li> the [changes() SQL function]
2836** <li> the [data_version pragma]
2837** </ul>
2838*/
2839SQLITE_API int sqlite3_changes(sqlite3*);
2840SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2841
2842/*
2843** CAPI3REF: Total Number Of Rows Modified
2844** METHOD: sqlite3
2845**
2846** ^These functions return the total number of rows inserted, modified or
2847** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2848** since the database connection was opened, including those executed as
2849** part of trigger programs. The two functions are identical except for the
2850** type of the return value and that if the number of rows modified by the
2851** connection exceeds the maximum value supported by type "int", then
2852** the return value of sqlite3_total_changes() is undefined. ^Executing
2853** any other type of SQL statement does not affect the value returned by
2854** sqlite3_total_changes().
2855**
2856** ^Changes made as part of [foreign key actions] are included in the
2857** count, but those made as part of REPLACE constraint resolution are
2858** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2859** are not counted.
2860**
2861** The [sqlite3_total_changes(D)] interface only reports the number
2862** of rows that changed due to SQL statement run against database
2863** connection D. Any changes by other database connections are ignored.
2864** To detect changes against a database file from other database
2865** connections use the [PRAGMA data_version] command or the
2866** [SQLITE_FCNTL_DATA_VERSION] [file control].
2867**
2868** If a separate thread makes changes on the same database connection
2869** while [sqlite3_total_changes()] is running then the value
2870** returned is unpredictable and not meaningful.
2871**
2872** See also:
2873** <ul>
2874** <li> the [sqlite3_changes()] interface
2875** <li> the [count_changes pragma]
2876** <li> the [changes() SQL function]
2877** <li> the [data_version pragma]
2878** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2879** </ul>
2880*/
2881SQLITE_API int sqlite3_total_changes(sqlite3*);
2882SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2883
2884/*
2885** CAPI3REF: Interrupt A Long-Running Query
2886** METHOD: sqlite3
2887**
2888** ^This function causes any pending database operation to abort and
2889** return at its earliest opportunity. This routine is typically
2890** called in response to a user action such as pressing "Cancel"
2891** or Ctrl-C where the user wants a long query operation to halt
2892** immediately.
2893**
2894** ^It is safe to call this routine from a thread different from the
2895** thread that is currently running the database operation. But it
2896** is not safe to call this routine with a [database connection] that
2897** is closed or might close before sqlite3_interrupt() returns.
2898**
2899** ^If an SQL operation is very nearly finished at the time when
2900** sqlite3_interrupt() is called, then it might not have an opportunity
2901** to be interrupted and might continue to completion.
2902**
2903** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2904** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2905** that is inside an explicit transaction, then the entire transaction
2906** will be rolled back automatically.
2907**
2908** ^The sqlite3_interrupt(D) call is in effect until all currently running
2909** SQL statements on [database connection] D complete. ^Any new SQL statements
2910** that are started after the sqlite3_interrupt() call and before the
2911** running statement count reaches zero are interrupted as if they had been
2912** running prior to the sqlite3_interrupt() call. ^New SQL statements
2913** that are started after the running statement count reaches zero are
2914** not effected by the sqlite3_interrupt().
2915** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2916** SQL statements is a no-op and has no effect on SQL statements
2917** that are started after the sqlite3_interrupt() call returns.
2918**
2919** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2920** or not an interrupt is currently in effect for [database connection] D.
2921** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2922*/
2923SQLITE_API void sqlite3_interrupt(sqlite3*);
2924SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2925
2926/*
2927** CAPI3REF: Determine If An SQL Statement Is Complete
2928**
2929** These routines are useful during command-line input to determine if the
2930** currently entered text seems to form a complete SQL statement or
2931** if additional input is needed before sending the text into
2932** SQLite for parsing. ^These routines return 1 if the input string
2933** appears to be a complete SQL statement. ^A statement is judged to be
2934** complete if it ends with a semicolon token and is not a prefix of a
2935** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2936** string literals or quoted identifier names or comments are not
2937** independent tokens (they are part of the token in which they are
2938** embedded) and thus do not count as a statement terminator. ^Whitespace
2939** and comments that follow the final semicolon are ignored.
2940**
2941** ^These routines return 0 if the statement is incomplete. ^If a
2942** memory allocation fails, then SQLITE_NOMEM is returned.
2943**
2944** ^These routines do not parse the SQL statements and thus
2945** will not detect syntactically incorrect SQL.
2946**
2947** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2948** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2949** automatically by sqlite3_complete16(). If that initialization fails,
2950** then the return value from sqlite3_complete16() will be non-zero
2951** regardless of whether or not the input SQL is complete.)^
2952**
2953** The input to [sqlite3_complete()] must be a zero-terminated
2954** UTF-8 string.
2955**
2956** The input to [sqlite3_complete16()] must be a zero-terminated
2957** UTF-16 string in native byte order.
2958*/
2959SQLITE_API int sqlite3_complete(const char *sql);
2960SQLITE_API int sqlite3_complete16(const void *sql);
2961
2962/*
2963** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2964** KEYWORDS: {busy-handler callback} {busy handler}
2965** METHOD: sqlite3
2966**
2967** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2968** that might be invoked with argument P whenever
2969** an attempt is made to access a database table associated with
2970** [database connection] D when another thread
2971** or process has the table locked.
2972** The sqlite3_busy_handler() interface is used to implement
2973** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2974**
2975** ^If the busy callback is NULL, then [SQLITE_BUSY]
2976** is returned immediately upon encountering the lock. ^If the busy callback
2977** is not NULL, then the callback might be invoked with two arguments.
2978**
2979** ^The first argument to the busy handler is a copy of the void* pointer which
2980** is the third argument to sqlite3_busy_handler(). ^The second argument to
2981** the busy handler callback is the number of times that the busy handler has
2982** been invoked previously for the same locking event. ^If the
2983** busy callback returns 0, then no additional attempts are made to
2984** access the database and [SQLITE_BUSY] is returned
2985** to the application.
2986** ^If the callback returns non-zero, then another attempt
2987** is made to access the database and the cycle repeats.
2988**
2989** The presence of a busy handler does not guarantee that it will be invoked
2990** when there is lock contention. ^If SQLite determines that invoking the busy
2991** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2992** to the application instead of invoking the
2993** busy handler.
2994** Consider a scenario where one process is holding a read lock that
2995** it is trying to promote to a reserved lock and
2996** a second process is holding a reserved lock that it is trying
2997** to promote to an exclusive lock. The first process cannot proceed
2998** because it is blocked by the second and the second process cannot
2999** proceed because it is blocked by the first. If both processes
3000** invoke the busy handlers, neither will make any progress. Therefore,
3001** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
3002** will induce the first process to release its read lock and allow
3003** the second process to proceed.
3004**
3005** ^The default busy callback is NULL.
3006**
3007** ^(There can only be a single busy handler defined for each
3008** [database connection]. Setting a new busy handler clears any
3009** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
3010** or evaluating [PRAGMA busy_timeout=N] will change the
3011** busy handler and thus clear any previously set busy handler.
3012**
3013** The busy callback should not take any actions which modify the
3014** database connection that invoked the busy handler. In other words,
3015** the busy handler is not reentrant. Any such actions
3016** result in undefined behavior.
3017**
3018** A busy handler must not close the database connection
3019** or [prepared statement] that invoked the busy handler.
3020*/
3021SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3022
3023/*
3024** CAPI3REF: Set A Busy Timeout
3025** METHOD: sqlite3
3026**
3027** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3028** for a specified amount of time when a table is locked. ^The handler
3029** will sleep multiple times until at least "ms" milliseconds of sleeping
3030** have accumulated. ^After at least "ms" milliseconds of sleeping,
3031** the handler returns 0 which causes [sqlite3_step()] to return
3032** [SQLITE_BUSY].
3033**
3034** ^Calling this routine with an argument less than or equal to zero
3035** turns off all busy handlers.
3036**
3037** ^(There can only be a single busy handler for a particular
3038** [database connection] at any given moment. If another busy handler
3039** was defined (using [sqlite3_busy_handler()]) prior to calling
3040** this routine, that other busy handler is cleared.)^
3041**
3042** See also: [PRAGMA busy_timeout]
3043*/
3044SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3045
3046/*
3047** CAPI3REF: Set the Setlk Timeout
3048** METHOD: sqlite3
3049**
3050** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3051** the VFS supports blocking locks, it sets the timeout in ms used by
3052** eligible locks taken on wal mode databases by the specified database
3053** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3054** not support blocking locks, this function is a no-op.
3055**
3056** Passing 0 to this function disables blocking locks altogether. Passing
3057** -1 to this function requests that the VFS blocks for a long time -
3058** indefinitely if possible. The results of passing any other negative value
3059** are undefined.
3060**
3061** Internally, each SQLite database handle stores two timeout values - the
3062** busy-timeout (used for rollback mode databases, or if the VFS does not
3063** support blocking locks) and the setlk-timeout (used for blocking locks
3064** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3065** values, this function sets only the setlk-timeout value. Therefore,
3066** to configure separate busy-timeout and setlk-timeout values for a single
3067** database handle, call sqlite3_busy_timeout() followed by this function.
3068**
3069** Whenever the number of connections to a wal mode database falls from
3070** 1 to 0, the last connection takes an exclusive lock on the database,
3071** then checkpoints and deletes the wal file. While it is doing this, any
3072** new connection that tries to read from the database fails with an
3073** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3074** passed to this API, the new connection blocks until the exclusive lock
3075** has been released.
3076*/
3077SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3078
3079/*
3080** CAPI3REF: Flags for sqlite3_setlk_timeout()
3081*/
3082#define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3083
3084/*
3085** CAPI3REF: Convenience Routines For Running Queries
3086** METHOD: sqlite3
3087**
3088** This is a legacy interface that is preserved for backwards compatibility.
3089** Use of this interface is not recommended.
3090**
3091** Definition: A <b>result table</b> is a memory data structure created by the
3092** [sqlite3_get_table()] interface. A result table records the
3093** complete query results from one or more queries.
3094**
3095** The table conceptually has a number of rows and columns. But
3096** these numbers are not part of the result table itself. These
3097** numbers are obtained separately. Let N be the number of rows
3098** and M be the number of columns.
3099**
3100** A result table is an array of pointers to zero-terminated UTF-8 strings.
3101** There are (N+1)*M elements in the array. The first M pointers point
3102** to zero-terminated strings that contain the names of the columns.
3103** The remaining entries all point to query results. NULL values result
3104** in NULL pointers. All other values are in their UTF-8 zero-terminated
3105** string representation as returned by [sqlite3_column_text()].
3106**
3107** A result table might consist of one or more memory allocations.
3108** It is not safe to pass a result table directly to [sqlite3_free()].
3109** A result table should be deallocated using [sqlite3_free_table()].
3110**
3111** ^(As an example of the result table format, suppose a query result
3112** is as follows:
3113**
3114** <blockquote><pre>
3115** Name | Age
3116** -----------------------
3117** Alice | 43
3118** Bob | 28
3119** Cindy | 21
3120** </pre></blockquote>
3121**
3122** There are two columns (M==2) and three rows (N==3). Thus the
3123** result table has 8 entries. Suppose the result table is stored
3124** in an array named azResult. Then azResult holds this content:
3125**
3126** <blockquote><pre>
3127** azResult&#91;0] = "Name";
3128** azResult&#91;1] = "Age";
3129** azResult&#91;2] = "Alice";
3130** azResult&#91;3] = "43";
3131** azResult&#91;4] = "Bob";
3132** azResult&#91;5] = "28";
3133** azResult&#91;6] = "Cindy";
3134** azResult&#91;7] = "21";
3135** </pre></blockquote>)^
3136**
3137** ^The sqlite3_get_table() function evaluates one or more
3138** semicolon-separated SQL statements in the zero-terminated UTF-8
3139** string of its 2nd parameter and returns a result table to the
3140** pointer given in its 3rd parameter.
3141**
3142** After the application has finished with the result from sqlite3_get_table(),
3143** it must pass the result table pointer to sqlite3_free_table() in order to
3144** release the memory that was malloced. Because of the way the
3145** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3146** function must not try to call [sqlite3_free()] directly. Only
3147** [sqlite3_free_table()] is able to release the memory properly and safely.
3148**
3149** The sqlite3_get_table() interface is implemented as a wrapper around
3150** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3151** to any internal data structures of SQLite. It uses only the public
3152** interface defined here. As a consequence, errors that occur in the
3153** wrapper layer outside of the internal [sqlite3_exec()] call are not
3154** reflected in subsequent calls to [sqlite3_errcode()] or
3155** [sqlite3_errmsg()].
3156*/
3157SQLITE_API int sqlite3_get_table(
3158 sqlite3 *db, /* An open database */
3159 const char *zSql, /* SQL to be evaluated */
3160 char ***pazResult, /* Results of the query */
3161 int *pnRow, /* Number of result rows written here */
3162 int *pnColumn, /* Number of result columns written here */
3163 char **pzErrmsg /* Error msg written here */
3164);
3165SQLITE_API void sqlite3_free_table(char **result);
3166
3167/*
3168** CAPI3REF: Formatted String Printing Functions
3169**
3170** These routines are work-alikes of the "printf()" family of functions
3171** from the standard C library.
3172** These routines understand most of the common formatting options from
3173** the standard library printf()
3174** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3175** See the [built-in printf()] documentation for details.
3176**
3177** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3178** results into memory obtained from [sqlite3_malloc64()].
3179** The strings returned by these two routines should be
3180** released by [sqlite3_free()]. ^Both routines return a
3181** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3182** memory to hold the resulting string.
3183**
3184** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3185** the standard C library. The result is written into the
3186** buffer supplied as the second parameter whose size is given by
3187** the first parameter. Note that the order of the
3188** first two parameters is reversed from snprintf().)^ This is an
3189** historical accident that cannot be fixed without breaking
3190** backwards compatibility. ^(Note also that sqlite3_snprintf()
3191** returns a pointer to its buffer instead of the number of
3192** characters actually written into the buffer.)^ We admit that
3193** the number of characters written would be a more useful return
3194** value but we cannot change the implementation of sqlite3_snprintf()
3195** now without breaking compatibility.
3196**
3197** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3198** guarantees that the buffer is always zero-terminated. ^The first
3199** parameter "n" is the total size of the buffer, including space for
3200** the zero terminator. So the longest string that can be completely
3201** written will be n-1 characters.
3202**
3203** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3204**
3205** See also: [built-in printf()], [printf() SQL function]
3206*/
3207SQLITE_API char *sqlite3_mprintf(const char*,...);
3208SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3209SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3210SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3211
3212/*
3213** CAPI3REF: Memory Allocation Subsystem
3214**
3215** The SQLite core uses these three routines for all of its own
3216** internal memory allocation needs. "Core" in the previous sentence
3217** does not include operating-system specific [VFS] implementation. The
3218** Windows VFS uses native malloc() and free() for some operations.
3219**
3220** ^The sqlite3_malloc() routine returns a pointer to a block
3221** of memory at least N bytes in length, where N is the parameter.
3222** ^If sqlite3_malloc() is unable to obtain sufficient free
3223** memory, it returns a NULL pointer. ^If the parameter N to
3224** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3225** a NULL pointer.
3226**
3227** ^The sqlite3_malloc64(N) routine works just like
3228** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3229** of a signed 32-bit integer.
3230**
3231** ^Calling sqlite3_free() with a pointer previously returned
3232** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3233** that it might be reused. ^The sqlite3_free() routine is
3234** a no-op if it is called with a NULL pointer. Passing a NULL pointer
3235** to sqlite3_free() is harmless. After being freed, memory
3236** should neither be read nor written. Even reading previously freed
3237** memory might result in a segmentation fault or other severe error.
3238** Memory corruption, a segmentation fault, or other severe error
3239** might result if sqlite3_free() is called with a non-NULL pointer that
3240** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3241**
3242** ^The sqlite3_realloc(X,N) interface attempts to resize a
3243** prior memory allocation X to be at least N bytes.
3244** ^If the X parameter to sqlite3_realloc(X,N)
3245** is a NULL pointer then its behavior is identical to calling
3246** sqlite3_malloc(N).
3247** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3248** negative then the behavior is exactly the same as calling
3249** sqlite3_free(X).
3250** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3251** of at least N bytes in size or NULL if insufficient memory is available.
3252** ^If M is the size of the prior allocation, then min(N,M) bytes of the
3253** prior allocation are copied into the beginning of the buffer returned
3254** by sqlite3_realloc(X,N) and the prior allocation is freed.
3255** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3256** prior allocation is not freed.
3257**
3258** ^The sqlite3_realloc64(X,N) interface works the same as
3259** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3260** of a 32-bit signed integer.
3261**
3262** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3263** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3264** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3265** ^The value returned by sqlite3_msize(X) might be larger than the number
3266** of bytes requested when X was allocated. ^If X is a NULL pointer then
3267** sqlite3_msize(X) returns zero. If X points to something that is not
3268** the beginning of memory allocation, or if it points to a formerly
3269** valid memory allocation that has now been freed, then the behavior
3270** of sqlite3_msize(X) is undefined and possibly harmful.
3271**
3272** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3273** sqlite3_malloc64(), and sqlite3_realloc64()
3274** is always aligned to at least an 8 byte boundary, or to a
3275** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3276** option is used.
3277**
3278** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3279** must be either NULL or else pointers obtained from a prior
3280** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3281** not yet been released.
3282**
3283** The application must not read or write any part of
3284** a block of memory after it has been released using
3285** [sqlite3_free()] or [sqlite3_realloc()].
3286*/
3287SQLITE_API void *sqlite3_malloc(int);
3288SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3289SQLITE_API void *sqlite3_realloc(void*, int);
3290SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3291SQLITE_API void sqlite3_free(void*);
3292SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3293
3294/*
3295** CAPI3REF: Memory Allocator Statistics
3296**
3297** SQLite provides these two interfaces for reporting on the status
3298** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3299** routines, which form the built-in memory allocation subsystem.
3300**
3301** ^The [sqlite3_memory_used()] routine returns the number of bytes
3302** of memory currently outstanding (malloced but not freed).
3303** ^The [sqlite3_memory_highwater()] routine returns the maximum
3304** value of [sqlite3_memory_used()] since the high-water mark
3305** was last reset. ^The values returned by [sqlite3_memory_used()] and
3306** [sqlite3_memory_highwater()] include any overhead
3307** added by SQLite in its implementation of [sqlite3_malloc()],
3308** but not overhead added by any underlying system library
3309** routines that [sqlite3_malloc()] may call.
3310**
3311** ^The memory high-water mark is reset to the current value of
3312** [sqlite3_memory_used()] if and only if the parameter to
3313** [sqlite3_memory_highwater()] is true. ^The value returned
3314** by [sqlite3_memory_highwater(1)] is the high-water mark
3315** prior to the reset.
3316*/
3317SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3318SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3319
3320/*
3321** CAPI3REF: Pseudo-Random Number Generator
3322**
3323** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3324** select random [ROWID | ROWIDs] when inserting new records into a table that
3325** already uses the largest possible [ROWID]. The PRNG is also used for
3326** the built-in random() and randomblob() SQL functions. This interface allows
3327** applications to access the same PRNG for other purposes.
3328**
3329** ^A call to this routine stores N bytes of randomness into buffer P.
3330** ^The P parameter can be a NULL pointer.
3331**
3332** ^If this routine has not been previously called or if the previous
3333** call had N less than one or a NULL pointer for P, then the PRNG is
3334** seeded using randomness obtained from the xRandomness method of
3335** the default [sqlite3_vfs] object.
3336** ^If the previous call to this routine had an N of 1 or more and a
3337** non-NULL P then the pseudo-randomness is generated
3338** internally and without recourse to the [sqlite3_vfs] xRandomness
3339** method.
3340*/
3341SQLITE_API void sqlite3_randomness(int N, void *P);
3342
3343/*
3344** CAPI3REF: Compile-Time Authorization Callbacks
3345** METHOD: sqlite3
3346** KEYWORDS: {authorizer callback}
3347**
3348** ^This routine registers an authorizer callback with a particular
3349** [database connection], supplied in the first argument.
3350** ^The authorizer callback is invoked as SQL statements are being compiled
3351** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3352** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3353** and [sqlite3_prepare16_v3()]. ^At various
3354** points during the compilation process, as logic is being created
3355** to perform various actions, the authorizer callback is invoked to
3356** see if those actions are allowed. ^The authorizer callback should
3357** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3358** specific action but allow the SQL statement to continue to be
3359** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3360** rejected with an error. ^If the authorizer callback returns
3361** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3362** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3363** the authorizer will fail with an error message.
3364**
3365** When the callback returns [SQLITE_OK], that means the operation
3366** requested is ok. ^When the callback returns [SQLITE_DENY], the
3367** [sqlite3_prepare_v2()] or equivalent call that triggered the
3368** authorizer will fail with an error message explaining that
3369** access is denied.
3370**
3371** ^The first parameter to the authorizer callback is a copy of the third
3372** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3373** to the callback is an integer [SQLITE_COPY | action code] that specifies
3374** the particular action to be authorized. ^The third through sixth parameters
3375** to the callback are either NULL pointers or zero-terminated strings
3376** that contain additional details about the action to be authorized.
3377** Applications must always be prepared to encounter a NULL pointer in any
3378** of the third through the sixth parameters of the authorization callback.
3379**
3380** ^If the action code is [SQLITE_READ]
3381** and the callback returns [SQLITE_IGNORE] then the
3382** [prepared statement] statement is constructed to substitute
3383** a NULL value in place of the table column that would have
3384** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3385** return can be used to deny an untrusted user access to individual
3386** columns of a table.
3387** ^When a table is referenced by a [SELECT] but no column values are
3388** extracted from that table (for example in a query like
3389** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3390** is invoked once for that table with a column name that is an empty string.
3391** ^If the action code is [SQLITE_DELETE] and the callback returns
3392** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3393** [truncate optimization] is disabled and all rows are deleted individually.
3394**
3395** An authorizer is used when [sqlite3_prepare | preparing]
3396** SQL statements from an untrusted source, to ensure that the SQL statements
3397** do not try to access data they are not allowed to see, or that they do not
3398** try to execute malicious statements that damage the database. For
3399** example, an application may allow a user to enter arbitrary
3400** SQL queries for evaluation by a database. But the application does
3401** not want the user to be able to make arbitrary changes to the
3402** database. An authorizer could then be put in place while the
3403** user-entered SQL is being [sqlite3_prepare | prepared] that
3404** disallows everything except [SELECT] statements.
3405**
3406** Applications that need to process SQL from untrusted sources
3407** might also consider lowering resource limits using [sqlite3_limit()]
3408** and limiting database size using the [max_page_count] [PRAGMA]
3409** in addition to using an authorizer.
3410**
3411** ^(Only a single authorizer can be in place on a database connection
3412** at a time. Each call to sqlite3_set_authorizer overrides the
3413** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3414** The authorizer is disabled by default.
3415**
3416** The authorizer callback must not do anything that will modify
3417** the database connection that invoked the authorizer callback.
3418** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3419** database connections for the meaning of "modify" in this paragraph.
3420**
3421** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3422** statement might be re-prepared during [sqlite3_step()] due to a
3423** schema change. Hence, the application should ensure that the
3424** correct authorizer callback remains in place during the [sqlite3_step()].
3425**
3426** ^Note that the authorizer callback is invoked only during
3427** [sqlite3_prepare()] or its variants. Authorization is not
3428** performed during statement evaluation in [sqlite3_step()], unless
3429** as stated in the previous paragraph, sqlite3_step() invokes
3430** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3431*/
3432SQLITE_API int sqlite3_set_authorizer(
3433 sqlite3*,
3434 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3435 void *pUserData
3436);
3437
3438/*
3439** CAPI3REF: Authorizer Return Codes
3440**
3441** The [sqlite3_set_authorizer | authorizer callback function] must
3442** return either [SQLITE_OK] or one of these two constants in order
3443** to signal SQLite whether or not the action is permitted. See the
3444** [sqlite3_set_authorizer | authorizer documentation] for additional
3445** information.
3446**
3447** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3448** returned from the [sqlite3_vtab_on_conflict()] interface.
3449*/
3450#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3451#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3452
3453/*
3454** CAPI3REF: Authorizer Action Codes
3455**
3456** The [sqlite3_set_authorizer()] interface registers a callback function
3457** that is invoked to authorize certain SQL statement actions. The
3458** second parameter to the callback is an integer code that specifies
3459** what action is being authorized. These are the integer action codes that
3460** the authorizer callback may be passed.
3461**
3462** These action code values signify what kind of operation is to be
3463** authorized. The 3rd and 4th parameters to the authorization
3464** callback function will be parameters or NULL depending on which of these
3465** codes is used as the second parameter. ^(The 5th parameter to the
3466** authorizer callback is the name of the database ("main", "temp",
3467** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3468** is the name of the inner-most trigger or view that is responsible for
3469** the access attempt or NULL if this access attempt is directly from
3470** top-level SQL code.
3471*/
3472/******************************************* 3rd ************ 4th ***********/
3473#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3474#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3475#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3476#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3477#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3478#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3479#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3480#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3481#define SQLITE_DELETE 9 /* Table Name NULL */
3482#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3483#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3484#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3485#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3486#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3487#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3488#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3489#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3490#define SQLITE_INSERT 18 /* Table Name NULL */
3491#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3492#define SQLITE_READ 20 /* Table Name Column Name */
3493#define SQLITE_SELECT 21 /* NULL NULL */
3494#define SQLITE_TRANSACTION 22 /* Operation NULL */
3495#define SQLITE_UPDATE 23 /* Table Name Column Name */
3496#define SQLITE_ATTACH 24 /* Filename NULL */
3497#define SQLITE_DETACH 25 /* Database Name NULL */
3498#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3499#define SQLITE_REINDEX 27 /* Index Name NULL */
3500#define SQLITE_ANALYZE 28 /* Table Name NULL */
3501#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3502#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3503#define SQLITE_FUNCTION 31 /* NULL Function Name */
3504#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3505#define SQLITE_COPY 0 /* No longer used */
3506#define SQLITE_RECURSIVE 33 /* NULL NULL */
3507
3508/*
3509** CAPI3REF: Deprecated Tracing And Profiling Functions
3510** DEPRECATED
3511**
3512** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3513** instead of the routines described here.
3514**
3515** These routines register callback functions that can be used for
3516** tracing and profiling the execution of SQL statements.
3517**
3518** ^The callback function registered by sqlite3_trace() is invoked at
3519** various times when an SQL statement is being run by [sqlite3_step()].
3520** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3521** SQL statement text as the statement first begins executing.
3522** ^(Additional sqlite3_trace() callbacks might occur
3523** as each triggered subprogram is entered. The callbacks for triggers
3524** contain a UTF-8 SQL comment that identifies the trigger.)^
3525**
3526** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3527** the length of [bound parameter] expansion in the output of sqlite3_trace().
3528**
3529** ^The callback function registered by sqlite3_profile() is invoked
3530** as each SQL statement finishes. ^The profile callback contains
3531** the original statement text and an estimate of wall-clock time
3532** of how long that statement took to run. ^The profile callback
3533** time is in units of nanoseconds, however the current implementation
3534** is only capable of millisecond resolution so the six least significant
3535** digits in the time are meaningless. Future versions of SQLite
3536** might provide greater resolution on the profiler callback. Invoking
3537** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3538** profile callback.
3539*/
3540SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3541 void(*xTrace)(void*,const char*), void*);
3542SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3543 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3544
3545/*
3546** CAPI3REF: SQL Trace Event Codes
3547** KEYWORDS: SQLITE_TRACE
3548**
3549** These constants identify classes of events that can be monitored
3550** using the [sqlite3_trace_v2()] tracing logic. The M argument
3551** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3552** the following constants. ^The first argument to the trace callback
3553** is one of the following constants.
3554**
3555** New tracing constants may be added in future releases.
3556**
3557** ^A trace callback has four arguments: xCallback(T,C,P,X).
3558** ^The T argument is one of the integer type codes above.
3559** ^The C argument is a copy of the context pointer passed in as the
3560** fourth argument to [sqlite3_trace_v2()].
3561** The P and X arguments are pointers whose meanings depend on T.
3562**
3563** <dl>
3564** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3565** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3566** first begins running and possibly at other times during the
3567** execution of the prepared statement, such as at the start of each
3568** trigger subprogram. ^The P argument is a pointer to the
3569** [prepared statement]. ^The X argument is a pointer to a string which
3570** is the unexpanded SQL text of the prepared statement or an SQL comment
3571** that indicates the invocation of a trigger. ^The callback can compute
3572** the same text that would have been returned by the legacy [sqlite3_trace()]
3573** interface by using the X argument when X begins with "--" and invoking
3574** [sqlite3_expanded_sql(P)] otherwise.
3575**
3576** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3577** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3578** information as is provided by the [sqlite3_profile()] callback.
3579** ^The P argument is a pointer to the [prepared statement] and the
3580** X argument points to a 64-bit integer which is approximately
3581** the number of nanoseconds that the prepared statement took to run.
3582** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3583**
3584** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3585** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3586** statement generates a single row of result.
3587** ^The P argument is a pointer to the [prepared statement] and the
3588** X argument is unused.
3589**
3590** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3591** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3592** connection closes.
3593** ^The P argument is a pointer to the [database connection] object
3594** and the X argument is unused.
3595** </dl>
3596*/
3597#define SQLITE_TRACE_STMT 0x01
3598#define SQLITE_TRACE_PROFILE 0x02
3599#define SQLITE_TRACE_ROW 0x04
3600#define SQLITE_TRACE_CLOSE 0x08
3601
3602/*
3603** CAPI3REF: SQL Trace Hook
3604** METHOD: sqlite3
3605**
3606** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3607** function X against [database connection] D, using property mask M
3608** and context pointer P. ^If the X callback is
3609** NULL or if the M mask is zero, then tracing is disabled. The
3610** M argument should be the bitwise OR-ed combination of
3611** zero or more [SQLITE_TRACE] constants.
3612**
3613** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3614** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3615** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3616** database connection may have at most one trace callback.
3617**
3618** ^The X callback is invoked whenever any of the events identified by
3619** mask M occur. ^The integer return value from the callback is currently
3620** ignored, though this may change in future releases. Callback
3621** implementations should return zero to ensure future compatibility.
3622**
3623** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3624** ^The T argument is one of the [SQLITE_TRACE]
3625** constants to indicate why the callback was invoked.
3626** ^The C argument is a copy of the context pointer.
3627** The P and X arguments are pointers whose meanings depend on T.
3628**
3629** The sqlite3_trace_v2() interface is intended to replace the legacy
3630** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3631** are deprecated.
3632*/
3633SQLITE_API int sqlite3_trace_v2(
3634 sqlite3*,
3635 unsigned uMask,
3636 int(*xCallback)(unsigned,void*,void*,void*),
3637 void *pCtx
3638);
3639
3640/*
3641** CAPI3REF: Query Progress Callbacks
3642** METHOD: sqlite3
3643**
3644** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3645** function X to be invoked periodically during long running calls to
3646** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3647** database connection D. An example use for this
3648** interface is to keep a GUI updated during a large query.
3649**
3650** ^The parameter P is passed through as the only parameter to the
3651** callback function X. ^The parameter N is the approximate number of
3652** [virtual machine instructions] that are evaluated between successive
3653** invocations of the callback X. ^If N is less than one then the progress
3654** handler is disabled.
3655**
3656** ^Only a single progress handler may be defined at one time per
3657** [database connection]; setting a new progress handler cancels the
3658** old one. ^Setting parameter X to NULL disables the progress handler.
3659** ^The progress handler is also disabled by setting N to a value less
3660** than 1.
3661**
3662** ^If the progress callback returns non-zero, the operation is
3663** interrupted. This feature can be used to implement a
3664** "Cancel" button on a GUI progress dialog box.
3665**
3666** The progress handler callback must not do anything that will modify
3667** the database connection that invoked the progress handler.
3668** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3669** database connections for the meaning of "modify" in this paragraph.
3670**
3671** The progress handler callback would originally only be invoked from the
3672** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3673** and similar because those routines might force a reparse of the schema
3674** which involves running the bytecode engine. However, beginning with
3675** SQLite version 3.41.0, the progress handler callback might also be
3676** invoked directly from [sqlite3_prepare()] while analyzing and generating
3677** code for complex queries.
3678*/
3679SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3680
3681/*
3682** CAPI3REF: Opening A New Database Connection
3683** CONSTRUCTOR: sqlite3
3684**
3685** ^These routines open an SQLite database file as specified by the
3686** filename argument. ^The filename argument is interpreted as UTF-8 for
3687** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3688** order for sqlite3_open16(). ^(A [database connection] handle is usually
3689** returned in *ppDb, even if an error occurs. The only exception is that
3690** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3691** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3692** object.)^ ^(If the database is opened (and/or created) successfully, then
3693** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3694** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3695** an English language description of the error following a failure of any
3696** of the sqlite3_open() routines.
3697**
3698** ^The default encoding will be UTF-8 for databases created using
3699** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3700** created using sqlite3_open16() will be UTF-16 in the native byte order.
3701**
3702** Whether or not an error occurs when it is opened, resources
3703** associated with the [database connection] handle should be released by
3704** passing it to [sqlite3_close()] when it is no longer required.
3705**
3706** The sqlite3_open_v2() interface works like sqlite3_open()
3707** except that it accepts two additional parameters for additional control
3708** over the new database connection. ^(The flags parameter to
3709** sqlite3_open_v2() must include, at a minimum, one of the following
3710** three flag combinations:)^
3711**
3712** <dl>
3713** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3714** <dd>The database is opened in read-only mode. If the database does
3715** not already exist, an error is returned.</dd>)^
3716**
3717** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3718** <dd>The database is opened for reading and writing if possible, or
3719** reading only if the file is write protected by the operating
3720** system. In either case the database must already exist, otherwise
3721** an error is returned. For historical reasons, if opening in
3722** read-write mode fails due to OS-level permissions, an attempt is
3723** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3724** used to determine whether the database is actually
3725** read-write.</dd>)^
3726**
3727** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3728** <dd>The database is opened for reading and writing, and is created if
3729** it does not already exist. This is the behavior that is always used for
3730** sqlite3_open() and sqlite3_open16().</dd>)^
3731** </dl>
3732**
3733** In addition to the required flags, the following optional flags are
3734** also supported:
3735**
3736** <dl>
3737** ^(<dt>[SQLITE_OPEN_URI]</dt>
3738** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3739**
3740** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3741** <dd>The database will be opened as an in-memory database. The database
3742** is named by the "filename" argument for the purposes of cache-sharing,
3743** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3744** </dd>)^
3745**
3746** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3747** <dd>The new database connection will use the "multi-thread"
3748** [threading mode].)^ This means that separate threads are allowed
3749** to use SQLite at the same time, as long as each thread is using
3750** a different [database connection].
3751**
3752** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3753** <dd>The new database connection will use the "serialized"
3754** [threading mode].)^ This means the multiple threads can safely
3755** attempt to use the same database connection at the same time.
3756** (Mutexes will block any actual concurrency, but in this mode
3757** there is no harm in trying.)
3758**
3759** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3760** <dd>The database is opened with [shared cache] enabled, overriding
3761** the default shared cache setting provided by
3762** [sqlite3_enable_shared_cache()].)^
3763** The [use of shared cache mode is discouraged] and hence shared cache
3764** capabilities may be omitted from many builds of SQLite. In such cases,
3765** this option is a no-op.
3766**
3767** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3768** <dd>The database is opened with [shared cache] disabled, overriding
3769** the default shared cache setting provided by
3770** [sqlite3_enable_shared_cache()].)^
3771**
3772** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3773** <dd>The database connection comes up in "extended result code mode".
3774** In other words, the database behaves as if
3775** [sqlite3_extended_result_codes(db,1)] were called on the database
3776** connection as soon as the connection is created. In addition to setting
3777** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3778** to return an extended result code.</dd>
3779**
3780** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3781** <dd>The database filename is not allowed to contain a symbolic link</dd>
3782** </dl>)^
3783**
3784** If the 3rd parameter to sqlite3_open_v2() is not one of the
3785** required combinations shown above optionally combined with other
3786** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3787** then the behavior is undefined. Historic versions of SQLite
3788** have silently ignored surplus bits in the flags parameter to
3789** sqlite3_open_v2(), however that behavior might not be carried through
3790** into future versions of SQLite and so applications should not rely
3791** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3792** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3793** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3794** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3795** by sqlite3_open_v2().
3796**
3797** ^The fourth parameter to sqlite3_open_v2() is the name of the
3798** [sqlite3_vfs] object that defines the operating system interface that
3799** the new database connection should use. ^If the fourth parameter is
3800** a NULL pointer then the default [sqlite3_vfs] object is used.
3801**
3802** ^If the filename is ":memory:", then a private, temporary in-memory database
3803** is created for the connection. ^This in-memory database will vanish when
3804** the database connection is closed. Future versions of SQLite might
3805** make use of additional special filenames that begin with the ":" character.
3806** It is recommended that when a database filename actually does begin with
3807** a ":" character you should prefix the filename with a pathname such as
3808** "./" to avoid ambiguity.
3809**
3810** ^If the filename is an empty string, then a private, temporary
3811** on-disk database will be created. ^This private database will be
3812** automatically deleted as soon as the database connection is closed.
3813**
3814** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3815**
3816** ^If [URI filename] interpretation is enabled, and the filename argument
3817** begins with "file:", then the filename is interpreted as a URI. ^URI
3818** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3819** set in the third argument to sqlite3_open_v2(), or if it has
3820** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3821** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3822** URI filename interpretation is turned off
3823** by default, but future releases of SQLite might enable URI filename
3824** interpretation by default. See "[URI filenames]" for additional
3825** information.
3826**
3827** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3828** authority, then it must be either an empty string or the string
3829** "localhost". ^If the authority is not an empty string or "localhost", an
3830** error is returned to the caller. ^The fragment component of a URI, if
3831** present, is ignored.
3832**
3833** ^SQLite uses the path component of the URI as the name of the disk file
3834** which contains the database. ^If the path begins with a '/' character,
3835** then it is interpreted as an absolute path. ^If the path does not begin
3836** with a '/' (meaning that the authority section is omitted from the URI)
3837** then the path is interpreted as a relative path.
3838** ^(On windows, the first component of an absolute path
3839** is a drive specification (e.g. "C:").)^
3840**
3841** [[core URI query parameters]]
3842** The query component of a URI may contain parameters that are interpreted
3843** either by SQLite itself, or by a [VFS | custom VFS implementation].
3844** SQLite and its built-in [VFSes] interpret the
3845** following query parameters:
3846**
3847** <ul>
3848** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3849** a VFS object that provides the operating system interface that should
3850** be used to access the database file on disk. ^If this option is set to
3851** an empty string the default VFS object is used. ^Specifying an unknown
3852** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3853** present, then the VFS specified by the option takes precedence over
3854** the value passed as the fourth parameter to sqlite3_open_v2().
3855**
3856** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3857** "rwc", or "memory". Attempting to set it to any other value is
3858** an error)^.
3859** ^If "ro" is specified, then the database is opened for read-only
3860** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3861** third argument to sqlite3_open_v2(). ^If the mode option is set to
3862** "rw", then the database is opened for read-write (but not create)
3863** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3864** been set. ^Value "rwc" is equivalent to setting both
3865** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3866** set to "memory" then a pure [in-memory database] that never reads
3867** or writes from disk is used. ^It is an error to specify a value for
3868** the mode parameter that is less restrictive than that specified by
3869** the flags passed in the third parameter to sqlite3_open_v2().
3870**
3871** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3872** "private". ^Setting it to "shared" is equivalent to setting the
3873** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3874** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3875** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3876** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3877** a URI filename, its value overrides any behavior requested by setting
3878** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3879**
3880** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3881** [powersafe overwrite] property does or does not apply to the
3882** storage media on which the database file resides.
3883**
3884** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3885** which if set disables file locking in rollback journal modes. This
3886** is useful for accessing a database on a filesystem that does not
3887** support locking. Caution: Database corruption might result if two
3888** or more processes write to the same database and any one of those
3889** processes uses nolock=1.
3890**
3891** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3892** parameter that indicates that the database file is stored on
3893** read-only media. ^When immutable is set, SQLite assumes that the
3894** database file cannot be changed, even by a process with higher
3895** privilege, and so the database is opened read-only and all locking
3896** and change detection is disabled. Caution: Setting the immutable
3897** property on a database file that does in fact change can result
3898** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3899** See also: [SQLITE_IOCAP_IMMUTABLE].
3900**
3901** </ul>
3902**
3903** ^Specifying an unknown parameter in the query component of a URI is not an
3904** error. Future versions of SQLite might understand additional query
3905** parameters. See "[query parameters with special meaning to SQLite]" for
3906** additional information.
3907**
3908** [[URI filename examples]] <h3>URI filename examples</h3>
3909**
3910** <table border="1" align=center cellpadding=5>
3911** <tr><th> URI filenames <th> Results
3912** <tr><td> file:data.db <td>
3913** Open the file "data.db" in the current directory.
3914** <tr><td> file:/home/fred/data.db<br>
3915** file:///home/fred/data.db <br>
3916** file://localhost/home/fred/data.db <br> <td>
3917** Open the database file "/home/fred/data.db".
3918** <tr><td> file://darkstar/home/fred/data.db <td>
3919** An error. "darkstar" is not a recognized authority.
3920** <tr><td style="white-space:nowrap">
3921** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3922** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3923** C:. Note that the %20 escaping in this example is not strictly
3924** necessary - space characters can be used literally
3925** in URI filenames.
3926** <tr><td> file:data.db?mode=ro&cache=private <td>
3927** Open file "data.db" in the current directory for read-only access.
3928** Regardless of whether or not shared-cache mode is enabled by
3929** default, use a private cache.
3930** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3931** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3932** that uses dot-files in place of posix advisory locking.
3933** <tr><td> file:data.db?mode=readonly <td>
3934** An error. "readonly" is not a valid option for the "mode" parameter.
3935** Use "ro" instead: "file:data.db?mode=ro".
3936** </table>
3937**
3938** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3939** query components of a URI. A hexadecimal escape sequence consists of a
3940** percent sign - "%" - followed by exactly two hexadecimal digits
3941** specifying an octet value. ^Before the path or query components of a
3942** URI filename are interpreted, they are encoded using UTF-8 and all
3943** hexadecimal escape sequences replaced by a single byte containing the
3944** corresponding octet. If this process generates an invalid UTF-8 encoding,
3945** the results are undefined.
3946**
3947** <b>Note to Windows users:</b> The encoding used for the filename argument
3948** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3949** codepage is currently defined. Filenames containing international
3950** characters must be converted to UTF-8 prior to passing them into
3951** sqlite3_open() or sqlite3_open_v2().
3952**
3953** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3954** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3955** features that require the use of temporary files may fail.
3956**
3957** See also: [sqlite3_temp_directory]
3958*/
3959SQLITE_API int sqlite3_open(
3960 const char *filename, /* Database filename (UTF-8) */
3961 sqlite3 **ppDb /* OUT: SQLite db handle */
3962);
3963SQLITE_API int sqlite3_open16(
3964 const void *filename, /* Database filename (UTF-16) */
3965 sqlite3 **ppDb /* OUT: SQLite db handle */
3966);
3967SQLITE_API int sqlite3_open_v2(
3968 const char *filename, /* Database filename (UTF-8) */
3969 sqlite3 **ppDb, /* OUT: SQLite db handle */
3970 int flags, /* Flags */
3971 const char *zVfs /* Name of VFS module to use */
3972);
3973
3974/*
3975** CAPI3REF: Obtain Values For URI Parameters
3976**
3977** These are utility routines, useful to [VFS|custom VFS implementations],
3978** that check if a database file was a URI that contained a specific query
3979** parameter, and if so obtains the value of that query parameter.
3980**
3981** The first parameter to these interfaces (hereafter referred to
3982** as F) must be one of:
3983** <ul>
3984** <li> A database filename pointer created by the SQLite core and
3985** passed into the xOpen() method of a VFS implementation, or
3986** <li> A filename obtained from [sqlite3_db_filename()], or
3987** <li> A new filename constructed using [sqlite3_create_filename()].
3988** </ul>
3989** If the F parameter is not one of the above, then the behavior is
3990** undefined and probably undesirable. Older versions of SQLite were
3991** more tolerant of invalid F parameters than newer versions.
3992**
3993** If F is a suitable filename (as described in the previous paragraph)
3994** and if P is the name of the query parameter, then
3995** sqlite3_uri_parameter(F,P) returns the value of the P
3996** parameter if it exists or a NULL pointer if P does not appear as a
3997** query parameter on F. If P is a query parameter of F and it
3998** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3999** a pointer to an empty string.
4000**
4001** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
4002** parameter and returns true (1) or false (0) according to the value
4003** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
4004** value of query parameter P is one of "yes", "true", or "on" in any
4005** case or if the value begins with a non-zero number. The
4006** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
4007** query parameter P is one of "no", "false", or "off" in any case or
4008** if the value begins with a numeric zero. If P is not a query
4009** parameter on F or if the value of P does not match any of the
4010** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
4011**
4012** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
4013** 64-bit signed integer and returns that integer, or D if P does not
4014** exist. If the value of P is something other than an integer, then
4015** zero is returned.
4016**
4017** The sqlite3_uri_key(F,N) returns a pointer to the name (not
4018** the value) of the N-th query parameter for filename F, or a NULL
4019** pointer if N is less than zero or greater than the number of query
4020** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4021** the name of the first query parameter, 1 for the second parameter, and
4022** so forth.
4023**
4024** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4025** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4026** is not a database file pathname pointer that the SQLite core passed
4027** into the xOpen VFS method, then the behavior of this routine is undefined
4028** and probably undesirable.
4029**
4030** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4031** parameter can also be the name of a rollback journal file or WAL file
4032** in addition to the main database file. Prior to version 3.31.0, these
4033** routines would only work if F was the name of the main database file.
4034** When the F parameter is the name of the rollback journal or WAL file,
4035** it has access to all the same query parameters as were found on the
4036** main database file.
4037**
4038** See the [URI filename] documentation for additional information.
4039*/
4040SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4041SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4042SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4043SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4044
4045/*
4046** CAPI3REF: Translate filenames
4047**
4048** These routines are available to [VFS|custom VFS implementations] for
4049** translating filenames between the main database file, the journal file,
4050** and the WAL file.
4051**
4052** If F is the name of an sqlite database file, journal file, or WAL file
4053** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4054** returns the name of the corresponding database file.
4055**
4056** If F is the name of an sqlite database file, journal file, or WAL file
4057** passed by the SQLite core into the VFS, or if F is a database filename
4058** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4059** returns the name of the corresponding rollback journal file.
4060**
4061** If F is the name of an sqlite database file, journal file, or WAL file
4062** that was passed by the SQLite core into the VFS, or if F is a database
4063** filename obtained from [sqlite3_db_filename()], then
4064** sqlite3_filename_wal(F) returns the name of the corresponding
4065** WAL file.
4066**
4067** In all of the above, if F is not the name of a database, journal or WAL
4068** filename passed into the VFS from the SQLite core and F is not the
4069** return value from [sqlite3_db_filename()], then the result is
4070** undefined and is likely a memory access violation.
4071*/
4072SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4073SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4074SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4075
4076/*
4077** CAPI3REF: Database File Corresponding To A Journal
4078**
4079** ^If X is the name of a rollback or WAL-mode journal file that is
4080** passed into the xOpen method of [sqlite3_vfs], then
4081** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4082** object that represents the main database file.
4083**
4084** This routine is intended for use in custom [VFS] implementations
4085** only. It is not a general-purpose interface.
4086** The argument sqlite3_file_object(X) must be a filename pointer that
4087** has been passed into [sqlite3_vfs].xOpen method where the
4088** flags parameter to xOpen contains one of the bits
4089** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4090** of this routine results in undefined and probably undesirable
4091** behavior.
4092*/
4093SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4094
4095/*
4096** CAPI3REF: Create and Destroy VFS Filenames
4097**
4098** These interfaces are provided for use by [VFS shim] implementations and
4099** are not useful outside of that context.
4100**
4101** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4102** database filename D with corresponding journal file J and WAL file W and
4103** an array P of N URI Key/Value pairs. The result from
4104** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4105** is safe to pass to routines like:
4106** <ul>
4107** <li> [sqlite3_uri_parameter()],
4108** <li> [sqlite3_uri_boolean()],
4109** <li> [sqlite3_uri_int64()],
4110** <li> [sqlite3_uri_key()],
4111** <li> [sqlite3_filename_database()],
4112** <li> [sqlite3_filename_journal()], or
4113** <li> [sqlite3_filename_wal()].
4114** </ul>
4115** If a memory allocation error occurs, sqlite3_create_filename() might
4116** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4117** must be released by a corresponding call to sqlite3_free_filename(Y).
4118**
4119** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4120** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4121** to a key and value for a query parameter. The P parameter may be a NULL
4122** pointer if N is zero. None of the 2*N pointers in the P array may be
4123** NULL pointers and key pointers should not be empty strings.
4124** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4125** be NULL pointers, though they can be empty strings.
4126**
4127** The sqlite3_free_filename(Y) routine releases a memory allocation
4128** previously obtained from sqlite3_create_filename(). Invoking
4129** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4130**
4131** If the Y parameter to sqlite3_free_filename(Y) is anything other
4132** than a NULL pointer or a pointer previously acquired from
4133** sqlite3_create_filename(), then bad things such as heap
4134** corruption or segfaults may occur. The value Y should not be
4135** used again after sqlite3_free_filename(Y) has been called. This means
4136** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4137** then the corresponding [sqlite3_module.xClose() method should also be
4138** invoked prior to calling sqlite3_free_filename(Y).
4139*/
4140SQLITE_API sqlite3_filename sqlite3_create_filename(
4141 const char *zDatabase,
4142 const char *zJournal,
4143 const char *zWal,
4144 int nParam,
4145 const char **azParam
4146);
4147SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4148
4149/*
4150** CAPI3REF: Error Codes And Messages
4151** METHOD: sqlite3
4152**
4153** ^If the most recent sqlite3_* API call associated with
4154** [database connection] D failed, then the sqlite3_errcode(D) interface
4155** returns the numeric [result code] or [extended result code] for that
4156** API call.
4157** ^The sqlite3_extended_errcode()
4158** interface is the same except that it always returns the
4159** [extended result code] even when extended result codes are
4160** disabled.
4161**
4162** The values returned by sqlite3_errcode() and/or
4163** sqlite3_extended_errcode() might change with each API call.
4164** Except, there are some interfaces that are guaranteed to never
4165** change the value of the error code. The error-code preserving
4166** interfaces include the following:
4167**
4168** <ul>
4169** <li> sqlite3_errcode()
4170** <li> sqlite3_extended_errcode()
4171** <li> sqlite3_errmsg()
4172** <li> sqlite3_errmsg16()
4173** <li> sqlite3_error_offset()
4174** </ul>
4175**
4176** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4177** text that describes the error, as either UTF-8 or UTF-16 respectively,
4178** or NULL if no error message is available.
4179** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4180** ^(Memory to hold the error message string is managed internally.
4181** The application does not need to worry about freeing the result.
4182** However, the error string might be overwritten or deallocated by
4183** subsequent calls to other SQLite interface functions.)^
4184**
4185** ^The sqlite3_errstr(E) interface returns the English-language text
4186** that describes the [result code] E, as UTF-8, or NULL if E is not a
4187** result code for which a text error message is available.
4188** ^(Memory to hold the error message string is managed internally
4189** and must not be freed by the application)^.
4190**
4191** ^If the most recent error references a specific token in the input
4192** SQL, the sqlite3_error_offset() interface returns the byte offset
4193** of the start of that token. ^The byte offset returned by
4194** sqlite3_error_offset() assumes that the input SQL is UTF-8.
4195** ^If the most recent error does not reference a specific token in the input
4196** SQL, then the sqlite3_error_offset() function returns -1.
4197**
4198** When the serialized [threading mode] is in use, it might be the
4199** case that a second error occurs on a separate thread in between
4200** the time of the first error and the call to these interfaces.
4201** When that happens, the second error will be reported since these
4202** interfaces always report the most recent result. To avoid
4203** this, each thread can obtain exclusive use of the [database connection] D
4204** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4205** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4206** all calls to the interfaces listed here are completed.
4207**
4208** If an interface fails with SQLITE_MISUSE, that means the interface
4209** was invoked incorrectly by the application. In that case, the
4210** error code and message may or may not be set.
4211*/
4212SQLITE_API int sqlite3_errcode(sqlite3 *db);
4213SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4214SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4215SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4216SQLITE_API const char *sqlite3_errstr(int);
4217SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4218
4219/*
4220** CAPI3REF: Set Error Codes And Message
4221** METHOD: sqlite3
4222**
4223** Set the error code of the database handle passed as the first argument
4224** to errcode, and the error message to a copy of nul-terminated string
4225** zErrMsg. If zErrMsg is passed NULL, then the error message is set to
4226** the default message associated with the supplied error code. Subsequent
4227** calls to [sqlite3_errcode()] and [sqlite3_errmsg()] and similar will
4228** return the values set by this routine in place of what was previously
4229** set by SQLite itself.
4230**
4231** This function returns SQLITE_OK if the error code and error message are
4232** successfully set, SQLITE_NOMEM if an OOM occurs, and SQLITE_MISUSE if
4233** the database handle is NULL or invalid.
4234**
4235** The error code and message set by this routine remains in effect until
4236** they are changed, either by another call to this routine or until they are
4237** changed to by SQLite itself to reflect the result of some subsquent
4238** API call.
4239**
4240** This function is intended for use by SQLite extensions or wrappers. The
4241** idea is that an extension or wrapper can use this routine to set error
4242** messages and error codes and thus behave more like a core SQLite
4243** feature from the point of view of an application.
4244*/
4245SQLITE_API int sqlite3_set_errmsg(sqlite3 *db, int errcode, const char *zErrMsg);
4246
4247/*
4248** CAPI3REF: Prepared Statement Object
4249** KEYWORDS: {prepared statement} {prepared statements}
4250**
4251** An instance of this object represents a single SQL statement that
4252** has been compiled into binary form and is ready to be evaluated.
4253**
4254** Think of each SQL statement as a separate computer program. The
4255** original SQL text is source code. A prepared statement object
4256** is the compiled object code. All SQL must be converted into a
4257** prepared statement before it can be run.
4258**
4259** The life-cycle of a prepared statement object usually goes like this:
4260**
4261** <ol>
4262** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4263** <li> Bind values to [parameters] using the sqlite3_bind_*()
4264** interfaces.
4265** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4266** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4267** to step 2. Do this zero or more times.
4268** <li> Destroy the object using [sqlite3_finalize()].
4269** </ol>
4270*/
4271typedef struct sqlite3_stmt sqlite3_stmt;
4272
4273/*
4274** CAPI3REF: Run-time Limits
4275** METHOD: sqlite3
4276**
4277** ^(This interface allows the size of various constructs to be limited
4278** on a connection by connection basis. The first parameter is the
4279** [database connection] whose limit is to be set or queried. The
4280** second parameter is one of the [limit categories] that define a
4281** class of constructs to be size limited. The third parameter is the
4282** new limit for that construct.)^
4283**
4284** ^If the new limit is a negative number, the limit is unchanged.
4285** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4286** [limits | hard upper bound]
4287** set at compile-time by a C preprocessor macro called
4288** [limits | SQLITE_MAX_<i>NAME</i>].
4289** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4290** ^Attempts to increase a limit above its hard upper bound are
4291** silently truncated to the hard upper bound.
4292**
4293** ^Regardless of whether or not the limit was changed, the
4294** [sqlite3_limit()] interface returns the prior value of the limit.
4295** ^Hence, to find the current value of a limit without changing it,
4296** simply invoke this interface with the third parameter set to -1.
4297**
4298** Run-time limits are intended for use in applications that manage
4299** both their own internal database and also databases that are controlled
4300** by untrusted external sources. An example application might be a
4301** web browser that has its own databases for storing history and
4302** separate databases controlled by JavaScript applications downloaded
4303** off the Internet. The internal databases can be given the
4304** large, default limits. Databases managed by external sources can
4305** be given much smaller limits designed to prevent a denial of service
4306** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4307** interface to further control untrusted SQL. The size of the database
4308** created by an untrusted script can be contained using the
4309** [max_page_count] [PRAGMA].
4310**
4311** New run-time limit categories may be added in future releases.
4312*/
4313SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4314
4315/*
4316** CAPI3REF: Run-Time Limit Categories
4317** KEYWORDS: {limit category} {*limit categories}
4318**
4319** These constants define various performance limits
4320** that can be lowered at run-time using [sqlite3_limit()].
4321** A concise description of these limits follows, and additional information
4322** is available at [limits | Limits in SQLite].
4323**
4324** <dl>
4325** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4326** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4327**
4328** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4329** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4330**
4331** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4332** <dd>The maximum number of columns in a table definition or in the
4333** result set of a [SELECT] or the maximum number of columns in an index
4334** or in an ORDER BY or GROUP BY clause.</dd>)^
4335**
4336** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4337** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4338**
4339** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4340** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4341**
4342** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4343** <dd>The maximum number of instructions in a virtual machine program
4344** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4345** the equivalent tries to allocate space for more than this many opcodes
4346** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4347**
4348** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4349** <dd>The maximum number of arguments on a function.</dd>)^
4350**
4351** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4352** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4353**
4354** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4355** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4356** <dd>The maximum length of the pattern argument to the [LIKE] or
4357** [GLOB] operators.</dd>)^
4358**
4359** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4360** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4361** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4362**
4363** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4364** <dd>The maximum depth of recursion for triggers.</dd>)^
4365**
4366** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4367** <dd>The maximum number of auxiliary worker threads that a single
4368** [prepared statement] may start.</dd>)^
4369** </dl>
4370*/
4371#define SQLITE_LIMIT_LENGTH 0
4372#define SQLITE_LIMIT_SQL_LENGTH 1
4373#define SQLITE_LIMIT_COLUMN 2
4374#define SQLITE_LIMIT_EXPR_DEPTH 3
4375#define SQLITE_LIMIT_COMPOUND_SELECT 4
4376#define SQLITE_LIMIT_VDBE_OP 5
4377#define SQLITE_LIMIT_FUNCTION_ARG 6
4378#define SQLITE_LIMIT_ATTACHED 7
4379#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4380#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4381#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4382#define SQLITE_LIMIT_WORKER_THREADS 11
4383
4384/*
4385** CAPI3REF: Prepare Flags
4386**
4387** These constants define various flags that can be passed into the
4388** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4389** [sqlite3_prepare16_v3()] interfaces.
4390**
4391** New flags may be added in future releases of SQLite.
4392**
4393** <dl>
4394** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4395** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4396** that the prepared statement will be retained for a long time and
4397** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4398** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4399** be used just once or at most a few times and then destroyed using
4400** [sqlite3_finalize()] relatively soon. The current implementation acts
4401** on this hint by avoiding the use of [lookaside memory] so as not to
4402** deplete the limited store of lookaside memory. Future versions of
4403** SQLite may act on this hint differently.
4404**
4405** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4406** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4407** to be required for any prepared statement that wanted to use the
4408** [sqlite3_normalized_sql()] interface. However, the
4409** [sqlite3_normalized_sql()] interface is now available to all
4410** prepared statements, regardless of whether or not they use this
4411** flag.
4412**
4413** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4414** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4415** to return an error (error code SQLITE_ERROR) if the statement uses
4416** any virtual tables.
4417**
4418** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4419** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4420** errors from being sent to the error log defined by
4421** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4422** compiles to see if some SQL syntax is well-formed, without generating
4423** messages on the global error log when it is not. If the test compile
4424** fails, the sqlite3_prepare_v3() call returns the same error indications
4425** with or without this flag; it just omits the call to [sqlite3_log()] that
4426** logs the error.
4427** </dl>
4428*/
4429#define SQLITE_PREPARE_PERSISTENT 0x01
4430#define SQLITE_PREPARE_NORMALIZE 0x02
4431#define SQLITE_PREPARE_NO_VTAB 0x04
4432#define SQLITE_PREPARE_DONT_LOG 0x10
4433
4434/*
4435** CAPI3REF: Compiling An SQL Statement
4436** KEYWORDS: {SQL statement compiler}
4437** METHOD: sqlite3
4438** CONSTRUCTOR: sqlite3_stmt
4439**
4440** To execute an SQL statement, it must first be compiled into a byte-code
4441** program using one of these routines. Or, in other words, these routines
4442** are constructors for the [prepared statement] object.
4443**
4444** The preferred routine to use is [sqlite3_prepare_v2()]. The
4445** [sqlite3_prepare()] interface is legacy and should be avoided.
4446** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4447** for special purposes.
4448**
4449** The use of the UTF-8 interfaces is preferred, as SQLite currently
4450** does all parsing using UTF-8. The UTF-16 interfaces are provided
4451** as a convenience. The UTF-16 interfaces work by converting the
4452** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4453**
4454** The first argument, "db", is a [database connection] obtained from a
4455** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4456** [sqlite3_open16()]. The database connection must not have been closed.
4457**
4458** The second argument, "zSql", is the statement to be compiled, encoded
4459** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4460** and sqlite3_prepare_v3()
4461** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4462** and sqlite3_prepare16_v3() use UTF-16.
4463**
4464** ^If the nByte argument is negative, then zSql is read up to the
4465** first zero terminator. ^If nByte is positive, then it is the maximum
4466** number of bytes read from zSql. When nByte is positive, zSql is read
4467** up to the first zero terminator or until the nByte bytes have been read,
4468** whichever comes first. ^If nByte is zero, then no prepared
4469** statement is generated.
4470** If the caller knows that the supplied string is nul-terminated, then
4471** there is a small performance advantage to passing an nByte parameter that
4472** is the number of bytes in the input string <i>including</i>
4473** the nul-terminator.
4474** Note that nByte measures the length of the input in bytes, not
4475** characters, even for the UTF-16 interfaces.
4476**
4477** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4478** past the end of the first SQL statement in zSql. These routines only
4479** compile the first statement in zSql, so *pzTail is left pointing to
4480** what remains uncompiled.
4481**
4482** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4483** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4484** to NULL. ^If the input text contains no SQL (if the input is an empty
4485** string or a comment) then *ppStmt is set to NULL.
4486** The calling procedure is responsible for deleting the compiled
4487** SQL statement using [sqlite3_finalize()] after it has finished with it.
4488** ppStmt may not be NULL.
4489**
4490** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4491** otherwise an [error code] is returned.
4492**
4493** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4494** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4495** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4496** are retained for backwards compatibility, but their use is discouraged.
4497** ^In the "vX" interfaces, the prepared statement
4498** that is returned (the [sqlite3_stmt] object) contains a copy of the
4499** original SQL text. This causes the [sqlite3_step()] interface to
4500** behave differently in three ways:
4501**
4502** <ol>
4503** <li>
4504** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4505** always used to do, [sqlite3_step()] will automatically recompile the SQL
4506** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4507** retries will occur before sqlite3_step() gives up and returns an error.
4508** </li>
4509**
4510** <li>
4511** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4512** [error codes] or [extended error codes]. ^The legacy behavior was that
4513** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4514** and the application would have to make a second call to [sqlite3_reset()]
4515** in order to find the underlying cause of the problem. With the "v2" prepare
4516** interfaces, the underlying reason for the error is returned immediately.
4517** </li>
4518**
4519** <li>
4520** ^If the specific value bound to a [parameter | host parameter] in the
4521** WHERE clause might influence the choice of query plan for a statement,
4522** then the statement will be automatically recompiled, as if there had been
4523** a schema change, on the first [sqlite3_step()] call following any change
4524** to the [sqlite3_bind_text | bindings] of that [parameter].
4525** ^The specific value of a WHERE-clause [parameter] might influence the
4526** choice of query plan if the parameter is the left-hand side of a [LIKE]
4527** or [GLOB] operator or if the parameter is compared to an indexed column
4528** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4529** </li>
4530** </ol>
4531**
4532** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4533** the extra prepFlags parameter, which is a bit array consisting of zero or
4534** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4535** sqlite3_prepare_v2() interface works exactly the same as
4536** sqlite3_prepare_v3() with a zero prepFlags parameter.
4537*/
4538SQLITE_API int sqlite3_prepare(
4539 sqlite3 *db, /* Database handle */
4540 const char *zSql, /* SQL statement, UTF-8 encoded */
4541 int nByte, /* Maximum length of zSql in bytes. */
4542 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4543 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4544);
4545SQLITE_API int sqlite3_prepare_v2(
4546 sqlite3 *db, /* Database handle */
4547 const char *zSql, /* SQL statement, UTF-8 encoded */
4548 int nByte, /* Maximum length of zSql in bytes. */
4549 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4550 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4551);
4552SQLITE_API int sqlite3_prepare_v3(
4553 sqlite3 *db, /* Database handle */
4554 const char *zSql, /* SQL statement, UTF-8 encoded */
4555 int nByte, /* Maximum length of zSql in bytes. */
4556 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4557 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4558 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4559);
4560SQLITE_API int sqlite3_prepare16(
4561 sqlite3 *db, /* Database handle */
4562 const void *zSql, /* SQL statement, UTF-16 encoded */
4563 int nByte, /* Maximum length of zSql in bytes. */
4564 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4565 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4566);
4567SQLITE_API int sqlite3_prepare16_v2(
4568 sqlite3 *db, /* Database handle */
4569 const void *zSql, /* SQL statement, UTF-16 encoded */
4570 int nByte, /* Maximum length of zSql in bytes. */
4571 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4572 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4573);
4574SQLITE_API int sqlite3_prepare16_v3(
4575 sqlite3 *db, /* Database handle */
4576 const void *zSql, /* SQL statement, UTF-16 encoded */
4577 int nByte, /* Maximum length of zSql in bytes. */
4578 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4579 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4580 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4581);
4582
4583/*
4584** CAPI3REF: Retrieving Statement SQL
4585** METHOD: sqlite3_stmt
4586**
4587** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4588** SQL text used to create [prepared statement] P if P was
4589** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4590** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4591** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4592** string containing the SQL text of prepared statement P with
4593** [bound parameters] expanded.
4594** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4595** string containing the normalized SQL text of prepared statement P. The
4596** semantics used to normalize a SQL statement are unspecified and subject
4597** to change. At a minimum, literal values will be replaced with suitable
4598** placeholders.
4599**
4600** ^(For example, if a prepared statement is created using the SQL
4601** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4602** and parameter :xyz is unbound, then sqlite3_sql() will return
4603** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4604** will return "SELECT 2345,NULL".)^
4605**
4606** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4607** is available to hold the result, or if the result would exceed the
4608** maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4609**
4610** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4611** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4612** option causes sqlite3_expanded_sql() to always return NULL.
4613**
4614** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4615** are managed by SQLite and are automatically freed when the prepared
4616** statement is finalized.
4617** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4618** is obtained from [sqlite3_malloc()] and must be freed by the application
4619** by passing it to [sqlite3_free()].
4620**
4621** ^The sqlite3_normalized_sql() interface is only available if
4622** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4623*/
4624SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4625SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4626#ifdef SQLITE_ENABLE_NORMALIZE
4627SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4628#endif
4629
4630/*
4631** CAPI3REF: Determine If An SQL Statement Writes The Database
4632** METHOD: sqlite3_stmt
4633**
4634** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4635** and only if the [prepared statement] X makes no direct changes to
4636** the content of the database file.
4637**
4638** Note that [application-defined SQL functions] or
4639** [virtual tables] might change the database indirectly as a side effect.
4640** ^(For example, if an application defines a function "eval()" that
4641** calls [sqlite3_exec()], then the following SQL statement would
4642** change the database file through side-effects:
4643**
4644** <blockquote><pre>
4645** SELECT eval('DELETE FROM t1') FROM t2;
4646** </pre></blockquote>
4647**
4648** But because the [SELECT] statement does not change the database file
4649** directly, sqlite3_stmt_readonly() would still return true.)^
4650**
4651** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4652** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4653** since the statements themselves do not actually modify the database but
4654** rather they control the timing of when other statements modify the
4655** database. ^The [ATTACH] and [DETACH] statements also cause
4656** sqlite3_stmt_readonly() to return true since, while those statements
4657** change the configuration of a database connection, they do not make
4658** changes to the content of the database files on disk.
4659** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4660** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4661** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4662** sqlite3_stmt_readonly() returns false for those commands.
4663**
4664** ^This routine returns false if there is any possibility that the
4665** statement might change the database file. ^A false return does
4666** not guarantee that the statement will change the database file.
4667** ^For example, an UPDATE statement might have a WHERE clause that
4668** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4669** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4670** read-only no-op if the table already exists, but
4671** sqlite3_stmt_readonly() still returns false for such a statement.
4672**
4673** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4674** statement, then sqlite3_stmt_readonly(X) returns the same value as
4675** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4676*/
4677SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4678
4679/*
4680** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4681** METHOD: sqlite3_stmt
4682**
4683** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4684** prepared statement S is an EXPLAIN statement, or 2 if the
4685** statement S is an EXPLAIN QUERY PLAN.
4686** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4687** an ordinary statement or a NULL pointer.
4688*/
4689SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4690
4691/*
4692** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4693** METHOD: sqlite3_stmt
4694**
4695** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4696** setting for [prepared statement] S. If E is zero, then S becomes
4697** a normal prepared statement. If E is 1, then S behaves as if
4698** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4699** its SQL text began with "[EXPLAIN QUERY PLAN]".
4700**
4701** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4702** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4703** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4704**
4705** Because of the potential need to reprepare, a call to
4706** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4707** reprepared because it was created using [sqlite3_prepare()] instead of
4708** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4709** hence has no saved SQL text with which to reprepare.
4710**
4711** Changing the explain setting for a prepared statement does not change
4712** the original SQL text for the statement. Hence, if the SQL text originally
4713** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4714** is called to convert the statement into an ordinary statement, the EXPLAIN
4715** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4716** output, even though the statement now acts like a normal SQL statement.
4717**
4718** This routine returns SQLITE_OK if the explain mode is successfully
4719** changed, or an error code if the explain mode could not be changed.
4720** The explain mode cannot be changed while a statement is active.
4721** Hence, it is good practice to call [sqlite3_reset(S)]
4722** immediately prior to calling sqlite3_stmt_explain(S,E).
4723*/
4724SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4725
4726/*
4727** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4728** METHOD: sqlite3_stmt
4729**
4730** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4731** [prepared statement] S has been stepped at least once using
4732** [sqlite3_step(S)] but has neither run to completion (returned
4733** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4734** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4735** interface returns false if S is a NULL pointer. If S is not a
4736** NULL pointer and is not a pointer to a valid [prepared statement]
4737** object, then the behavior is undefined and probably undesirable.
4738**
4739** This interface can be used in combination [sqlite3_next_stmt()]
4740** to locate all prepared statements associated with a database
4741** connection that are in need of being reset. This can be used,
4742** for example, in diagnostic routines to search for prepared
4743** statements that are holding a transaction open.
4744*/
4745SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4746
4747/*
4748** CAPI3REF: Dynamically Typed Value Object
4749** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4750**
4751** SQLite uses the sqlite3_value object to represent all values
4752** that can be stored in a database table. SQLite uses dynamic typing
4753** for the values it stores. ^Values stored in sqlite3_value objects
4754** can be integers, floating point values, strings, BLOBs, or NULL.
4755**
4756** An sqlite3_value object may be either "protected" or "unprotected".
4757** Some interfaces require a protected sqlite3_value. Other interfaces
4758** will accept either a protected or an unprotected sqlite3_value.
4759** Every interface that accepts sqlite3_value arguments specifies
4760** whether or not it requires a protected sqlite3_value. The
4761** [sqlite3_value_dup()] interface can be used to construct a new
4762** protected sqlite3_value from an unprotected sqlite3_value.
4763**
4764** The terms "protected" and "unprotected" refer to whether or not
4765** a mutex is held. An internal mutex is held for a protected
4766** sqlite3_value object but no mutex is held for an unprotected
4767** sqlite3_value object. If SQLite is compiled to be single-threaded
4768** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4769** or if SQLite is run in one of reduced mutex modes
4770** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4771** then there is no distinction between protected and unprotected
4772** sqlite3_value objects and they can be used interchangeably. However,
4773** for maximum code portability it is recommended that applications
4774** still make the distinction between protected and unprotected
4775** sqlite3_value objects even when not strictly required.
4776**
4777** ^The sqlite3_value objects that are passed as parameters into the
4778** implementation of [application-defined SQL functions] are protected.
4779** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4780** are protected.
4781** ^The sqlite3_value object returned by
4782** [sqlite3_column_value()] is unprotected.
4783** Unprotected sqlite3_value objects may only be used as arguments
4784** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4785** [sqlite3_value_dup()].
4786** The [sqlite3_value_blob | sqlite3_value_type()] family of
4787** interfaces require protected sqlite3_value objects.
4788*/
4789typedef struct sqlite3_value sqlite3_value;
4790
4791/*
4792** CAPI3REF: SQL Function Context Object
4793**
4794** The context in which an SQL function executes is stored in an
4795** sqlite3_context object. ^A pointer to an sqlite3_context object
4796** is always the first parameter to [application-defined SQL functions].
4797** The application-defined SQL function implementation will pass this
4798** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4799** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4800** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4801** and/or [sqlite3_set_auxdata()].
4802*/
4803typedef struct sqlite3_context sqlite3_context;
4804
4805/*
4806** CAPI3REF: Binding Values To Prepared Statements
4807** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4808** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4809** METHOD: sqlite3_stmt
4810**
4811** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4812** literals may be replaced by a [parameter] that matches one of the following
4813** templates:
4814**
4815** <ul>
4816** <li> ?
4817** <li> ?NNN
4818** <li> :VVV
4819** <li> @VVV
4820** <li> $VVV
4821** </ul>
4822**
4823** In the templates above, NNN represents an integer literal,
4824** and VVV represents an alphanumeric identifier.)^ ^The values of these
4825** parameters (also called "host parameter names" or "SQL parameters")
4826** can be set using the sqlite3_bind_*() routines defined here.
4827**
4828** ^The first argument to the sqlite3_bind_*() routines is always
4829** a pointer to the [sqlite3_stmt] object returned from
4830** [sqlite3_prepare_v2()] or its variants.
4831**
4832** ^The second argument is the index of the SQL parameter to be set.
4833** ^The leftmost SQL parameter has an index of 1. ^When the same named
4834** SQL parameter is used more than once, second and subsequent
4835** occurrences have the same index as the first occurrence.
4836** ^The index for named parameters can be looked up using the
4837** [sqlite3_bind_parameter_index()] API if desired. ^The index
4838** for "?NNN" parameters is the value of NNN.
4839** ^The NNN value must be between 1 and the [sqlite3_limit()]
4840** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4841**
4842** ^The third argument is the value to bind to the parameter.
4843** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4844** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4845** is ignored and the end result is the same as sqlite3_bind_null().
4846** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4847** it should be a pointer to well-formed UTF8 text.
4848** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4849** it should be a pointer to well-formed UTF16 text.
4850** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4851** it should be a pointer to a well-formed unicode string that is
4852** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4853** otherwise.
4854**
4855** [[byte-order determination rules]] ^The byte-order of
4856** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4857** found in the first character, which is removed, or in the absence of a BOM
4858** the byte order is the native byte order of the host
4859** machine for sqlite3_bind_text16() or the byte order specified in
4860** the 6th parameter for sqlite3_bind_text64().)^
4861** ^If UTF16 input text contains invalid unicode
4862** characters, then SQLite might change those invalid characters
4863** into the unicode replacement character: U+FFFD.
4864**
4865** ^(In those routines that have a fourth argument, its value is the
4866** number of bytes in the parameter. To be clear: the value is the
4867** number of <u>bytes</u> in the value, not the number of characters.)^
4868** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4869** is negative, then the length of the string is
4870** the number of bytes up to the first zero terminator.
4871** If the fourth parameter to sqlite3_bind_blob() is negative, then
4872** the behavior is undefined.
4873** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4874** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4875** that parameter must be the byte offset
4876** where the NUL terminator would occur assuming the string were NUL
4877** terminated. If any NUL characters occur at byte offsets less than
4878** the value of the fourth parameter then the resulting string value will
4879** contain embedded NULs. The result of expressions involving strings
4880** with embedded NULs is undefined.
4881**
4882** ^The fifth argument to the BLOB and string binding interfaces controls
4883** or indicates the lifetime of the object referenced by the third parameter.
4884** These three options exist:
4885** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4886** with it may be passed. ^It is called to dispose of the BLOB or string even
4887** if the call to the bind API fails, except the destructor is not called if
4888** the third parameter is a NULL pointer or the fourth parameter is negative.
4889** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4890** the application remains responsible for disposing of the object. ^In this
4891** case, the object and the provided pointer to it must remain valid until
4892** either the prepared statement is finalized or the same SQL parameter is
4893** bound to something else, whichever occurs sooner.
4894** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4895** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4896** object and pointer to it must remain valid until then. ^SQLite will then
4897** manage the lifetime of its private copy.
4898**
4899** ^The sixth argument to sqlite3_bind_text64() must be one of
4900** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4901** to specify the encoding of the text in the third parameter. If
4902** the sixth argument to sqlite3_bind_text64() is not one of the
4903** allowed values shown above, or if the text encoding is different
4904** from the encoding specified by the sixth parameter, then the behavior
4905** is undefined.
4906**
4907** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4908** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4909** (just an integer to hold its size) while it is being processed.
4910** Zeroblobs are intended to serve as placeholders for BLOBs whose
4911** content is later written using
4912** [sqlite3_blob_open | incremental BLOB I/O] routines.
4913** ^A negative value for the zeroblob results in a zero-length BLOB.
4914**
4915** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4916** [prepared statement] S to have an SQL value of NULL, but to also be
4917** associated with the pointer P of type T. ^D is either a NULL pointer or
4918** a pointer to a destructor function for P. ^SQLite will invoke the
4919** destructor D with a single argument of P when it is finished using
4920** P, even if the call to sqlite3_bind_pointer() fails. Due to a
4921** historical design quirk, results are undefined if D is
4922** SQLITE_TRANSIENT. The T parameter should be a static string,
4923** preferably a string literal. The sqlite3_bind_pointer() routine is
4924** part of the [pointer passing interface] added for SQLite 3.20.0.
4925**
4926** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4927** for the [prepared statement] or with a prepared statement for which
4928** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4929** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4930** routine is passed a [prepared statement] that has been finalized, the
4931** result is undefined and probably harmful.
4932**
4933** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4934** ^Unbound parameters are interpreted as NULL.
4935**
4936** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4937** [error code] if anything goes wrong.
4938** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4939** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4940** [SQLITE_MAX_LENGTH].
4941** ^[SQLITE_RANGE] is returned if the parameter
4942** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4943**
4944** See also: [sqlite3_bind_parameter_count()],
4945** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4946*/
4947SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4948SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4949 void(*)(void*));
4950SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4951SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4952SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4953SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4954SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4955SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4956SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4957 void(*)(void*), unsigned char encoding);
4958SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4959SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4960SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4961SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4962
4963/*
4964** CAPI3REF: Number Of SQL Parameters
4965** METHOD: sqlite3_stmt
4966**
4967** ^This routine can be used to find the number of [SQL parameters]
4968** in a [prepared statement]. SQL parameters are tokens of the
4969** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4970** placeholders for values that are [sqlite3_bind_blob | bound]
4971** to the parameters at a later time.
4972**
4973** ^(This routine actually returns the index of the largest (rightmost)
4974** parameter. For all forms except ?NNN, this will correspond to the
4975** number of unique parameters. If parameters of the ?NNN form are used,
4976** there may be gaps in the list.)^
4977**
4978** See also: [sqlite3_bind_blob|sqlite3_bind()],
4979** [sqlite3_bind_parameter_name()], and
4980** [sqlite3_bind_parameter_index()].
4981*/
4982SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4983
4984/*
4985** CAPI3REF: Name Of A Host Parameter
4986** METHOD: sqlite3_stmt
4987**
4988** ^The sqlite3_bind_parameter_name(P,N) interface returns
4989** the name of the N-th [SQL parameter] in the [prepared statement] P.
4990** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4991** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4992** respectively.
4993** In other words, the initial ":" or "$" or "@" or "?"
4994** is included as part of the name.)^
4995** ^Parameters of the form "?" without a following integer have no name
4996** and are referred to as "nameless" or "anonymous parameters".
4997**
4998** ^The first host parameter has an index of 1, not 0.
4999**
5000** ^If the value N is out of range or if the N-th parameter is
5001** nameless, then NULL is returned. ^The returned string is
5002** always in UTF-8 encoding even if the named parameter was
5003** originally specified as UTF-16 in [sqlite3_prepare16()],
5004** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
5005**
5006** See also: [sqlite3_bind_blob|sqlite3_bind()],
5007** [sqlite3_bind_parameter_count()], and
5008** [sqlite3_bind_parameter_index()].
5009*/
5010SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
5011
5012/*
5013** CAPI3REF: Index Of A Parameter With A Given Name
5014** METHOD: sqlite3_stmt
5015**
5016** ^Return the index of an SQL parameter given its name. ^The
5017** index value returned is suitable for use as the second
5018** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
5019** is returned if no matching parameter is found. ^The parameter
5020** name must be given in UTF-8 even if the original statement
5021** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
5022** [sqlite3_prepare16_v3()].
5023**
5024** See also: [sqlite3_bind_blob|sqlite3_bind()],
5025** [sqlite3_bind_parameter_count()], and
5026** [sqlite3_bind_parameter_name()].
5027*/
5028SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
5029
5030/*
5031** CAPI3REF: Reset All Bindings On A Prepared Statement
5032** METHOD: sqlite3_stmt
5033**
5034** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
5035** the [sqlite3_bind_blob | bindings] on a [prepared statement].
5036** ^Use this routine to reset all host parameters to NULL.
5037*/
5038SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
5039
5040/*
5041** CAPI3REF: Number Of Columns In A Result Set
5042** METHOD: sqlite3_stmt
5043**
5044** ^Return the number of columns in the result set returned by the
5045** [prepared statement]. ^If this routine returns 0, that means the
5046** [prepared statement] returns no data (for example an [UPDATE]).
5047** ^However, just because this routine returns a positive number does not
5048** mean that one or more rows of data will be returned. ^A SELECT statement
5049** will always have a positive sqlite3_column_count() but depending on the
5050** WHERE clause constraints and the table content, it might return no rows.
5051**
5052** See also: [sqlite3_data_count()]
5053*/
5054SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
5055
5056/*
5057** CAPI3REF: Column Names In A Result Set
5058** METHOD: sqlite3_stmt
5059**
5060** ^These routines return the name assigned to a particular column
5061** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
5062** interface returns a pointer to a zero-terminated UTF-8 string
5063** and sqlite3_column_name16() returns a pointer to a zero-terminated
5064** UTF-16 string. ^The first parameter is the [prepared statement]
5065** that implements the [SELECT] statement. ^The second parameter is the
5066** column number. ^The leftmost column is number 0.
5067**
5068** ^The returned string pointer is valid until either the [prepared statement]
5069** is destroyed by [sqlite3_finalize()] or until the statement is automatically
5070** reprepared by the first call to [sqlite3_step()] for a particular run
5071** or until the next call to
5072** sqlite3_column_name() or sqlite3_column_name16() on the same column.
5073**
5074** ^If sqlite3_malloc() fails during the processing of either routine
5075** (for example during a conversion from UTF-8 to UTF-16) then a
5076** NULL pointer is returned.
5077**
5078** ^The name of a result column is the value of the "AS" clause for
5079** that column, if there is an AS clause. If there is no AS clause
5080** then the name of the column is unspecified and may change from
5081** one release of SQLite to the next.
5082*/
5083SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
5084SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
5085
5086/*
5087** CAPI3REF: Source Of Data In A Query Result
5088** METHOD: sqlite3_stmt
5089**
5090** ^These routines provide a means to determine the database, table, and
5091** table column that is the origin of a particular result column in a
5092** [SELECT] statement.
5093** ^The name of the database or table or column can be returned as
5094** either a UTF-8 or UTF-16 string. ^The _database_ routines return
5095** the database name, the _table_ routines return the table name, and
5096** the origin_ routines return the column name.
5097** ^The returned string is valid until the [prepared statement] is destroyed
5098** using [sqlite3_finalize()] or until the statement is automatically
5099** reprepared by the first call to [sqlite3_step()] for a particular run
5100** or until the same information is requested
5101** again in a different encoding.
5102**
5103** ^The names returned are the original un-aliased names of the
5104** database, table, and column.
5105**
5106** ^The first argument to these interfaces is a [prepared statement].
5107** ^These functions return information about the Nth result column returned by
5108** the statement, where N is the second function argument.
5109** ^The left-most column is column 0 for these routines.
5110**
5111** ^If the Nth column returned by the statement is an expression or
5112** subquery and is not a column value, then all of these functions return
5113** NULL. ^These routines might also return NULL if a memory allocation error
5114** occurs. ^Otherwise, they return the name of the attached database, table,
5115** or column that query result column was extracted from.
5116**
5117** ^As with all other SQLite APIs, those whose names end with "16" return
5118** UTF-16 encoded strings and the other functions return UTF-8.
5119**
5120** ^These APIs are only available if the library was compiled with the
5121** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
5122**
5123** If two or more threads call one or more
5124** [sqlite3_column_database_name | column metadata interfaces]
5125** for the same [prepared statement] and result column
5126** at the same time then the results are undefined.
5127*/
5128SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
5129SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
5130SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
5131SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
5132SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
5133SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
5134
5135/*
5136** CAPI3REF: Declared Datatype Of A Query Result
5137** METHOD: sqlite3_stmt
5138**
5139** ^(The first parameter is a [prepared statement].
5140** If this statement is a [SELECT] statement and the Nth column of the
5141** returned result set of that [SELECT] is a table column (not an
5142** expression or subquery) then the declared type of the table
5143** column is returned.)^ ^If the Nth column of the result set is an
5144** expression or subquery, then a NULL pointer is returned.
5145** ^The returned string is always UTF-8 encoded.
5146**
5147** ^(For example, given the database schema:
5148**
5149** CREATE TABLE t1(c1 VARIANT);
5150**
5151** and the following statement to be compiled:
5152**
5153** SELECT c1 + 1, c1 FROM t1;
5154**
5155** this routine would return the string "VARIANT" for the second result
5156** column (i==1), and a NULL pointer for the first result column (i==0).)^
5157**
5158** ^SQLite uses dynamic run-time typing. ^So just because a column
5159** is declared to contain a particular type does not mean that the
5160** data stored in that column is of the declared type. SQLite is
5161** strongly typed, but the typing is dynamic not static. ^Type
5162** is associated with individual values, not with the containers
5163** used to hold those values.
5164*/
5165SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
5166SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
5167
5168/*
5169** CAPI3REF: Evaluate An SQL Statement
5170** METHOD: sqlite3_stmt
5171**
5172** After a [prepared statement] has been prepared using any of
5173** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
5174** or [sqlite3_prepare16_v3()] or one of the legacy
5175** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
5176** must be called one or more times to evaluate the statement.
5177**
5178** The details of the behavior of the sqlite3_step() interface depend
5179** on whether the statement was prepared using the newer "vX" interfaces
5180** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
5181** [sqlite3_prepare16_v2()] or the older legacy
5182** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
5183** new "vX" interface is recommended for new applications but the legacy
5184** interface will continue to be supported.
5185**
5186** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
5187** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
5188** ^With the "v2" interface, any of the other [result codes] or
5189** [extended result codes] might be returned as well.
5190**
5191** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
5192** database locks it needs to do its job. ^If the statement is a [COMMIT]
5193** or occurs outside of an explicit transaction, then you can retry the
5194** statement. If the statement is not a [COMMIT] and occurs within an
5195** explicit transaction then you should rollback the transaction before
5196** continuing.
5197**
5198** ^[SQLITE_DONE] means that the statement has finished executing
5199** successfully. sqlite3_step() should not be called again on this virtual
5200** machine without first calling [sqlite3_reset()] to reset the virtual
5201** machine back to its initial state.
5202**
5203** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
5204** is returned each time a new row of data is ready for processing by the
5205** caller. The values may be accessed using the [column access functions].
5206** sqlite3_step() is called again to retrieve the next row of data.
5207**
5208** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
5209** violation) has occurred. sqlite3_step() should not be called again on
5210** the VM. More information may be found by calling [sqlite3_errmsg()].
5211** ^With the legacy interface, a more specific error code (for example,
5212** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
5213** can be obtained by calling [sqlite3_reset()] on the
5214** [prepared statement]. ^In the "v2" interface,
5215** the more specific error code is returned directly by sqlite3_step().
5216**
5217** [SQLITE_MISUSE] means that the this routine was called inappropriately.
5218** Perhaps it was called on a [prepared statement] that has
5219** already been [sqlite3_finalize | finalized] or on one that had
5220** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
5221** be the case that the same database connection is being used by two or
5222** more threads at the same moment in time.
5223**
5224** For all versions of SQLite up to and including 3.6.23.1, a call to
5225** [sqlite3_reset()] was required after sqlite3_step() returned anything
5226** other than [SQLITE_ROW] before any subsequent invocation of
5227** sqlite3_step(). Failure to reset the prepared statement using
5228** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
5229** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]),
5230** sqlite3_step() began
5231** calling [sqlite3_reset()] automatically in this circumstance rather
5232** than returning [SQLITE_MISUSE]. This is not considered a compatibility
5233** break because any application that ever receives an SQLITE_MISUSE error
5234** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
5235** can be used to restore the legacy behavior.
5236**
5237** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
5238** API always returns a generic error code, [SQLITE_ERROR], following any
5239** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
5240** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
5241** specific [error codes] that better describes the error.
5242** We admit that this is a goofy design. The problem has been fixed
5243** with the "v2" interface. If you prepare all of your SQL statements
5244** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
5245** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5246** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5247** then the more specific [error codes] are returned directly
5248** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5249*/
5250SQLITE_API int sqlite3_step(sqlite3_stmt*);
5251
5252/*
5253** CAPI3REF: Number of columns in a result set
5254** METHOD: sqlite3_stmt
5255**
5256** ^The sqlite3_data_count(P) interface returns the number of columns in the
5257** current row of the result set of [prepared statement] P.
5258** ^If prepared statement P does not have results ready to return
5259** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5260** interfaces) then sqlite3_data_count(P) returns 0.
5261** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5262** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5263** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5264** will return non-zero if previous call to [sqlite3_step](P) returned
5265** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5266** where it always returns zero since each step of that multi-step
5267** pragma returns 0 columns of data.
5268**
5269** See also: [sqlite3_column_count()]
5270*/
5271SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5272
5273/*
5274** CAPI3REF: Fundamental Datatypes
5275** KEYWORDS: SQLITE_TEXT
5276**
5277** ^(Every value in SQLite has one of five fundamental datatypes:
5278**
5279** <ul>
5280** <li> 64-bit signed integer
5281** <li> 64-bit IEEE floating point number
5282** <li> string
5283** <li> BLOB
5284** <li> NULL
5285** </ul>)^
5286**
5287** These constants are codes for each of those types.
5288**
5289** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5290** for a completely different meaning. Software that links against both
5291** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5292** SQLITE_TEXT.
5293*/
5294#define SQLITE_INTEGER 1
5295#define SQLITE_FLOAT 2
5296#define SQLITE_BLOB 4
5297#define SQLITE_NULL 5
5298#ifdef SQLITE_TEXT
5299# undef SQLITE_TEXT
5300#else
5301# define SQLITE_TEXT 3
5302#endif
5303#define SQLITE3_TEXT 3
5304
5305/*
5306** CAPI3REF: Result Values From A Query
5307** KEYWORDS: {column access functions}
5308** METHOD: sqlite3_stmt
5309**
5310** <b>Summary:</b>
5311** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5312** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
5313** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
5314** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
5315** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
5316** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
5317** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
5318** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
5319** [sqlite3_value|unprotected sqlite3_value] object.
5320** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5321** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
5322** or a UTF-8 TEXT result in bytes
5323** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
5324** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5325** TEXT in bytes
5326** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
5327** datatype of the result
5328** </table></blockquote>
5329**
5330** <b>Details:</b>
5331**
5332** ^These routines return information about a single column of the current
5333** result row of a query. ^In every case the first argument is a pointer
5334** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5335** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5336** and the second argument is the index of the column for which information
5337** should be returned. ^The leftmost column of the result set has the index 0.
5338** ^The number of columns in the result can be determined using
5339** [sqlite3_column_count()].
5340**
5341** If the SQL statement does not currently point to a valid row, or if the
5342** column index is out of range, the result is undefined.
5343** These routines may only be called when the most recent call to
5344** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5345** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5346** If any of these routines are called after [sqlite3_reset()] or
5347** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5348** something other than [SQLITE_ROW], the results are undefined.
5349** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5350** are called from a different thread while any of these routines
5351** are pending, then the results are undefined.
5352**
5353** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5354** each return the value of a result column in a specific data format. If
5355** the result column is not initially in the requested format (for example,
5356** if the query returns an integer but the sqlite3_column_text() interface
5357** is used to extract the value) then an automatic type conversion is performed.
5358**
5359** ^The sqlite3_column_type() routine returns the
5360** [SQLITE_INTEGER | datatype code] for the initial data type
5361** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5362** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5363** The return value of sqlite3_column_type() can be used to decide which
5364** of the first six interface should be used to extract the column value.
5365** The value returned by sqlite3_column_type() is only meaningful if no
5366** automatic type conversions have occurred for the value in question.
5367** After a type conversion, the result of calling sqlite3_column_type()
5368** is undefined, though harmless. Future
5369** versions of SQLite may change the behavior of sqlite3_column_type()
5370** following a type conversion.
5371**
5372** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5373** or sqlite3_column_bytes16() interfaces can be used to determine the size
5374** of that BLOB or string.
5375**
5376** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5377** routine returns the number of bytes in that BLOB or string.
5378** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5379** the string to UTF-8 and then returns the number of bytes.
5380** ^If the result is a numeric value then sqlite3_column_bytes() uses
5381** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5382** the number of bytes in that string.
5383** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5384**
5385** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5386** routine returns the number of bytes in that BLOB or string.
5387** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5388** the string to UTF-16 and then returns the number of bytes.
5389** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5390** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5391** the number of bytes in that string.
5392** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5393**
5394** ^The values returned by [sqlite3_column_bytes()] and
5395** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5396** of the string. ^For clarity: the values returned by
5397** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5398** bytes in the string, not the number of characters.
5399**
5400** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5401** even empty strings, are always zero-terminated. ^The return
5402** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5403**
5404** ^Strings returned by sqlite3_column_text16() always have the endianness
5405** which is native to the platform, regardless of the text encoding set
5406** for the database.
5407**
5408** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5409** [unprotected sqlite3_value] object. In a multithreaded environment,
5410** an unprotected sqlite3_value object may only be used safely with
5411** [sqlite3_bind_value()] and [sqlite3_result_value()].
5412** If the [unprotected sqlite3_value] object returned by
5413** [sqlite3_column_value()] is used in any other way, including calls
5414** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5415** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5416** Hence, the sqlite3_column_value() interface
5417** is normally only useful within the implementation of
5418** [application-defined SQL functions] or [virtual tables], not within
5419** top-level application code.
5420**
5421** These routines may attempt to convert the datatype of the result.
5422** ^For example, if the internal representation is FLOAT and a text result
5423** is requested, [sqlite3_snprintf()] is used internally to perform the
5424** conversion automatically. ^(The following table details the conversions
5425** that are applied:
5426**
5427** <blockquote>
5428** <table border="1">
5429** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5430**
5431** <tr><td> NULL <td> INTEGER <td> Result is 0
5432** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5433** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5434** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5435** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5436** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5437** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5438** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5439** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5440** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5441** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5442** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5443** <tr><td> TEXT <td> BLOB <td> No change
5444** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5445** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5446** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5447** </table>
5448** </blockquote>)^
5449**
5450** Note that when type conversions occur, pointers returned by prior
5451** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5452** sqlite3_column_text16() may be invalidated.
5453** Type conversions and pointer invalidations might occur
5454** in the following cases:
5455**
5456** <ul>
5457** <li> The initial content is a BLOB and sqlite3_column_text() or
5458** sqlite3_column_text16() is called. A zero-terminator might
5459** need to be added to the string.</li>
5460** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5461** sqlite3_column_text16() is called. The content must be converted
5462** to UTF-16.</li>
5463** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5464** sqlite3_column_text() is called. The content must be converted
5465** to UTF-8.</li>
5466** </ul>
5467**
5468** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5469** not invalidate a prior pointer, though of course the content of the buffer
5470** that the prior pointer references will have been modified. Other kinds
5471** of conversion are done in place when it is possible, but sometimes they
5472** are not possible and in those cases prior pointers are invalidated.
5473**
5474** The safest policy is to invoke these routines
5475** in one of the following ways:
5476**
5477** <ul>
5478** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5479** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5480** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5481** </ul>
5482**
5483** In other words, you should call sqlite3_column_text(),
5484** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5485** into the desired format, then invoke sqlite3_column_bytes() or
5486** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5487** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5488** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5489** with calls to sqlite3_column_bytes().
5490**
5491** ^The pointers returned are valid until a type conversion occurs as
5492** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5493** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5494** and BLOBs is freed automatically. Do not pass the pointers returned
5495** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5496** [sqlite3_free()].
5497**
5498** As long as the input parameters are correct, these routines will only
5499** fail if an out-of-memory error occurs during a format conversion.
5500** Only the following subset of interfaces are subject to out-of-memory
5501** errors:
5502**
5503** <ul>
5504** <li> sqlite3_column_blob()
5505** <li> sqlite3_column_text()
5506** <li> sqlite3_column_text16()
5507** <li> sqlite3_column_bytes()
5508** <li> sqlite3_column_bytes16()
5509** </ul>
5510**
5511** If an out-of-memory error occurs, then the return value from these
5512** routines is the same as if the column had contained an SQL NULL value.
5513** Valid SQL NULL returns can be distinguished from out-of-memory errors
5514** by invoking the [sqlite3_errcode()] immediately after the suspect
5515** return value is obtained and before any
5516** other SQLite interface is called on the same [database connection].
5517*/
5518SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5519SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5520SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5521SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5522SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5523SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5524SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5525SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5526SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5527SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5528
5529/*
5530** CAPI3REF: Destroy A Prepared Statement Object
5531** DESTRUCTOR: sqlite3_stmt
5532**
5533** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5534** ^If the most recent evaluation of the statement encountered no errors
5535** or if the statement has never been evaluated, then sqlite3_finalize() returns
5536** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5537** sqlite3_finalize(S) returns the appropriate [error code] or
5538** [extended error code].
5539**
5540** ^The sqlite3_finalize(S) routine can be called at any point during
5541** the life cycle of [prepared statement] S:
5542** before statement S is ever evaluated, after
5543** one or more calls to [sqlite3_reset()], or after any call
5544** to [sqlite3_step()] regardless of whether or not the statement has
5545** completed execution.
5546**
5547** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5548**
5549** The application must finalize every [prepared statement] in order to avoid
5550** resource leaks. It is a grievous error for the application to try to use
5551** a prepared statement after it has been finalized. Any use of a prepared
5552** statement after it has been finalized can result in undefined and
5553** undesirable behavior such as segfaults and heap corruption.
5554*/
5555SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5556
5557/*
5558** CAPI3REF: Reset A Prepared Statement Object
5559** METHOD: sqlite3_stmt
5560**
5561** The sqlite3_reset() function is called to reset a [prepared statement]
5562** object back to its initial state, ready to be re-executed.
5563** ^Any SQL statement variables that had values bound to them using
5564** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5565** Use [sqlite3_clear_bindings()] to reset the bindings.
5566**
5567** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5568** back to the beginning of its program.
5569**
5570** ^The return code from [sqlite3_reset(S)] indicates whether or not
5571** the previous evaluation of prepared statement S completed successfully.
5572** ^If [sqlite3_step(S)] has never before been called on S or if
5573** [sqlite3_step(S)] has not been called since the previous call
5574** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5575** [SQLITE_OK].
5576**
5577** ^If the most recent call to [sqlite3_step(S)] for the
5578** [prepared statement] S indicated an error, then
5579** [sqlite3_reset(S)] returns an appropriate [error code].
5580** ^The [sqlite3_reset(S)] interface might also return an [error code]
5581** if there were no prior errors but the process of resetting
5582** the prepared statement caused a new error. ^For example, if an
5583** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5584** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5585** the overall statement might still fail and the [sqlite3_reset(S)] call
5586** might return SQLITE_BUSY if locking constraints prevent the
5587** database change from committing. Therefore, it is important that
5588** applications check the return code from [sqlite3_reset(S)] even if
5589** no prior call to [sqlite3_step(S)] indicated a problem.
5590**
5591** ^The [sqlite3_reset(S)] interface does not change the values
5592** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5593*/
5594SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5595
5596
5597/*
5598** CAPI3REF: Create Or Redefine SQL Functions
5599** KEYWORDS: {function creation routines}
5600** METHOD: sqlite3
5601**
5602** ^These functions (collectively known as "function creation routines")
5603** are used to add SQL functions or aggregates or to redefine the behavior
5604** of existing SQL functions or aggregates. The only differences between
5605** the three "sqlite3_create_function*" routines are the text encoding
5606** expected for the second parameter (the name of the function being
5607** created) and the presence or absence of a destructor callback for
5608** the application data pointer. Function sqlite3_create_window_function()
5609** is similar, but allows the user to supply the extra callback functions
5610** needed by [aggregate window functions].
5611**
5612** ^The first parameter is the [database connection] to which the SQL
5613** function is to be added. ^If an application uses more than one database
5614** connection then application-defined SQL functions must be added
5615** to each database connection separately.
5616**
5617** ^The second parameter is the name of the SQL function to be created or
5618** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5619** representation, exclusive of the zero-terminator. ^Note that the name
5620** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5621** ^Any attempt to create a function with a longer name
5622** will result in [SQLITE_MISUSE] being returned.
5623**
5624** ^The third parameter (nArg)
5625** is the number of arguments that the SQL function or
5626** aggregate takes. ^If this parameter is -1, then the SQL function or
5627** aggregate may take any number of arguments between 0 and the limit
5628** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5629** parameter is less than -1 or greater than 127 then the behavior is
5630** undefined.
5631**
5632** ^The fourth parameter, eTextRep, specifies what
5633** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5634** its parameters. The application should set this parameter to
5635** [SQLITE_UTF16LE] if the function implementation invokes
5636** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5637** implementation invokes [sqlite3_value_text16be()] on an input, or
5638** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5639** otherwise. ^The same SQL function may be registered multiple times using
5640** different preferred text encodings, with different implementations for
5641** each encoding.
5642** ^When multiple implementations of the same function are available, SQLite
5643** will pick the one that involves the least amount of data conversion.
5644**
5645** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5646** to signal that the function will always return the same result given
5647** the same inputs within a single SQL statement. Most SQL functions are
5648** deterministic. The built-in [random()] SQL function is an example of a
5649** function that is not deterministic. The SQLite query planner is able to
5650** perform additional optimizations on deterministic functions, so use
5651** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5652**
5653** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5654** flag, which if present prevents the function from being invoked from
5655** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5656** index expressions, or the WHERE clause of partial indexes.
5657**
5658** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5659** all application-defined SQL functions that do not need to be
5660** used inside of triggers, views, CHECK constraints, or other elements of
5661** the database schema. This flag is especially recommended for SQL
5662** functions that have side effects or reveal internal application state.
5663** Without this flag, an attacker might be able to modify the schema of
5664** a database file to include invocations of the function with parameters
5665** chosen by the attacker, which the application will then execute when
5666** the database file is opened and read.
5667**
5668** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5669** function can gain access to this pointer using [sqlite3_user_data()].)^
5670**
5671** ^The sixth, seventh and eighth parameters passed to the three
5672** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5673** pointers to C-language functions that implement the SQL function or
5674** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5675** callback only; NULL pointers must be passed as the xStep and xFinal
5676** parameters. ^An aggregate SQL function requires an implementation of xStep
5677** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5678** SQL function or aggregate, pass NULL pointers for all three function
5679** callbacks.
5680**
5681** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5682** and xInverse) passed to sqlite3_create_window_function are pointers to
5683** C-language callbacks that implement the new function. xStep and xFinal
5684** must both be non-NULL. xValue and xInverse may either both be NULL, in
5685** which case a regular aggregate function is created, or must both be
5686** non-NULL, in which case the new function may be used as either an aggregate
5687** or aggregate window function. More details regarding the implementation
5688** of aggregate window functions are
5689** [user-defined window functions|available here].
5690**
5691** ^(If the final parameter to sqlite3_create_function_v2() or
5692** sqlite3_create_window_function() is not NULL, then it is the destructor for
5693** the application data pointer. The destructor is invoked when the function
5694** is deleted, either by being overloaded or when the database connection
5695** closes.)^ ^The destructor is also invoked if the call to
5696** sqlite3_create_function_v2() fails. ^When the destructor callback is
5697** invoked, it is passed a single argument which is a copy of the application
5698** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5699**
5700** ^It is permitted to register multiple implementations of the same
5701** functions with the same name but with either differing numbers of
5702** arguments or differing preferred text encodings. ^SQLite will use
5703** the implementation that most closely matches the way in which the
5704** SQL function is used. ^A function implementation with a non-negative
5705** nArg parameter is a better match than a function implementation with
5706** a negative nArg. ^A function where the preferred text encoding
5707** matches the database encoding is a better
5708** match than a function where the encoding is different.
5709** ^A function where the encoding difference is between UTF16le and UTF16be
5710** is a closer match than a function where the encoding difference is
5711** between UTF8 and UTF16.
5712**
5713** ^Built-in functions may be overloaded by new application-defined functions.
5714**
5715** ^An application-defined function is permitted to call other
5716** SQLite interfaces. However, such calls must not
5717** close the database connection nor finalize or reset the prepared
5718** statement in which the function is running.
5719*/
5720SQLITE_API int sqlite3_create_function(
5721 sqlite3 *db,
5722 const char *zFunctionName,
5723 int nArg,
5724 int eTextRep,
5725 void *pApp,
5726 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5727 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5728 void (*xFinal)(sqlite3_context*)
5729);
5730SQLITE_API int sqlite3_create_function16(
5731 sqlite3 *db,
5732 const void *zFunctionName,
5733 int nArg,
5734 int eTextRep,
5735 void *pApp,
5736 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5737 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5738 void (*xFinal)(sqlite3_context*)
5739);
5740SQLITE_API int sqlite3_create_function_v2(
5741 sqlite3 *db,
5742 const char *zFunctionName,
5743 int nArg,
5744 int eTextRep,
5745 void *pApp,
5746 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5747 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5748 void (*xFinal)(sqlite3_context*),
5749 void(*xDestroy)(void*)
5750);
5751SQLITE_API int sqlite3_create_window_function(
5752 sqlite3 *db,
5753 const char *zFunctionName,
5754 int nArg,
5755 int eTextRep,
5756 void *pApp,
5757 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5758 void (*xFinal)(sqlite3_context*),
5759 void (*xValue)(sqlite3_context*),
5760 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5761 void(*xDestroy)(void*)
5762);
5763
5764/*
5765** CAPI3REF: Text Encodings
5766**
5767** These constants define integer codes that represent the various
5768** text encodings supported by SQLite.
5769*/
5770#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5771#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5772#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5773#define SQLITE_UTF16 4 /* Use native byte order */
5774#define SQLITE_ANY 5 /* Deprecated */
5775#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5776
5777/*
5778** CAPI3REF: Function Flags
5779**
5780** These constants may be ORed together with the
5781** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5782** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5783** [sqlite3_create_function_v2()].
5784**
5785** <dl>
5786** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5787** The SQLITE_DETERMINISTIC flag means that the new function always gives
5788** the same output when the input parameters are the same.
5789** The [abs|abs() function] is deterministic, for example, but
5790** [randomblob|randomblob()] is not. Functions must
5791** be deterministic in order to be used in certain contexts such as
5792** with the WHERE clause of [partial indexes] or in [generated columns].
5793** SQLite might also optimize deterministic functions by factoring them
5794** out of inner loops.
5795** </dd>
5796**
5797** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5798** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5799** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5800** schema structures such as [CHECK constraints], [DEFAULT clauses],
5801** [expression indexes], [partial indexes], or [generated columns].
5802** <p>
5803** The SQLITE_DIRECTONLY flag is recommended for any
5804** [application-defined SQL function]
5805** that has side-effects or that could potentially leak sensitive information.
5806** This will prevent attacks in which an application is tricked
5807** into using a database file that has had its schema surreptitiously
5808** modified to invoke the application-defined function in ways that are
5809** harmful.
5810** <p>
5811** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5812** [application-defined SQL functions], regardless of whether or not they
5813** are security sensitive, as doing so prevents those functions from being used
5814** inside of the database schema, and thus ensures that the database
5815** can be inspected and modified using generic tools (such as the [CLI])
5816** that do not have access to the application-defined functions.
5817** </dd>
5818**
5819** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5820** The SQLITE_INNOCUOUS flag means that the function is unlikely
5821** to cause problems even if misused. An innocuous function should have
5822** no side effects and should not depend on any values other than its
5823** input parameters. The [abs|abs() function] is an example of an
5824** innocuous function.
5825** The [load_extension() SQL function] is not innocuous because of its
5826** side effects.
5827** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5828** exactly the same. The [random|random() function] is an example of a
5829** function that is innocuous but not deterministic.
5830** <p>Some heightened security settings
5831** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5832** disable the use of SQL functions inside views and triggers and in
5833** schema structures such as [CHECK constraints], [DEFAULT clauses],
5834** [expression indexes], [partial indexes], and [generated columns] unless
5835** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5836** are innocuous. Developers are advised to avoid using the
5837** SQLITE_INNOCUOUS flag for application-defined functions unless the
5838** function has been carefully audited and found to be free of potentially
5839** security-adverse side-effects and information-leaks.
5840** </dd>
5841**
5842** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5843** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5844** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5845** This flag instructs SQLite to omit some corner-case optimizations that
5846** might disrupt the operation of the [sqlite3_value_subtype()] function,
5847** causing it to return zero rather than the correct subtype().
5848** All SQL functions that invoke [sqlite3_value_subtype()] should have this
5849** property. If the SQLITE_SUBTYPE property is omitted, then the return
5850** value from [sqlite3_value_subtype()] might sometimes be zero even though
5851** a non-zero subtype was specified by the function argument expression.
5852**
5853** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5854** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5855** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5856** result.
5857** Every function that invokes [sqlite3_result_subtype()] should have this
5858** property. If it does not, then the call to [sqlite3_result_subtype()]
5859** might become a no-op if the function is used as a term in an
5860** [expression index]. On the other hand, SQL functions that never invoke
5861** [sqlite3_result_subtype()] should avoid setting this property, as the
5862** purpose of this property is to disable certain optimizations that are
5863** incompatible with subtypes.
5864**
5865** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
5866** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
5867** that internally orders the values provided to the first argument. The
5868** ordered-set aggregate SQL notation with a single ORDER BY term can be
5869** used to invoke this function. If the ordered-set aggregate notation is
5870** used on a function that lacks this flag, then an error is raised. Note
5871** that the ordered-set aggregate syntax is only available if SQLite is
5872** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
5873** </dd>
5874** </dl>
5875*/
5876#define SQLITE_DETERMINISTIC 0x000000800
5877#define SQLITE_DIRECTONLY 0x000080000
5878#define SQLITE_SUBTYPE 0x000100000
5879#define SQLITE_INNOCUOUS 0x000200000
5880#define SQLITE_RESULT_SUBTYPE 0x001000000
5881#define SQLITE_SELFORDER1 0x002000000
5882
5883/*
5884** CAPI3REF: Deprecated Functions
5885** DEPRECATED
5886**
5887** These functions are [deprecated]. In order to maintain
5888** backwards compatibility with older code, these functions continue
5889** to be supported. However, new applications should avoid
5890** the use of these functions. To encourage programmers to avoid
5891** these functions, we will not explain what they do.
5892*/
5893#ifndef SQLITE_OMIT_DEPRECATED
5894SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5895SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5896SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5897SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5898SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5899SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5900 void*,sqlite3_int64);
5901#endif
5902
5903/*
5904** CAPI3REF: Obtaining SQL Values
5905** METHOD: sqlite3_value
5906**
5907** <b>Summary:</b>
5908** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5909** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5910** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5911** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5912** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5913** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5914** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5915** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5916** the native byteorder
5917** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5918** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5919** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5920** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5921** or a UTF-8 TEXT in bytes
5922** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5923** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5924** TEXT in bytes
5925** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5926** datatype of the value
5927** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5928** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5929** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5930** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5931** against a virtual table.
5932** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5933** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5934** </table></blockquote>
5935**
5936** <b>Details:</b>
5937**
5938** These routines extract type, size, and content information from
5939** [protected sqlite3_value] objects. Protected sqlite3_value objects
5940** are used to pass parameter information into the functions that
5941** implement [application-defined SQL functions] and [virtual tables].
5942**
5943** These routines work only with [protected sqlite3_value] objects.
5944** Any attempt to use these routines on an [unprotected sqlite3_value]
5945** is not threadsafe.
5946**
5947** ^These routines work just like the corresponding [column access functions]
5948** except that these routines take a single [protected sqlite3_value] object
5949** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5950**
5951** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5952** in the native byte-order of the host machine. ^The
5953** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5954** extract UTF-16 strings as big-endian and little-endian respectively.
5955**
5956** ^If [sqlite3_value] object V was initialized
5957** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5958** and if X and Y are strings that compare equal according to strcmp(X,Y),
5959** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5960** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5961** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5962**
5963** ^(The sqlite3_value_type(V) interface returns the
5964** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5965** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5966** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5967** Other interfaces might change the datatype for an sqlite3_value object.
5968** For example, if the datatype is initially SQLITE_INTEGER and
5969** sqlite3_value_text(V) is called to extract a text value for that
5970** integer, then subsequent calls to sqlite3_value_type(V) might return
5971** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5972** occurs is undefined and may change from one release of SQLite to the next.
5973**
5974** ^(The sqlite3_value_numeric_type() interface attempts to apply
5975** numeric affinity to the value. This means that an attempt is
5976** made to convert the value to an integer or floating point. If
5977** such a conversion is possible without loss of information (in other
5978** words, if the value is a string that looks like a number)
5979** then the conversion is performed. Otherwise no conversion occurs.
5980** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5981**
5982** ^Within the [xUpdate] method of a [virtual table], the
5983** sqlite3_value_nochange(X) interface returns true if and only if
5984** the column corresponding to X is unchanged by the UPDATE operation
5985** that the xUpdate method call was invoked to implement and if
5986** the prior [xColumn] method call that was invoked to extract
5987** the value for that column returned without setting a result (probably
5988** because it queried [sqlite3_vtab_nochange()] and found that the column
5989** was unchanging). ^Within an [xUpdate] method, any value for which
5990** sqlite3_value_nochange(X) is true will in all other respects appear
5991** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5992** than within an [xUpdate] method call for an UPDATE statement, then
5993** the return value is arbitrary and meaningless.
5994**
5995** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5996** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5997** interfaces. ^If X comes from an SQL literal value, or a table column,
5998** or an expression, then sqlite3_value_frombind(X) returns zero.
5999**
6000** Please pay particular attention to the fact that the pointer returned
6001** from [sqlite3_value_blob()], [sqlite3_value_text()], or
6002** [sqlite3_value_text16()] can be invalidated by a subsequent call to
6003** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
6004** or [sqlite3_value_text16()].
6005**
6006** These routines must be called from the same thread as
6007** the SQL function that supplied the [sqlite3_value*] parameters.
6008**
6009** As long as the input parameter is correct, these routines can only
6010** fail if an out-of-memory error occurs during a format conversion.
6011** Only the following subset of interfaces are subject to out-of-memory
6012** errors:
6013**
6014** <ul>
6015** <li> sqlite3_value_blob()
6016** <li> sqlite3_value_text()
6017** <li> sqlite3_value_text16()
6018** <li> sqlite3_value_text16le()
6019** <li> sqlite3_value_text16be()
6020** <li> sqlite3_value_bytes()
6021** <li> sqlite3_value_bytes16()
6022** </ul>
6023**
6024** If an out-of-memory error occurs, then the return value from these
6025** routines is the same as if the column had contained an SQL NULL value.
6026** Valid SQL NULL returns can be distinguished from out-of-memory errors
6027** by invoking the [sqlite3_errcode()] immediately after the suspect
6028** return value is obtained and before any
6029** other SQLite interface is called on the same [database connection].
6030*/
6031SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
6032SQLITE_API double sqlite3_value_double(sqlite3_value*);
6033SQLITE_API int sqlite3_value_int(sqlite3_value*);
6034SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
6035SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
6036SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
6037SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
6038SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
6039SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
6040SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
6041SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
6042SQLITE_API int sqlite3_value_type(sqlite3_value*);
6043SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
6044SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
6045SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
6046
6047/*
6048** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
6049** METHOD: sqlite3_value
6050**
6051** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
6052** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
6053** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
6054** returns something other than SQLITE_TEXT, then the return value from
6055** sqlite3_value_encoding(X) is meaningless. ^Calls to
6056** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
6057** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
6058** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
6059** thus change the return from subsequent calls to sqlite3_value_encoding(X).
6060**
6061** This routine is intended for used by applications that test and validate
6062** the SQLite implementation. This routine is inquiring about the opaque
6063** internal state of an [sqlite3_value] object. Ordinary applications should
6064** not need to know what the internal state of an sqlite3_value object is and
6065** hence should not need to use this interface.
6066*/
6067SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
6068
6069/*
6070** CAPI3REF: Finding The Subtype Of SQL Values
6071** METHOD: sqlite3_value
6072**
6073** The sqlite3_value_subtype(V) function returns the subtype for
6074** an [application-defined SQL function] argument V. The subtype
6075** information can be used to pass a limited amount of context from
6076** one SQL function to another. Use the [sqlite3_result_subtype()]
6077** routine to set the subtype for the return value of an SQL function.
6078**
6079** Every [application-defined SQL function] that invokes this interface
6080** should include the [SQLITE_SUBTYPE] property in the text
6081** encoding argument when the function is [sqlite3_create_function|registered].
6082** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
6083** might return zero instead of the upstream subtype in some corner cases.
6084*/
6085SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
6086
6087/*
6088** CAPI3REF: Copy And Free SQL Values
6089** METHOD: sqlite3_value
6090**
6091** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
6092** object V and returns a pointer to that copy. ^The [sqlite3_value] returned
6093** is a [protected sqlite3_value] object even if the input is not.
6094** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
6095** memory allocation fails. ^If V is a [pointer value], then the result
6096** of sqlite3_value_dup(V) is a NULL value.
6097**
6098** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
6099** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
6100** then sqlite3_value_free(V) is a harmless no-op.
6101*/
6102SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
6103SQLITE_API void sqlite3_value_free(sqlite3_value*);
6104
6105/*
6106** CAPI3REF: Obtain Aggregate Function Context
6107** METHOD: sqlite3_context
6108**
6109** Implementations of aggregate SQL functions use this
6110** routine to allocate memory for storing their state.
6111**
6112** ^The first time the sqlite3_aggregate_context(C,N) routine is called
6113** for a particular aggregate function, SQLite allocates
6114** N bytes of memory, zeroes out that memory, and returns a pointer
6115** to the new memory. ^On second and subsequent calls to
6116** sqlite3_aggregate_context() for the same aggregate function instance,
6117** the same buffer is returned. Sqlite3_aggregate_context() is normally
6118** called once for each invocation of the xStep callback and then one
6119** last time when the xFinal callback is invoked. ^(When no rows match
6120** an aggregate query, the xStep() callback of the aggregate function
6121** implementation is never called and xFinal() is called exactly once.
6122** In those cases, sqlite3_aggregate_context() might be called for the
6123** first time from within xFinal().)^
6124**
6125** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
6126** when first called if N is less than or equal to zero or if a memory
6127** allocation error occurs.
6128**
6129** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
6130** determined by the N parameter on the first successful call. Changing the
6131** value of N in any subsequent call to sqlite3_aggregate_context() within
6132** the same aggregate function instance will not resize the memory
6133** allocation.)^ Within the xFinal callback, it is customary to set
6134** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
6135** pointless memory allocations occur.
6136**
6137** ^SQLite automatically frees the memory allocated by
6138** sqlite3_aggregate_context() when the aggregate query concludes.
6139**
6140** The first parameter must be a copy of the
6141** [sqlite3_context | SQL function context] that is the first parameter
6142** to the xStep or xFinal callback routine that implements the aggregate
6143** function.
6144**
6145** This routine must be called from the same thread in which
6146** the aggregate SQL function is running.
6147*/
6148SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
6149
6150/*
6151** CAPI3REF: User Data For Functions
6152** METHOD: sqlite3_context
6153**
6154** ^The sqlite3_user_data() interface returns a copy of
6155** the pointer that was the pUserData parameter (the 5th parameter)
6156** of the [sqlite3_create_function()]
6157** and [sqlite3_create_function16()] routines that originally
6158** registered the application defined function.
6159**
6160** This routine must be called from the same thread in which
6161** the application-defined function is running.
6162*/
6163SQLITE_API void *sqlite3_user_data(sqlite3_context*);
6164
6165/*
6166** CAPI3REF: Database Connection For Functions
6167** METHOD: sqlite3_context
6168**
6169** ^The sqlite3_context_db_handle() interface returns a copy of
6170** the pointer to the [database connection] (the 1st parameter)
6171** of the [sqlite3_create_function()]
6172** and [sqlite3_create_function16()] routines that originally
6173** registered the application defined function.
6174*/
6175SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
6176
6177/*
6178** CAPI3REF: Function Auxiliary Data
6179** METHOD: sqlite3_context
6180**
6181** These functions may be used by (non-aggregate) SQL functions to
6182** associate auxiliary data with argument values. If the same argument
6183** value is passed to multiple invocations of the same SQL function during
6184** query execution, under some circumstances the associated auxiliary data
6185** might be preserved. An example of where this might be useful is in a
6186** regular-expression matching function. The compiled version of the regular
6187** expression can be stored as auxiliary data associated with the pattern string.
6188** Then as long as the pattern string remains the same,
6189** the compiled regular expression can be reused on multiple
6190** invocations of the same function.
6191**
6192** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
6193** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
6194** value to the application-defined function. ^N is zero for the left-most
6195** function argument. ^If there is no auxiliary data
6196** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
6197** returns a NULL pointer.
6198**
6199** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
6200** N-th argument of the application-defined function. ^Subsequent
6201** calls to sqlite3_get_auxdata(C,N) return P from the most recent
6202** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
6203** NULL if the auxiliary data has been discarded.
6204** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
6205** SQLite will invoke the destructor function X with parameter P exactly
6206** once, when the auxiliary data is discarded.
6207** SQLite is free to discard the auxiliary data at any time, including: <ul>
6208** <li> ^(when the corresponding function parameter changes)^, or
6209** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
6210** SQL statement)^, or
6211** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
6212** parameter)^, or
6213** <li> ^(during the original sqlite3_set_auxdata() call when a memory
6214** allocation error occurs.)^
6215** <li> ^(during the original sqlite3_set_auxdata() call if the function
6216** is evaluated during query planning instead of during query execution,
6217** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
6218**
6219** Note the last two bullets in particular. The destructor X in
6220** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
6221** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
6222** should be called near the end of the function implementation and the
6223** function implementation should not make any use of P after
6224** sqlite3_set_auxdata() has been called. Furthermore, a call to
6225** sqlite3_get_auxdata() that occurs immediately after a corresponding call
6226** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
6227** condition occurred during the sqlite3_set_auxdata() call or if the
6228** function is being evaluated during query planning rather than during
6229** query execution.
6230**
6231** ^(In practice, auxiliary data is preserved between function calls for
6232** function parameters that are compile-time constants, including literal
6233** values and [parameters] and expressions composed from the same.)^
6234**
6235** The value of the N parameter to these interfaces should be non-negative.
6236** Future enhancements may make use of negative N values to define new
6237** kinds of function caching behavior.
6238**
6239** These routines must be called from the same thread in which
6240** the SQL function is running.
6241**
6242** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
6243*/
6244SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
6245SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
6246
6247/*
6248** CAPI3REF: Database Connection Client Data
6249** METHOD: sqlite3
6250**
6251** These functions are used to associate one or more named pointers
6252** with a [database connection].
6253** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
6254** to be attached to [database connection] D using name N. Subsequent
6255** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6256** or a NULL pointer if there were no prior calls to
6257** sqlite3_set_clientdata() with the same values of D and N.
6258** Names are compared using strcmp() and are thus case sensitive.
6259** It returns 0 on success and SQLITE_NOMEM on allocation failure.
6260**
6261** If P and X are both non-NULL, then the destructor X is invoked with
6262** argument P on the first of the following occurrences:
6263** <ul>
6264** <li> An out-of-memory error occurs during the call to
6265** sqlite3_set_clientdata() which attempts to register pointer P.
6266** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6267** with the same D and N parameters.
6268** <li> The database connection closes. SQLite does not make any guarantees
6269** about the order in which destructors are called, only that all
6270** destructors will be called exactly once at some point during the
6271** database connection closing process.
6272** </ul>
6273**
6274** SQLite does not do anything with client data other than invoke
6275** destructors on the client data at the appropriate time. The intended
6276** use for client data is to provide a mechanism for wrapper libraries
6277** to store additional information about an SQLite database connection.
6278**
6279** There is no limit (other than available memory) on the number of different
6280** client data pointers (with different names) that can be attached to a
6281** single database connection. However, the implementation is optimized
6282** for the case of having only one or two different client data names.
6283** Applications and wrapper libraries are discouraged from using more than
6284** one client data name each.
6285**
6286** There is no way to enumerate the client data pointers
6287** associated with a database connection. The N parameter can be thought
6288** of as a secret key such that only code that knows the secret key is able
6289** to access the associated data.
6290**
6291** Security Warning: These interfaces should not be exposed in scripting
6292** languages or in other circumstances where it might be possible for an
6293** attacker to invoke them. Any agent that can invoke these interfaces
6294** can probably also take control of the process.
6295**
6296** Database connection client data is only available for SQLite
6297** version 3.44.0 ([dateof:3.44.0]) and later.
6298**
6299** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6300*/
6301SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6302SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6303
6304/*
6305** CAPI3REF: Constants Defining Special Destructor Behavior
6306**
6307** These are special values for the destructor that is passed in as the
6308** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6309** argument is SQLITE_STATIC, it means that the content pointer is constant
6310** and will never change. It does not need to be destroyed. ^The
6311** SQLITE_TRANSIENT value means that the content will likely change in
6312** the near future and that SQLite should make its own private copy of
6313** the content before returning.
6314**
6315** The typedef is necessary to work around problems in certain
6316** C++ compilers.
6317*/
6318typedef void (*sqlite3_destructor_type)(void*);
6319#define SQLITE_STATIC ((sqlite3_destructor_type)0)
6320#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6321
6322/*
6323** CAPI3REF: Setting The Result Of An SQL Function
6324** METHOD: sqlite3_context
6325**
6326** These routines are used by the xFunc or xFinal callbacks that
6327** implement SQL functions and aggregates. See
6328** [sqlite3_create_function()] and [sqlite3_create_function16()]
6329** for additional information.
6330**
6331** These functions work very much like the [parameter binding] family of
6332** functions used to bind values to host parameters in prepared statements.
6333** Refer to the [SQL parameter] documentation for additional information.
6334**
6335** ^The sqlite3_result_blob() interface sets the result from
6336** an application-defined function to be the BLOB whose content is pointed
6337** to by the second parameter and which is N bytes long where N is the
6338** third parameter.
6339**
6340** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6341** interfaces set the result of the application-defined function to be
6342** a BLOB containing all zero bytes and N bytes in size.
6343**
6344** ^The sqlite3_result_double() interface sets the result from
6345** an application-defined function to be a floating point value specified
6346** by its 2nd argument.
6347**
6348** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6349** cause the implemented SQL function to throw an exception.
6350** ^SQLite uses the string pointed to by the
6351** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6352** as the text of an error message. ^SQLite interprets the error
6353** message string from sqlite3_result_error() as UTF-8. ^SQLite
6354** interprets the string from sqlite3_result_error16() as UTF-16 using
6355** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6356** ^If the third parameter to sqlite3_result_error()
6357** or sqlite3_result_error16() is negative then SQLite takes as the error
6358** message all text up through the first zero character.
6359** ^If the third parameter to sqlite3_result_error() or
6360** sqlite3_result_error16() is non-negative then SQLite takes that many
6361** bytes (not characters) from the 2nd parameter as the error message.
6362** ^The sqlite3_result_error() and sqlite3_result_error16()
6363** routines make a private copy of the error message text before
6364** they return. Hence, the calling function can deallocate or
6365** modify the text after they return without harm.
6366** ^The sqlite3_result_error_code() function changes the error code
6367** returned by SQLite as a result of an error in a function. ^By default,
6368** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6369** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6370**
6371** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6372** error indicating that a string or BLOB is too long to represent.
6373**
6374** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6375** error indicating that a memory allocation failed.
6376**
6377** ^The sqlite3_result_int() interface sets the return value
6378** of the application-defined function to be the 32-bit signed integer
6379** value given in the 2nd argument.
6380** ^The sqlite3_result_int64() interface sets the return value
6381** of the application-defined function to be the 64-bit signed integer
6382** value given in the 2nd argument.
6383**
6384** ^The sqlite3_result_null() interface sets the return value
6385** of the application-defined function to be NULL.
6386**
6387** ^The sqlite3_result_text(), sqlite3_result_text16(),
6388** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6389** set the return value of the application-defined function to be
6390** a text string which is represented as UTF-8, UTF-16 native byte order,
6391** UTF-16 little endian, or UTF-16 big endian, respectively.
6392** ^The sqlite3_result_text64() interface sets the return value of an
6393** application-defined function to be a text string in an encoding
6394** specified by the fifth (and last) parameter, which must be one
6395** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6396** ^SQLite takes the text result from the application from
6397** the 2nd parameter of the sqlite3_result_text* interfaces.
6398** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6399** other than sqlite3_result_text64() is negative, then SQLite computes
6400** the string length itself by searching the 2nd parameter for the first
6401** zero character.
6402** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6403** is non-negative, then as many bytes (not characters) of the text
6404** pointed to by the 2nd parameter are taken as the application-defined
6405** function result. If the 3rd parameter is non-negative, then it
6406** must be the byte offset into the string where the NUL terminator would
6407** appear if the string were NUL terminated. If any NUL characters occur
6408** in the string at a byte offset that is less than the value of the 3rd
6409** parameter, then the resulting string will contain embedded NULs and the
6410** result of expressions operating on strings with embedded NULs is undefined.
6411** ^If the 4th parameter to the sqlite3_result_text* interfaces
6412** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6413** function as the destructor on the text or BLOB result when it has
6414** finished using that result.
6415** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6416** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6417** assumes that the text or BLOB result is in constant space and does not
6418** copy the content of the parameter nor call a destructor on the content
6419** when it has finished using that result.
6420** ^If the 4th parameter to the sqlite3_result_text* interfaces
6421** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6422** then SQLite makes a copy of the result into space obtained
6423** from [sqlite3_malloc()] before it returns.
6424**
6425** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6426** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6427** when the encoding is not UTF8, if the input UTF16 begins with a
6428** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6429** string and the rest of the string is interpreted according to the
6430** byte-order specified by the BOM. ^The byte-order specified by
6431** the BOM at the beginning of the text overrides the byte-order
6432** specified by the interface procedure. ^So, for example, if
6433** sqlite3_result_text16le() is invoked with text that begins
6434** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6435** first two bytes of input are skipped and the remaining input
6436** is interpreted as UTF16BE text.
6437**
6438** ^For UTF16 input text to the sqlite3_result_text16(),
6439** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6440** sqlite3_result_text64() routines, if the text contains invalid
6441** UTF16 characters, the invalid characters might be converted
6442** into the unicode replacement character, U+FFFD.
6443**
6444** ^The sqlite3_result_value() interface sets the result of
6445** the application-defined function to be a copy of the
6446** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6447** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6448** so that the [sqlite3_value] specified in the parameter may change or
6449** be deallocated after sqlite3_result_value() returns without harm.
6450** ^A [protected sqlite3_value] object may always be used where an
6451** [unprotected sqlite3_value] object is required, so either
6452** kind of [sqlite3_value] object can be used with this interface.
6453**
6454** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6455** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6456** also associates the host-language pointer P or type T with that
6457** NULL value such that the pointer can be retrieved within an
6458** [application-defined SQL function] using [sqlite3_value_pointer()].
6459** ^If the D parameter is not NULL, then it is a pointer to a destructor
6460** for the P parameter. ^SQLite invokes D with P as its only argument
6461** when SQLite is finished with P. The T parameter should be a static
6462** string and preferably a string literal. The sqlite3_result_pointer()
6463** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6464**
6465** If these routines are called from within a different thread
6466** than the one containing the application-defined function that received
6467** the [sqlite3_context] pointer, the results are undefined.
6468*/
6469SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6470SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6471 sqlite3_uint64,void(*)(void*));
6472SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6473SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6474SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6475SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6476SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6477SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6478SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6479SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6480SQLITE_API void sqlite3_result_null(sqlite3_context*);
6481SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6482SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6483 void(*)(void*), unsigned char encoding);
6484SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6485SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6486SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6487SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6488SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6489SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6490SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6491
6492
6493/*
6494** CAPI3REF: Setting The Subtype Of An SQL Function
6495** METHOD: sqlite3_context
6496**
6497** The sqlite3_result_subtype(C,T) function causes the subtype of
6498** the result from the [application-defined SQL function] with
6499** [sqlite3_context] C to be the value T. Only the lower 8 bits
6500** of the subtype T are preserved in current versions of SQLite;
6501** higher order bits are discarded.
6502** The number of subtype bytes preserved by SQLite might increase
6503** in future releases of SQLite.
6504**
6505** Every [application-defined SQL function] that invokes this interface
6506** should include the [SQLITE_RESULT_SUBTYPE] property in its
6507** text encoding argument when the SQL function is
6508** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6509** property is omitted from the function that invokes sqlite3_result_subtype(),
6510** then in some cases the sqlite3_result_subtype() might fail to set
6511** the result subtype.
6512**
6513** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6514** SQL function that invokes the sqlite3_result_subtype() interface
6515** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6516** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6517** by default.
6518*/
6519SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6520
6521/*
6522** CAPI3REF: Define New Collating Sequences
6523** METHOD: sqlite3
6524**
6525** ^These functions add, remove, or modify a [collation] associated
6526** with the [database connection] specified as the first argument.
6527**
6528** ^The name of the collation is a UTF-8 string
6529** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6530** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6531** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6532** considered to be the same name.
6533**
6534** ^(The third argument (eTextRep) must be one of the constants:
6535** <ul>
6536** <li> [SQLITE_UTF8],
6537** <li> [SQLITE_UTF16LE],
6538** <li> [SQLITE_UTF16BE],
6539** <li> [SQLITE_UTF16], or
6540** <li> [SQLITE_UTF16_ALIGNED].
6541** </ul>)^
6542** ^The eTextRep argument determines the encoding of strings passed
6543** to the collating function callback, xCompare.
6544** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6545** force strings to be UTF16 with native byte order.
6546** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6547** on an even byte address.
6548**
6549** ^The fourth argument, pArg, is an application data pointer that is passed
6550** through as the first argument to the collating function callback.
6551**
6552** ^The fifth argument, xCompare, is a pointer to the collating function.
6553** ^Multiple collating functions can be registered using the same name but
6554** with different eTextRep parameters and SQLite will use whichever
6555** function requires the least amount of data transformation.
6556** ^If the xCompare argument is NULL then the collating function is
6557** deleted. ^When all collating functions having the same name are deleted,
6558** that collation is no longer usable.
6559**
6560** ^The collating function callback is invoked with a copy of the pArg
6561** application data pointer and with two strings in the encoding specified
6562** by the eTextRep argument. The two integer parameters to the collating
6563** function callback are the length of the two strings, in bytes. The collating
6564** function must return an integer that is negative, zero, or positive
6565** if the first string is less than, equal to, or greater than the second,
6566** respectively. A collating function must always return the same answer
6567** given the same inputs. If two or more collating functions are registered
6568** to the same collation name (using different eTextRep values) then all
6569** must give an equivalent answer when invoked with equivalent strings.
6570** The collating function must obey the following properties for all
6571** strings A, B, and C:
6572**
6573** <ol>
6574** <li> If A==B then B==A.
6575** <li> If A==B and B==C then A==C.
6576** <li> If A&lt;B THEN B&gt;A.
6577** <li> If A&lt;B and B&lt;C then A&lt;C.
6578** </ol>
6579**
6580** If a collating function fails any of the above constraints and that
6581** collating function is registered and used, then the behavior of SQLite
6582** is undefined.
6583**
6584** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6585** with the addition that the xDestroy callback is invoked on pArg when
6586** the collating function is deleted.
6587** ^Collating functions are deleted when they are overridden by later
6588** calls to the collation creation functions or when the
6589** [database connection] is closed using [sqlite3_close()].
6590**
6591** ^The xDestroy callback is <u>not</u> called if the
6592** sqlite3_create_collation_v2() function fails. Applications that invoke
6593** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6594** check the return code and dispose of the application data pointer
6595** themselves rather than expecting SQLite to deal with it for them.
6596** This is different from every other SQLite interface. The inconsistency
6597** is unfortunate but cannot be changed without breaking backwards
6598** compatibility.
6599**
6600** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6601*/
6602SQLITE_API int sqlite3_create_collation(
6603 sqlite3*,
6604 const char *zName,
6605 int eTextRep,
6606 void *pArg,
6607 int(*xCompare)(void*,int,const void*,int,const void*)
6608);
6609SQLITE_API int sqlite3_create_collation_v2(
6610 sqlite3*,
6611 const char *zName,
6612 int eTextRep,
6613 void *pArg,
6614 int(*xCompare)(void*,int,const void*,int,const void*),
6615 void(*xDestroy)(void*)
6616);
6617SQLITE_API int sqlite3_create_collation16(
6618 sqlite3*,
6619 const void *zName,
6620 int eTextRep,
6621 void *pArg,
6622 int(*xCompare)(void*,int,const void*,int,const void*)
6623);
6624
6625/*
6626** CAPI3REF: Collation Needed Callbacks
6627** METHOD: sqlite3
6628**
6629** ^To avoid having to register all collation sequences before a database
6630** can be used, a single callback function may be registered with the
6631** [database connection] to be invoked whenever an undefined collation
6632** sequence is required.
6633**
6634** ^If the function is registered using the sqlite3_collation_needed() API,
6635** then it is passed the names of undefined collation sequences as strings
6636** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6637** the names are passed as UTF-16 in machine native byte order.
6638** ^A call to either function replaces the existing collation-needed callback.
6639**
6640** ^(When the callback is invoked, the first argument passed is a copy
6641** of the second argument to sqlite3_collation_needed() or
6642** sqlite3_collation_needed16(). The second argument is the database
6643** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6644** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6645** sequence function required. The fourth parameter is the name of the
6646** required collation sequence.)^
6647**
6648** The callback function should register the desired collation using
6649** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6650** [sqlite3_create_collation_v2()].
6651*/
6652SQLITE_API int sqlite3_collation_needed(
6653 sqlite3*,
6654 void*,
6655 void(*)(void*,sqlite3*,int eTextRep,const char*)
6656);
6657SQLITE_API int sqlite3_collation_needed16(
6658 sqlite3*,
6659 void*,
6660 void(*)(void*,sqlite3*,int eTextRep,const void*)
6661);
6662
6663#ifdef SQLITE_ENABLE_CEROD
6664/*
6665** Specify the activation key for a CEROD database. Unless
6666** activated, none of the CEROD routines will work.
6667*/
6668SQLITE_API void sqlite3_activate_cerod(
6669 const char *zPassPhrase /* Activation phrase */
6670);
6671#endif
6672
6673/*
6674** CAPI3REF: Suspend Execution For A Short Time
6675**
6676** The sqlite3_sleep() function causes the current thread to suspend execution
6677** for at least a number of milliseconds specified in its parameter.
6678**
6679** If the operating system does not support sleep requests with
6680** millisecond time resolution, then the time will be rounded up to
6681** the nearest second. The number of milliseconds of sleep actually
6682** requested from the operating system is returned.
6683**
6684** ^SQLite implements this interface by calling the xSleep()
6685** method of the default [sqlite3_vfs] object. If the xSleep() method
6686** of the default VFS is not implemented correctly, or not implemented at
6687** all, then the behavior of sqlite3_sleep() may deviate from the description
6688** in the previous paragraphs.
6689**
6690** If a negative argument is passed to sqlite3_sleep() the results vary by
6691** VFS and operating system. Some system treat a negative argument as an
6692** instruction to sleep forever. Others understand it to mean do not sleep
6693** at all. ^In SQLite version 3.42.0 and later, a negative
6694** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6695** down into the xSleep method of the VFS.
6696*/
6697SQLITE_API int sqlite3_sleep(int);
6698
6699/*
6700** CAPI3REF: Name Of The Folder Holding Temporary Files
6701**
6702** ^(If this global variable is made to point to a string which is
6703** the name of a folder (a.k.a. directory), then all temporary files
6704** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6705** will be placed in that directory.)^ ^If this variable
6706** is a NULL pointer, then SQLite performs a search for an appropriate
6707** temporary file directory.
6708**
6709** Applications are strongly discouraged from using this global variable.
6710** It is required to set a temporary folder on Windows Runtime (WinRT).
6711** But for all other platforms, it is highly recommended that applications
6712** neither read nor write this variable. This global variable is a relic
6713** that exists for backwards compatibility of legacy applications and should
6714** be avoided in new projects.
6715**
6716** It is not safe to read or modify this variable in more than one
6717** thread at a time. It is not safe to read or modify this variable
6718** if a [database connection] is being used at the same time in a separate
6719** thread.
6720** It is intended that this variable be set once
6721** as part of process initialization and before any SQLite interface
6722** routines have been called and that this variable remain unchanged
6723** thereafter.
6724**
6725** ^The [temp_store_directory pragma] may modify this variable and cause
6726** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6727** the [temp_store_directory pragma] always assumes that any string
6728** that this variable points to is held in memory obtained from
6729** [sqlite3_malloc] and the pragma may attempt to free that memory
6730** using [sqlite3_free].
6731** Hence, if this variable is modified directly, either it should be
6732** made NULL or made to point to memory obtained from [sqlite3_malloc]
6733** or else the use of the [temp_store_directory pragma] should be avoided.
6734** Except when requested by the [temp_store_directory pragma], SQLite
6735** does not free the memory that sqlite3_temp_directory points to. If
6736** the application wants that memory to be freed, it must do
6737** so itself, taking care to only do so after all [database connection]
6738** objects have been destroyed.
6739**
6740** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6741** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6742** features that require the use of temporary files may fail. Here is an
6743** example of how to do this using C++ with the Windows Runtime:
6744**
6745** <blockquote><pre>
6746** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6747** &nbsp; TemporaryFolder->Path->Data();
6748** char zPathBuf&#91;MAX_PATH + 1&#93;;
6749** memset(zPathBuf, 0, sizeof(zPathBuf));
6750** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6751** &nbsp; NULL, NULL);
6752** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6753** </pre></blockquote>
6754*/
6755SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6756
6757/*
6758** CAPI3REF: Name Of The Folder Holding Database Files
6759**
6760** ^(If this global variable is made to point to a string which is
6761** the name of a folder (a.k.a. directory), then all database files
6762** specified with a relative pathname and created or accessed by
6763** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6764** to be relative to that directory.)^ ^If this variable is a NULL
6765** pointer, then SQLite assumes that all database files specified
6766** with a relative pathname are relative to the current directory
6767** for the process. Only the windows VFS makes use of this global
6768** variable; it is ignored by the unix VFS.
6769**
6770** Changing the value of this variable while a database connection is
6771** open can result in a corrupt database.
6772**
6773** It is not safe to read or modify this variable in more than one
6774** thread at a time. It is not safe to read or modify this variable
6775** if a [database connection] is being used at the same time in a separate
6776** thread.
6777** It is intended that this variable be set once
6778** as part of process initialization and before any SQLite interface
6779** routines have been called and that this variable remain unchanged
6780** thereafter.
6781**
6782** ^The [data_store_directory pragma] may modify this variable and cause
6783** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6784** the [data_store_directory pragma] always assumes that any string
6785** that this variable points to is held in memory obtained from
6786** [sqlite3_malloc] and the pragma may attempt to free that memory
6787** using [sqlite3_free].
6788** Hence, if this variable is modified directly, either it should be
6789** made NULL or made to point to memory obtained from [sqlite3_malloc]
6790** or else the use of the [data_store_directory pragma] should be avoided.
6791*/
6792SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6793
6794/*
6795** CAPI3REF: Win32 Specific Interface
6796**
6797** These interfaces are available only on Windows. The
6798** [sqlite3_win32_set_directory] interface is used to set the value associated
6799** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6800** zValue, depending on the value of the type parameter. The zValue parameter
6801** should be NULL to cause the previous value to be freed via [sqlite3_free];
6802** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6803** prior to being used. The [sqlite3_win32_set_directory] interface returns
6804** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6805** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6806** [sqlite3_data_directory] variable is intended to act as a replacement for
6807** the current directory on the sub-platforms of Win32 where that concept is
6808** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6809** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6810** sqlite3_win32_set_directory interface except the string parameter must be
6811** UTF-8 or UTF-16, respectively.
6812*/
6813SQLITE_API int sqlite3_win32_set_directory(
6814 unsigned long type, /* Identifier for directory being set or reset */
6815 void *zValue /* New value for directory being set or reset */
6816);
6817SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6818SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6819
6820/*
6821** CAPI3REF: Win32 Directory Types
6822**
6823** These macros are only available on Windows. They define the allowed values
6824** for the type argument to the [sqlite3_win32_set_directory] interface.
6825*/
6826#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6827#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6828
6829/*
6830** CAPI3REF: Test For Auto-Commit Mode
6831** KEYWORDS: {autocommit mode}
6832** METHOD: sqlite3
6833**
6834** ^The sqlite3_get_autocommit() interface returns non-zero or
6835** zero if the given database connection is or is not in autocommit mode,
6836** respectively. ^Autocommit mode is on by default.
6837** ^Autocommit mode is disabled by a [BEGIN] statement.
6838** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6839**
6840** If certain kinds of errors occur on a statement within a multi-statement
6841** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6842** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6843** transaction might be rolled back automatically. The only way to
6844** find out whether SQLite automatically rolled back the transaction after
6845** an error is to use this function.
6846**
6847** If another thread changes the autocommit status of the database
6848** connection while this routine is running, then the return value
6849** is undefined.
6850*/
6851SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6852
6853/*
6854** CAPI3REF: Find The Database Handle Of A Prepared Statement
6855** METHOD: sqlite3_stmt
6856**
6857** ^The sqlite3_db_handle interface returns the [database connection] handle
6858** to which a [prepared statement] belongs. ^The [database connection]
6859** returned by sqlite3_db_handle is the same [database connection]
6860** that was the first argument
6861** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6862** create the statement in the first place.
6863*/
6864SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6865
6866/*
6867** CAPI3REF: Return The Schema Name For A Database Connection
6868** METHOD: sqlite3
6869**
6870** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6871** for the N-th database on database connection D, or a NULL pointer if N is
6872** out of range. An N value of 0 means the main database file. An N of 1 is
6873** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6874** databases.
6875**
6876** Space to hold the string that is returned by sqlite3_db_name() is managed
6877** by SQLite itself. The string might be deallocated by any operation that
6878** changes the schema, including [ATTACH] or [DETACH] or calls to
6879** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6880** occur on a different thread. Applications that need to
6881** remember the string long-term should make their own copy. Applications that
6882** are accessing the same database connection simultaneously on multiple
6883** threads should mutex-protect calls to this API and should make their own
6884** private copy of the result prior to releasing the mutex.
6885*/
6886SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6887
6888/*
6889** CAPI3REF: Return The Filename For A Database Connection
6890** METHOD: sqlite3
6891**
6892** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6893** associated with database N of connection D.
6894** ^If there is no attached database N on the database
6895** connection D, or if database N is a temporary or in-memory database, then
6896** this function will return either a NULL pointer or an empty string.
6897**
6898** ^The string value returned by this routine is owned and managed by
6899** the database connection. ^The value will be valid until the database N
6900** is [DETACH]-ed or until the database connection closes.
6901**
6902** ^The filename returned by this function is the output of the
6903** xFullPathname method of the [VFS]. ^In other words, the filename
6904** will be an absolute pathname, even if the filename used
6905** to open the database originally was a URI or relative pathname.
6906**
6907** If the filename pointer returned by this routine is not NULL, then it
6908** can be used as the filename input parameter to these routines:
6909** <ul>
6910** <li> [sqlite3_uri_parameter()]
6911** <li> [sqlite3_uri_boolean()]
6912** <li> [sqlite3_uri_int64()]
6913** <li> [sqlite3_filename_database()]
6914** <li> [sqlite3_filename_journal()]
6915** <li> [sqlite3_filename_wal()]
6916** </ul>
6917*/
6918SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6919
6920/*
6921** CAPI3REF: Determine if a database is read-only
6922** METHOD: sqlite3
6923**
6924** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6925** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6926** the name of a database on connection D.
6927*/
6928SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6929
6930/*
6931** CAPI3REF: Determine the transaction state of a database
6932** METHOD: sqlite3
6933**
6934** ^The sqlite3_txn_state(D,S) interface returns the current
6935** [transaction state] of schema S in database connection D. ^If S is NULL,
6936** then the highest transaction state of any schema on database connection D
6937** is returned. Transaction states are (in order of lowest to highest):
6938** <ol>
6939** <li value="0"> SQLITE_TXN_NONE
6940** <li value="1"> SQLITE_TXN_READ
6941** <li value="2"> SQLITE_TXN_WRITE
6942** </ol>
6943** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6944** a valid schema, then -1 is returned.
6945*/
6946SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6947
6948/*
6949** CAPI3REF: Allowed return values from sqlite3_txn_state()
6950** KEYWORDS: {transaction state}
6951**
6952** These constants define the current transaction state of a database file.
6953** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6954** constants in order to describe the transaction state of schema S
6955** in [database connection] D.
6956**
6957** <dl>
6958** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6959** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6960** pending.</dd>
6961**
6962** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6963** <dd>The SQLITE_TXN_READ state means that the database is currently
6964** in a read transaction. Content has been read from the database file
6965** but nothing in the database file has changed. The transaction state
6966** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
6967** no other conflicting concurrent write transactions. The transaction
6968** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6969** [COMMIT].</dd>
6970**
6971** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6972** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6973** in a write transaction. Content has been written to the database file
6974** but has not yet committed. The transaction state will change to
6975** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6976*/
6977#define SQLITE_TXN_NONE 0
6978#define SQLITE_TXN_READ 1
6979#define SQLITE_TXN_WRITE 2
6980
6981/*
6982** CAPI3REF: Find the next prepared statement
6983** METHOD: sqlite3
6984**
6985** ^This interface returns a pointer to the next [prepared statement] after
6986** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6987** then this interface returns a pointer to the first prepared statement
6988** associated with the database connection pDb. ^If no prepared statement
6989** satisfies the conditions of this routine, it returns NULL.
6990**
6991** The [database connection] pointer D in a call to
6992** [sqlite3_next_stmt(D,S)] must refer to an open database
6993** connection and in particular must not be a NULL pointer.
6994*/
6995SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6996
6997/*
6998** CAPI3REF: Commit And Rollback Notification Callbacks
6999** METHOD: sqlite3
7000**
7001** ^The sqlite3_commit_hook() interface registers a callback
7002** function to be invoked whenever a transaction is [COMMIT | committed].
7003** ^Any callback set by a previous call to sqlite3_commit_hook()
7004** for the same database connection is overridden.
7005** ^The sqlite3_rollback_hook() interface registers a callback
7006** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
7007** ^Any callback set by a previous call to sqlite3_rollback_hook()
7008** for the same database connection is overridden.
7009** ^The pArg argument is passed through to the callback.
7010** ^If the callback on a commit hook function returns non-zero,
7011** then the commit is converted into a rollback.
7012**
7013** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
7014** return the P argument from the previous call of the same function
7015** on the same [database connection] D, or NULL for
7016** the first call for each function on D.
7017**
7018** The commit and rollback hook callbacks are not reentrant.
7019** The callback implementation must not do anything that will modify
7020** the database connection that invoked the callback. Any actions
7021** to modify the database connection must be deferred until after the
7022** completion of the [sqlite3_step()] call that triggered the commit
7023** or rollback hook in the first place.
7024** Note that running any other SQL statements, including SELECT statements,
7025** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
7026** the database connections for the meaning of "modify" in this paragraph.
7027**
7028** ^Registering a NULL function disables the callback.
7029**
7030** ^When the commit hook callback routine returns zero, the [COMMIT]
7031** operation is allowed to continue normally. ^If the commit hook
7032** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
7033** ^The rollback hook is invoked on a rollback that results from a commit
7034** hook returning non-zero, just as it would be with any other rollback.
7035**
7036** ^For the purposes of this API, a transaction is said to have been
7037** rolled back if an explicit "ROLLBACK" statement is executed, or
7038** an error or constraint causes an implicit rollback to occur.
7039** ^The rollback callback is not invoked if a transaction is
7040** automatically rolled back because the database connection is closed.
7041**
7042** See also the [sqlite3_update_hook()] interface.
7043*/
7044SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
7045SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
7046
7047/*
7048** CAPI3REF: Autovacuum Compaction Amount Callback
7049** METHOD: sqlite3
7050**
7051** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
7052** function C that is invoked prior to each autovacuum of the database
7053** file. ^The callback is passed a copy of the generic data pointer (P),
7054** the schema-name of the attached database that is being autovacuumed,
7055** the size of the database file in pages, the number of free pages,
7056** and the number of bytes per page, respectively. The callback should
7057** return the number of free pages that should be removed by the
7058** autovacuum. ^If the callback returns zero, then no autovacuum happens.
7059** ^If the value returned is greater than or equal to the number of
7060** free pages, then a complete autovacuum happens.
7061**
7062** <p>^If there are multiple ATTACH-ed database files that are being
7063** modified as part of a transaction commit, then the autovacuum pages
7064** callback is invoked separately for each file.
7065**
7066** <p><b>The callback is not reentrant.</b> The callback function should
7067** not attempt to invoke any other SQLite interface. If it does, bad
7068** things may happen, including segmentation faults and corrupt database
7069** files. The callback function should be a simple function that
7070** does some arithmetic on its input parameters and returns a result.
7071**
7072** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
7073** destructor for the P parameter. ^If X is not NULL, then X(P) is
7074** invoked whenever the database connection closes or when the callback
7075** is overwritten by another invocation of sqlite3_autovacuum_pages().
7076**
7077** <p>^There is only one autovacuum pages callback per database connection.
7078** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
7079** previous invocations for that database connection. ^If the callback
7080** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
7081** then the autovacuum steps callback is canceled. The return value
7082** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
7083** be some other error code if something goes wrong. The current
7084** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
7085** return codes might be added in future releases.
7086**
7087** <p>If no autovacuum pages callback is specified (the usual case) or
7088** a NULL pointer is provided for the callback,
7089** then the default behavior is to vacuum all free pages. So, in other
7090** words, the default behavior is the same as if the callback function
7091** were something like this:
7092**
7093** <blockquote><pre>
7094** &nbsp; unsigned int demonstration_autovac_pages_callback(
7095** &nbsp; void *pClientData,
7096** &nbsp; const char *zSchema,
7097** &nbsp; unsigned int nDbPage,
7098** &nbsp; unsigned int nFreePage,
7099** &nbsp; unsigned int nBytePerPage
7100** &nbsp; ){
7101** &nbsp; return nFreePage;
7102** &nbsp; }
7103** </pre></blockquote>
7104*/
7105SQLITE_API int sqlite3_autovacuum_pages(
7106 sqlite3 *db,
7107 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
7108 void*,
7109 void(*)(void*)
7110);
7111
7112
7113/*
7114** CAPI3REF: Data Change Notification Callbacks
7115** METHOD: sqlite3
7116**
7117** ^The sqlite3_update_hook() interface registers a callback function
7118** with the [database connection] identified by the first argument
7119** to be invoked whenever a row is updated, inserted or deleted in
7120** a [rowid table].
7121** ^Any callback set by a previous call to this function
7122** for the same database connection is overridden.
7123**
7124** ^The second argument is a pointer to the function to invoke when a
7125** row is updated, inserted or deleted in a rowid table.
7126** ^The update hook is disabled by invoking sqlite3_update_hook()
7127** with a NULL pointer as the second parameter.
7128** ^The first argument to the callback is a copy of the third argument
7129** to sqlite3_update_hook().
7130** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
7131** or [SQLITE_UPDATE], depending on the operation that caused the callback
7132** to be invoked.
7133** ^The third and fourth arguments to the callback contain pointers to the
7134** database and table name containing the affected row.
7135** ^The final callback parameter is the [rowid] of the row.
7136** ^In the case of an update, this is the [rowid] after the update takes place.
7137**
7138** ^(The update hook is not invoked when internal system tables are
7139** modified (i.e. sqlite_sequence).)^
7140** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
7141**
7142** ^In the current implementation, the update hook
7143** is not invoked when conflicting rows are deleted because of an
7144** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
7145** invoked when rows are deleted using the [truncate optimization].
7146** The exceptions defined in this paragraph might change in a future
7147** release of SQLite.
7148**
7149** Whether the update hook is invoked before or after the
7150** corresponding change is currently unspecified and may differ
7151** depending on the type of change. Do not rely on the order of the
7152** hook call with regards to the final result of the operation which
7153** triggers the hook.
7154**
7155** The update hook implementation must not do anything that will modify
7156** the database connection that invoked the update hook. Any actions
7157** to modify the database connection must be deferred until after the
7158** completion of the [sqlite3_step()] call that triggered the update hook.
7159** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
7160** database connections for the meaning of "modify" in this paragraph.
7161**
7162** ^The sqlite3_update_hook(D,C,P) function
7163** returns the P argument from the previous call
7164** on the same [database connection] D, or NULL for
7165** the first call on D.
7166**
7167** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
7168** and [sqlite3_preupdate_hook()] interfaces.
7169*/
7170SQLITE_API void *sqlite3_update_hook(
7171 sqlite3*,
7172 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
7173 void*
7174);
7175
7176/*
7177** CAPI3REF: Enable Or Disable Shared Pager Cache
7178**
7179** ^(This routine enables or disables the sharing of the database cache
7180** and schema data structures between [database connection | connections]
7181** to the same database. Sharing is enabled if the argument is true
7182** and disabled if the argument is false.)^
7183**
7184** This interface is omitted if SQLite is compiled with
7185** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
7186** compile-time option is recommended because the
7187** [use of shared cache mode is discouraged].
7188**
7189** ^Cache sharing is enabled and disabled for an entire process.
7190** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
7191** In prior versions of SQLite,
7192** sharing was enabled or disabled for each thread separately.
7193**
7194** ^(The cache sharing mode set by this interface effects all subsequent
7195** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
7196** Existing database connections continue to use the sharing mode
7197** that was in effect at the time they were opened.)^
7198**
7199** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
7200** successfully. An [error code] is returned otherwise.)^
7201**
7202** ^Shared cache is disabled by default. It is recommended that it stay
7203** that way. In other words, do not use this routine. This interface
7204** continues to be provided for historical compatibility, but its use is
7205** discouraged. Any use of shared cache is discouraged. If shared cache
7206** must be used, it is recommended that shared cache only be enabled for
7207** individual database connections using the [sqlite3_open_v2()] interface
7208** with the [SQLITE_OPEN_SHAREDCACHE] flag.
7209**
7210** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
7211** and will always return SQLITE_MISUSE. On those systems,
7212** shared cache mode should be enabled per-database connection via
7213** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
7214**
7215** This interface is threadsafe on processors where writing a
7216** 32-bit integer is atomic.
7217**
7218** See Also: [SQLite Shared-Cache Mode]
7219*/
7220SQLITE_API int sqlite3_enable_shared_cache(int);
7221
7222/*
7223** CAPI3REF: Attempt To Free Heap Memory
7224**
7225** ^The sqlite3_release_memory() interface attempts to free N bytes
7226** of heap memory by deallocating non-essential memory allocations
7227** held by the database library. Memory used to cache database
7228** pages to improve performance is an example of non-essential memory.
7229** ^sqlite3_release_memory() returns the number of bytes actually freed,
7230** which might be more or less than the amount requested.
7231** ^The sqlite3_release_memory() routine is a no-op returning zero
7232** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
7233**
7234** See also: [sqlite3_db_release_memory()]
7235*/
7236SQLITE_API int sqlite3_release_memory(int);
7237
7238/*
7239** CAPI3REF: Free Memory Used By A Database Connection
7240** METHOD: sqlite3
7241**
7242** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
7243** memory as possible from database connection D. Unlike the
7244** [sqlite3_release_memory()] interface, this interface is in effect even
7245** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
7246** omitted.
7247**
7248** See also: [sqlite3_release_memory()]
7249*/
7250SQLITE_API int sqlite3_db_release_memory(sqlite3*);
7251
7252/*
7253** CAPI3REF: Impose A Limit On Heap Size
7254**
7255** These interfaces impose limits on the amount of heap memory that will be
7256** used by all database connections within a single process.
7257**
7258** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7259** soft limit on the amount of heap memory that may be allocated by SQLite.
7260** ^SQLite strives to keep heap memory utilization below the soft heap
7261** limit by reducing the number of pages held in the page cache
7262** as heap memory usages approaches the limit.
7263** ^The soft heap limit is "soft" because even though SQLite strives to stay
7264** below the limit, it will exceed the limit rather than generate
7265** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7266** is advisory only.
7267**
7268** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7269** N bytes on the amount of memory that will be allocated. ^The
7270** sqlite3_hard_heap_limit64(N) interface is similar to
7271** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7272** when the hard heap limit is reached.
7273**
7274** ^The return value from both sqlite3_soft_heap_limit64() and
7275** sqlite3_hard_heap_limit64() is the size of
7276** the heap limit prior to the call, or negative in the case of an
7277** error. ^If the argument N is negative
7278** then no change is made to the heap limit. Hence, the current
7279** size of heap limits can be determined by invoking
7280** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7281**
7282** ^Setting the heap limits to zero disables the heap limiter mechanism.
7283**
7284** ^The soft heap limit may not be greater than the hard heap limit.
7285** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7286** is invoked with a value of N that is greater than the hard heap limit,
7287** the soft heap limit is set to the value of the hard heap limit.
7288** ^The soft heap limit is automatically enabled whenever the hard heap
7289** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7290** the soft heap limit is outside the range of 1..N, then the soft heap
7291** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7292** hard heap limit is enabled makes the soft heap limit equal to the
7293** hard heap limit.
7294**
7295** The memory allocation limits can also be adjusted using
7296** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7297**
7298** ^(The heap limits are not enforced in the current implementation
7299** if one or more of following conditions are true:
7300**
7301** <ul>
7302** <li> The limit value is set to zero.
7303** <li> Memory accounting is disabled using a combination of the
7304** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7305** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7306** <li> An alternative page cache implementation is specified using
7307** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7308** <li> The page cache allocates from its own memory pool supplied
7309** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7310** from the heap.
7311** </ul>)^
7312**
7313** The circumstances under which SQLite will enforce the heap limits may
7314** change in future releases of SQLite.
7315*/
7316SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7317SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7318
7319/*
7320** CAPI3REF: Deprecated Soft Heap Limit Interface
7321** DEPRECATED
7322**
7323** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7324** interface. This routine is provided for historical compatibility
7325** only. All new applications should use the
7326** [sqlite3_soft_heap_limit64()] interface rather than this one.
7327*/
7328SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7329
7330
7331/*
7332** CAPI3REF: Extract Metadata About A Column Of A Table
7333** METHOD: sqlite3
7334**
7335** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7336** information about column C of table T in database D
7337** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7338** interface returns SQLITE_OK and fills in the non-NULL pointers in
7339** the final five arguments with appropriate values if the specified
7340** column exists. ^The sqlite3_table_column_metadata() interface returns
7341** SQLITE_ERROR if the specified column does not exist.
7342** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7343** NULL pointer, then this routine simply checks for the existence of the
7344** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7345** does not. If the table name parameter T in a call to
7346** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7347** undefined behavior.
7348**
7349** ^The column is identified by the second, third and fourth parameters to
7350** this function. ^(The second parameter is either the name of the database
7351** (i.e. "main", "temp", or an attached database) containing the specified
7352** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7353** for the table using the same algorithm used by the database engine to
7354** resolve unqualified table references.
7355**
7356** ^The third and fourth parameters to this function are the table and column
7357** name of the desired column, respectively.
7358**
7359** ^Metadata is returned by writing to the memory locations passed as the 5th
7360** and subsequent parameters to this function. ^Any of these arguments may be
7361** NULL, in which case the corresponding element of metadata is omitted.
7362**
7363** ^(<blockquote>
7364** <table border="1">
7365** <tr><th> Parameter <th> Output<br>Type <th> Description
7366**
7367** <tr><td> 5th <td> const char* <td> Data type
7368** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7369** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7370** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7371** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7372** </table>
7373** </blockquote>)^
7374**
7375** ^The memory pointed to by the character pointers returned for the
7376** declaration type and collation sequence is valid until the next
7377** call to any SQLite API function.
7378**
7379** ^If the specified table is actually a view, an [error code] is returned.
7380**
7381** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7382** is not a [WITHOUT ROWID] table and an
7383** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7384** parameters are set for the explicitly declared column. ^(If there is no
7385** [INTEGER PRIMARY KEY] column, then the outputs
7386** for the [rowid] are set as follows:
7387**
7388** <pre>
7389** data type: "INTEGER"
7390** collation sequence: "BINARY"
7391** not null: 0
7392** primary key: 1
7393** auto increment: 0
7394** </pre>)^
7395**
7396** ^This function causes all database schemas to be read from disk and
7397** parsed, if that has not already been done, and returns an error if
7398** any errors are encountered while loading the schema.
7399*/
7400SQLITE_API int sqlite3_table_column_metadata(
7401 sqlite3 *db, /* Connection handle */
7402 const char *zDbName, /* Database name or NULL */
7403 const char *zTableName, /* Table name */
7404 const char *zColumnName, /* Column name */
7405 char const **pzDataType, /* OUTPUT: Declared data type */
7406 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7407 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7408 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7409 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7410);
7411
7412/*
7413** CAPI3REF: Load An Extension
7414** METHOD: sqlite3
7415**
7416** ^This interface loads an SQLite extension library from the named file.
7417**
7418** ^The sqlite3_load_extension() interface attempts to load an
7419** [SQLite extension] library contained in the file zFile. If
7420** the file cannot be loaded directly, attempts are made to load
7421** with various operating-system specific extensions added.
7422** So for example, if "samplelib" cannot be loaded, then names like
7423** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7424** be tried also.
7425**
7426** ^The entry point is zProc.
7427** ^(zProc may be 0, in which case SQLite will try to come up with an
7428** entry point name on its own. It first tries "sqlite3_extension_init".
7429** If that does not work, it constructs a name "sqlite3_X_init" where
7430** X consists of the lower-case equivalent of all ASCII alphabetic
7431** characters in the filename from the last "/" to the first following
7432** "." and omitting any initial "lib".)^
7433** ^The sqlite3_load_extension() interface returns
7434** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7435** ^If an error occurs and pzErrMsg is not 0, then the
7436** [sqlite3_load_extension()] interface shall attempt to
7437** fill *pzErrMsg with error message text stored in memory
7438** obtained from [sqlite3_malloc()]. The calling function
7439** should free this memory by calling [sqlite3_free()].
7440**
7441** ^Extension loading must be enabled using
7442** [sqlite3_enable_load_extension()] or
7443** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7444** prior to calling this API,
7445** otherwise an error will be returned.
7446**
7447** <b>Security warning:</b> It is recommended that the
7448** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7449** interface. The use of the [sqlite3_enable_load_extension()] interface
7450** should be avoided. This will keep the SQL function [load_extension()]
7451** disabled and prevent SQL injections from giving attackers
7452** access to extension loading capabilities.
7453**
7454** See also the [load_extension() SQL function].
7455*/
7456SQLITE_API int sqlite3_load_extension(
7457 sqlite3 *db, /* Load the extension into this database connection */
7458 const char *zFile, /* Name of the shared library containing extension */
7459 const char *zProc, /* Entry point. Derived from zFile if 0 */
7460 char **pzErrMsg /* Put error message here if not 0 */
7461);
7462
7463/*
7464** CAPI3REF: Enable Or Disable Extension Loading
7465** METHOD: sqlite3
7466**
7467** ^So as not to open security holes in older applications that are
7468** unprepared to deal with [extension loading], and as a means of disabling
7469** [extension loading] while evaluating user-entered SQL, the following API
7470** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7471**
7472** ^Extension loading is off by default.
7473** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7474** to turn extension loading on and call it with onoff==0 to turn
7475** it back off again.
7476**
7477** ^This interface enables or disables both the C-API
7478** [sqlite3_load_extension()] and the SQL function [load_extension()].
7479** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7480** to enable or disable only the C-API.)^
7481**
7482** <b>Security warning:</b> It is recommended that extension loading
7483** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7484** rather than this interface, so the [load_extension()] SQL function
7485** remains disabled. This will prevent SQL injections from giving attackers
7486** access to extension loading capabilities.
7487*/
7488SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7489
7490/*
7491** CAPI3REF: Automatically Load Statically Linked Extensions
7492**
7493** ^This interface causes the xEntryPoint() function to be invoked for
7494** each new [database connection] that is created. The idea here is that
7495** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7496** that is to be automatically loaded into all new database connections.
7497**
7498** ^(Even though the function prototype shows that xEntryPoint() takes
7499** no arguments and returns void, SQLite invokes xEntryPoint() with three
7500** arguments and expects an integer result as if the signature of the
7501** entry point were as follows:
7502**
7503** <blockquote><pre>
7504** &nbsp; int xEntryPoint(
7505** &nbsp; sqlite3 *db,
7506** &nbsp; const char **pzErrMsg,
7507** &nbsp; const struct sqlite3_api_routines *pThunk
7508** &nbsp; );
7509** </pre></blockquote>)^
7510**
7511** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7512** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7513** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7514** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7515** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7516** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7517** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7518**
7519** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7520** on the list of automatic extensions is a harmless no-op. ^No entry point
7521** will be called more than once for each database connection that is opened.
7522**
7523** See also: [sqlite3_reset_auto_extension()]
7524** and [sqlite3_cancel_auto_extension()]
7525*/
7526SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7527
7528/*
7529** CAPI3REF: Cancel Automatic Extension Loading
7530**
7531** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7532** initialization routine X that was registered using a prior call to
7533** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7534** routine returns 1 if initialization routine X was successfully
7535** unregistered and it returns 0 if X was not on the list of initialization
7536** routines.
7537*/
7538SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7539
7540/*
7541** CAPI3REF: Reset Automatic Extension Loading
7542**
7543** ^This interface disables all automatic extensions previously
7544** registered using [sqlite3_auto_extension()].
7545*/
7546SQLITE_API void sqlite3_reset_auto_extension(void);
7547
7548/*
7549** Structures used by the virtual table interface
7550*/
7551typedef struct sqlite3_vtab sqlite3_vtab;
7552typedef struct sqlite3_index_info sqlite3_index_info;
7553typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7554typedef struct sqlite3_module sqlite3_module;
7555
7556/*
7557** CAPI3REF: Virtual Table Object
7558** KEYWORDS: sqlite3_module {virtual table module}
7559**
7560** This structure, sometimes called a "virtual table module",
7561** defines the implementation of a [virtual table].
7562** This structure consists mostly of methods for the module.
7563**
7564** ^A virtual table module is created by filling in a persistent
7565** instance of this structure and passing a pointer to that instance
7566** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7567** ^The registration remains valid until it is replaced by a different
7568** module or until the [database connection] closes. The content
7569** of this structure must not change while it is registered with
7570** any database connection.
7571*/
7572struct sqlite3_module {
7573 int iVersion;
7574 int (*xCreate)(sqlite3*, void *pAux,
7575 int argc, const char *const*argv,
7576 sqlite3_vtab **ppVTab, char**);
7577 int (*xConnect)(sqlite3*, void *pAux,
7578 int argc, const char *const*argv,
7579 sqlite3_vtab **ppVTab, char**);
7580 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7581 int (*xDisconnect)(sqlite3_vtab *pVTab);
7582 int (*xDestroy)(sqlite3_vtab *pVTab);
7583 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7584 int (*xClose)(sqlite3_vtab_cursor*);
7585 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7586 int argc, sqlite3_value **argv);
7587 int (*xNext)(sqlite3_vtab_cursor*);
7588 int (*xEof)(sqlite3_vtab_cursor*);
7589 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7590 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7591 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7592 int (*xBegin)(sqlite3_vtab *pVTab);
7593 int (*xSync)(sqlite3_vtab *pVTab);
7594 int (*xCommit)(sqlite3_vtab *pVTab);
7595 int (*xRollback)(sqlite3_vtab *pVTab);
7596 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7597 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7598 void **ppArg);
7599 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7600 /* The methods above are in version 1 of the sqlite_module object. Those
7601 ** below are for version 2 and greater. */
7602 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7603 int (*xRelease)(sqlite3_vtab *pVTab, int);
7604 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7605 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7606 ** Those below are for version 3 and greater. */
7607 int (*xShadowName)(const char*);
7608 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7609 ** Those below are for version 4 and greater. */
7610 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7611 const char *zTabName, int mFlags, char **pzErr);
7612};
7613
7614/*
7615** CAPI3REF: Virtual Table Indexing Information
7616** KEYWORDS: sqlite3_index_info
7617**
7618** The sqlite3_index_info structure and its substructures is used as part
7619** of the [virtual table] interface to
7620** pass information into and receive the reply from the [xBestIndex]
7621** method of a [virtual table module]. The fields under **Inputs** are the
7622** inputs to xBestIndex and are read-only. xBestIndex inserts its
7623** results into the **Outputs** fields.
7624**
7625** ^(The aConstraint[] array records WHERE clause constraints of the form:
7626**
7627** <blockquote>column OP expr</blockquote>
7628**
7629** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7630** stored in aConstraint[].op using one of the
7631** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7632** ^(The index of the column is stored in
7633** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7634** expr on the right-hand side can be evaluated (and thus the constraint
7635** is usable) and false if it cannot.)^
7636**
7637** ^The optimizer automatically inverts terms of the form "expr OP column"
7638** and makes other simplifications to the WHERE clause in an attempt to
7639** get as many WHERE clause terms into the form shown above as possible.
7640** ^The aConstraint[] array only reports WHERE clause terms that are
7641** relevant to the particular virtual table being queried.
7642**
7643** ^Information about the ORDER BY clause is stored in aOrderBy[].
7644** ^Each term of aOrderBy records a column of the ORDER BY clause.
7645**
7646** The colUsed field indicates which columns of the virtual table may be
7647** required by the current scan. Virtual table columns are numbered from
7648** zero in the order in which they appear within the CREATE TABLE statement
7649** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7650** the corresponding bit is set within the colUsed mask if the column may be
7651** required by SQLite. If the table has at least 64 columns and any column
7652** to the right of the first 63 is required, then bit 63 of colUsed is also
7653** set. In other words, column iCol may be required if the expression
7654** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7655** non-zero.
7656**
7657** The [xBestIndex] method must fill aConstraintUsage[] with information
7658** about what parameters to pass to xFilter. ^If argvIndex>0 then
7659** the right-hand side of the corresponding aConstraint[] is evaluated
7660** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7661** is true, then the constraint is assumed to be fully handled by the
7662** virtual table and might not be checked again by the byte code.)^ ^(The
7663** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7664** is left in its default setting of false, the constraint will always be
7665** checked separately in byte code. If the omit flag is changed to true, then
7666** the constraint may or may not be checked in byte code. In other words,
7667** when the omit flag is true there is no guarantee that the constraint will
7668** not be checked again using byte code.)^
7669**
7670** ^The idxNum and idxStr values are recorded and passed into the
7671** [xFilter] method.
7672** ^[sqlite3_free()] is used to free idxStr if and only if
7673** needToFreeIdxStr is true.
7674**
7675** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7676** the correct order to satisfy the ORDER BY clause so that no separate
7677** sorting step is required.
7678**
7679** ^The estimatedCost value is an estimate of the cost of a particular
7680** strategy. A cost of N indicates that the cost of the strategy is similar
7681** to a linear scan of an SQLite table with N rows. A cost of log(N)
7682** indicates that the expense of the operation is similar to that of a
7683** binary search on a unique indexed field of an SQLite table with N rows.
7684**
7685** ^The estimatedRows value is an estimate of the number of rows that
7686** will be returned by the strategy.
7687**
7688** The xBestIndex method may optionally populate the idxFlags field with a
7689** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
7690** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
7691** output to show the idxNum as hex instead of as decimal. Another flag is
7692** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
7693** return at most one row.
7694**
7695** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7696** SQLite also assumes that if a call to the xUpdate() method is made as
7697** part of the same statement to delete or update a virtual table row and the
7698** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7699** any database changes. In other words, if the xUpdate() returns
7700** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7701** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7702** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7703** the xUpdate method are automatically rolled back by SQLite.
7704**
7705** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7706** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7707** If a virtual table extension is
7708** used with an SQLite version earlier than 3.8.2, the results of attempting
7709** to read or write the estimatedRows field are undefined (but are likely
7710** to include crashing the application). The estimatedRows field should
7711** therefore only be used if [sqlite3_libversion_number()] returns a
7712** value greater than or equal to 3008002. Similarly, the idxFlags field
7713** was added for [version 3.9.0] ([dateof:3.9.0]).
7714** It may therefore only be used if
7715** sqlite3_libversion_number() returns a value greater than or equal to
7716** 3009000.
7717*/
7718struct sqlite3_index_info {
7719 /* Inputs */
7720 int nConstraint; /* Number of entries in aConstraint */
7721 struct sqlite3_index_constraint {
7722 int iColumn; /* Column constrained. -1 for ROWID */
7723 unsigned char op; /* Constraint operator */
7724 unsigned char usable; /* True if this constraint is usable */
7725 int iTermOffset; /* Used internally - xBestIndex should ignore */
7726 } *aConstraint; /* Table of WHERE clause constraints */
7727 int nOrderBy; /* Number of terms in the ORDER BY clause */
7728 struct sqlite3_index_orderby {
7729 int iColumn; /* Column number */
7730 unsigned char desc; /* True for DESC. False for ASC. */
7731 } *aOrderBy; /* The ORDER BY clause */
7732 /* Outputs */
7733 struct sqlite3_index_constraint_usage {
7734 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7735 unsigned char omit; /* Do not code a test for this constraint */
7736 } *aConstraintUsage;
7737 int idxNum; /* Number used to identify the index */
7738 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7739 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7740 int orderByConsumed; /* True if output is already ordered */
7741 double estimatedCost; /* Estimated cost of using this index */
7742 /* Fields below are only available in SQLite 3.8.2 and later */
7743 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7744 /* Fields below are only available in SQLite 3.9.0 and later */
7745 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7746 /* Fields below are only available in SQLite 3.10.0 and later */
7747 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7748};
7749
7750/*
7751** CAPI3REF: Virtual Table Scan Flags
7752**
7753** Virtual table implementations are allowed to set the
7754** [sqlite3_index_info].idxFlags field to some combination of
7755** these bits.
7756*/
7757#define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
7758#define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */
7759 /* in EXPLAIN QUERY PLAN */
7760
7761/*
7762** CAPI3REF: Virtual Table Constraint Operator Codes
7763**
7764** These macros define the allowed values for the
7765** [sqlite3_index_info].aConstraint[].op field. Each value represents
7766** an operator that is part of a constraint term in the WHERE clause of
7767** a query that uses a [virtual table].
7768**
7769** ^The left-hand operand of the operator is given by the corresponding
7770** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7771** operand is the rowid.
7772** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7773** operators have no left-hand operand, and so for those operators the
7774** corresponding aConstraint[].iColumn is meaningless and should not be
7775** used.
7776**
7777** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7778** value 255 are reserved to represent functions that are overloaded
7779** by the [xFindFunction|xFindFunction method] of the virtual table
7780** implementation.
7781**
7782** The right-hand operands for each constraint might be accessible using
7783** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7784** operand is only available if it appears as a single constant literal
7785** in the input SQL. If the right-hand operand is another column or an
7786** expression (even a constant expression) or a parameter, then the
7787** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7788** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7789** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7790** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7791** always return SQLITE_NOTFOUND.
7792**
7793** The collating sequence to be used for comparison can be found using
7794** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7795** tables, the collating sequence of constraints does not matter (for example
7796** because the constraints are numeric) and so the sqlite3_vtab_collation()
7797** interface is not commonly needed.
7798*/
7799#define SQLITE_INDEX_CONSTRAINT_EQ 2
7800#define SQLITE_INDEX_CONSTRAINT_GT 4
7801#define SQLITE_INDEX_CONSTRAINT_LE 8
7802#define SQLITE_INDEX_CONSTRAINT_LT 16
7803#define SQLITE_INDEX_CONSTRAINT_GE 32
7804#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7805#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7806#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7807#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7808#define SQLITE_INDEX_CONSTRAINT_NE 68
7809#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7810#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7811#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7812#define SQLITE_INDEX_CONSTRAINT_IS 72
7813#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7814#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7815#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7816
7817/*
7818** CAPI3REF: Register A Virtual Table Implementation
7819** METHOD: sqlite3
7820**
7821** ^These routines are used to register a new [virtual table module] name.
7822** ^Module names must be registered before
7823** creating a new [virtual table] using the module and before using a
7824** preexisting [virtual table] for the module.
7825**
7826** ^The module name is registered on the [database connection] specified
7827** by the first parameter. ^The name of the module is given by the
7828** second parameter. ^The third parameter is a pointer to
7829** the implementation of the [virtual table module]. ^The fourth
7830** parameter is an arbitrary client data pointer that is passed through
7831** into the [xCreate] and [xConnect] methods of the virtual table module
7832** when a new virtual table is being created or reinitialized.
7833**
7834** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7835** is a pointer to a destructor for the pClientData. ^SQLite will
7836** invoke the destructor function (if it is not NULL) when SQLite
7837** no longer needs the pClientData pointer. ^The destructor will also
7838** be invoked if the call to sqlite3_create_module_v2() fails.
7839** ^The sqlite3_create_module()
7840** interface is equivalent to sqlite3_create_module_v2() with a NULL
7841** destructor.
7842**
7843** ^If the third parameter (the pointer to the sqlite3_module object) is
7844** NULL then no new module is created and any existing modules with the
7845** same name are dropped.
7846**
7847** See also: [sqlite3_drop_modules()]
7848*/
7849SQLITE_API int sqlite3_create_module(
7850 sqlite3 *db, /* SQLite connection to register module with */
7851 const char *zName, /* Name of the module */
7852 const sqlite3_module *p, /* Methods for the module */
7853 void *pClientData /* Client data for xCreate/xConnect */
7854);
7855SQLITE_API int sqlite3_create_module_v2(
7856 sqlite3 *db, /* SQLite connection to register module with */
7857 const char *zName, /* Name of the module */
7858 const sqlite3_module *p, /* Methods for the module */
7859 void *pClientData, /* Client data for xCreate/xConnect */
7860 void(*xDestroy)(void*) /* Module destructor function */
7861);
7862
7863/*
7864** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7865** METHOD: sqlite3
7866**
7867** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7868** table modules from database connection D except those named on list L.
7869** The L parameter must be either NULL or a pointer to an array of pointers
7870** to strings where the array is terminated by a single NULL pointer.
7871** ^If the L parameter is NULL, then all virtual table modules are removed.
7872**
7873** See also: [sqlite3_create_module()]
7874*/
7875SQLITE_API int sqlite3_drop_modules(
7876 sqlite3 *db, /* Remove modules from this connection */
7877 const char **azKeep /* Except, do not remove the ones named here */
7878);
7879
7880/*
7881** CAPI3REF: Virtual Table Instance Object
7882** KEYWORDS: sqlite3_vtab
7883**
7884** Every [virtual table module] implementation uses a subclass
7885** of this object to describe a particular instance
7886** of the [virtual table]. Each subclass will
7887** be tailored to the specific needs of the module implementation.
7888** The purpose of this superclass is to define certain fields that are
7889** common to all module implementations.
7890**
7891** ^Virtual tables methods can set an error message by assigning a
7892** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7893** take care that any prior string is freed by a call to [sqlite3_free()]
7894** prior to assigning a new string to zErrMsg. ^After the error message
7895** is delivered up to the client application, the string will be automatically
7896** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7897*/
7898struct sqlite3_vtab {
7899 const sqlite3_module *pModule; /* The module for this virtual table */
7900 int nRef; /* Number of open cursors */
7901 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7902 /* Virtual table implementations will typically add additional fields */
7903};
7904
7905/*
7906** CAPI3REF: Virtual Table Cursor Object
7907** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7908**
7909** Every [virtual table module] implementation uses a subclass of the
7910** following structure to describe cursors that point into the
7911** [virtual table] and are used
7912** to loop through the virtual table. Cursors are created using the
7913** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7914** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7915** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7916** of the module. Each module implementation will define
7917** the content of a cursor structure to suit its own needs.
7918**
7919** This superclass exists in order to define fields of the cursor that
7920** are common to all implementations.
7921*/
7922struct sqlite3_vtab_cursor {
7923 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7924 /* Virtual table implementations will typically add additional fields */
7925};
7926
7927/*
7928** CAPI3REF: Declare The Schema Of A Virtual Table
7929**
7930** ^The [xCreate] and [xConnect] methods of a
7931** [virtual table module] call this interface
7932** to declare the format (the names and datatypes of the columns) of
7933** the virtual tables they implement.
7934*/
7935SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7936
7937/*
7938** CAPI3REF: Overload A Function For A Virtual Table
7939** METHOD: sqlite3
7940**
7941** ^(Virtual tables can provide alternative implementations of functions
7942** using the [xFindFunction] method of the [virtual table module].
7943** But global versions of those functions
7944** must exist in order to be overloaded.)^
7945**
7946** ^(This API makes sure a global version of a function with a particular
7947** name and number of parameters exists. If no such function exists
7948** before this API is called, a new function is created.)^ ^The implementation
7949** of the new function always causes an exception to be thrown. So
7950** the new function is not good for anything by itself. Its only
7951** purpose is to be a placeholder function that can be overloaded
7952** by a [virtual table].
7953*/
7954SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7955
7956/*
7957** CAPI3REF: A Handle To An Open BLOB
7958** KEYWORDS: {BLOB handle} {BLOB handles}
7959**
7960** An instance of this object represents an open BLOB on which
7961** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7962** ^Objects of this type are created by [sqlite3_blob_open()]
7963** and destroyed by [sqlite3_blob_close()].
7964** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7965** can be used to read or write small subsections of the BLOB.
7966** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7967*/
7968typedef struct sqlite3_blob sqlite3_blob;
7969
7970/*
7971** CAPI3REF: Open A BLOB For Incremental I/O
7972** METHOD: sqlite3
7973** CONSTRUCTOR: sqlite3_blob
7974**
7975** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7976** in row iRow, column zColumn, table zTable in database zDb;
7977** in other words, the same BLOB that would be selected by:
7978**
7979** <pre>
7980** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7981** </pre>)^
7982**
7983** ^(Parameter zDb is not the filename that contains the database, but
7984** rather the symbolic name of the database. For attached databases, this is
7985** the name that appears after the AS keyword in the [ATTACH] statement.
7986** For the main database file, the database name is "main". For TEMP
7987** tables, the database name is "temp".)^
7988**
7989** ^If the flags parameter is non-zero, then the BLOB is opened for read
7990** and write access. ^If the flags parameter is zero, the BLOB is opened for
7991** read-only access.
7992**
7993** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7994** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7995** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7996** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7997** on *ppBlob after this function returns.
7998**
7999** This function fails with SQLITE_ERROR if any of the following are true:
8000** <ul>
8001** <li> ^(Database zDb does not exist)^,
8002** <li> ^(Table zTable does not exist within database zDb)^,
8003** <li> ^(Table zTable is a WITHOUT ROWID table)^,
8004** <li> ^(Column zColumn does not exist)^,
8005** <li> ^(Row iRow is not present in the table)^,
8006** <li> ^(The specified column of row iRow contains a value that is not
8007** a TEXT or BLOB value)^,
8008** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
8009** constraint and the blob is being opened for read/write access)^,
8010** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
8011** column zColumn is part of a [child key] definition and the blob is
8012** being opened for read/write access)^.
8013** </ul>
8014**
8015** ^Unless it returns SQLITE_MISUSE, this function sets the
8016** [database connection] error code and message accessible via
8017** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8018**
8019** A BLOB referenced by sqlite3_blob_open() may be read using the
8020** [sqlite3_blob_read()] interface and modified by using
8021** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
8022** different row of the same table using the [sqlite3_blob_reopen()]
8023** interface. However, the column, table, or database of a [BLOB handle]
8024** cannot be changed after the [BLOB handle] is opened.
8025**
8026** ^(If the row that a BLOB handle points to is modified by an
8027** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
8028** then the BLOB handle is marked as "expired".
8029** This is true if any column of the row is changed, even a column
8030** other than the one the BLOB handle is open on.)^
8031** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
8032** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
8033** ^(Changes written into a BLOB prior to the BLOB expiring are not
8034** rolled back by the expiration of the BLOB. Such changes will eventually
8035** commit if the transaction continues to completion.)^
8036**
8037** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
8038** the opened blob. ^The size of a blob may not be changed by this
8039** interface. Use the [UPDATE] SQL command to change the size of a
8040** blob.
8041**
8042** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
8043** and the built-in [zeroblob] SQL function may be used to create a
8044** zero-filled blob to read or write using the incremental-blob interface.
8045**
8046** To avoid a resource leak, every open [BLOB handle] should eventually
8047** be released by a call to [sqlite3_blob_close()].
8048**
8049** See also: [sqlite3_blob_close()],
8050** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
8051** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
8052*/
8053SQLITE_API int sqlite3_blob_open(
8054 sqlite3*,
8055 const char *zDb,
8056 const char *zTable,
8057 const char *zColumn,
8058 sqlite3_int64 iRow,
8059 int flags,
8060 sqlite3_blob **ppBlob
8061);
8062
8063/*
8064** CAPI3REF: Move a BLOB Handle to a New Row
8065** METHOD: sqlite3_blob
8066**
8067** ^This function is used to move an existing [BLOB handle] so that it points
8068** to a different row of the same database table. ^The new row is identified
8069** by the rowid value passed as the second argument. Only the row can be
8070** changed. ^The database, table and column on which the blob handle is open
8071** remain the same. Moving an existing [BLOB handle] to a new row is
8072** faster than closing the existing handle and opening a new one.
8073**
8074** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
8075** it must exist and there must be either a blob or text value stored in
8076** the nominated column.)^ ^If the new row is not present in the table, or if
8077** it does not contain a blob or text value, or if another error occurs, an
8078** SQLite error code is returned and the blob handle is considered aborted.
8079** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
8080** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
8081** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
8082** always returns zero.
8083**
8084** ^This function sets the database handle error code and message.
8085*/
8086SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
8087
8088/*
8089** CAPI3REF: Close A BLOB Handle
8090** DESTRUCTOR: sqlite3_blob
8091**
8092** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
8093** unconditionally. Even if this routine returns an error code, the
8094** handle is still closed.)^
8095**
8096** ^If the blob handle being closed was opened for read-write access, and if
8097** the database is in auto-commit mode and there are no other open read-write
8098** blob handles or active write statements, the current transaction is
8099** committed. ^If an error occurs while committing the transaction, an error
8100** code is returned and the transaction rolled back.
8101**
8102** Calling this function with an argument that is not a NULL pointer or an
8103** open blob handle results in undefined behavior. ^Calling this routine
8104** with a null pointer (such as would be returned by a failed call to
8105** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
8106** is passed a valid open blob handle, the values returned by the
8107** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
8108*/
8109SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
8110
8111/*
8112** CAPI3REF: Return The Size Of An Open BLOB
8113** METHOD: sqlite3_blob
8114**
8115** ^Returns the size in bytes of the BLOB accessible via the
8116** successfully opened [BLOB handle] in its only argument. ^The
8117** incremental blob I/O routines can only read or overwrite existing
8118** blob content; they cannot change the size of a blob.
8119**
8120** This routine only works on a [BLOB handle] which has been created
8121** by a prior successful call to [sqlite3_blob_open()] and which has not
8122** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8123** to this routine results in undefined and probably undesirable behavior.
8124*/
8125SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
8126
8127/*
8128** CAPI3REF: Read Data From A BLOB Incrementally
8129** METHOD: sqlite3_blob
8130**
8131** ^(This function is used to read data from an open [BLOB handle] into a
8132** caller-supplied buffer. N bytes of data are copied into buffer Z
8133** from the open BLOB, starting at offset iOffset.)^
8134**
8135** ^If offset iOffset is less than N bytes from the end of the BLOB,
8136** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
8137** less than zero, [SQLITE_ERROR] is returned and no data is read.
8138** ^The size of the blob (and hence the maximum value of N+iOffset)
8139** can be determined using the [sqlite3_blob_bytes()] interface.
8140**
8141** ^An attempt to read from an expired [BLOB handle] fails with an
8142** error code of [SQLITE_ABORT].
8143**
8144** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
8145** Otherwise, an [error code] or an [extended error code] is returned.)^
8146**
8147** This routine only works on a [BLOB handle] which has been created
8148** by a prior successful call to [sqlite3_blob_open()] and which has not
8149** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8150** to this routine results in undefined and probably undesirable behavior.
8151**
8152** See also: [sqlite3_blob_write()].
8153*/
8154SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
8155
8156/*
8157** CAPI3REF: Write Data Into A BLOB Incrementally
8158** METHOD: sqlite3_blob
8159**
8160** ^(This function is used to write data into an open [BLOB handle] from a
8161** caller-supplied buffer. N bytes of data are copied from the buffer Z
8162** into the open BLOB, starting at offset iOffset.)^
8163**
8164** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
8165** Otherwise, an [error code] or an [extended error code] is returned.)^
8166** ^Unless SQLITE_MISUSE is returned, this function sets the
8167** [database connection] error code and message accessible via
8168** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8169**
8170** ^If the [BLOB handle] passed as the first argument was not opened for
8171** writing (the flags parameter to [sqlite3_blob_open()] was zero),
8172** this function returns [SQLITE_READONLY].
8173**
8174** This function may only modify the contents of the BLOB; it is
8175** not possible to increase the size of a BLOB using this API.
8176** ^If offset iOffset is less than N bytes from the end of the BLOB,
8177** [SQLITE_ERROR] is returned and no data is written. The size of the
8178** BLOB (and hence the maximum value of N+iOffset) can be determined
8179** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
8180** than zero [SQLITE_ERROR] is returned and no data is written.
8181**
8182** ^An attempt to write to an expired [BLOB handle] fails with an
8183** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
8184** before the [BLOB handle] expired are not rolled back by the
8185** expiration of the handle, though of course those changes might
8186** have been overwritten by the statement that expired the BLOB handle
8187** or by other independent statements.
8188**
8189** This routine only works on a [BLOB handle] which has been created
8190** by a prior successful call to [sqlite3_blob_open()] and which has not
8191** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8192** to this routine results in undefined and probably undesirable behavior.
8193**
8194** See also: [sqlite3_blob_read()].
8195*/
8196SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
8197
8198/*
8199** CAPI3REF: Virtual File System Objects
8200**
8201** A virtual filesystem (VFS) is an [sqlite3_vfs] object
8202** that SQLite uses to interact
8203** with the underlying operating system. Most SQLite builds come with a
8204** single default VFS that is appropriate for the host computer.
8205** New VFSes can be registered and existing VFSes can be unregistered.
8206** The following interfaces are provided.
8207**
8208** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
8209** ^Names are case sensitive.
8210** ^Names are zero-terminated UTF-8 strings.
8211** ^If there is no match, a NULL pointer is returned.
8212** ^If zVfsName is NULL then the default VFS is returned.
8213**
8214** ^New VFSes are registered with sqlite3_vfs_register().
8215** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
8216** ^The same VFS can be registered multiple times without injury.
8217** ^To make an existing VFS into the default VFS, register it again
8218** with the makeDflt flag set. If two different VFSes with the
8219** same name are registered, the behavior is undefined. If a
8220** VFS is registered with a name that is NULL or an empty string,
8221** then the behavior is undefined.
8222**
8223** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
8224** ^(If the default VFS is unregistered, another VFS is chosen as
8225** the default. The choice for the new VFS is arbitrary.)^
8226*/
8227SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
8228SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
8229SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
8230
8231/*
8232** CAPI3REF: Mutexes
8233**
8234** The SQLite core uses these routines for thread
8235** synchronization. Though they are intended for internal
8236** use by SQLite, code that links against SQLite is
8237** permitted to use any of these routines.
8238**
8239** The SQLite source code contains multiple implementations
8240** of these mutex routines. An appropriate implementation
8241** is selected automatically at compile-time. The following
8242** implementations are available in the SQLite core:
8243**
8244** <ul>
8245** <li> SQLITE_MUTEX_PTHREADS
8246** <li> SQLITE_MUTEX_W32
8247** <li> SQLITE_MUTEX_NOOP
8248** </ul>
8249**
8250** The SQLITE_MUTEX_NOOP implementation is a set of routines
8251** that does no real locking and is appropriate for use in
8252** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
8253** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
8254** and Windows.
8255**
8256** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
8257** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
8258** implementation is included with the library. In this case the
8259** application must supply a custom mutex implementation using the
8260** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
8261** before calling sqlite3_initialize() or any other public sqlite3_
8262** function that calls sqlite3_initialize().
8263**
8264** ^The sqlite3_mutex_alloc() routine allocates a new
8265** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8266** routine returns NULL if it is unable to allocate the requested
8267** mutex. The argument to sqlite3_mutex_alloc() must be one of these
8268** integer constants:
8269**
8270** <ul>
8271** <li> SQLITE_MUTEX_FAST
8272** <li> SQLITE_MUTEX_RECURSIVE
8273** <li> SQLITE_MUTEX_STATIC_MAIN
8274** <li> SQLITE_MUTEX_STATIC_MEM
8275** <li> SQLITE_MUTEX_STATIC_OPEN
8276** <li> SQLITE_MUTEX_STATIC_PRNG
8277** <li> SQLITE_MUTEX_STATIC_LRU
8278** <li> SQLITE_MUTEX_STATIC_PMEM
8279** <li> SQLITE_MUTEX_STATIC_APP1
8280** <li> SQLITE_MUTEX_STATIC_APP2
8281** <li> SQLITE_MUTEX_STATIC_APP3
8282** <li> SQLITE_MUTEX_STATIC_VFS1
8283** <li> SQLITE_MUTEX_STATIC_VFS2
8284** <li> SQLITE_MUTEX_STATIC_VFS3
8285** </ul>
8286**
8287** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8288** cause sqlite3_mutex_alloc() to create
8289** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8290** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8291** The mutex implementation does not need to make a distinction
8292** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8293** not want to. SQLite will only request a recursive mutex in
8294** cases where it really needs one. If a faster non-recursive mutex
8295** implementation is available on the host platform, the mutex subsystem
8296** might return such a mutex in response to SQLITE_MUTEX_FAST.
8297**
8298** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8299** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8300** a pointer to a static preexisting mutex. ^Nine static mutexes are
8301** used by the current version of SQLite. Future versions of SQLite
8302** may add additional static mutexes. Static mutexes are for internal
8303** use by SQLite only. Applications that use SQLite mutexes should
8304** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8305** SQLITE_MUTEX_RECURSIVE.
8306**
8307** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8308** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8309** returns a different mutex on every call. ^For the static
8310** mutex types, the same mutex is returned on every call that has
8311** the same type number.
8312**
8313** ^The sqlite3_mutex_free() routine deallocates a previously
8314** allocated dynamic mutex. Attempting to deallocate a static
8315** mutex results in undefined behavior.
8316**
8317** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8318** to enter a mutex. ^If another thread is already within the mutex,
8319** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8320** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8321** upon successful entry. ^(Mutexes created using
8322** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8323** In such cases, the
8324** mutex must be exited an equal number of times before another thread
8325** can enter.)^ If the same thread tries to enter any mutex other
8326** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8327**
8328** ^(Some systems (for example, Windows 95) do not support the operation
8329** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8330** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8331** sqlite3_mutex_try() as an optimization, so this is acceptable
8332** behavior. The exceptions are unix builds that set the
8333** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8334** sqlite3_mutex_try() is required.)^
8335**
8336** ^The sqlite3_mutex_leave() routine exits a mutex that was
8337** previously entered by the same thread. The behavior
8338** is undefined if the mutex is not currently entered by the
8339** calling thread or is not currently allocated.
8340**
8341** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8342** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8343** then any of the four routines behaves as a no-op.
8344**
8345** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8346*/
8347SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8348SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8349SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8350SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8351SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8352
8353/*
8354** CAPI3REF: Mutex Methods Object
8355**
8356** An instance of this structure defines the low-level routines
8357** used to allocate and use mutexes.
8358**
8359** Usually, the default mutex implementations provided by SQLite are
8360** sufficient, however the application has the option of substituting a custom
8361** implementation for specialized deployments or systems for which SQLite
8362** does not provide a suitable implementation. In this case, the application
8363** creates and populates an instance of this structure to pass
8364** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8365** Additionally, an instance of this structure can be used as an
8366** output variable when querying the system for the current mutex
8367** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8368**
8369** ^The xMutexInit method defined by this structure is invoked as
8370** part of system initialization by the sqlite3_initialize() function.
8371** ^The xMutexInit routine is called by SQLite exactly once for each
8372** effective call to [sqlite3_initialize()].
8373**
8374** ^The xMutexEnd method defined by this structure is invoked as
8375** part of system shutdown by the sqlite3_shutdown() function. The
8376** implementation of this method is expected to release all outstanding
8377** resources obtained by the mutex methods implementation, especially
8378** those obtained by the xMutexInit method. ^The xMutexEnd()
8379** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8380**
8381** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8382** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8383** xMutexNotheld) implement the following interfaces (respectively):
8384**
8385** <ul>
8386** <li> [sqlite3_mutex_alloc()] </li>
8387** <li> [sqlite3_mutex_free()] </li>
8388** <li> [sqlite3_mutex_enter()] </li>
8389** <li> [sqlite3_mutex_try()] </li>
8390** <li> [sqlite3_mutex_leave()] </li>
8391** <li> [sqlite3_mutex_held()] </li>
8392** <li> [sqlite3_mutex_notheld()] </li>
8393** </ul>)^
8394**
8395** The only difference is that the public sqlite3_XXX functions enumerated
8396** above silently ignore any invocations that pass a NULL pointer instead
8397** of a valid mutex handle. The implementations of the methods defined
8398** by this structure are not required to handle this case. The results
8399** of passing a NULL pointer instead of a valid mutex handle are undefined
8400** (i.e. it is acceptable to provide an implementation that segfaults if
8401** it is passed a NULL pointer).
8402**
8403** The xMutexInit() method must be threadsafe. It must be harmless to
8404** invoke xMutexInit() multiple times within the same process and without
8405** intervening calls to xMutexEnd(). Second and subsequent calls to
8406** xMutexInit() must be no-ops.
8407**
8408** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8409** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8410** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8411** memory allocation for a fast or recursive mutex.
8412**
8413** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8414** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8415** If xMutexInit fails in any way, it is expected to clean up after itself
8416** prior to returning.
8417*/
8418typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8419struct sqlite3_mutex_methods {
8420 int (*xMutexInit)(void);
8421 int (*xMutexEnd)(void);
8422 sqlite3_mutex *(*xMutexAlloc)(int);
8423 void (*xMutexFree)(sqlite3_mutex *);
8424 void (*xMutexEnter)(sqlite3_mutex *);
8425 int (*xMutexTry)(sqlite3_mutex *);
8426 void (*xMutexLeave)(sqlite3_mutex *);
8427 int (*xMutexHeld)(sqlite3_mutex *);
8428 int (*xMutexNotheld)(sqlite3_mutex *);
8429};
8430
8431/*
8432** CAPI3REF: Mutex Verification Routines
8433**
8434** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8435** are intended for use inside assert() statements. The SQLite core
8436** never uses these routines except inside an assert() and applications
8437** are advised to follow the lead of the core. The SQLite core only
8438** provides implementations for these routines when it is compiled
8439** with the SQLITE_DEBUG flag. External mutex implementations
8440** are only required to provide these routines if SQLITE_DEBUG is
8441** defined and if NDEBUG is not defined.
8442**
8443** These routines should return true if the mutex in their argument
8444** is held or not held, respectively, by the calling thread.
8445**
8446** The implementation is not required to provide versions of these
8447** routines that actually work. If the implementation does not provide working
8448** versions of these routines, it should at least provide stubs that always
8449** return true so that one does not get spurious assertion failures.
8450**
8451** If the argument to sqlite3_mutex_held() is a NULL pointer then
8452** the routine should return 1. This seems counter-intuitive since
8453** clearly the mutex cannot be held if it does not exist. But
8454** the reason the mutex does not exist is because the build is not
8455** using mutexes. And we do not want the assert() containing the
8456** call to sqlite3_mutex_held() to fail, so a non-zero return is
8457** the appropriate thing to do. The sqlite3_mutex_notheld()
8458** interface should also return 1 when given a NULL pointer.
8459*/
8460#ifndef NDEBUG
8461SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8462SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8463#endif
8464
8465/*
8466** CAPI3REF: Mutex Types
8467**
8468** The [sqlite3_mutex_alloc()] interface takes a single argument
8469** which is one of these integer constants.
8470**
8471** The set of static mutexes may change from one SQLite release to the
8472** next. Applications that override the built-in mutex logic must be
8473** prepared to accommodate additional static mutexes.
8474*/
8475#define SQLITE_MUTEX_FAST 0
8476#define SQLITE_MUTEX_RECURSIVE 1
8477#define SQLITE_MUTEX_STATIC_MAIN 2
8478#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8479#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8480#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8481#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8482#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8483#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8484#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8485#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8486#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8487#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8488#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8489#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8490#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8491
8492/* Legacy compatibility: */
8493#define SQLITE_MUTEX_STATIC_MASTER 2
8494
8495
8496/*
8497** CAPI3REF: Retrieve the mutex for a database connection
8498** METHOD: sqlite3
8499**
8500** ^This interface returns a pointer to the [sqlite3_mutex] object that
8501** serializes access to the [database connection] given in the argument
8502** when the [threading mode] is Serialized.
8503** ^If the [threading mode] is Single-thread or Multi-thread then this
8504** routine returns a NULL pointer.
8505*/
8506SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8507
8508/*
8509** CAPI3REF: Low-Level Control Of Database Files
8510** METHOD: sqlite3
8511** KEYWORDS: {file control}
8512**
8513** ^The [sqlite3_file_control()] interface makes a direct call to the
8514** xFileControl method for the [sqlite3_io_methods] object associated
8515** with a particular database identified by the second argument. ^The
8516** name of the database is "main" for the main database or "temp" for the
8517** TEMP database, or the name that appears after the AS keyword for
8518** databases that are added using the [ATTACH] SQL command.
8519** ^A NULL pointer can be used in place of "main" to refer to the
8520** main database file.
8521** ^The third and fourth parameters to this routine
8522** are passed directly through to the second and third parameters of
8523** the xFileControl method. ^The return value of the xFileControl
8524** method becomes the return value of this routine.
8525**
8526** A few opcodes for [sqlite3_file_control()] are handled directly
8527** by the SQLite core and never invoke the
8528** sqlite3_io_methods.xFileControl method.
8529** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8530** a pointer to the underlying [sqlite3_file] object to be written into
8531** the space pointed to by the 4th parameter. The
8532** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8533** the [sqlite3_file] object associated with the journal file instead of
8534** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8535** a pointer to the underlying [sqlite3_vfs] object for the file.
8536** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8537** from the pager.
8538**
8539** ^If the second parameter (zDbName) does not match the name of any
8540** open database file, then SQLITE_ERROR is returned. ^This error
8541** code is not remembered and will not be recalled by [sqlite3_errcode()]
8542** or [sqlite3_errmsg()]. The underlying xFileControl method might
8543** also return SQLITE_ERROR. There is no way to distinguish between
8544** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8545** xFileControl method.
8546**
8547** See also: [file control opcodes]
8548*/
8549SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8550
8551/*
8552** CAPI3REF: Testing Interface
8553**
8554** ^The sqlite3_test_control() interface is used to read out internal
8555** state of SQLite and to inject faults into SQLite for testing
8556** purposes. ^The first parameter is an operation code that determines
8557** the number, meaning, and operation of all subsequent parameters.
8558**
8559** This interface is not for use by applications. It exists solely
8560** for verifying the correct operation of the SQLite library. Depending
8561** on how the SQLite library is compiled, this interface might not exist.
8562**
8563** The details of the operation codes, their meanings, the parameters
8564** they take, and what they do are all subject to change without notice.
8565** Unlike most of the SQLite API, this function is not guaranteed to
8566** operate consistently from one release to the next.
8567*/
8568SQLITE_API int sqlite3_test_control(int op, ...);
8569
8570/*
8571** CAPI3REF: Testing Interface Operation Codes
8572**
8573** These constants are the valid operation code parameters used
8574** as the first argument to [sqlite3_test_control()].
8575**
8576** These parameters and their meanings are subject to change
8577** without notice. These values are for testing purposes only.
8578** Applications should not use any of these parameters or the
8579** [sqlite3_test_control()] interface.
8580*/
8581#define SQLITE_TESTCTRL_FIRST 5
8582#define SQLITE_TESTCTRL_PRNG_SAVE 5
8583#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8584#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8585#define SQLITE_TESTCTRL_FK_NO_ACTION 7
8586#define SQLITE_TESTCTRL_BITVEC_TEST 8
8587#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8588#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8589#define SQLITE_TESTCTRL_PENDING_BYTE 11
8590#define SQLITE_TESTCTRL_ASSERT 12
8591#define SQLITE_TESTCTRL_ALWAYS 13
8592#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8593#define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8594#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8595#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8596#define SQLITE_TESTCTRL_GETOPT 16
8597#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8598#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8599#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8600#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8601#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8602#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8603#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8604#define SQLITE_TESTCTRL_BYTEORDER 22
8605#define SQLITE_TESTCTRL_ISINIT 23
8606#define SQLITE_TESTCTRL_SORTER_MMAP 24
8607#define SQLITE_TESTCTRL_IMPOSTER 25
8608#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8609#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8610#define SQLITE_TESTCTRL_PRNG_SEED 28
8611#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8612#define SQLITE_TESTCTRL_SEEK_COUNT 30
8613#define SQLITE_TESTCTRL_TRACEFLAGS 31
8614#define SQLITE_TESTCTRL_TUNE 32
8615#define SQLITE_TESTCTRL_LOGEST 33
8616#define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */
8617#define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8618
8619/*
8620** CAPI3REF: SQL Keyword Checking
8621**
8622** These routines provide access to the set of SQL language keywords
8623** recognized by SQLite. Applications can use these routines to determine
8624** whether or not a specific identifier needs to be escaped (for example,
8625** by enclosing in double-quotes) so as not to confuse the parser.
8626**
8627** The sqlite3_keyword_count() interface returns the number of distinct
8628** keywords understood by SQLite.
8629**
8630** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8631** makes *Z point to that keyword expressed as UTF8 and writes the number
8632** of bytes in the keyword into *L. The string that *Z points to is not
8633** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8634** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8635** or L are NULL or invalid pointers then calls to
8636** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8637**
8638** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8639** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8640** if it is and zero if not.
8641**
8642** The parser used by SQLite is forgiving. It is often possible to use
8643** a keyword as an identifier as long as such use does not result in a
8644** parsing ambiguity. For example, the statement
8645** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8646** creates a new table named "BEGIN" with three columns named
8647** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8648** using keywords as identifiers. Common techniques used to avoid keyword
8649** name collisions include:
8650** <ul>
8651** <li> Put all identifier names inside double-quotes. This is the official
8652** SQL way to escape identifier names.
8653** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8654** but it is what SQL Server does and so lots of programmers use this
8655** technique.
8656** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8657** with "Z".
8658** <li> Include a digit somewhere in every identifier name.
8659** </ul>
8660**
8661** Note that the number of keywords understood by SQLite can depend on
8662** compile-time options. For example, "VACUUM" is not a keyword if
8663** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8664** new keywords may be added to future releases of SQLite.
8665*/
8666SQLITE_API int sqlite3_keyword_count(void);
8667SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8668SQLITE_API int sqlite3_keyword_check(const char*,int);
8669
8670/*
8671** CAPI3REF: Dynamic String Object
8672** KEYWORDS: {dynamic string}
8673**
8674** An instance of the sqlite3_str object contains a dynamically-sized
8675** string under construction.
8676**
8677** The lifecycle of an sqlite3_str object is as follows:
8678** <ol>
8679** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8680** <li> ^Text is appended to the sqlite3_str object using various
8681** methods, such as [sqlite3_str_appendf()].
8682** <li> ^The sqlite3_str object is destroyed and the string it created
8683** is returned using the [sqlite3_str_finish()] interface.
8684** </ol>
8685*/
8686typedef struct sqlite3_str sqlite3_str;
8687
8688/*
8689** CAPI3REF: Create A New Dynamic String Object
8690** CONSTRUCTOR: sqlite3_str
8691**
8692** ^The [sqlite3_str_new(D)] interface allocates and initializes
8693** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8694** [sqlite3_str_new()] must be freed by a subsequent call to
8695** [sqlite3_str_finish(X)].
8696**
8697** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8698** valid [sqlite3_str] object, though in the event of an out-of-memory
8699** error the returned object might be a special singleton that will
8700** silently reject new text, always return SQLITE_NOMEM from
8701** [sqlite3_str_errcode()], always return 0 for
8702** [sqlite3_str_length()], and always return NULL from
8703** [sqlite3_str_finish(X)]. It is always safe to use the value
8704** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8705** to any of the other [sqlite3_str] methods.
8706**
8707** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8708** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8709** length of the string contained in the [sqlite3_str] object will be
8710** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8711** of [SQLITE_MAX_LENGTH].
8712*/
8713SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8714
8715/*
8716** CAPI3REF: Finalize A Dynamic String
8717** DESTRUCTOR: sqlite3_str
8718**
8719** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8720** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8721** that contains the constructed string. The calling application should
8722** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8723** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8724** errors were encountered during construction of the string. ^The
8725** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8726** string in [sqlite3_str] object X is zero bytes long.
8727*/
8728SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8729
8730/*
8731** CAPI3REF: Add Content To A Dynamic String
8732** METHOD: sqlite3_str
8733**
8734** These interfaces add content to an sqlite3_str object previously obtained
8735** from [sqlite3_str_new()].
8736**
8737** ^The [sqlite3_str_appendf(X,F,...)] and
8738** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8739** functionality of SQLite to append formatted text onto the end of
8740** [sqlite3_str] object X.
8741**
8742** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8743** onto the end of the [sqlite3_str] object X. N must be non-negative.
8744** S must contain at least N non-zero bytes of content. To append a
8745** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8746** method instead.
8747**
8748** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8749** zero-terminated string S onto the end of [sqlite3_str] object X.
8750**
8751** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8752** single-byte character C onto the end of [sqlite3_str] object X.
8753** ^This method can be used, for example, to add whitespace indentation.
8754**
8755** ^The [sqlite3_str_reset(X)] method resets the string under construction
8756** inside [sqlite3_str] object X back to zero bytes in length.
8757**
8758** These methods do not return a result code. ^If an error occurs, that fact
8759** is recorded in the [sqlite3_str] object and can be recovered by a
8760** subsequent call to [sqlite3_str_errcode(X)].
8761*/
8762SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8763SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8764SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8765SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8766SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8767SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8768
8769/*
8770** CAPI3REF: Status Of A Dynamic String
8771** METHOD: sqlite3_str
8772**
8773** These interfaces return the current status of an [sqlite3_str] object.
8774**
8775** ^If any prior errors have occurred while constructing the dynamic string
8776** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8777** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8778** [SQLITE_NOMEM] following any out-of-memory error, or
8779** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8780** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8781**
8782** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8783** of the dynamic string under construction in [sqlite3_str] object X.
8784** ^The length returned by [sqlite3_str_length(X)] does not include the
8785** zero-termination byte.
8786**
8787** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8788** content of the dynamic string under construction in X. The value
8789** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8790** and might be freed or altered by any subsequent method on the same
8791** [sqlite3_str] object. Applications must not use the pointer returned by
8792** [sqlite3_str_value(X)] after any subsequent method call on the same
8793** object. ^Applications may change the content of the string returned
8794** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8795** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8796** write any byte after any subsequent sqlite3_str method call.
8797*/
8798SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8799SQLITE_API int sqlite3_str_length(sqlite3_str*);
8800SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8801
8802/*
8803** CAPI3REF: SQLite Runtime Status
8804**
8805** ^These interfaces are used to retrieve runtime status information
8806** about the performance of SQLite, and optionally to reset various
8807** highwater marks. ^The first argument is an integer code for
8808** the specific parameter to measure. ^(Recognized integer codes
8809** are of the form [status parameters | SQLITE_STATUS_...].)^
8810** ^The current value of the parameter is returned into *pCurrent.
8811** ^The highest recorded value is returned in *pHighwater. ^If the
8812** resetFlag is true, then the highest record value is reset after
8813** *pHighwater is written. ^(Some parameters do not record the highest
8814** value. For those parameters
8815** nothing is written into *pHighwater and the resetFlag is ignored.)^
8816** ^(Other parameters record only the highwater mark and not the current
8817** value. For these latter parameters nothing is written into *pCurrent.)^
8818**
8819** ^The sqlite3_status() and sqlite3_status64() routines return
8820** SQLITE_OK on success and a non-zero [error code] on failure.
8821**
8822** If either the current value or the highwater mark is too large to
8823** be represented by a 32-bit integer, then the values returned by
8824** sqlite3_status() are undefined.
8825**
8826** See also: [sqlite3_db_status()]
8827*/
8828SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8829SQLITE_API int sqlite3_status64(
8830 int op,
8831 sqlite3_int64 *pCurrent,
8832 sqlite3_int64 *pHighwater,
8833 int resetFlag
8834);
8835
8836
8837/*
8838** CAPI3REF: Status Parameters
8839** KEYWORDS: {status parameters}
8840**
8841** These integer constants designate various run-time status parameters
8842** that can be returned by [sqlite3_status()].
8843**
8844** <dl>
8845** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8846** <dd>This parameter is the current amount of memory checked out
8847** using [sqlite3_malloc()], either directly or indirectly. The
8848** figure includes calls made to [sqlite3_malloc()] by the application
8849** and internal memory usage by the SQLite library. Auxiliary page-cache
8850** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8851** this parameter. The amount returned is the sum of the allocation
8852** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8853**
8854** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8855** <dd>This parameter records the largest memory allocation request
8856** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8857** internal equivalents). Only the value returned in the
8858** *pHighwater parameter to [sqlite3_status()] is of interest.
8859** The value written into the *pCurrent parameter is undefined.</dd>)^
8860**
8861** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8862** <dd>This parameter records the number of separate memory allocations
8863** currently checked out.</dd>)^
8864**
8865** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8866** <dd>This parameter returns the number of pages used out of the
8867** [pagecache memory allocator] that was configured using
8868** [SQLITE_CONFIG_PAGECACHE]. The
8869** value returned is in pages, not in bytes.</dd>)^
8870**
8871** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8872** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8873** <dd>This parameter returns the number of bytes of page cache
8874** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8875** buffer and where forced to overflow to [sqlite3_malloc()]. The
8876** returned value includes allocations that overflowed because they
8877** were too large (they were larger than the "sz" parameter to
8878** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8879** no space was left in the page cache.</dd>)^
8880**
8881** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8882** <dd>This parameter records the largest memory allocation request
8883** handed to the [pagecache memory allocator]. Only the value returned in the
8884** *pHighwater parameter to [sqlite3_status()] is of interest.
8885** The value written into the *pCurrent parameter is undefined.</dd>)^
8886**
8887** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8888** <dd>No longer used.</dd>
8889**
8890** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8891** <dd>No longer used.</dd>
8892**
8893** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8894** <dd>No longer used.</dd>
8895**
8896** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8897** <dd>The *pHighwater parameter records the deepest parser stack.
8898** The *pCurrent value is undefined. The *pHighwater value is only
8899** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8900** </dl>
8901**
8902** New status parameters may be added from time to time.
8903*/
8904#define SQLITE_STATUS_MEMORY_USED 0
8905#define SQLITE_STATUS_PAGECACHE_USED 1
8906#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8907#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8908#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8909#define SQLITE_STATUS_MALLOC_SIZE 5
8910#define SQLITE_STATUS_PARSER_STACK 6
8911#define SQLITE_STATUS_PAGECACHE_SIZE 7
8912#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8913#define SQLITE_STATUS_MALLOC_COUNT 9
8914
8915/*
8916** CAPI3REF: Database Connection Status
8917** METHOD: sqlite3
8918**
8919** ^This interface is used to retrieve runtime status information
8920** about a single [database connection]. ^The first argument is the
8921** database connection object to be interrogated. ^The second argument
8922** is an integer constant, taken from the set of
8923** [SQLITE_DBSTATUS options], that
8924** determines the parameter to interrogate. The set of
8925** [SQLITE_DBSTATUS options] is likely
8926** to grow in future releases of SQLite.
8927**
8928** ^The current value of the requested parameter is written into *pCur
8929** and the highest instantaneous value is written into *pHiwtr. ^If
8930** the resetFlg is true, then the highest instantaneous value is
8931** reset back down to the current value.
8932**
8933** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8934** non-zero [error code] on failure.
8935**
8936** ^The sqlite3_db_status64(D,O,C,H,R) routine works exactly the same
8937** way as sqlite3_db_status(D,O,C,H,R) routine except that the C and H
8938** parameters are pointer to 64-bit integers (type: sqlite3_int64) instead
8939** of pointers to 32-bit integers, which allows larger status values
8940** to be returned. If a status value exceeds 2,147,483,647 then
8941** sqlite3_db_status() will truncate the value whereas sqlite3_db_status64()
8942** will return the full value.
8943**
8944** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8945*/
8946SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8947SQLITE_API int sqlite3_db_status64(sqlite3*,int,sqlite3_int64*,sqlite3_int64*,int);
8948
8949/*
8950** CAPI3REF: Status Parameters for database connections
8951** KEYWORDS: {SQLITE_DBSTATUS options}
8952**
8953** These constants are the available integer "verbs" that can be passed as
8954** the second argument to the [sqlite3_db_status()] interface.
8955**
8956** New verbs may be added in future releases of SQLite. Existing verbs
8957** might be discontinued. Applications should check the return code from
8958** [sqlite3_db_status()] to make sure that the call worked.
8959** The [sqlite3_db_status()] interface will return a non-zero error code
8960** if a discontinued or unsupported verb is invoked.
8961**
8962** <dl>
8963** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8964** <dd>This parameter returns the number of lookaside memory slots currently
8965** checked out.</dd>)^
8966**
8967** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8968** <dd>This parameter returns the number of malloc attempts that were
8969** satisfied using lookaside memory. Only the high-water value is meaningful;
8970** the current value is always zero.</dd>)^
8971**
8972** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8973** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8974** <dd>This parameter returns the number of malloc attempts that might have
8975** been satisfied using lookaside memory but failed due to the amount of
8976** memory requested being larger than the lookaside slot size.
8977** Only the high-water value is meaningful;
8978** the current value is always zero.</dd>)^
8979**
8980** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8981** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8982** <dd>This parameter returns the number of malloc attempts that might have
8983** been satisfied using lookaside memory but failed due to all lookaside
8984** memory already being in use.
8985** Only the high-water value is meaningful;
8986** the current value is always zero.</dd>)^
8987**
8988** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8989** <dd>This parameter returns the approximate number of bytes of heap
8990** memory used by all pager caches associated with the database connection.)^
8991** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8992** </dd>
8993**
8994** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8995** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8996** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8997** pager cache is shared between two or more connections the bytes of heap
8998** memory used by that pager cache is divided evenly between the attached
8999** connections.)^ In other words, if none of the pager caches associated
9000** with the database connection are shared, this request returns the same
9001** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
9002** shared, the value returned by this call will be smaller than that returned
9003** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
9004** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
9005**
9006** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
9007** <dd>This parameter returns the approximate number of bytes of heap
9008** memory used to store the schema for all databases associated
9009** with the connection - main, temp, and any [ATTACH]-ed databases.)^
9010** ^The full amount of memory used by the schemas is reported, even if the
9011** schema memory is shared with other database connections due to
9012** [shared cache mode] being enabled.
9013** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
9014** </dd>
9015**
9016** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
9017** <dd>This parameter returns the approximate number of bytes of heap
9018** and lookaside memory used by all prepared statements associated with
9019** the database connection.)^
9020** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
9021** </dd>
9022**
9023** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
9024** <dd>This parameter returns the number of pager cache hits that have
9025** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
9026** is always 0.
9027** </dd>
9028**
9029** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
9030** <dd>This parameter returns the number of pager cache misses that have
9031** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
9032** is always 0.
9033** </dd>
9034**
9035** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
9036** <dd>This parameter returns the number of dirty cache entries that have
9037** been written to disk. Specifically, the number of pages written to the
9038** wal file in wal mode databases, or the number of pages written to the
9039** database file in rollback mode databases. Any pages written as part of
9040** transaction rollback or database recovery operations are not included.
9041** If an IO or other error occurs while writing a page to disk, the effect
9042** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
9043** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
9044** <p>
9045** ^(There is overlap between the quantities measured by this parameter
9046** (SQLITE_DBSTATUS_CACHE_WRITE) and SQLITE_DBSTATUS_TEMPBUF_SPILL.
9047** Resetting one will reduce the other.)^
9048** </dd>
9049**
9050** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
9051** <dd>This parameter returns the number of dirty cache entries that have
9052** been written to disk in the middle of a transaction due to the page
9053** cache overflowing. Transactions are more efficient if they are written
9054** to disk all at once. When pages spill mid-transaction, that introduces
9055** additional overhead. This parameter can be used to help identify
9056** inefficiencies that can be resolved by increasing the cache size.
9057** </dd>
9058**
9059** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
9060** <dd>This parameter returns zero for the current value if and only if
9061** all foreign key constraints (deferred or immediate) have been
9062** resolved.)^ ^The highwater mark is always 0.
9063**
9064** [[SQLITE_DBSTATUS_TEMPBUF_SPILL] ^(<dt>SQLITE_DBSTATUS_TEMPBUF_SPILL</dt>
9065** <dd>^(This parameter returns the number of bytes written to temporary
9066** files on disk that could have been kept in memory had sufficient memory
9067** been available. This value includes writes to intermediate tables that
9068** are part of complex queries, external sorts that spill to disk, and
9069** writes to TEMP tables.)^
9070** ^The highwater mark is always 0.
9071** <p>
9072** ^(There is overlap between the quantities measured by this parameter
9073** (SQLITE_DBSTATUS_TEMPBUF_SPILL) and SQLITE_DBSTATUS_CACHE_WRITE.
9074** Resetting one will reduce the other.)^
9075** </dd>
9076** </dl>
9077*/
9078#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
9079#define SQLITE_DBSTATUS_CACHE_USED 1
9080#define SQLITE_DBSTATUS_SCHEMA_USED 2
9081#define SQLITE_DBSTATUS_STMT_USED 3
9082#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
9083#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
9084#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
9085#define SQLITE_DBSTATUS_CACHE_HIT 7
9086#define SQLITE_DBSTATUS_CACHE_MISS 8
9087#define SQLITE_DBSTATUS_CACHE_WRITE 9
9088#define SQLITE_DBSTATUS_DEFERRED_FKS 10
9089#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
9090#define SQLITE_DBSTATUS_CACHE_SPILL 12
9091#define SQLITE_DBSTATUS_TEMPBUF_SPILL 13
9092#define SQLITE_DBSTATUS_MAX 13 /* Largest defined DBSTATUS */
9093
9094
9095/*
9096** CAPI3REF: Prepared Statement Status
9097** METHOD: sqlite3_stmt
9098**
9099** ^(Each prepared statement maintains various
9100** [SQLITE_STMTSTATUS counters] that measure the number
9101** of times it has performed specific operations.)^ These counters can
9102** be used to monitor the performance characteristics of the prepared
9103** statements. For example, if the number of table steps greatly exceeds
9104** the number of table searches or result rows, that would tend to indicate
9105** that the prepared statement is using a full table scan rather than
9106** an index.
9107**
9108** ^(This interface is used to retrieve and reset counter values from
9109** a [prepared statement]. The first argument is the prepared statement
9110** object to be interrogated. The second argument
9111** is an integer code for a specific [SQLITE_STMTSTATUS counter]
9112** to be interrogated.)^
9113** ^The current value of the requested counter is returned.
9114** ^If the resetFlg is true, then the counter is reset to zero after this
9115** interface call returns.
9116**
9117** See also: [sqlite3_status()] and [sqlite3_db_status()].
9118*/
9119SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
9120
9121/*
9122** CAPI3REF: Status Parameters for prepared statements
9123** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
9124**
9125** These preprocessor macros define integer codes that name counter
9126** values associated with the [sqlite3_stmt_status()] interface.
9127** The meanings of the various counters are as follows:
9128**
9129** <dl>
9130** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
9131** <dd>^This is the number of times that SQLite has stepped forward in
9132** a table as part of a full table scan. Large numbers for this counter
9133** may indicate opportunities for performance improvement through
9134** careful use of indices.</dd>
9135**
9136** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
9137** <dd>^This is the number of sort operations that have occurred.
9138** A non-zero value in this counter may indicate an opportunity to
9139** improve performance through careful use of indices.</dd>
9140**
9141** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
9142** <dd>^This is the number of rows inserted into transient indices that
9143** were created automatically in order to help joins run faster.
9144** A non-zero value in this counter may indicate an opportunity to
9145** improve performance by adding permanent indices that do not
9146** need to be reinitialized each time the statement is run.</dd>
9147**
9148** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
9149** <dd>^This is the number of virtual machine operations executed
9150** by the prepared statement if that number is less than or equal
9151** to 2147483647. The number of virtual machine operations can be
9152** used as a proxy for the total work done by the prepared statement.
9153** If the number of virtual machine operations exceeds 2147483647
9154** then the value returned by this statement status code is undefined.</dd>
9155**
9156** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
9157** <dd>^This is the number of times that the prepare statement has been
9158** automatically regenerated due to schema changes or changes to
9159** [bound parameters] that might affect the query plan.</dd>
9160**
9161** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
9162** <dd>^This is the number of times that the prepared statement has
9163** been run. A single "run" for the purposes of this counter is one
9164** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
9165** The counter is incremented on the first [sqlite3_step()] call of each
9166** cycle.</dd>
9167**
9168** [[SQLITE_STMTSTATUS_FILTER_MISS]]
9169** [[SQLITE_STMTSTATUS_FILTER HIT]]
9170** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
9171** SQLITE_STMTSTATUS_FILTER_MISS</dt>
9172** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
9173** step was bypassed because a Bloom filter returned not-found. The
9174** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
9175** times that the Bloom filter returned a find, and thus the join step
9176** had to be processed as normal.</dd>
9177**
9178** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
9179** <dd>^This is the approximate number of bytes of heap memory
9180** used to store the prepared statement. ^This value is not actually
9181** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
9182** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
9183** </dd>
9184** </dl>
9185*/
9186#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
9187#define SQLITE_STMTSTATUS_SORT 2
9188#define SQLITE_STMTSTATUS_AUTOINDEX 3
9189#define SQLITE_STMTSTATUS_VM_STEP 4
9190#define SQLITE_STMTSTATUS_REPREPARE 5
9191#define SQLITE_STMTSTATUS_RUN 6
9192#define SQLITE_STMTSTATUS_FILTER_MISS 7
9193#define SQLITE_STMTSTATUS_FILTER_HIT 8
9194#define SQLITE_STMTSTATUS_MEMUSED 99
9195
9196/*
9197** CAPI3REF: Custom Page Cache Object
9198**
9199** The sqlite3_pcache type is opaque. It is implemented by
9200** the pluggable module. The SQLite core has no knowledge of
9201** its size or internal structure and never deals with the
9202** sqlite3_pcache object except by holding and passing pointers
9203** to the object.
9204**
9205** See [sqlite3_pcache_methods2] for additional information.
9206*/
9207typedef struct sqlite3_pcache sqlite3_pcache;
9208
9209/*
9210** CAPI3REF: Custom Page Cache Object
9211**
9212** The sqlite3_pcache_page object represents a single page in the
9213** page cache. The page cache will allocate instances of this
9214** object. Various methods of the page cache use pointers to instances
9215** of this object as parameters or as their return value.
9216**
9217** See [sqlite3_pcache_methods2] for additional information.
9218*/
9219typedef struct sqlite3_pcache_page sqlite3_pcache_page;
9220struct sqlite3_pcache_page {
9221 void *pBuf; /* The content of the page */
9222 void *pExtra; /* Extra information associated with the page */
9223};
9224
9225/*
9226** CAPI3REF: Application Defined Page Cache.
9227** KEYWORDS: {page cache}
9228**
9229** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
9230** register an alternative page cache implementation by passing in an
9231** instance of the sqlite3_pcache_methods2 structure.)^
9232** In many applications, most of the heap memory allocated by
9233** SQLite is used for the page cache.
9234** By implementing a
9235** custom page cache using this API, an application can better control
9236** the amount of memory consumed by SQLite, the way in which
9237** that memory is allocated and released, and the policies used to
9238** determine exactly which parts of a database file are cached and for
9239** how long.
9240**
9241** The alternative page cache mechanism is an
9242** extreme measure that is only needed by the most demanding applications.
9243** The built-in page cache is recommended for most uses.
9244**
9245** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
9246** internal buffer by SQLite within the call to [sqlite3_config]. Hence
9247** the application may discard the parameter after the call to
9248** [sqlite3_config()] returns.)^
9249**
9250** [[the xInit() page cache method]]
9251** ^(The xInit() method is called once for each effective
9252** call to [sqlite3_initialize()])^
9253** (usually only once during the lifetime of the process). ^(The xInit()
9254** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
9255** The intent of the xInit() method is to set up global data structures
9256** required by the custom page cache implementation.
9257** ^(If the xInit() method is NULL, then the
9258** built-in default page cache is used instead of the application defined
9259** page cache.)^
9260**
9261** [[the xShutdown() page cache method]]
9262** ^The xShutdown() method is called by [sqlite3_shutdown()].
9263** It can be used to clean up
9264** any outstanding resources before process shutdown, if required.
9265** ^The xShutdown() method may be NULL.
9266**
9267** ^SQLite automatically serializes calls to the xInit method,
9268** so the xInit method need not be threadsafe. ^The
9269** xShutdown method is only called from [sqlite3_shutdown()] so it does
9270** not need to be threadsafe either. All other methods must be threadsafe
9271** in multithreaded applications.
9272**
9273** ^SQLite will never invoke xInit() more than once without an intervening
9274** call to xShutdown().
9275**
9276** [[the xCreate() page cache methods]]
9277** ^SQLite invokes the xCreate() method to construct a new cache instance.
9278** SQLite will typically create one cache instance for each open database file,
9279** though this is not guaranteed. ^The
9280** first parameter, szPage, is the size in bytes of the pages that must
9281** be allocated by the cache. ^szPage will always be a power of two. ^The
9282** second parameter szExtra is a number of bytes of extra storage
9283** associated with each page cache entry. ^The szExtra parameter will be
9284** a number less than 250. SQLite will use the
9285** extra szExtra bytes on each page to store metadata about the underlying
9286** database page on disk. The value passed into szExtra depends
9287** on the SQLite version, the target platform, and how SQLite was compiled.
9288** ^The third argument to xCreate(), bPurgeable, is true if the cache being
9289** created will be used to cache database pages of a file stored on disk, or
9290** false if it is used for an in-memory database. The cache implementation
9291** does not have to do anything special based upon the value of bPurgeable;
9292** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9293** never invoke xUnpin() except to deliberately delete a page.
9294** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9295** false will always have the "discard" flag set to true.
9296** ^Hence, a cache created with bPurgeable set to false will
9297** never contain any unpinned pages.
9298**
9299** [[the xCachesize() page cache method]]
9300** ^(The xCachesize() method may be called at any time by SQLite to set the
9301** suggested maximum cache-size (number of pages stored) for the cache
9302** instance passed as the first argument. This is the value configured using
9303** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9304** parameter, the implementation is not required to do anything with this
9305** value; it is advisory only.
9306**
9307** [[the xPagecount() page cache methods]]
9308** The xPagecount() method must return the number of pages currently
9309** stored in the cache, both pinned and unpinned.
9310**
9311** [[the xFetch() page cache methods]]
9312** The xFetch() method locates a page in the cache and returns a pointer to
9313** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9314** The pBuf element of the returned sqlite3_pcache_page object will be a
9315** pointer to a buffer of szPage bytes used to store the content of a
9316** single database page. The pExtra element of sqlite3_pcache_page will be
9317** a pointer to the szExtra bytes of extra storage that SQLite has requested
9318** for each entry in the page cache.
9319**
9320** The page to be fetched is determined by the key. ^The minimum key value
9321** is 1. After it has been retrieved using xFetch, the page is considered
9322** to be "pinned".
9323**
9324** If the requested page is already in the page cache, then the page cache
9325** implementation must return a pointer to the page buffer with its content
9326** intact. If the requested page is not already in the cache, then the
9327** cache implementation should use the value of the createFlag
9328** parameter to help it determine what action to take:
9329**
9330** <table border=1 width=85% align=center>
9331** <tr><th> createFlag <th> Behavior when page is not already in cache
9332** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9333** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so.
9334** Otherwise return NULL.
9335** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9336** NULL if allocating a new page is effectively impossible.
9337** </table>
9338**
9339** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9340** will only use a createFlag of 2 after a prior call with a createFlag of 1
9341** failed.)^ In between the xFetch() calls, SQLite may
9342** attempt to unpin one or more cache pages by spilling the content of
9343** pinned pages to disk and synching the operating system disk cache.
9344**
9345** [[the xUnpin() page cache method]]
9346** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9347** as its second argument. If the third parameter, discard, is non-zero,
9348** then the page must be evicted from the cache.
9349** ^If the discard parameter is
9350** zero, then the page may be discarded or retained at the discretion of the
9351** page cache implementation. ^The page cache implementation
9352** may choose to evict unpinned pages at any time.
9353**
9354** The cache must not perform any reference counting. A single
9355** call to xUnpin() unpins the page regardless of the number of prior calls
9356** to xFetch().
9357**
9358** [[the xRekey() page cache methods]]
9359** The xRekey() method is used to change the key value associated with the
9360** page passed as the second argument. If the cache
9361** previously contains an entry associated with newKey, it must be
9362** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9363** to be pinned.
9364**
9365** When SQLite calls the xTruncate() method, the cache must discard all
9366** existing cache entries with page numbers (keys) greater than or equal
9367** to the value of the iLimit parameter passed to xTruncate(). If any
9368** of these pages are pinned, they become implicitly unpinned, meaning that
9369** they can be safely discarded.
9370**
9371** [[the xDestroy() page cache method]]
9372** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9373** All resources associated with the specified cache should be freed. ^After
9374** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9375** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9376** functions.
9377**
9378** [[the xShrink() page cache method]]
9379** ^SQLite invokes the xShrink() method when it wants the page cache to
9380** free up as much of heap memory as possible. The page cache implementation
9381** is not obligated to free any memory, but well-behaved implementations should
9382** do their best.
9383*/
9384typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9385struct sqlite3_pcache_methods2 {
9386 int iVersion;
9387 void *pArg;
9388 int (*xInit)(void*);
9389 void (*xShutdown)(void*);
9390 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9391 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9392 int (*xPagecount)(sqlite3_pcache*);
9393 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9394 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9395 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9396 unsigned oldKey, unsigned newKey);
9397 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9398 void (*xDestroy)(sqlite3_pcache*);
9399 void (*xShrink)(sqlite3_pcache*);
9400};
9401
9402/*
9403** This is the obsolete pcache_methods object that has now been replaced
9404** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9405** retained in the header file for backwards compatibility only.
9406*/
9407typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9408struct sqlite3_pcache_methods {
9409 void *pArg;
9410 int (*xInit)(void*);
9411 void (*xShutdown)(void*);
9412 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9413 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9414 int (*xPagecount)(sqlite3_pcache*);
9415 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9416 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9417 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9418 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9419 void (*xDestroy)(sqlite3_pcache*);
9420};
9421
9422
9423/*
9424** CAPI3REF: Online Backup Object
9425**
9426** The sqlite3_backup object records state information about an ongoing
9427** online backup operation. ^The sqlite3_backup object is created by
9428** a call to [sqlite3_backup_init()] and is destroyed by a call to
9429** [sqlite3_backup_finish()].
9430**
9431** See Also: [Using the SQLite Online Backup API]
9432*/
9433typedef struct sqlite3_backup sqlite3_backup;
9434
9435/*
9436** CAPI3REF: Online Backup API.
9437**
9438** The backup API copies the content of one database into another.
9439** It is useful either for creating backups of databases or
9440** for copying in-memory databases to or from persistent files.
9441**
9442** See Also: [Using the SQLite Online Backup API]
9443**
9444** ^SQLite holds a write transaction open on the destination database file
9445** for the duration of the backup operation.
9446** ^The source database is read-locked only while it is being read;
9447** it is not locked continuously for the entire backup operation.
9448** ^Thus, the backup may be performed on a live source database without
9449** preventing other database connections from
9450** reading or writing to the source database while the backup is underway.
9451**
9452** ^(To perform a backup operation:
9453** <ol>
9454** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9455** backup,
9456** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9457** the data between the two databases, and finally
9458** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9459** associated with the backup operation.
9460** </ol>)^
9461** There should be exactly one call to sqlite3_backup_finish() for each
9462** successful call to sqlite3_backup_init().
9463**
9464** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9465**
9466** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9467** [database connection] associated with the destination database
9468** and the database name, respectively.
9469** ^The database name is "main" for the main database, "temp" for the
9470** temporary database, or the name specified after the AS keyword in
9471** an [ATTACH] statement for an attached database.
9472** ^The S and M arguments passed to
9473** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9474** and database name of the source database, respectively.
9475** ^The source and destination [database connections] (parameters S and D)
9476** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9477** an error.
9478**
9479** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9480** there is already a read or read-write transaction open on the
9481** destination database.
9482**
9483** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9484** returned and an error code and error message are stored in the
9485** destination [database connection] D.
9486** ^The error code and message for the failed call to sqlite3_backup_init()
9487** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9488** [sqlite3_errmsg16()] functions.
9489** ^A successful call to sqlite3_backup_init() returns a pointer to an
9490** [sqlite3_backup] object.
9491** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9492** sqlite3_backup_finish() functions to perform the specified backup
9493** operation.
9494**
9495** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9496**
9497** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9498** the source and destination databases specified by [sqlite3_backup] object B.
9499** ^If N is negative, all remaining source pages are copied.
9500** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9501** are still more pages to be copied, then the function returns [SQLITE_OK].
9502** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9503** from source to destination, then it returns [SQLITE_DONE].
9504** ^If an error occurs while running sqlite3_backup_step(B,N),
9505** then an [error code] is returned. ^As well as [SQLITE_OK] and
9506** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9507** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9508** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9509**
9510** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9511** <ol>
9512** <li> the destination database was opened read-only, or
9513** <li> the destination database is using write-ahead-log journaling
9514** and the destination and source page sizes differ, or
9515** <li> the destination database is an in-memory database and the
9516** destination and source page sizes differ.
9517** </ol>)^
9518**
9519** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9520** the [sqlite3_busy_handler | busy-handler function]
9521** is invoked (if one is specified). ^If the
9522** busy-handler returns non-zero before the lock is available, then
9523** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9524** sqlite3_backup_step() can be retried later. ^If the source
9525** [database connection]
9526** is being used to write to the source database when sqlite3_backup_step()
9527** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9528** case the call to sqlite3_backup_step() can be retried later on. ^(If
9529** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9530** [SQLITE_READONLY] is returned, then
9531** there is no point in retrying the call to sqlite3_backup_step(). These
9532** errors are considered fatal.)^ The application must accept
9533** that the backup operation has failed and pass the backup operation handle
9534** to the sqlite3_backup_finish() to release associated resources.
9535**
9536** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9537** on the destination file. ^The exclusive lock is not released until either
9538** sqlite3_backup_finish() is called or the backup operation is complete
9539** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9540** sqlite3_backup_step() obtains a [shared lock] on the source database that
9541** lasts for the duration of the sqlite3_backup_step() call.
9542** ^Because the source database is not locked between calls to
9543** sqlite3_backup_step(), the source database may be modified mid-way
9544** through the backup process. ^If the source database is modified by an
9545** external process or via a database connection other than the one being
9546** used by the backup operation, then the backup will be automatically
9547** restarted by the next call to sqlite3_backup_step(). ^If the source
9548** database is modified by using the same database connection as is used
9549** by the backup operation, then the backup database is automatically
9550** updated at the same time.
9551**
9552** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9553**
9554** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9555** application wishes to abandon the backup operation, the application
9556** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9557** ^The sqlite3_backup_finish() interfaces releases all
9558** resources associated with the [sqlite3_backup] object.
9559** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9560** active write-transaction on the destination database is rolled back.
9561** The [sqlite3_backup] object is invalid
9562** and may not be used following a call to sqlite3_backup_finish().
9563**
9564** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9565** sqlite3_backup_step() errors occurred, regardless of whether or not
9566** sqlite3_backup_step() completed.
9567** ^If an out-of-memory condition or IO error occurred during any prior
9568** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9569** sqlite3_backup_finish() returns the corresponding [error code].
9570**
9571** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9572** is not a permanent error and does not affect the return value of
9573** sqlite3_backup_finish().
9574**
9575** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9576** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9577**
9578** ^The sqlite3_backup_remaining() routine returns the number of pages still
9579** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9580** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9581** in the source database at the conclusion of the most recent
9582** sqlite3_backup_step().
9583** ^(The values returned by these functions are only updated by
9584** sqlite3_backup_step(). If the source database is modified in a way that
9585** changes the size of the source database or the number of pages remaining,
9586** those changes are not reflected in the output of sqlite3_backup_pagecount()
9587** and sqlite3_backup_remaining() until after the next
9588** sqlite3_backup_step().)^
9589**
9590** <b>Concurrent Usage of Database Handles</b>
9591**
9592** ^The source [database connection] may be used by the application for other
9593** purposes while a backup operation is underway or being initialized.
9594** ^If SQLite is compiled and configured to support threadsafe database
9595** connections, then the source database connection may be used concurrently
9596** from within other threads.
9597**
9598** However, the application must guarantee that the destination
9599** [database connection] is not passed to any other API (by any thread) after
9600** sqlite3_backup_init() is called and before the corresponding call to
9601** sqlite3_backup_finish(). SQLite does not currently check to see
9602** if the application incorrectly accesses the destination [database connection]
9603** and so no error code is reported, but the operations may malfunction
9604** nevertheless. Use of the destination database connection while a
9605** backup is in progress might also cause a mutex deadlock.
9606**
9607** If running in [shared cache mode], the application must
9608** guarantee that the shared cache used by the destination database
9609** is not accessed while the backup is running. In practice this means
9610** that the application must guarantee that the disk file being
9611** backed up to is not accessed by any connection within the process,
9612** not just the specific connection that was passed to sqlite3_backup_init().
9613**
9614** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9615** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9616** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9617** APIs are not strictly speaking threadsafe. If they are invoked at the
9618** same time as another thread is invoking sqlite3_backup_step() it is
9619** possible that they return invalid values.
9620**
9621** <b>Alternatives To Using The Backup API</b>
9622**
9623** Other techniques for safely creating a consistent backup of an SQLite
9624** database include:
9625**
9626** <ul>
9627** <li> The [VACUUM INTO] command.
9628** <li> The [sqlite3_rsync] utility program.
9629** </ul>
9630*/
9631SQLITE_API sqlite3_backup *sqlite3_backup_init(
9632 sqlite3 *pDest, /* Destination database handle */
9633 const char *zDestName, /* Destination database name */
9634 sqlite3 *pSource, /* Source database handle */
9635 const char *zSourceName /* Source database name */
9636);
9637SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9638SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9639SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9640SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9641
9642/*
9643** CAPI3REF: Unlock Notification
9644** METHOD: sqlite3
9645**
9646** ^When running in shared-cache mode, a database operation may fail with
9647** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9648** individual tables within the shared-cache cannot be obtained. See
9649** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9650** ^This API may be used to register a callback that SQLite will invoke
9651** when the connection currently holding the required lock relinquishes it.
9652** ^This API is only available if the library was compiled with the
9653** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9654**
9655** See Also: [Using the SQLite Unlock Notification Feature].
9656**
9657** ^Shared-cache locks are released when a database connection concludes
9658** its current transaction, either by committing it or rolling it back.
9659**
9660** ^When a connection (known as the blocked connection) fails to obtain a
9661** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9662** identity of the database connection (the blocking connection) that
9663** has locked the required resource is stored internally. ^After an
9664** application receives an SQLITE_LOCKED error, it may call the
9665** sqlite3_unlock_notify() method with the blocked connection handle as
9666** the first argument to register for a callback that will be invoked
9667** when the blocking connection's current transaction is concluded. ^The
9668** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9669** call that concludes the blocking connection's transaction.
9670**
9671** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9672** there is a chance that the blocking connection will have already
9673** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9674** If this happens, then the specified callback is invoked immediately,
9675** from within the call to sqlite3_unlock_notify().)^
9676**
9677** ^If the blocked connection is attempting to obtain a write-lock on a
9678** shared-cache table, and more than one other connection currently holds
9679** a read-lock on the same table, then SQLite arbitrarily selects one of
9680** the other connections to use as the blocking connection.
9681**
9682** ^(There may be at most one unlock-notify callback registered by a
9683** blocked connection. If sqlite3_unlock_notify() is called when the
9684** blocked connection already has a registered unlock-notify callback,
9685** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9686** called with a NULL pointer as its second argument, then any existing
9687** unlock-notify callback is canceled. ^The blocked connection's
9688** unlock-notify callback may also be canceled by closing the blocked
9689** connection using [sqlite3_close()].
9690**
9691** The unlock-notify callback is not reentrant. If an application invokes
9692** any sqlite3_xxx API functions from within an unlock-notify callback, a
9693** crash or deadlock may be the result.
9694**
9695** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9696** returns SQLITE_OK.
9697**
9698** <b>Callback Invocation Details</b>
9699**
9700** When an unlock-notify callback is registered, the application provides a
9701** single void* pointer that is passed to the callback when it is invoked.
9702** However, the signature of the callback function allows SQLite to pass
9703** it an array of void* context pointers. The first argument passed to
9704** an unlock-notify callback is a pointer to an array of void* pointers,
9705** and the second is the number of entries in the array.
9706**
9707** When a blocking connection's transaction is concluded, there may be
9708** more than one blocked connection that has registered for an unlock-notify
9709** callback. ^If two or more such blocked connections have specified the
9710** same callback function, then instead of invoking the callback function
9711** multiple times, it is invoked once with the set of void* context pointers
9712** specified by the blocked connections bundled together into an array.
9713** This gives the application an opportunity to prioritize any actions
9714** related to the set of unblocked database connections.
9715**
9716** <b>Deadlock Detection</b>
9717**
9718** Assuming that after registering for an unlock-notify callback a
9719** database waits for the callback to be issued before taking any further
9720** action (a reasonable assumption), then using this API may cause the
9721** application to deadlock. For example, if connection X is waiting for
9722** connection Y's transaction to be concluded, and similarly connection
9723** Y is waiting on connection X's transaction, then neither connection
9724** will proceed and the system may remain deadlocked indefinitely.
9725**
9726** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9727** detection. ^If a given call to sqlite3_unlock_notify() would put the
9728** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9729** unlock-notify callback is registered. The system is said to be in
9730** a deadlocked state if connection A has registered for an unlock-notify
9731** callback on the conclusion of connection B's transaction, and connection
9732** B has itself registered for an unlock-notify callback when connection
9733** A's transaction is concluded. ^Indirect deadlock is also detected, so
9734** the system is also considered to be deadlocked if connection B has
9735** registered for an unlock-notify callback on the conclusion of connection
9736** C's transaction, where connection C is waiting on connection A. ^Any
9737** number of levels of indirection are allowed.
9738**
9739** <b>The "DROP TABLE" Exception</b>
9740**
9741** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9742** always appropriate to call sqlite3_unlock_notify(). There is however,
9743** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9744** SQLite checks if there are any currently executing SELECT statements
9745** that belong to the same connection. If there are, SQLITE_LOCKED is
9746** returned. In this case there is no "blocking connection", so invoking
9747** sqlite3_unlock_notify() results in the unlock-notify callback being
9748** invoked immediately. If the application then re-attempts the "DROP TABLE"
9749** or "DROP INDEX" query, an infinite loop might be the result.
9750**
9751** One way around this problem is to check the extended error code returned
9752** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9753** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9754** the special "DROP TABLE/INDEX" case, the extended error code is just
9755** SQLITE_LOCKED.)^
9756*/
9757SQLITE_API int sqlite3_unlock_notify(
9758 sqlite3 *pBlocked, /* Waiting connection */
9759 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9760 void *pNotifyArg /* Argument to pass to xNotify */
9761);
9762
9763
9764/*
9765** CAPI3REF: String Comparison
9766**
9767** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9768** and extensions to compare the contents of two buffers containing UTF-8
9769** strings in a case-independent fashion, using the same definition of "case
9770** independence" that SQLite uses internally when comparing identifiers.
9771*/
9772SQLITE_API int sqlite3_stricmp(const char *, const char *);
9773SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9774
9775/*
9776** CAPI3REF: String Globbing
9777*
9778** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9779** string X matches the [GLOB] pattern P.
9780** ^The definition of [GLOB] pattern matching used in
9781** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9782** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9783** is case sensitive.
9784**
9785** Note that this routine returns zero on a match and non-zero if the strings
9786** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9787**
9788** See also: [sqlite3_strlike()].
9789*/
9790SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9791
9792/*
9793** CAPI3REF: String LIKE Matching
9794*
9795** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9796** string X matches the [LIKE] pattern P with escape character E.
9797** ^The definition of [LIKE] pattern matching used in
9798** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9799** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9800** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9801** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9802** insensitive - equivalent upper and lower case ASCII characters match
9803** one another.
9804**
9805** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9806** only ASCII characters are case folded.
9807**
9808** Note that this routine returns zero on a match and non-zero if the strings
9809** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9810**
9811** See also: [sqlite3_strglob()].
9812*/
9813SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9814
9815/*
9816** CAPI3REF: Error Logging Interface
9817**
9818** ^The [sqlite3_log()] interface writes a message into the [error log]
9819** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9820** ^If logging is enabled, the zFormat string and subsequent arguments are
9821** used with [sqlite3_snprintf()] to generate the final output string.
9822**
9823** The sqlite3_log() interface is intended for use by extensions such as
9824** virtual tables, collating functions, and SQL functions. While there is
9825** nothing to prevent an application from calling sqlite3_log(), doing so
9826** is considered bad form.
9827**
9828** The zFormat string must not be NULL.
9829**
9830** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9831** will not use dynamically allocated memory. The log message is stored in
9832** a fixed-length buffer on the stack. If the log message is longer than
9833** a few hundred characters, it will be truncated to the length of the
9834** buffer.
9835*/
9836SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9837
9838/*
9839** CAPI3REF: Write-Ahead Log Commit Hook
9840** METHOD: sqlite3
9841**
9842** ^The [sqlite3_wal_hook()] function is used to register a callback that
9843** is invoked each time data is committed to a database in wal mode.
9844**
9845** ^(The callback is invoked by SQLite after the commit has taken place and
9846** the associated write-lock on the database released)^, so the implementation
9847** may read, write or [checkpoint] the database as required.
9848**
9849** ^The first parameter passed to the callback function when it is invoked
9850** is a copy of the third parameter passed to sqlite3_wal_hook() when
9851** registering the callback. ^The second is a copy of the database handle.
9852** ^The third parameter is the name of the database that was written to -
9853** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9854** is the number of pages currently in the write-ahead log file,
9855** including those that were just committed.
9856**
9857** ^The callback function should normally return [SQLITE_OK]. ^If an error
9858** code is returned, that error will propagate back up through the
9859** SQLite code base to cause the statement that provoked the callback
9860** to report an error, though the commit will have still occurred. If the
9861** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9862** that does not correspond to any valid SQLite error code, the results
9863** are undefined.
9864**
9865** ^A single database handle may have at most a single write-ahead log
9866** callback registered at one time. ^Calling [sqlite3_wal_hook()]
9867** replaces the default behavior or previously registered write-ahead
9868** log callback.
9869**
9870** ^The return value is a copy of the third parameter from the
9871** previous call, if any, or 0.
9872**
9873** ^The [sqlite3_wal_autocheckpoint()] interface and the
9874** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and
9875** will overwrite any prior [sqlite3_wal_hook()] settings.
9876**
9877** ^If a write-ahead log callback is set using this function then
9878** [sqlite3_wal_checkpoint_v2()] or [PRAGMA wal_checkpoint]
9879** should be invoked periodically to keep the write-ahead log file
9880** from growing without bound.
9881**
9882** ^Passing a NULL pointer for the callback disables automatic
9883** checkpointing entirely. To re-enable the default behavior, call
9884** sqlite3_wal_autocheckpoint(db,1000) or use [PRAGMA wal_checkpoint].
9885*/
9886SQLITE_API void *sqlite3_wal_hook(
9887 sqlite3*,
9888 int(*)(void *,sqlite3*,const char*,int),
9889 void*
9890);
9891
9892/*
9893** CAPI3REF: Configure an auto-checkpoint
9894** METHOD: sqlite3
9895**
9896** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9897** [sqlite3_wal_hook()] that causes any database on [database connection] D
9898** to automatically [checkpoint]
9899** after committing a transaction if there are N or
9900** more frames in the [write-ahead log] file. ^Passing zero or
9901** a negative value as the N parameter disables automatic
9902** checkpoints entirely.
9903**
9904** ^The callback registered by this function replaces any existing callback
9905** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9906** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9907** configured by this function.
9908**
9909** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9910** from SQL.
9911**
9912** ^Checkpoints initiated by this mechanism are
9913** [sqlite3_wal_checkpoint_v2|PASSIVE].
9914**
9915** ^Every new [database connection] defaults to having the auto-checkpoint
9916** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9917** pages.
9918**
9919** ^The use of this interface is only necessary if the default setting
9920** is found to be suboptimal for a particular application.
9921*/
9922SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9923
9924/*
9925** CAPI3REF: Checkpoint a database
9926** METHOD: sqlite3
9927**
9928** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9929** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9930**
9931** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9932** [write-ahead log] for database X on [database connection] D to be
9933** transferred into the database file and for the write-ahead log to
9934** be reset. See the [checkpointing] documentation for addition
9935** information.
9936**
9937** This interface used to be the only way to cause a checkpoint to
9938** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9939** interface was added. This interface is retained for backwards
9940** compatibility and as a convenience for applications that need to manually
9941** start a callback but which do not need the full power (and corresponding
9942** complication) of [sqlite3_wal_checkpoint_v2()].
9943*/
9944SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9945
9946/*
9947** CAPI3REF: Checkpoint a database
9948** METHOD: sqlite3
9949**
9950** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9951** operation on database X of [database connection] D in mode M. Status
9952** information is written back into integers pointed to by L and C.)^
9953** ^(The M parameter must be a valid [checkpoint mode]:)^
9954**
9955** <dl>
9956** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9957** ^Checkpoint as many frames as possible without waiting for any database
9958** readers or writers to finish, then sync the database file if all frames
9959** in the log were checkpointed. ^The [busy-handler callback]
9960** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9961** ^On the other hand, passive mode might leave the checkpoint unfinished
9962** if there are concurrent readers or writers.
9963**
9964** <dt>SQLITE_CHECKPOINT_FULL<dd>
9965** ^This mode blocks (it invokes the
9966** [sqlite3_busy_handler|busy-handler callback]) until there is no
9967** database writer and all readers are reading from the most recent database
9968** snapshot. ^It then checkpoints all frames in the log file and syncs the
9969** database file. ^This mode blocks new database writers while it is pending,
9970** but new database readers are allowed to continue unimpeded.
9971**
9972** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9973** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9974** that after checkpointing the log file it blocks (calls the
9975** [busy-handler callback])
9976** until all readers are reading from the database file only. ^This ensures
9977** that the next writer will restart the log file from the beginning.
9978** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9979** database writer attempts while it is pending, but does not impede readers.
9980**
9981** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9982** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9983** addition that it also truncates the log file to zero bytes just prior
9984** to a successful return.
9985**
9986** <dt>SQLITE_CHECKPOINT_NOOP<dd>
9987** ^This mode always checkpoints zero frames. The only reason to invoke
9988** a NOOP checkpoint is to access the values returned by
9989** sqlite3_wal_checkpoint_v2() via output parameters *pnLog and *pnCkpt.
9990** </dl>
9991**
9992** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9993** the log file or to -1 if the checkpoint could not run because
9994** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9995** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9996** log file (including any that were already checkpointed before the function
9997** was called) or to -1 if the checkpoint could not run due to an error or
9998** because the database is not in WAL mode. ^Note that upon successful
9999** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
10000** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
10001**
10002** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
10003** any other process is running a checkpoint operation at the same time, the
10004** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
10005** busy-handler configured, it will not be invoked in this case.
10006**
10007** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
10008** exclusive "writer" lock on the database file. ^If the writer lock cannot be
10009** obtained immediately, and a busy-handler is configured, it is invoked and
10010** the writer lock retried until either the busy-handler returns 0 or the lock
10011** is successfully obtained. ^The busy-handler is also invoked while waiting for
10012** database readers as described above. ^If the busy-handler returns 0 before
10013** the writer lock is obtained or while waiting for database readers, the
10014** checkpoint operation proceeds from that point in the same way as
10015** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
10016** without blocking any further. ^SQLITE_BUSY is returned in this case.
10017**
10018** ^If parameter zDb is NULL or points to a zero length string, then the
10019** specified operation is attempted on all WAL databases [attached] to
10020** [database connection] db. In this case the
10021** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
10022** an SQLITE_BUSY error is encountered when processing one or more of the
10023** attached WAL databases, the operation is still attempted on any remaining
10024** attached databases and SQLITE_BUSY is returned at the end. ^If any other
10025** error occurs while processing an attached database, processing is abandoned
10026** and the error code is returned to the caller immediately. ^If no error
10027** (SQLITE_BUSY or otherwise) is encountered while processing the attached
10028** databases, SQLITE_OK is returned.
10029**
10030** ^If database zDb is the name of an attached database that is not in WAL
10031** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
10032** zDb is not NULL (or a zero length string) and is not the name of any
10033** attached database, SQLITE_ERROR is returned to the caller.
10034**
10035** ^Unless it returns SQLITE_MISUSE,
10036** the sqlite3_wal_checkpoint_v2() interface
10037** sets the error information that is queried by
10038** [sqlite3_errcode()] and [sqlite3_errmsg()].
10039**
10040** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
10041** from SQL.
10042*/
10043SQLITE_API int sqlite3_wal_checkpoint_v2(
10044 sqlite3 *db, /* Database handle */
10045 const char *zDb, /* Name of attached database (or NULL) */
10046 int eMode, /* SQLITE_CHECKPOINT_* value */
10047 int *pnLog, /* OUT: Size of WAL log in frames */
10048 int *pnCkpt /* OUT: Total number of frames checkpointed */
10049);
10050
10051/*
10052** CAPI3REF: Checkpoint Mode Values
10053** KEYWORDS: {checkpoint mode}
10054**
10055** These constants define all valid values for the "checkpoint mode" passed
10056** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
10057** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
10058** meaning of each of these checkpoint modes.
10059*/
10060#define SQLITE_CHECKPOINT_NOOP -1 /* Do no work at all */
10061#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
10062#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
10063#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
10064#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
10065
10066/*
10067** CAPI3REF: Virtual Table Interface Configuration
10068**
10069** This function may be called by either the [xConnect] or [xCreate] method
10070** of a [virtual table] implementation to configure
10071** various facets of the virtual table interface.
10072**
10073** If this interface is invoked outside the context of an xConnect or
10074** xCreate virtual table method then the behavior is undefined.
10075**
10076** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
10077** [database connection] in which the virtual table is being created and
10078** which is passed in as the first argument to the [xConnect] or [xCreate]
10079** method that is invoking sqlite3_vtab_config(). The C parameter is one
10080** of the [virtual table configuration options]. The presence and meaning
10081** of parameters after C depend on which [virtual table configuration option]
10082** is used.
10083*/
10084SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
10085
10086/*
10087** CAPI3REF: Virtual Table Configuration Options
10088** KEYWORDS: {virtual table configuration options}
10089** KEYWORDS: {virtual table configuration option}
10090**
10091** These macros define the various options to the
10092** [sqlite3_vtab_config()] interface that [virtual table] implementations
10093** can use to customize and optimize their behavior.
10094**
10095** <dl>
10096** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
10097** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
10098** <dd>Calls of the form
10099** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
10100** where X is an integer. If X is zero, then the [virtual table] whose
10101** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
10102** support constraints. In this configuration (which is the default) if
10103** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
10104** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
10105** specified as part of the user's SQL statement, regardless of the actual
10106** ON CONFLICT mode specified.
10107**
10108** If X is non-zero, then the virtual table implementation guarantees
10109** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
10110** any modifications to internal or persistent data structures have been made.
10111** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
10112** is able to roll back a statement or database transaction, and abandon
10113** or continue processing the current SQL statement as appropriate.
10114** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
10115** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
10116** had been ABORT.
10117**
10118** Virtual table implementations that are required to handle OR REPLACE
10119** must do so within the [xUpdate] method. If a call to the
10120** [sqlite3_vtab_on_conflict()] function indicates that the current ON
10121** CONFLICT policy is REPLACE, the virtual table implementation should
10122** silently replace the appropriate rows within the xUpdate callback and
10123** return SQLITE_OK. Or, if this is not possible, it may return
10124** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
10125** constraint handling.
10126** </dd>
10127**
10128** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
10129** <dd>Calls of the form
10130** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
10131** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10132** prohibits that virtual table from being used from within triggers and
10133** views.
10134** </dd>
10135**
10136** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
10137** <dd>Calls of the form
10138** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
10139** [xConnect] or [xCreate] methods of a [virtual table] implementation
10140** identify that virtual table as being safe to use from within triggers
10141** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
10142** virtual table can do no serious harm even if it is controlled by a
10143** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
10144** flag unless absolutely necessary.
10145** </dd>
10146**
10147** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
10148** <dd>Calls of the form
10149** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
10150** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10151** instruct the query planner to begin at least a read transaction on
10152** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
10153** virtual table is used.
10154** </dd>
10155** </dl>
10156*/
10157#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
10158#define SQLITE_VTAB_INNOCUOUS 2
10159#define SQLITE_VTAB_DIRECTONLY 3
10160#define SQLITE_VTAB_USES_ALL_SCHEMAS 4
10161
10162/*
10163** CAPI3REF: Determine The Virtual Table Conflict Policy
10164**
10165** This function may only be called from within a call to the [xUpdate] method
10166** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
10167** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
10168** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
10169** of the SQL statement that triggered the call to the [xUpdate] method of the
10170** [virtual table].
10171*/
10172SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
10173
10174/*
10175** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
10176**
10177** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
10178** method of a [virtual table], then it might return true if the
10179** column is being fetched as part of an UPDATE operation during which the
10180** column value will not change. The virtual table implementation can use
10181** this hint as permission to substitute a return value that is less
10182** expensive to compute and that the corresponding
10183** [xUpdate] method understands as a "no-change" value.
10184**
10185** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
10186** the column is not changed by the UPDATE statement, then the xColumn
10187** method can optionally return without setting a result, without calling
10188** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
10189** In that case, [sqlite3_value_nochange(X)] will return true for the
10190** same column in the [xUpdate] method.
10191**
10192** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
10193** implementations should continue to give a correct answer even if the
10194** sqlite3_vtab_nochange() interface were to always return false. In the
10195** current implementation, the sqlite3_vtab_nochange() interface does always
10196** returns false for the enhanced [UPDATE FROM] statement.
10197*/
10198SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
10199
10200/*
10201** CAPI3REF: Determine The Collation For a Virtual Table Constraint
10202** METHOD: sqlite3_index_info
10203**
10204** This function may only be called from within a call to the [xBestIndex]
10205** method of a [virtual table]. This function returns a pointer to a string
10206** that is the name of the appropriate collation sequence to use for text
10207** comparisons on the constraint identified by its arguments.
10208**
10209** The first argument must be the pointer to the [sqlite3_index_info] object
10210** that is the first parameter to the xBestIndex() method. The second argument
10211** must be an index into the aConstraint[] array belonging to the
10212** sqlite3_index_info structure passed to xBestIndex.
10213**
10214** Important:
10215** The first parameter must be the same pointer that is passed into the
10216** xBestMethod() method. The first parameter may not be a pointer to a
10217** different [sqlite3_index_info] object, even an exact copy.
10218**
10219** The return value is computed as follows:
10220**
10221** <ol>
10222** <li><p> If the constraint comes from a WHERE clause expression that contains
10223** a [COLLATE operator], then the name of the collation specified by
10224** that COLLATE operator is returned.
10225** <li><p> If there is no COLLATE operator, but the column that is the subject
10226** of the constraint specifies an alternative collating sequence via
10227** a [COLLATE clause] on the column definition within the CREATE TABLE
10228** statement that was passed into [sqlite3_declare_vtab()], then the
10229** name of that alternative collating sequence is returned.
10230** <li><p> Otherwise, "BINARY" is returned.
10231** </ol>
10232*/
10233SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
10234
10235/*
10236** CAPI3REF: Determine if a virtual table query is DISTINCT
10237** METHOD: sqlite3_index_info
10238**
10239** This API may only be used from within an [xBestIndex|xBestIndex method]
10240** of a [virtual table] implementation. The result of calling this
10241** interface from outside of xBestIndex() is undefined and probably harmful.
10242**
10243** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
10244** 3. The integer returned by sqlite3_vtab_distinct()
10245** gives the virtual table additional information about how the query
10246** planner wants the output to be ordered. As long as the virtual table
10247** can meet the ordering requirements of the query planner, it may set
10248** the "orderByConsumed" flag.
10249**
10250** <ol><li value="0"><p>
10251** ^If the sqlite3_vtab_distinct() interface returns 0, that means
10252** that the query planner needs the virtual table to return all rows in the
10253** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
10254** [sqlite3_index_info] object. This is the default expectation. If the
10255** virtual table outputs all rows in sorted order, then it is always safe for
10256** the xBestIndex method to set the "orderByConsumed" flag, regardless of
10257** the return value from sqlite3_vtab_distinct().
10258** <li value="1"><p>
10259** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
10260** that the query planner does not need the rows to be returned in sorted order
10261** as long as all rows with the same values in all columns identified by the
10262** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
10263** is doing a GROUP BY.
10264** <li value="2"><p>
10265** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
10266** that the query planner does not need the rows returned in any particular
10267** order, as long as rows with the same values in all columns identified
10268** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
10269** contain the same values for all columns identified by "colUsed", all but
10270** one such row may optionally be omitted from the result.)^
10271** The virtual table is not required to omit rows that are duplicates
10272** over the "colUsed" columns, but if the virtual table can do that without
10273** too much extra effort, it could potentially help the query to run faster.
10274** This mode is used for a DISTINCT query.
10275** <li value="3"><p>
10276** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
10277** virtual table must return rows in the order defined by "aOrderBy" as
10278** if the sqlite3_vtab_distinct() interface had returned 0. However if
10279** two or more rows in the result have the same values for all columns
10280** identified by "colUsed", then all but one such row may optionally be
10281** omitted.)^ Like when the return value is 2, the virtual table
10282** is not required to omit rows that are duplicates over the "colUsed"
10283** columns, but if the virtual table can do that without
10284** too much extra effort, it could potentially help the query to run faster.
10285** This mode is used for queries
10286** that have both DISTINCT and ORDER BY clauses.
10287** </ol>
10288**
10289** <p>The following table summarizes the conditions under which the
10290** virtual table is allowed to set the "orderByConsumed" flag based on
10291** the value returned by sqlite3_vtab_distinct(). This table is a
10292** restatement of the previous four paragraphs:
10293**
10294** <table border=1 cellspacing=0 cellpadding=10 width="90%">
10295** <tr>
10296** <td valign="top">sqlite3_vtab_distinct() return value
10297** <td valign="top">Rows are returned in aOrderBy order
10298** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
10299** <td valign="top">Duplicates over all colUsed columns may be omitted
10300** <tr><td>0<td>yes<td>yes<td>no
10301** <tr><td>1<td>no<td>yes<td>no
10302** <tr><td>2<td>no<td>yes<td>yes
10303** <tr><td>3<td>yes<td>yes<td>yes
10304** </table>
10305**
10306** ^For the purposes of comparing virtual table output values to see if the
10307** values are the same value for sorting purposes, two NULL values are considered
10308** to be the same. In other words, the comparison operator is "IS"
10309** (or "IS NOT DISTINCT FROM") and not "==".
10310**
10311** If a virtual table implementation is unable to meet the requirements
10312** specified above, then it must not set the "orderByConsumed" flag in the
10313** [sqlite3_index_info] object or an incorrect answer may result.
10314**
10315** ^A virtual table implementation is always free to return rows in any order
10316** it wants, as long as the "orderByConsumed" flag is not set. ^When the
10317** "orderByConsumed" flag is unset, the query planner will add extra
10318** [bytecode] to ensure that the final results returned by the SQL query are
10319** ordered correctly. The use of the "orderByConsumed" flag and the
10320** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
10321** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10322** flag might help queries against a virtual table to run faster. Being
10323** overly aggressive and setting the "orderByConsumed" flag when it is not
10324** valid to do so, on the other hand, might cause SQLite to return incorrect
10325** results.
10326*/
10327SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10328
10329/*
10330** CAPI3REF: Identify and handle IN constraints in xBestIndex
10331**
10332** This interface may only be used from within an
10333** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10334** The result of invoking this interface from any other context is
10335** undefined and probably harmful.
10336**
10337** ^(A constraint on a virtual table of the form
10338** "[IN operator|column IN (...)]" is
10339** communicated to the xBestIndex method as a
10340** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10341** this constraint, it must set the corresponding
10342** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10343** the usual mode of handling IN operators, SQLite generates [bytecode]
10344** that invokes the [xFilter|xFilter() method] once for each value
10345** on the right-hand side of the IN operator.)^ Thus the virtual table
10346** only sees a single value from the right-hand side of the IN operator
10347** at a time.
10348**
10349** In some cases, however, it would be advantageous for the virtual
10350** table to see all values on the right-hand of the IN operator all at
10351** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10352**
10353** <ol>
10354** <li><p>
10355** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10356** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10357** is an [IN operator] that can be processed all at once. ^In other words,
10358** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10359** by which the virtual table can ask SQLite if all-at-once processing
10360** of the IN operator is even possible.
10361**
10362** <li><p>
10363** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10364** to SQLite that the virtual table does or does not want to process
10365** the IN operator all-at-once, respectively. ^Thus when the third
10366** parameter (F) is non-negative, this interface is the mechanism by
10367** which the virtual table tells SQLite how it wants to process the
10368** IN operator.
10369** </ol>
10370**
10371** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10372** within the same xBestIndex method call. ^For any given P,N pair,
10373** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10374** within the same xBestIndex call. ^If the interface returns true
10375** (non-zero), that means that the constraint is an IN operator
10376** that can be processed all-at-once. ^If the constraint is not an IN
10377** operator or cannot be processed all-at-once, then the interface returns
10378** false.
10379**
10380** ^(All-at-once processing of the IN operator is selected if both of the
10381** following conditions are met:
10382**
10383** <ol>
10384** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10385** integer. This is how the virtual table tells SQLite that it wants to
10386** use the N-th constraint.
10387**
10388** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10389** non-negative had F>=1.
10390** </ol>)^
10391**
10392** ^If either or both of the conditions above are false, then SQLite uses
10393** the traditional one-at-a-time processing strategy for the IN constraint.
10394** ^If both conditions are true, then the argvIndex-th parameter to the
10395** xFilter method will be an [sqlite3_value] that appears to be NULL,
10396** but which can be passed to [sqlite3_vtab_in_first()] and
10397** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10398** of the IN constraint.
10399*/
10400SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10401
10402/*
10403** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10404**
10405** These interfaces are only useful from within the
10406** [xFilter|xFilter() method] of a [virtual table] implementation.
10407** The result of invoking these interfaces from any other context
10408** is undefined and probably harmful.
10409**
10410** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10411** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10412** xFilter method which invokes these routines, and specifically
10413** a parameter that was previously selected for all-at-once IN constraint
10414** processing using the [sqlite3_vtab_in()] interface in the
10415** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10416** an xFilter argument that was selected for all-at-once IN constraint
10417** processing, then these routines return [SQLITE_ERROR].)^
10418**
10419** ^(Use these routines to access all values on the right-hand side
10420** of the IN constraint using code like the following:
10421**
10422** <blockquote><pre>
10423** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
10424** &nbsp; rc==SQLITE_OK && pVal;
10425** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
10426** &nbsp; ){
10427** &nbsp; // do something with pVal
10428** &nbsp; }
10429** &nbsp; if( rc!=SQLITE_DONE ){
10430** &nbsp; // an error has occurred
10431** &nbsp; }
10432** </pre></blockquote>)^
10433**
10434** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10435** routines return SQLITE_OK and set *P to point to the first or next value
10436** on the RHS of the IN constraint. ^If there are no more values on the
10437** right hand side of the IN constraint, then *P is set to NULL and these
10438** routines return [SQLITE_DONE]. ^The return value might be
10439** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10440**
10441** The *ppOut values returned by these routines are only valid until the
10442** next call to either of these routines or until the end of the xFilter
10443** method from which these routines were called. If the virtual table
10444** implementation needs to retain the *ppOut values for longer, it must make
10445** copies. The *ppOut values are [protected sqlite3_value|protected].
10446*/
10447SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10448SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10449
10450/*
10451** CAPI3REF: Constraint values in xBestIndex()
10452** METHOD: sqlite3_index_info
10453**
10454** This API may only be used from within the [xBestIndex|xBestIndex method]
10455** of a [virtual table] implementation. The result of calling this interface
10456** from outside of an xBestIndex method are undefined and probably harmful.
10457**
10458** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10459** the [xBestIndex] method of a [virtual table] implementation, with P being
10460** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10461** J being a 0-based index into P->aConstraint[], then this routine
10462** attempts to set *V to the value of the right-hand operand of
10463** that constraint if the right-hand operand is known. ^If the
10464** right-hand operand is not known, then *V is set to a NULL pointer.
10465** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10466** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10467** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10468** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10469** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if
10470** something goes wrong.
10471**
10472** The sqlite3_vtab_rhs_value() interface is usually only successful if
10473** the right-hand operand of a constraint is a literal value in the original
10474** SQL statement. If the right-hand operand is an expression or a reference
10475** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10476** will probably return [SQLITE_NOTFOUND].
10477**
10478** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10479** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10480** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10481**
10482** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10483** and remains valid for the duration of the xBestIndex method call.
10484** ^When xBestIndex returns, the sqlite3_value object returned by
10485** sqlite3_vtab_rhs_value() is automatically deallocated.
10486**
10487** The "_rhs_" in the name of this routine is an abbreviation for
10488** "Right-Hand Side".
10489*/
10490SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10491
10492/*
10493** CAPI3REF: Conflict resolution modes
10494** KEYWORDS: {conflict resolution mode}
10495**
10496** These constants are returned by [sqlite3_vtab_on_conflict()] to
10497** inform a [virtual table] implementation of the [ON CONFLICT] mode
10498** for the SQL statement being evaluated.
10499**
10500** Note that the [SQLITE_IGNORE] constant is also used as a potential
10501** return value from the [sqlite3_set_authorizer()] callback and that
10502** [SQLITE_ABORT] is also a [result code].
10503*/
10504#define SQLITE_ROLLBACK 1
10505/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10506#define SQLITE_FAIL 3
10507/* #define SQLITE_ABORT 4 // Also an error code */
10508#define SQLITE_REPLACE 5
10509
10510/*
10511** CAPI3REF: Prepared Statement Scan Status Opcodes
10512** KEYWORDS: {scanstatus options}
10513**
10514** The following constants can be used for the T parameter to the
10515** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10516** different metric for sqlite3_stmt_scanstatus() to return.
10517**
10518** When the value returned to V is a string, space to hold that string is
10519** managed by the prepared statement S and will be automatically freed when
10520** S is finalized.
10521**
10522** Not all values are available for all query elements. When a value is
10523** not available, the output variable is set to -1 if the value is numeric,
10524** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10525**
10526** <dl>
10527** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10528** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10529** set to the total number of times that the X-th loop has run.</dd>
10530**
10531** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10532** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10533** to the total number of rows examined by all iterations of the X-th loop.</dd>
10534**
10535** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10536** <dd>^The "double" variable pointed to by the V parameter will be set to the
10537** query planner's estimate for the average number of rows output from each
10538** iteration of the X-th loop. If the query planner's estimate was accurate,
10539** then this value will approximate the quotient NVISIT/NLOOP and the
10540** product of this value for all prior loops with the same SELECTID will
10541** be the NLOOP value for the current loop.</dd>
10542**
10543** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10544** <dd>^The "const char *" variable pointed to by the V parameter will be set
10545** to a zero-terminated UTF-8 string containing the name of the index or table
10546** used for the X-th loop.</dd>
10547**
10548** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10549** <dd>^The "const char *" variable pointed to by the V parameter will be set
10550** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10551** description for the X-th loop.</dd>
10552**
10553** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10554** <dd>^The "int" variable pointed to by the V parameter will be set to the
10555** id for the X-th query plan element. The id value is unique within the
10556** statement. The select-id is the same value as is output in the first
10557** column of an [EXPLAIN QUERY PLAN] query.</dd>
10558**
10559** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10560** <dd>The "int" variable pointed to by the V parameter will be set to the
10561** id of the parent of the current query element, if applicable, or
10562** to zero if the query element has no parent. This is the same value as
10563** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd>
10564**
10565** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10566** <dd>The sqlite3_int64 output value is set to the number of cycles,
10567** according to the processor time-stamp counter, that elapsed while the
10568** query element was being processed. This value is not available for
10569** all query elements - if it is unavailable the output variable is
10570** set to -1.</dd>
10571** </dl>
10572*/
10573#define SQLITE_SCANSTAT_NLOOP 0
10574#define SQLITE_SCANSTAT_NVISIT 1
10575#define SQLITE_SCANSTAT_EST 2
10576#define SQLITE_SCANSTAT_NAME 3
10577#define SQLITE_SCANSTAT_EXPLAIN 4
10578#define SQLITE_SCANSTAT_SELECTID 5
10579#define SQLITE_SCANSTAT_PARENTID 6
10580#define SQLITE_SCANSTAT_NCYCLE 7
10581
10582/*
10583** CAPI3REF: Prepared Statement Scan Status
10584** METHOD: sqlite3_stmt
10585**
10586** These interfaces return information about the predicted and measured
10587** performance for pStmt. Advanced applications can use this
10588** interface to compare the predicted and the measured performance and
10589** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10590**
10591** Since this interface is expected to be rarely used, it is only
10592** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10593** compile-time option.
10594**
10595** The "iScanStatusOp" parameter determines which status information to return.
10596** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10597** of this interface is undefined. ^The requested measurement is written into
10598** a variable pointed to by the "pOut" parameter.
10599**
10600** The "flags" parameter must be passed a mask of flags. At present only
10601** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10602** is specified, then status information is available for all elements
10603** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10604** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10605** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10606** the EXPLAIN QUERY PLAN output) are available. Invoking API
10607** sqlite3_stmt_scanstatus() is equivalent to calling
10608** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10609**
10610** Parameter "idx" identifies the specific query element to retrieve statistics
10611** for. Query elements are numbered starting from zero. A value of -1 may
10612** retrieve statistics for the entire query. ^If idx is out of range
10613** - less than -1 or greater than or equal to the total number of query
10614** elements used to implement the statement - a non-zero value is returned and
10615** the variable that pOut points to is unchanged.
10616**
10617** See also: [sqlite3_stmt_scanstatus_reset()]
10618*/
10619SQLITE_API int sqlite3_stmt_scanstatus(
10620 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10621 int idx, /* Index of loop to report on */
10622 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10623 void *pOut /* Result written here */
10624);
10625SQLITE_API int sqlite3_stmt_scanstatus_v2(
10626 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10627 int idx, /* Index of loop to report on */
10628 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10629 int flags, /* Mask of flags defined below */
10630 void *pOut /* Result written here */
10631);
10632
10633/*
10634** CAPI3REF: Prepared Statement Scan Status
10635** KEYWORDS: {scan status flags}
10636*/
10637#define SQLITE_SCANSTAT_COMPLEX 0x0001
10638
10639/*
10640** CAPI3REF: Zero Scan-Status Counters
10641** METHOD: sqlite3_stmt
10642**
10643** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10644**
10645** This API is only available if the library is built with pre-processor
10646** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10647*/
10648SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10649
10650/*
10651** CAPI3REF: Flush caches to disk mid-transaction
10652** METHOD: sqlite3
10653**
10654** ^If a write-transaction is open on [database connection] D when the
10655** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
10656** pages in the pager-cache that are not currently in use are written out
10657** to disk. A dirty page may be in use if a database cursor created by an
10658** active SQL statement is reading from it, or if it is page 1 of a database
10659** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10660** interface flushes caches for all schemas - "main", "temp", and
10661** any [attached] databases.
10662**
10663** ^If this function needs to obtain extra database locks before dirty pages
10664** can be flushed to disk, it does so. ^If those locks cannot be obtained
10665** immediately and there is a busy-handler callback configured, it is invoked
10666** in the usual manner. ^If the required lock still cannot be obtained, then
10667** the database is skipped and an attempt made to flush any dirty pages
10668** belonging to the next (if any) database. ^If any databases are skipped
10669** because locks cannot be obtained, but no other error occurs, this
10670** function returns SQLITE_BUSY.
10671**
10672** ^If any other error occurs while flushing dirty pages to disk (for
10673** example an IO error or out-of-memory condition), then processing is
10674** abandoned and an SQLite [error code] is returned to the caller immediately.
10675**
10676** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10677**
10678** ^This function does not set the database handle error code or message
10679** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10680*/
10681SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10682
10683/*
10684** CAPI3REF: The pre-update hook.
10685** METHOD: sqlite3
10686**
10687** ^These interfaces are only available if SQLite is compiled using the
10688** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10689**
10690** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10691** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10692** on a database table.
10693** ^At most one preupdate hook may be registered at a time on a single
10694** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10695** the previous setting.
10696** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10697** with a NULL pointer as the second parameter.
10698** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10699** the first parameter to callbacks.
10700**
10701** ^The preupdate hook only fires for changes to real database tables; the
10702** preupdate hook is not invoked for changes to [virtual tables] or to
10703** system tables like sqlite_sequence or sqlite_stat1.
10704**
10705** ^The second parameter to the preupdate callback is a pointer to
10706** the [database connection] that registered the preupdate hook.
10707** ^The third parameter to the preupdate callback is one of the constants
10708** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10709** kind of update operation that is about to occur.
10710** ^(The fourth parameter to the preupdate callback is the name of the
10711** database within the database connection that is being modified. This
10712** will be "main" for the main database or "temp" for TEMP tables or
10713** the name given after the AS keyword in the [ATTACH] statement for attached
10714** databases.)^
10715** ^The fifth parameter to the preupdate callback is the name of the
10716** table that is being modified.
10717**
10718** For an UPDATE or DELETE operation on a [rowid table], the sixth
10719** parameter passed to the preupdate callback is the initial [rowid] of the
10720** row being modified or deleted. For an INSERT operation on a rowid table,
10721** or any operation on a WITHOUT ROWID table, the value of the sixth
10722** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10723** seventh parameter is the final rowid value of the row being inserted
10724** or updated. The value of the seventh parameter passed to the callback
10725** function is not defined for operations on WITHOUT ROWID tables, or for
10726** DELETE operations on rowid tables.
10727**
10728** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10729** the previous call on the same [database connection] D, or NULL for
10730** the first call on D.
10731**
10732** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10733** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10734** provide additional information about a preupdate event. These routines
10735** may only be called from within a preupdate callback. Invoking any of
10736** these routines from outside of a preupdate callback or with a
10737** [database connection] pointer that is different from the one supplied
10738** to the preupdate callback results in undefined and probably undesirable
10739** behavior.
10740**
10741** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10742** in the row that is being inserted, updated, or deleted.
10743**
10744** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10745** a [protected sqlite3_value] that contains the value of the Nth column of
10746** the table row before it is updated. The N parameter must be between 0
10747** and one less than the number of columns or the behavior will be
10748** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10749** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10750** behavior is undefined. The [sqlite3_value] that P points to
10751** will be destroyed when the preupdate callback returns.
10752**
10753** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10754** a [protected sqlite3_value] that contains the value of the Nth column of
10755** the table row after it is updated. The N parameter must be between 0
10756** and one less than the number of columns or the behavior will be
10757** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10758** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10759** behavior is undefined. The [sqlite3_value] that P points to
10760** will be destroyed when the preupdate callback returns.
10761**
10762** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10763** callback was invoked as a result of a direct insert, update, or delete
10764** operation; or 1 for inserts, updates, or deletes invoked by top-level
10765** triggers; or 2 for changes resulting from triggers called by top-level
10766** triggers; and so forth.
10767**
10768** When the [sqlite3_blob_write()] API is used to update a blob column,
10769** the pre-update hook is invoked with SQLITE_DELETE, because
10770** the new values are not yet available. In this case, when a
10771** callback made with op==SQLITE_DELETE is actually a write using the
10772** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10773** the index of the column being written. In other cases, where the
10774** pre-update hook is being invoked for some other reason, including a
10775** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10776**
10777** See also: [sqlite3_update_hook()]
10778*/
10779#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10780SQLITE_API void *sqlite3_preupdate_hook(
10781 sqlite3 *db,
10782 void(*xPreUpdate)(
10783 void *pCtx, /* Copy of third arg to preupdate_hook() */
10784 sqlite3 *db, /* Database handle */
10785 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10786 char const *zDb, /* Database name */
10787 char const *zName, /* Table name */
10788 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10789 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10790 ),
10791 void*
10792);
10793SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10794SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10795SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10796SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10797SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10798#endif
10799
10800/*
10801** CAPI3REF: Low-level system error code
10802** METHOD: sqlite3
10803**
10804** ^Attempt to return the underlying operating system error code or error
10805** number that caused the most recent I/O error or failure to open a file.
10806** The return value is OS-dependent. For example, on unix systems, after
10807** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10808** called to get back the underlying "errno" that caused the problem, such
10809** as ENOSPC, EAUTH, EISDIR, and so forth.
10810*/
10811SQLITE_API int sqlite3_system_errno(sqlite3*);
10812
10813/*
10814** CAPI3REF: Database Snapshot
10815** KEYWORDS: {snapshot} {sqlite3_snapshot}
10816**
10817** An instance of the snapshot object records the state of a [WAL mode]
10818** database for some specific point in history.
10819**
10820** In [WAL mode], multiple [database connections] that are open on the
10821** same database file can each be reading a different historical version
10822** of the database file. When a [database connection] begins a read
10823** transaction, that connection sees an unchanging copy of the database
10824** as it existed for the point in time when the transaction first started.
10825** Subsequent changes to the database from other connections are not seen
10826** by the reader until a new read transaction is started.
10827**
10828** The sqlite3_snapshot object records state information about an historical
10829** version of the database file so that it is possible to later open a new read
10830** transaction that sees that historical version of the database rather than
10831** the most recent version.
10832*/
10833typedef struct sqlite3_snapshot {
10834 unsigned char hidden[48];
10835} sqlite3_snapshot;
10836
10837/*
10838** CAPI3REF: Record A Database Snapshot
10839** CONSTRUCTOR: sqlite3_snapshot
10840**
10841** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10842** new [sqlite3_snapshot] object that records the current state of
10843** schema S in database connection D. ^On success, the
10844** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10845** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10846** If there is not already a read-transaction open on schema S when
10847** this function is called, one is opened automatically.
10848**
10849** If a read-transaction is opened by this function, then it is guaranteed
10850** that the returned snapshot object may not be invalidated by a database
10851** writer or checkpointer until after the read-transaction is closed. This
10852** is not guaranteed if a read-transaction is already open when this
10853** function is called. In that case, any subsequent write or checkpoint
10854** operation on the database may invalidate the returned snapshot handle,
10855** even while the read-transaction remains open.
10856**
10857** The following must be true for this function to succeed. If any of
10858** the following statements are false when sqlite3_snapshot_get() is
10859** called, SQLITE_ERROR is returned. The final value of *P is undefined
10860** in this case.
10861**
10862** <ul>
10863** <li> The database handle must not be in [autocommit mode].
10864**
10865** <li> Schema S of [database connection] D must be a [WAL mode] database.
10866**
10867** <li> There must not be a write transaction open on schema S of database
10868** connection D.
10869**
10870** <li> One or more transactions must have been written to the current wal
10871** file since it was created on disk (by any connection). This means
10872** that a snapshot cannot be taken on a wal mode database with no wal
10873** file immediately after it is first opened. At least one transaction
10874** must be written to it first.
10875** </ul>
10876**
10877** This function may also return SQLITE_NOMEM. If it is called with the
10878** database handle in autocommit mode but fails for some other reason,
10879** whether or not a read transaction is opened on schema S is undefined.
10880**
10881** The [sqlite3_snapshot] object returned from a successful call to
10882** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10883** to avoid a memory leak.
10884**
10885** The [sqlite3_snapshot_get()] interface is only available when the
10886** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10887*/
10888SQLITE_API int sqlite3_snapshot_get(
10889 sqlite3 *db,
10890 const char *zSchema,
10891 sqlite3_snapshot **ppSnapshot
10892);
10893
10894/*
10895** CAPI3REF: Start a read transaction on an historical snapshot
10896** METHOD: sqlite3_snapshot
10897**
10898** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10899** transaction or upgrades an existing one for schema S of
10900** [database connection] D such that the read transaction refers to
10901** historical [snapshot] P, rather than the most recent change to the
10902** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10903** on success or an appropriate [error code] if it fails.
10904**
10905** ^In order to succeed, the database connection must not be in
10906** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10907** is already a read transaction open on schema S, then the database handle
10908** must have no active statements (SELECT statements that have been passed
10909** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10910** SQLITE_ERROR is returned if either of these conditions is violated, or
10911** if schema S does not exist, or if the snapshot object is invalid.
10912**
10913** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10914** snapshot has been overwritten by a [checkpoint]. In this case
10915** SQLITE_ERROR_SNAPSHOT is returned.
10916**
10917** If there is already a read transaction open when this function is
10918** invoked, then the same read transaction remains open (on the same
10919** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10920** is returned. If another error code - for example SQLITE_PROTOCOL or an
10921** SQLITE_IOERR error code - is returned, then the final state of the
10922** read transaction is undefined. If SQLITE_OK is returned, then the
10923** read transaction is now open on database snapshot P.
10924**
10925** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10926** database connection D does not know that the database file for
10927** schema S is in [WAL mode]. A database connection might not know
10928** that the database file is in [WAL mode] if there has been no prior
10929** I/O on that database connection, or if the database entered [WAL mode]
10930** after the most recent I/O on the database connection.)^
10931** (Hint: Run "[PRAGMA application_id]" against a newly opened
10932** database connection in order to make it ready to use snapshots.)
10933**
10934** The [sqlite3_snapshot_open()] interface is only available when the
10935** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10936*/
10937SQLITE_API int sqlite3_snapshot_open(
10938 sqlite3 *db,
10939 const char *zSchema,
10940 sqlite3_snapshot *pSnapshot
10941);
10942
10943/*
10944** CAPI3REF: Destroy a snapshot
10945** DESTRUCTOR: sqlite3_snapshot
10946**
10947** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10948** The application must eventually free every [sqlite3_snapshot] object
10949** using this routine to avoid a memory leak.
10950**
10951** The [sqlite3_snapshot_free()] interface is only available when the
10952** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10953*/
10954SQLITE_API void sqlite3_snapshot_free(sqlite3_snapshot*);
10955
10956/*
10957** CAPI3REF: Compare the ages of two snapshot handles.
10958** METHOD: sqlite3_snapshot
10959**
10960** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10961** of two valid snapshot handles.
10962**
10963** If the two snapshot handles are not associated with the same database
10964** file, the result of the comparison is undefined.
10965**
10966** Additionally, the result of the comparison is only valid if both of the
10967** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10968** last time the wal file was deleted. The wal file is deleted when the
10969** database is changed back to rollback mode or when the number of database
10970** clients drops to zero. If either snapshot handle was obtained before the
10971** wal file was last deleted, the value returned by this function
10972** is undefined.
10973**
10974** Otherwise, this API returns a negative value if P1 refers to an older
10975** snapshot than P2, zero if the two handles refer to the same database
10976** snapshot, and a positive value if P1 is a newer snapshot than P2.
10977**
10978** This interface is only available if SQLite is compiled with the
10979** [SQLITE_ENABLE_SNAPSHOT] option.
10980*/
10981SQLITE_API int sqlite3_snapshot_cmp(
10982 sqlite3_snapshot *p1,
10983 sqlite3_snapshot *p2
10984);
10985
10986/*
10987** CAPI3REF: Recover snapshots from a wal file
10988** METHOD: sqlite3_snapshot
10989**
10990** If a [WAL file] remains on disk after all database connections close
10991** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10992** or because the last process to have the database opened exited without
10993** calling [sqlite3_close()]) and a new connection is subsequently opened
10994** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10995** will only be able to open the last transaction added to the WAL file
10996** even though the WAL file contains other valid transactions.
10997**
10998** This function attempts to scan the WAL file associated with database zDb
10999** of database handle db and make all valid snapshots available to
11000** sqlite3_snapshot_open(). It is an error if there is already a read
11001** transaction open on the database, or if the database is not a WAL mode
11002** database.
11003**
11004** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
11005**
11006** This interface is only available if SQLite is compiled with the
11007** [SQLITE_ENABLE_SNAPSHOT] option.
11008*/
11009SQLITE_API int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
11010
11011/*
11012** CAPI3REF: Serialize a database
11013**
11014** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
11015** memory that is a serialization of the S database on
11016** [database connection] D. If S is a NULL pointer, the main database is used.
11017** If P is not a NULL pointer, then the size of the database in bytes
11018** is written into *P.
11019**
11020** For an ordinary on-disk database file, the serialization is just a
11021** copy of the disk file. For an in-memory database or a "TEMP" database,
11022** the serialization is the same sequence of bytes which would be written
11023** to disk if that database were backed up to disk.
11024**
11025** The usual case is that sqlite3_serialize() copies the serialization of
11026** the database into memory obtained from [sqlite3_malloc64()] and returns
11027** a pointer to that memory. The caller is responsible for freeing the
11028** returned value to avoid a memory leak. However, if the F argument
11029** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
11030** are made, and the sqlite3_serialize() function will return a pointer
11031** to the contiguous memory representation of the database that SQLite
11032** is currently using for that database, or NULL if no such contiguous
11033** memory representation of the database exists. A contiguous memory
11034** representation of the database will usually only exist if there has
11035** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
11036** values of D and S.
11037** The size of the database is written into *P even if the
11038** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
11039** of the database exists.
11040**
11041** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
11042** the returned buffer content will remain accessible and unchanged
11043** until either the next write operation on the connection or when
11044** the connection is closed, and applications must not modify the
11045** buffer. If the bit had been clear, the returned buffer will not
11046** be accessed by SQLite after the call.
11047**
11048** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
11049** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
11050** allocation error occurs.
11051**
11052** This interface is omitted if SQLite is compiled with the
11053** [SQLITE_OMIT_DESERIALIZE] option.
11054*/
11055SQLITE_API unsigned char *sqlite3_serialize(
11056 sqlite3 *db, /* The database connection */
11057 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
11058 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
11059 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
11060);
11061
11062/*
11063** CAPI3REF: Flags for sqlite3_serialize
11064**
11065** Zero or more of the following constants can be OR-ed together for
11066** the F argument to [sqlite3_serialize(D,S,P,F)].
11067**
11068** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
11069** a pointer to contiguous in-memory database that it is currently using,
11070** without making a copy of the database. If SQLite is not currently using
11071** a contiguous in-memory database, then this option causes
11072** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
11073** using a contiguous in-memory database if it has been initialized by a
11074** prior call to [sqlite3_deserialize()].
11075*/
11076#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
11077
11078/*
11079** CAPI3REF: Deserialize a database
11080**
11081** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
11082** [database connection] D to disconnect from database S and then
11083** reopen S as an in-memory database based on the serialization
11084** contained in P. If S is a NULL pointer, the main database is
11085** used. The serialized database P is N bytes in size. M is the size
11086** of the buffer P, which might be larger than N. If M is larger than
11087** N, and the SQLITE_DESERIALIZE_READONLY bit is not set in F, then
11088** SQLite is permitted to add content to the in-memory database as
11089** long as the total size does not exceed M bytes.
11090**
11091** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
11092** invoke sqlite3_free() on the serialization buffer when the database
11093** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
11094** SQLite will try to increase the buffer size using sqlite3_realloc64()
11095** if writes on the database cause it to grow larger than M bytes.
11096**
11097** Applications must not modify the buffer P or invalidate it before
11098** the database connection D is closed.
11099**
11100** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
11101** database is currently in a read transaction or is involved in a backup
11102** operation.
11103**
11104** It is not possible to deserialize into the TEMP database. If the
11105** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
11106** function returns SQLITE_ERROR.
11107**
11108** The deserialized database should not be in [WAL mode]. If the database
11109** is in WAL mode, then any attempt to use the database file will result
11110** in an [SQLITE_CANTOPEN] error. The application can set the
11111** [file format version numbers] (bytes 18 and 19) of the input database P
11112** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
11113** database file into rollback mode and work around this limitation.
11114**
11115** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
11116** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
11117** [sqlite3_free()] is invoked on argument P prior to returning.
11118**
11119** This interface is omitted if SQLite is compiled with the
11120** [SQLITE_OMIT_DESERIALIZE] option.
11121*/
11122SQLITE_API int sqlite3_deserialize(
11123 sqlite3 *db, /* The database connection */
11124 const char *zSchema, /* Which DB to reopen with the deserialization */
11125 unsigned char *pData, /* The serialized database content */
11126 sqlite3_int64 szDb, /* Number of bytes in the deserialization */
11127 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
11128 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
11129);
11130
11131/*
11132** CAPI3REF: Flags for sqlite3_deserialize()
11133**
11134** The following are allowed values for the 6th argument (the F argument) to
11135** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
11136**
11137** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
11138** in the P argument is held in memory obtained from [sqlite3_malloc64()]
11139** and that SQLite should take ownership of this memory and automatically
11140** free it when it has finished using it. Without this flag, the caller
11141** is responsible for freeing any dynamically allocated memory.
11142**
11143** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
11144** grow the size of the database using calls to [sqlite3_realloc64()]. This
11145** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
11146** Without this flag, the deserialized database cannot increase in size beyond
11147** the number of bytes specified by the M parameter.
11148**
11149** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
11150** should be treated as read-only.
11151*/
11152#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
11153#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
11154#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
11155
11156/*
11157** CAPI3REF: Bind array values to the CARRAY table-valued function
11158**
11159** The sqlite3_carray_bind(S,I,P,N,F,X) interface binds an array value to
11160** one of the first argument of the [carray() table-valued function]. The
11161** S parameter is a pointer to the [prepared statement] that uses the carray()
11162** functions. I is the parameter index to be bound. P is a pointer to the
11163** array to be bound, and N is the number of eements in the array. The
11164** F argument is one of constants [SQLITE_CARRAY_INT32], [SQLITE_CARRAY_INT64],
11165** [SQLITE_CARRAY_DOUBLE], [SQLITE_CARRAY_TEXT], or [SQLITE_CARRAY_BLOB] to
11166** indicate the datatype of the array being bound. The X argument is not a
11167** NULL pointer, then SQLite will invoke the function X on the P parameter
11168** after it has finished using P, even if the call to
11169** sqlite3_carray_bind() fails. The special-case finalizer
11170** SQLITE_TRANSIENT has no effect here.
11171*/
11172SQLITE_API int sqlite3_carray_bind(
11173 sqlite3_stmt *pStmt, /* Statement to be bound */
11174 int i, /* Parameter index */
11175 void *aData, /* Pointer to array data */
11176 int nData, /* Number of data elements */
11177 int mFlags, /* CARRAY flags */
11178 void (*xDel)(void*) /* Destructor for aData */
11179);
11180
11181/*
11182** CAPI3REF: Datatypes for the CARRAY table-valued function
11183**
11184** The fifth argument to the [sqlite3_carray_bind()] interface musts be
11185** one of the following constants, to specify the datatype of the array
11186** that is being bound into the [carray table-valued function].
11187*/
11188#define SQLITE_CARRAY_INT32 0 /* Data is 32-bit signed integers */
11189#define SQLITE_CARRAY_INT64 1 /* Data is 64-bit signed integers */
11190#define SQLITE_CARRAY_DOUBLE 2 /* Data is doubles */
11191#define SQLITE_CARRAY_TEXT 3 /* Data is char* */
11192#define SQLITE_CARRAY_BLOB 4 /* Data is struct iovec */
11193
11194/*
11195** Versions of the above #defines that omit the initial SQLITE_, for
11196** legacy compatibility.
11197*/
11198#define CARRAY_INT32 0 /* Data is 32-bit signed integers */
11199#define CARRAY_INT64 1 /* Data is 64-bit signed integers */
11200#define CARRAY_DOUBLE 2 /* Data is doubles */
11201#define CARRAY_TEXT 3 /* Data is char* */
11202#define CARRAY_BLOB 4 /* Data is struct iovec */
11203
11204/*
11205** Undo the hack that converts floating point types to integer for
11206** builds on processors without floating point support.
11207*/
11208#ifdef SQLITE_OMIT_FLOATING_POINT
11209# undef double
11210#endif
11211
11212#if defined(__wasi__)
11213# undef SQLITE_WASI
11214# define SQLITE_WASI 1
11215# ifndef SQLITE_OMIT_LOAD_EXTENSION
11216# define SQLITE_OMIT_LOAD_EXTENSION
11217# endif
11218# ifndef SQLITE_THREADSAFE
11219# define SQLITE_THREADSAFE 0
11220# endif
11221#endif
11222
11223#ifdef __cplusplus
11224} /* End of the 'extern "C"' block */
11225#endif
11226/* #endif for SQLITE3_H will be added by mksqlite3.tcl */
11227
11228/******** Begin file sqlite3rtree.h *********/
11229/*
11230** 2010 August 30
11231**
11232** The author disclaims copyright to this source code. In place of
11233** a legal notice, here is a blessing:
11234**
11235** May you do good and not evil.
11236** May you find forgiveness for yourself and forgive others.
11237** May you share freely, never taking more than you give.
11238**
11239*************************************************************************
11240*/
11241
11242#ifndef _SQLITE3RTREE_H_
11243#define _SQLITE3RTREE_H_
11244
11245
11246#ifdef __cplusplus
11247extern "C" {
11248#endif
11249
11250typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
11251typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
11252
11253/* The double-precision datatype used by RTree depends on the
11254** SQLITE_RTREE_INT_ONLY compile-time option.
11255*/
11256#ifdef SQLITE_RTREE_INT_ONLY
11257 typedef sqlite3_int64 sqlite3_rtree_dbl;
11258#else
11259 typedef double sqlite3_rtree_dbl;
11260#endif
11261
11262/*
11263** Register a geometry callback named zGeom that can be used as part of an
11264** R-Tree geometry query as follows:
11265**
11266** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
11267*/
11268SQLITE_API int sqlite3_rtree_geometry_callback(
11269 sqlite3 *db,
11270 const char *zGeom,
11271 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
11272 void *pContext
11273);
11274
11275
11276/*
11277** A pointer to a structure of the following type is passed as the first
11278** argument to callbacks registered using rtree_geometry_callback().
11279*/
11280struct sqlite3_rtree_geometry {
11281 void *pContext; /* Copy of pContext passed to s_r_g_c() */
11282 int nParam; /* Size of array aParam[] */
11283 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
11284 void *pUser; /* Callback implementation user data */
11285 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
11286};
11287
11288/*
11289** Register a 2nd-generation geometry callback named zScore that can be
11290** used as part of an R-Tree geometry query as follows:
11291**
11292** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
11293*/
11294SQLITE_API int sqlite3_rtree_query_callback(
11295 sqlite3 *db,
11296 const char *zQueryFunc,
11297 int (*xQueryFunc)(sqlite3_rtree_query_info*),
11298 void *pContext,
11299 void (*xDestructor)(void*)
11300);
11301
11302
11303/*
11304** A pointer to a structure of the following type is passed as the
11305** argument to scored geometry callback registered using
11306** sqlite3_rtree_query_callback().
11307**
11308** Note that the first 5 fields of this structure are identical to
11309** sqlite3_rtree_geometry. This structure is a subclass of
11310** sqlite3_rtree_geometry.
11311*/
11312struct sqlite3_rtree_query_info {
11313 void *pContext; /* pContext from when function registered */
11314 int nParam; /* Number of function parameters */
11315 sqlite3_rtree_dbl *aParam; /* value of function parameters */
11316 void *pUser; /* callback can use this, if desired */
11317 void (*xDelUser)(void*); /* function to free pUser */
11318 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
11319 unsigned int *anQueue; /* Number of pending entries in the queue */
11320 int nCoord; /* Number of coordinates */
11321 int iLevel; /* Level of current node or entry */
11322 int mxLevel; /* The largest iLevel value in the tree */
11323 sqlite3_int64 iRowid; /* Rowid for current entry */
11324 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
11325 int eParentWithin; /* Visibility of parent node */
11326 int eWithin; /* OUT: Visibility */
11327 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
11328 /* The following fields are only available in 3.8.11 and later */
11329 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
11330};
11331
11332/*
11333** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
11334*/
11335#define NOT_WITHIN 0 /* Object completely outside of query region */
11336#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
11337#define FULLY_WITHIN 2 /* Object fully contained within query region */
11338
11339
11340#ifdef __cplusplus
11341} /* end of the 'extern "C"' block */
11342#endif
11343
11344#endif /* ifndef _SQLITE3RTREE_H_ */
11345
11346/******** End of sqlite3rtree.h *********/
11347/******** Begin file sqlite3session.h *********/
11348
11349#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
11350#define __SQLITESESSION_H_ 1
11351
11352/*
11353** Make sure we can call this stuff from C++.
11354*/
11355#ifdef __cplusplus
11356extern "C" {
11357#endif
11358
11359
11360/*
11361** CAPI3REF: Session Object Handle
11362**
11363** An instance of this object is a [session] that can be used to
11364** record changes to a database.
11365*/
11366typedef struct sqlite3_session sqlite3_session;
11367
11368/*
11369** CAPI3REF: Changeset Iterator Handle
11370**
11371** An instance of this object acts as a cursor for iterating
11372** over the elements of a [changeset] or [patchset].
11373*/
11374typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
11375
11376/*
11377** CAPI3REF: Create A New Session Object
11378** CONSTRUCTOR: sqlite3_session
11379**
11380** Create a new session object attached to database handle db. If successful,
11381** a pointer to the new object is written to *ppSession and SQLITE_OK is
11382** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11383** error code (e.g. SQLITE_NOMEM) is returned.
11384**
11385** It is possible to create multiple session objects attached to a single
11386** database handle.
11387**
11388** Session objects created using this function should be deleted using the
11389** [sqlite3session_delete()] function before the database handle that they
11390** are attached to is itself closed. If the database handle is closed before
11391** the session object is deleted, then the results of calling any session
11392** module function, including [sqlite3session_delete()] on the session object
11393** are undefined.
11394**
11395** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11396** is not possible for an application to register a pre-update hook on a
11397** database handle that has one or more session objects attached. Nor is
11398** it possible to create a session object attached to a database handle for
11399** which a pre-update hook is already defined. The results of attempting
11400** either of these things are undefined.
11401**
11402** The session object will be used to create changesets for tables in
11403** database zDb, where zDb is either "main", or "temp", or the name of an
11404** attached database. It is not an error if database zDb is not attached
11405** to the database when the session object is created.
11406*/
11407SQLITE_API int sqlite3session_create(
11408 sqlite3 *db, /* Database handle */
11409 const char *zDb, /* Name of db (e.g. "main") */
11410 sqlite3_session **ppSession /* OUT: New session object */
11411);
11412
11413/*
11414** CAPI3REF: Delete A Session Object
11415** DESTRUCTOR: sqlite3_session
11416**
11417** Delete a session object previously allocated using
11418** [sqlite3session_create()]. Once a session object has been deleted, the
11419** results of attempting to use pSession with any other session module
11420** function are undefined.
11421**
11422** Session objects must be deleted before the database handle to which they
11423** are attached is closed. Refer to the documentation for
11424** [sqlite3session_create()] for details.
11425*/
11426SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11427
11428/*
11429** CAPI3REF: Configure a Session Object
11430** METHOD: sqlite3_session
11431**
11432** This method is used to configure a session object after it has been
11433** created. At present the only valid values for the second parameter are
11434** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11435**
11436*/
11437SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11438
11439/*
11440** CAPI3REF: Options for sqlite3session_object_config
11441**
11442** The following values may passed as the the 2nd parameter to
11443** sqlite3session_object_config().
11444**
11445** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11446** This option is used to set, clear or query the flag that enables
11447** the [sqlite3session_changeset_size()] API. Because it imposes some
11448** computational overhead, this API is disabled by default. Argument
11449** pArg must point to a value of type (int). If the value is initially
11450** 0, then the sqlite3session_changeset_size() API is disabled. If it
11451** is greater than 0, then the same API is enabled. Or, if the initial
11452** value is less than zero, no change is made. In all cases the (int)
11453** variable is set to 1 if the sqlite3session_changeset_size() API is
11454** enabled following the current call, or 0 otherwise.
11455**
11456** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11457** the first table has been attached to the session object.
11458**
11459** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11460** This option is used to set, clear or query the flag that enables
11461** collection of data for tables with no explicit PRIMARY KEY.
11462**
11463** Normally, tables with no explicit PRIMARY KEY are simply ignored
11464** by the sessions module. However, if this flag is set, it behaves
11465** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11466** as their leftmost columns.
11467**
11468** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11469** the first table has been attached to the session object.
11470*/
11471#define SQLITE_SESSION_OBJCONFIG_SIZE 1
11472#define SQLITE_SESSION_OBJCONFIG_ROWID 2
11473
11474/*
11475** CAPI3REF: Enable Or Disable A Session Object
11476** METHOD: sqlite3_session
11477**
11478** Enable or disable the recording of changes by a session object. When
11479** enabled, a session object records changes made to the database. When
11480** disabled - it does not. A newly created session object is enabled.
11481** Refer to the documentation for [sqlite3session_changeset()] for further
11482** details regarding how enabling and disabling a session object affects
11483** the eventual changesets.
11484**
11485** Passing zero to this function disables the session. Passing a value
11486** greater than zero enables it. Passing a value less than zero is a
11487** no-op, and may be used to query the current state of the session.
11488**
11489** The return value indicates the final state of the session object: 0 if
11490** the session is disabled, or 1 if it is enabled.
11491*/
11492SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11493
11494/*
11495** CAPI3REF: Set Or Clear the Indirect Change Flag
11496** METHOD: sqlite3_session
11497**
11498** Each change recorded by a session object is marked as either direct or
11499** indirect. A change is marked as indirect if either:
11500**
11501** <ul>
11502** <li> The session object "indirect" flag is set when the change is
11503** made, or
11504** <li> The change is made by an SQL trigger or foreign key action
11505** instead of directly as a result of a users SQL statement.
11506** </ul>
11507**
11508** If a single row is affected by more than one operation within a session,
11509** then the change is considered indirect if all operations meet the criteria
11510** for an indirect change above, or direct otherwise.
11511**
11512** This function is used to set, clear or query the session object indirect
11513** flag. If the second argument passed to this function is zero, then the
11514** indirect flag is cleared. If it is greater than zero, the indirect flag
11515** is set. Passing a value less than zero does not modify the current value
11516** of the indirect flag, and may be used to query the current state of the
11517** indirect flag for the specified session object.
11518**
11519** The return value indicates the final state of the indirect flag: 0 if
11520** it is clear, or 1 if it is set.
11521*/
11522SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11523
11524/*
11525** CAPI3REF: Attach A Table To A Session Object
11526** METHOD: sqlite3_session
11527**
11528** If argument zTab is not NULL, then it is the name of a table to attach
11529** to the session object passed as the first argument. All subsequent changes
11530** made to the table while the session object is enabled will be recorded. See
11531** documentation for [sqlite3session_changeset()] for further details.
11532**
11533** Or, if argument zTab is NULL, then changes are recorded for all tables
11534** in the database. If additional tables are added to the database (by
11535** executing "CREATE TABLE" statements) after this call is made, changes for
11536** the new tables are also recorded.
11537**
11538** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11539** defined as part of their CREATE TABLE statement. It does not matter if the
11540** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11541** KEY may consist of a single column, or may be a composite key.
11542**
11543** It is not an error if the named table does not exist in the database. Nor
11544** is it an error if the named table does not have a PRIMARY KEY. However,
11545** no changes will be recorded in either of these scenarios.
11546**
11547** Changes are not recorded for individual rows that have NULL values stored
11548** in one or more of their PRIMARY KEY columns.
11549**
11550** SQLITE_OK is returned if the call completes without error. Or, if an error
11551** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11552**
11553** <h3>Special sqlite_stat1 Handling</h3>
11554**
11555** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11556** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11557** <pre>
11558** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
11559** </pre>
11560**
11561** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11562** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11563** are recorded for rows for which (idx IS NULL) is true. However, for such
11564** rows a zero-length blob (SQL value X'') is stored in the changeset or
11565** patchset instead of a NULL value. This allows such changesets to be
11566** manipulated by legacy implementations of sqlite3changeset_invert(),
11567** concat() and similar.
11568**
11569** The sqlite3changeset_apply() function automatically converts the
11570** zero-length blob back to a NULL value when updating the sqlite_stat1
11571** table. However, if the application calls sqlite3changeset_new(),
11572** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11573** iterator directly (including on a changeset iterator passed to a
11574** conflict-handler callback) then the X'' value is returned. The application
11575** must translate X'' to NULL itself if required.
11576**
11577** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11578** changes made to the sqlite_stat1 table. Legacy versions of the
11579** sqlite3changeset_apply() function silently ignore any modifications to the
11580** sqlite_stat1 table that are part of a changeset or patchset.
11581*/
11582SQLITE_API int sqlite3session_attach(
11583 sqlite3_session *pSession, /* Session object */
11584 const char *zTab /* Table name */
11585);
11586
11587/*
11588** CAPI3REF: Set a table filter on a Session Object.
11589** METHOD: sqlite3_session
11590**
11591** The second argument (xFilter) is the "filter callback". For changes to rows
11592** in tables that are not attached to the Session object, the filter is called
11593** to determine whether changes to the table's rows should be tracked or not.
11594** If xFilter returns 0, changes are not tracked. Note that once a table is
11595** attached, xFilter will not be called again.
11596*/
11597SQLITE_API void sqlite3session_table_filter(
11598 sqlite3_session *pSession, /* Session object */
11599 int(*xFilter)(
11600 void *pCtx, /* Copy of third arg to _filter_table() */
11601 const char *zTab /* Table name */
11602 ),
11603 void *pCtx /* First argument passed to xFilter */
11604);
11605
11606/*
11607** CAPI3REF: Generate A Changeset From A Session Object
11608** METHOD: sqlite3_session
11609**
11610** Obtain a changeset containing changes to the tables attached to the
11611** session object passed as the first argument. If successful,
11612** set *ppChangeset to point to a buffer containing the changeset
11613** and *pnChangeset to the size of the changeset in bytes before returning
11614** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11615** zero and return an SQLite error code.
11616**
11617** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11618** each representing a change to a single row of an attached table. An INSERT
11619** change contains the values of each field of a new database row. A DELETE
11620** contains the original values of each field of a deleted database row. An
11621** UPDATE change contains the original values of each field of an updated
11622** database row along with the updated values for each updated non-primary-key
11623** column. It is not possible for an UPDATE change to represent a change that
11624** modifies the values of primary key columns. If such a change is made, it
11625** is represented in a changeset as a DELETE followed by an INSERT.
11626**
11627** Changes are not recorded for rows that have NULL values stored in one or
11628** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11629** no corresponding change is present in the changesets returned by this
11630** function. If an existing row with one or more NULL values stored in
11631** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11632** only an INSERT is appears in the changeset. Similarly, if an existing row
11633** with non-NULL PRIMARY KEY values is updated so that one or more of its
11634** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11635** DELETE change only.
11636**
11637** The contents of a changeset may be traversed using an iterator created
11638** using the [sqlite3changeset_start()] API. A changeset may be applied to
11639** a database with a compatible schema using the [sqlite3changeset_apply()]
11640** API.
11641**
11642** Within a changeset generated by this function, all changes related to a
11643** single table are grouped together. In other words, when iterating through
11644** a changeset or when applying a changeset to a database, all changes related
11645** to a single table are processed before moving on to the next table. Tables
11646** are sorted in the same order in which they were attached (or auto-attached)
11647** to the sqlite3_session object. The order in which the changes related to
11648** a single table are stored is undefined.
11649**
11650** Following a successful call to this function, it is the responsibility of
11651** the caller to eventually free the buffer that *ppChangeset points to using
11652** [sqlite3_free()].
11653**
11654** <h3>Changeset Generation</h3>
11655**
11656** Once a table has been attached to a session object, the session object
11657** records the primary key values of all new rows inserted into the table.
11658** It also records the original primary key and other column values of any
11659** deleted or updated rows. For each unique primary key value, data is only
11660** recorded once - the first time a row with said primary key is inserted,
11661** updated or deleted in the lifetime of the session.
11662**
11663** There is one exception to the previous paragraph: when a row is inserted,
11664** updated or deleted, if one or more of its primary key columns contain a
11665** NULL value, no record of the change is made.
11666**
11667** The session object therefore accumulates two types of records - those
11668** that consist of primary key values only (created when the user inserts
11669** a new record) and those that consist of the primary key values and the
11670** original values of other table columns (created when the users deletes
11671** or updates a record).
11672**
11673** When this function is called, the requested changeset is created using
11674** both the accumulated records and the current contents of the database
11675** file. Specifically:
11676**
11677** <ul>
11678** <li> For each record generated by an insert, the database is queried
11679** for a row with a matching primary key. If one is found, an INSERT
11680** change is added to the changeset. If no such row is found, no change
11681** is added to the changeset.
11682**
11683** <li> For each record generated by an update or delete, the database is
11684** queried for a row with a matching primary key. If such a row is
11685** found and one or more of the non-primary key fields have been
11686** modified from their original values, an UPDATE change is added to
11687** the changeset. Or, if no such row is found in the table, a DELETE
11688** change is added to the changeset. If there is a row with a matching
11689** primary key in the database, but all fields contain their original
11690** values, no change is added to the changeset.
11691** </ul>
11692**
11693** This means, amongst other things, that if a row is inserted and then later
11694** deleted while a session object is active, neither the insert nor the delete
11695** will be present in the changeset. Or if a row is deleted and then later a
11696** row with the same primary key values inserted while a session object is
11697** active, the resulting changeset will contain an UPDATE change instead of
11698** a DELETE and an INSERT.
11699**
11700** When a session object is disabled (see the [sqlite3session_enable()] API),
11701** it does not accumulate records when rows are inserted, updated or deleted.
11702** This may appear to have some counter-intuitive effects if a single row
11703** is written to more than once during a session. For example, if a row
11704** is inserted while a session object is enabled, then later deleted while
11705** the same session object is disabled, no INSERT record will appear in the
11706** changeset, even though the delete took place while the session was disabled.
11707** Or, if one field of a row is updated while a session is enabled, and
11708** then another field of the same row is updated while the session is disabled,
11709** the resulting changeset will contain an UPDATE change that updates both
11710** fields.
11711*/
11712SQLITE_API int sqlite3session_changeset(
11713 sqlite3_session *pSession, /* Session object */
11714 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11715 void **ppChangeset /* OUT: Buffer containing changeset */
11716);
11717
11718/*
11719** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11720** METHOD: sqlite3_session
11721**
11722** By default, this function always returns 0. For it to return
11723** a useful result, the sqlite3_session object must have been configured
11724** to enable this API using sqlite3session_object_config() with the
11725** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11726**
11727** When enabled, this function returns an upper limit, in bytes, for the size
11728** of the changeset that might be produced if sqlite3session_changeset() were
11729** called. The final changeset size might be equal to or smaller than the
11730** size in bytes returned by this function.
11731*/
11732SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11733
11734/*
11735** CAPI3REF: Load The Difference Between Tables Into A Session
11736** METHOD: sqlite3_session
11737**
11738** If it is not already attached to the session object passed as the first
11739** argument, this function attaches table zTbl in the same manner as the
11740** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11741** does not have a primary key, this function is a no-op (but does not return
11742** an error).
11743**
11744** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11745** attached to the same database handle as the session object that contains
11746** a table compatible with the table attached to the session by this function.
11747** A table is considered compatible if it:
11748**
11749** <ul>
11750** <li> Has the same name,
11751** <li> Has the same set of columns declared in the same order, and
11752** <li> Has the same PRIMARY KEY definition.
11753** </ul>
11754**
11755** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11756** are compatible but do not have any PRIMARY KEY columns, it is not an error
11757** but no changes are added to the session object. As with other session
11758** APIs, tables without PRIMARY KEYs are simply ignored.
11759**
11760** This function adds a set of changes to the session object that could be
11761** used to update the table in database zFrom (call this the "from-table")
11762** so that its content is the same as the table attached to the session
11763** object (call this the "to-table"). Specifically:
11764**
11765** <ul>
11766** <li> For each row (primary key) that exists in the to-table but not in
11767** the from-table, an INSERT record is added to the session object.
11768**
11769** <li> For each row (primary key) that exists in the to-table but not in
11770** the from-table, a DELETE record is added to the session object.
11771**
11772** <li> For each row (primary key) that exists in both tables, but features
11773** different non-PK values in each, an UPDATE record is added to the
11774** session.
11775** </ul>
11776**
11777** To clarify, if this function is called and then a changeset constructed
11778** using [sqlite3session_changeset()], then after applying that changeset to
11779** database zFrom the contents of the two compatible tables would be
11780** identical.
11781**
11782** Unless the call to this function is a no-op as described above, it is an
11783** error if database zFrom does not exist or does not contain the required
11784** compatible table.
11785**
11786** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11787** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11788** may be set to point to a buffer containing an English language error
11789** message. It is the responsibility of the caller to free this buffer using
11790** sqlite3_free().
11791*/
11792SQLITE_API int sqlite3session_diff(
11793 sqlite3_session *pSession,
11794 const char *zFromDb,
11795 const char *zTbl,
11796 char **pzErrMsg
11797);
11798
11799
11800/*
11801** CAPI3REF: Generate A Patchset From A Session Object
11802** METHOD: sqlite3_session
11803**
11804** The differences between a patchset and a changeset are that:
11805**
11806** <ul>
11807** <li> DELETE records consist of the primary key fields only. The
11808** original values of other fields are omitted.
11809** <li> The original values of any modified fields are omitted from
11810** UPDATE records.
11811** </ul>
11812**
11813** A patchset blob may be used with up to date versions of all
11814** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11815** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11816** attempting to use a patchset blob with old versions of the
11817** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11818**
11819** Because the non-primary key "old.*" fields are omitted, no
11820** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11821** is passed to the sqlite3changeset_apply() API. Other conflict types work
11822** in the same way as for changesets.
11823**
11824** Changes within a patchset are ordered in the same way as for changesets
11825** generated by the sqlite3session_changeset() function (i.e. all changes for
11826** a single table are grouped together, tables appear in the order in which
11827** they were attached to the session object).
11828*/
11829SQLITE_API int sqlite3session_patchset(
11830 sqlite3_session *pSession, /* Session object */
11831 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11832 void **ppPatchset /* OUT: Buffer containing patchset */
11833);
11834
11835/*
11836** CAPI3REF: Test if a changeset has recorded any changes.
11837**
11838** Return non-zero if no changes to attached tables have been recorded by
11839** the session object passed as the first argument. Otherwise, if one or
11840** more changes have been recorded, return zero.
11841**
11842** Even if this function returns zero, it is possible that calling
11843** [sqlite3session_changeset()] on the session handle may still return a
11844** changeset that contains no changes. This can happen when a row in
11845** an attached table is modified and then later on the original values
11846** are restored. However, if this function returns non-zero, then it is
11847** guaranteed that a call to sqlite3session_changeset() will return a
11848** changeset containing zero changes.
11849*/
11850SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11851
11852/*
11853** CAPI3REF: Query for the amount of heap memory used by a session object.
11854**
11855** This API returns the total amount of heap memory in bytes currently
11856** used by the session object passed as the only argument.
11857*/
11858SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11859
11860/*
11861** CAPI3REF: Create An Iterator To Traverse A Changeset
11862** CONSTRUCTOR: sqlite3_changeset_iter
11863**
11864** Create an iterator used to iterate through the contents of a changeset.
11865** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11866** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11867** SQLite error code is returned.
11868**
11869** The following functions can be used to advance and query a changeset
11870** iterator created by this function:
11871**
11872** <ul>
11873** <li> [sqlite3changeset_next()]
11874** <li> [sqlite3changeset_op()]
11875** <li> [sqlite3changeset_new()]
11876** <li> [sqlite3changeset_old()]
11877** </ul>
11878**
11879** It is the responsibility of the caller to eventually destroy the iterator
11880** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11881** changeset (pChangeset) must remain valid until after the iterator is
11882** destroyed.
11883**
11884** Assuming the changeset blob was created by one of the
11885** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11886** [sqlite3changeset_invert()] functions, all changes within the changeset
11887** that apply to a single table are grouped together. This means that when
11888** an application iterates through a changeset using an iterator created by
11889** this function, all changes that relate to a single table are visited
11890** consecutively. There is no chance that the iterator will visit a change
11891** the applies to table X, then one for table Y, and then later on visit
11892** another change for table X.
11893**
11894** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11895** may be modified by passing a combination of
11896** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11897**
11898** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11899** and therefore subject to change.
11900*/
11901SQLITE_API int sqlite3changeset_start(
11902 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11903 int nChangeset, /* Size of changeset blob in bytes */
11904 void *pChangeset /* Pointer to blob containing changeset */
11905);
11906SQLITE_API int sqlite3changeset_start_v2(
11907 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11908 int nChangeset, /* Size of changeset blob in bytes */
11909 void *pChangeset, /* Pointer to blob containing changeset */
11910 int flags /* SESSION_CHANGESETSTART_* flags */
11911);
11912
11913/*
11914** CAPI3REF: Flags for sqlite3changeset_start_v2
11915**
11916** The following flags may passed via the 4th parameter to
11917** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11918**
11919** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
11920** Invert the changeset while iterating through it. This is equivalent to
11921** inverting a changeset using sqlite3changeset_invert() before applying it.
11922** It is an error to specify this flag with a patchset.
11923*/
11924#define SQLITE_CHANGESETSTART_INVERT 0x0002
11925
11926
11927/*
11928** CAPI3REF: Advance A Changeset Iterator
11929** METHOD: sqlite3_changeset_iter
11930**
11931** This function may only be used with iterators created by the function
11932** [sqlite3changeset_start()]. If it is called on an iterator passed to
11933** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11934** is returned and the call has no effect.
11935**
11936** Immediately after an iterator is created by sqlite3changeset_start(), it
11937** does not point to any change in the changeset. Assuming the changeset
11938** is not empty, the first call to this function advances the iterator to
11939** point to the first change in the changeset. Each subsequent call advances
11940** the iterator to point to the next change in the changeset (if any). If
11941** no error occurs and the iterator points to a valid change after a call
11942** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11943** Otherwise, if all changes in the changeset have already been visited,
11944** SQLITE_DONE is returned.
11945**
11946** If an error occurs, an SQLite error code is returned. Possible error
11947** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11948** SQLITE_NOMEM.
11949*/
11950SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11951
11952/*
11953** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11954** METHOD: sqlite3_changeset_iter
11955**
11956** The pIter argument passed to this function may either be an iterator
11957** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11958** created by [sqlite3changeset_start()]. In the latter case, the most recent
11959** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11960** is not the case, this function returns [SQLITE_MISUSE].
11961**
11962** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11963** outputs are set through these pointers:
11964**
11965** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11966** depending on the type of change that the iterator currently points to;
11967**
11968** *pnCol is set to the number of columns in the table affected by the change; and
11969**
11970** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11971** the name of the table affected by the current change. The buffer remains
11972** valid until either sqlite3changeset_next() is called on the iterator
11973** or until the conflict-handler function returns.
11974**
11975** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11976** is an indirect change, or false (0) otherwise. See the documentation for
11977** [sqlite3session_indirect()] for a description of direct and indirect
11978** changes.
11979**
11980** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11981** SQLite error code is returned. The values of the output variables may not
11982** be trusted in this case.
11983*/
11984SQLITE_API int sqlite3changeset_op(
11985 sqlite3_changeset_iter *pIter, /* Iterator object */
11986 const char **pzTab, /* OUT: Pointer to table name */
11987 int *pnCol, /* OUT: Number of columns in table */
11988 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11989 int *pbIndirect /* OUT: True for an 'indirect' change */
11990);
11991
11992/*
11993** CAPI3REF: Obtain The Primary Key Definition Of A Table
11994** METHOD: sqlite3_changeset_iter
11995**
11996** For each modified table, a changeset includes the following:
11997**
11998** <ul>
11999** <li> The number of columns in the table, and
12000** <li> Which of those columns make up the tables PRIMARY KEY.
12001** </ul>
12002**
12003** This function is used to find which columns comprise the PRIMARY KEY of
12004** the table modified by the change that iterator pIter currently points to.
12005** If successful, *pabPK is set to point to an array of nCol entries, where
12006** nCol is the number of columns in the table. Elements of *pabPK are set to
12007** 0x01 if the corresponding column is part of the tables primary key, or
12008** 0x00 if it is not.
12009**
12010** If argument pnCol is not NULL, then *pnCol is set to the number of columns
12011** in the table.
12012**
12013** If this function is called when the iterator does not point to a valid
12014** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
12015** SQLITE_OK is returned and the output variables populated as described
12016** above.
12017*/
12018SQLITE_API int sqlite3changeset_pk(
12019 sqlite3_changeset_iter *pIter, /* Iterator object */
12020 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
12021 int *pnCol /* OUT: Number of entries in output array */
12022);
12023
12024/*
12025** CAPI3REF: Obtain old.* Values From A Changeset Iterator
12026** METHOD: sqlite3_changeset_iter
12027**
12028** The pIter argument passed to this function may either be an iterator
12029** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12030** created by [sqlite3changeset_start()]. In the latter case, the most recent
12031** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12032** Furthermore, it may only be called if the type of change that the iterator
12033** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
12034** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12035**
12036** Argument iVal must be greater than or equal to 0, and less than the number
12037** of columns in the table affected by the current change. Otherwise,
12038** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12039**
12040** If successful, this function sets *ppValue to point to a protected
12041** sqlite3_value object containing the iVal'th value from the vector of
12042** original row values stored as part of the UPDATE or DELETE change and
12043** returns SQLITE_OK. The name of the function comes from the fact that this
12044** is similar to the "old.*" columns available to update or delete triggers.
12045**
12046** If some other error occurs (e.g. an OOM condition), an SQLite error code
12047** is returned and *ppValue is set to NULL.
12048*/
12049SQLITE_API int sqlite3changeset_old(
12050 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12051 int iVal, /* Column number */
12052 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
12053);
12054
12055/*
12056** CAPI3REF: Obtain new.* Values From A Changeset Iterator
12057** METHOD: sqlite3_changeset_iter
12058**
12059** The pIter argument passed to this function may either be an iterator
12060** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12061** created by [sqlite3changeset_start()]. In the latter case, the most recent
12062** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12063** Furthermore, it may only be called if the type of change that the iterator
12064** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
12065** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12066**
12067** Argument iVal must be greater than or equal to 0, and less than the number
12068** of columns in the table affected by the current change. Otherwise,
12069** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12070**
12071** If successful, this function sets *ppValue to point to a protected
12072** sqlite3_value object containing the iVal'th value from the vector of
12073** new row values stored as part of the UPDATE or INSERT change and
12074** returns SQLITE_OK. If the change is an UPDATE and does not include
12075** a new value for the requested column, *ppValue is set to NULL and
12076** SQLITE_OK returned. The name of the function comes from the fact that
12077** this is similar to the "new.*" columns available to update or delete
12078** triggers.
12079**
12080** If some other error occurs (e.g. an OOM condition), an SQLite error code
12081** is returned and *ppValue is set to NULL.
12082*/
12083SQLITE_API int sqlite3changeset_new(
12084 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12085 int iVal, /* Column number */
12086 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
12087);
12088
12089/*
12090** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
12091** METHOD: sqlite3_changeset_iter
12092**
12093** This function should only be used with iterator objects passed to a
12094** conflict-handler callback by [sqlite3changeset_apply()] with either
12095** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
12096** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
12097** is set to NULL.
12098**
12099** Argument iVal must be greater than or equal to 0, and less than the number
12100** of columns in the table affected by the current change. Otherwise,
12101** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12102**
12103** If successful, this function sets *ppValue to point to a protected
12104** sqlite3_value object containing the iVal'th value from the
12105** "conflicting row" associated with the current conflict-handler callback
12106** and returns SQLITE_OK.
12107**
12108** If some other error occurs (e.g. an OOM condition), an SQLite error code
12109** is returned and *ppValue is set to NULL.
12110*/
12111SQLITE_API int sqlite3changeset_conflict(
12112 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12113 int iVal, /* Column number */
12114 sqlite3_value **ppValue /* OUT: Value from conflicting row */
12115);
12116
12117/*
12118** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
12119** METHOD: sqlite3_changeset_iter
12120**
12121** This function may only be called with an iterator passed to an
12122** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
12123** it sets the output variable to the total number of known foreign key
12124** violations in the destination database and returns SQLITE_OK.
12125**
12126** In all other cases this function returns SQLITE_MISUSE.
12127*/
12128SQLITE_API int sqlite3changeset_fk_conflicts(
12129 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12130 int *pnOut /* OUT: Number of FK violations */
12131);
12132
12133
12134/*
12135** CAPI3REF: Finalize A Changeset Iterator
12136** METHOD: sqlite3_changeset_iter
12137**
12138** This function is used to finalize an iterator allocated with
12139** [sqlite3changeset_start()].
12140**
12141** This function should only be called on iterators created using the
12142** [sqlite3changeset_start()] function. If an application calls this
12143** function with an iterator passed to a conflict-handler by
12144** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
12145** call has no effect.
12146**
12147** If an error was encountered within a call to an sqlite3changeset_xxx()
12148** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
12149** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
12150** to that error is returned by this function. Otherwise, SQLITE_OK is
12151** returned. This is to allow the following pattern (pseudo-code):
12152**
12153** <pre>
12154** sqlite3changeset_start();
12155** while( SQLITE_ROW==sqlite3changeset_next() ){
12156** // Do something with change.
12157** }
12158** rc = sqlite3changeset_finalize();
12159** if( rc!=SQLITE_OK ){
12160** // An error has occurred
12161** }
12162** </pre>
12163*/
12164SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
12165
12166/*
12167** CAPI3REF: Invert A Changeset
12168**
12169** This function is used to "invert" a changeset object. Applying an inverted
12170** changeset to a database reverses the effects of applying the uninverted
12171** changeset. Specifically:
12172**
12173** <ul>
12174** <li> Each DELETE change is changed to an INSERT, and
12175** <li> Each INSERT change is changed to a DELETE, and
12176** <li> For each UPDATE change, the old.* and new.* values are exchanged.
12177** </ul>
12178**
12179** This function does not change the order in which changes appear within
12180** the changeset. It merely reverses the sense of each individual change.
12181**
12182** If successful, a pointer to a buffer containing the inverted changeset
12183** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
12184** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
12185** zeroed and an SQLite error code returned.
12186**
12187** It is the responsibility of the caller to eventually call sqlite3_free()
12188** on the *ppOut pointer to free the buffer allocation following a successful
12189** call to this function.
12190**
12191** WARNING/TODO: This function currently assumes that the input is a valid
12192** changeset. If it is not, the results are undefined.
12193*/
12194SQLITE_API int sqlite3changeset_invert(
12195 int nIn, const void *pIn, /* Input changeset */
12196 int *pnOut, void **ppOut /* OUT: Inverse of input */
12197);
12198
12199/*
12200** CAPI3REF: Concatenate Two Changeset Objects
12201**
12202** This function is used to concatenate two changesets, A and B, into a
12203** single changeset. The result is a changeset equivalent to applying
12204** changeset A followed by changeset B.
12205**
12206** This function combines the two input changesets using an
12207** sqlite3_changegroup object. Calling it produces similar results as the
12208** following code fragment:
12209**
12210** <pre>
12211** sqlite3_changegroup *pGrp;
12212** rc = sqlite3_changegroup_new(&pGrp);
12213** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
12214** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
12215** if( rc==SQLITE_OK ){
12216** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
12217** }else{
12218** *ppOut = 0;
12219** *pnOut = 0;
12220** }
12221** </pre>
12222**
12223** Refer to the sqlite3_changegroup documentation below for details.
12224*/
12225SQLITE_API int sqlite3changeset_concat(
12226 int nA, /* Number of bytes in buffer pA */
12227 void *pA, /* Pointer to buffer containing changeset A */
12228 int nB, /* Number of bytes in buffer pB */
12229 void *pB, /* Pointer to buffer containing changeset B */
12230 int *pnOut, /* OUT: Number of bytes in output changeset */
12231 void **ppOut /* OUT: Buffer containing output changeset */
12232);
12233
12234/*
12235** CAPI3REF: Changegroup Handle
12236**
12237** A changegroup is an object used to combine two or more
12238** [changesets] or [patchsets]
12239*/
12240typedef struct sqlite3_changegroup sqlite3_changegroup;
12241
12242/*
12243** CAPI3REF: Create A New Changegroup Object
12244** CONSTRUCTOR: sqlite3_changegroup
12245**
12246** An sqlite3_changegroup object is used to combine two or more changesets
12247** (or patchsets) into a single changeset (or patchset). A single changegroup
12248** object may combine changesets or patchsets, but not both. The output is
12249** always in the same format as the input.
12250**
12251** If successful, this function returns SQLITE_OK and populates (*pp) with
12252** a pointer to a new sqlite3_changegroup object before returning. The caller
12253** should eventually free the returned object using a call to
12254** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
12255** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
12256**
12257** The usual usage pattern for an sqlite3_changegroup object is as follows:
12258**
12259** <ul>
12260** <li> It is created using a call to sqlite3changegroup_new().
12261**
12262** <li> Zero or more changesets (or patchsets) are added to the object
12263** by calling sqlite3changegroup_add().
12264**
12265** <li> The result of combining all input changesets together is obtained
12266** by the application via a call to sqlite3changegroup_output().
12267**
12268** <li> The object is deleted using a call to sqlite3changegroup_delete().
12269** </ul>
12270**
12271** Any number of calls to add() and output() may be made between the calls to
12272** new() and delete(), and in any order.
12273**
12274** As well as the regular sqlite3changegroup_add() and
12275** sqlite3changegroup_output() functions, also available are the streaming
12276** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
12277*/
12278SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
12279
12280/*
12281** CAPI3REF: Add a Schema to a Changegroup
12282** METHOD: sqlite3_changegroup_schema
12283**
12284** This method may be used to optionally enforce the rule that the changesets
12285** added to the changegroup handle must match the schema of database zDb
12286** ("main", "temp", or the name of an attached database). If
12287** sqlite3changegroup_add() is called to add a changeset that is not compatible
12288** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
12289** object is left in an undefined state.
12290**
12291** A changeset schema is considered compatible with the database schema in
12292** the same way as for sqlite3changeset_apply(). Specifically, for each
12293** table in the changeset, there exists a database table with:
12294**
12295** <ul>
12296** <li> The name identified by the changeset, and
12297** <li> at least as many columns as recorded in the changeset, and
12298** <li> the primary key columns in the same position as recorded in
12299** the changeset.
12300** </ul>
12301**
12302** The output of the changegroup object always has the same schema as the
12303** database nominated using this function. In cases where changesets passed
12304** to sqlite3changegroup_add() have fewer columns than the corresponding table
12305** in the database schema, these are filled in using the default column
12306** values from the database schema. This makes it possible to combined
12307** changesets that have different numbers of columns for a single table
12308** within a changegroup, provided that they are otherwise compatible.
12309*/
12310SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
12311
12312/*
12313** CAPI3REF: Add A Changeset To A Changegroup
12314** METHOD: sqlite3_changegroup
12315**
12316** Add all changes within the changeset (or patchset) in buffer pData (size
12317** nData bytes) to the changegroup.
12318**
12319** If the buffer contains a patchset, then all prior calls to this function
12320** on the same changegroup object must also have specified patchsets. Or, if
12321** the buffer contains a changeset, so must have the earlier calls to this
12322** function. Otherwise, SQLITE_ERROR is returned and no changes are added
12323** to the changegroup.
12324**
12325** Rows within the changeset and changegroup are identified by the values in
12326** their PRIMARY KEY columns. A change in the changeset is considered to
12327** apply to the same row as a change already present in the changegroup if
12328** the two rows have the same primary key.
12329**
12330** Changes to rows that do not already appear in the changegroup are
12331** simply copied into it. Or, if both the new changeset and the changegroup
12332** contain changes that apply to a single row, the final contents of the
12333** changegroup depends on the type of each change, as follows:
12334**
12335** <table border=1 style="margin-left:8ex;margin-right:8ex">
12336** <tr><th style="white-space:pre">Existing Change </th>
12337** <th style="white-space:pre">New Change </th>
12338** <th>Output Change
12339** <tr><td>INSERT <td>INSERT <td>
12340** The new change is ignored. This case does not occur if the new
12341** changeset was recorded immediately after the changesets already
12342** added to the changegroup.
12343** <tr><td>INSERT <td>UPDATE <td>
12344** The INSERT change remains in the changegroup. The values in the
12345** INSERT change are modified as if the row was inserted by the
12346** existing change and then updated according to the new change.
12347** <tr><td>INSERT <td>DELETE <td>
12348** The existing INSERT is removed from the changegroup. The DELETE is
12349** not added.
12350** <tr><td>UPDATE <td>INSERT <td>
12351** The new change is ignored. This case does not occur if the new
12352** changeset was recorded immediately after the changesets already
12353** added to the changegroup.
12354** <tr><td>UPDATE <td>UPDATE <td>
12355** The existing UPDATE remains within the changegroup. It is amended
12356** so that the accompanying values are as if the row was updated once
12357** by the existing change and then again by the new change.
12358** <tr><td>UPDATE <td>DELETE <td>
12359** The existing UPDATE is replaced by the new DELETE within the
12360** changegroup.
12361** <tr><td>DELETE <td>INSERT <td>
12362** If one or more of the column values in the row inserted by the
12363** new change differ from those in the row deleted by the existing
12364** change, the existing DELETE is replaced by an UPDATE within the
12365** changegroup. Otherwise, if the inserted row is exactly the same
12366** as the deleted row, the existing DELETE is simply discarded.
12367** <tr><td>DELETE <td>UPDATE <td>
12368** The new change is ignored. This case does not occur if the new
12369** changeset was recorded immediately after the changesets already
12370** added to the changegroup.
12371** <tr><td>DELETE <td>DELETE <td>
12372** The new change is ignored. This case does not occur if the new
12373** changeset was recorded immediately after the changesets already
12374** added to the changegroup.
12375** </table>
12376**
12377** If the new changeset contains changes to a table that is already present
12378** in the changegroup, then the number of columns and the position of the
12379** primary key columns for the table must be consistent. If this is not the
12380** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12381** object has been configured with a database schema using the
12382** sqlite3changegroup_schema() API, then it is possible to combine changesets
12383** with different numbers of columns for a single table, provided that
12384** they are otherwise compatible.
12385**
12386** If the input changeset appears to be corrupt and the corruption is
12387** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12388** occurs during processing, this function returns SQLITE_NOMEM.
12389**
12390** In all cases, if an error occurs the state of the final contents of the
12391** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12392*/
12393SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12394
12395/*
12396** CAPI3REF: Add A Single Change To A Changegroup
12397** METHOD: sqlite3_changegroup
12398**
12399** This function adds the single change currently indicated by the iterator
12400** passed as the second argument to the changegroup object. The rules for
12401** adding the change are just as described for [sqlite3changegroup_add()].
12402**
12403** If the change is successfully added to the changegroup, SQLITE_OK is
12404** returned. Otherwise, an SQLite error code is returned.
12405**
12406** The iterator must point to a valid entry when this function is called.
12407** If it does not, SQLITE_ERROR is returned and no change is added to the
12408** changegroup. Additionally, the iterator must not have been opened with
12409** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12410** returned.
12411*/
12412SQLITE_API int sqlite3changegroup_add_change(
12413 sqlite3_changegroup*,
12414 sqlite3_changeset_iter*
12415);
12416
12417
12418
12419/*
12420** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12421** METHOD: sqlite3_changegroup
12422**
12423** Obtain a buffer containing a changeset (or patchset) representing the
12424** current contents of the changegroup. If the inputs to the changegroup
12425** were themselves changesets, the output is a changeset. Or, if the
12426** inputs were patchsets, the output is also a patchset.
12427**
12428** As with the output of the sqlite3session_changeset() and
12429** sqlite3session_patchset() functions, all changes related to a single
12430** table are grouped together in the output of this function. Tables appear
12431** in the same order as for the very first changeset added to the changegroup.
12432** If the second or subsequent changesets added to the changegroup contain
12433** changes for tables that do not appear in the first changeset, they are
12434** appended onto the end of the output changeset, again in the order in
12435** which they are first encountered.
12436**
12437** If an error occurs, an SQLite error code is returned and the output
12438** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12439** is returned and the output variables are set to the size of and a
12440** pointer to the output buffer, respectively. In this case it is the
12441** responsibility of the caller to eventually free the buffer using a
12442** call to sqlite3_free().
12443*/
12444SQLITE_API int sqlite3changegroup_output(
12445 sqlite3_changegroup*,
12446 int *pnData, /* OUT: Size of output buffer in bytes */
12447 void **ppData /* OUT: Pointer to output buffer */
12448);
12449
12450/*
12451** CAPI3REF: Delete A Changegroup Object
12452** DESTRUCTOR: sqlite3_changegroup
12453*/
12454SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12455
12456/*
12457** CAPI3REF: Apply A Changeset To A Database
12458**
12459** Apply a changeset or patchset to a database. These functions attempt to
12460** update the "main" database attached to handle db with the changes found in
12461** the changeset passed via the second and third arguments.
12462**
12463** All changes made by these functions are enclosed in a savepoint transaction.
12464** If any other error (aside from a constraint failure when attempting to
12465** write to the target database) occurs, then the savepoint transaction is
12466** rolled back, restoring the target database to its original state, and an
12467** SQLite error code returned. Additionally, starting with version 3.51.0,
12468** an error code and error message that may be accessed using the
12469** [sqlite3_errcode()] and [sqlite3_errmsg()] APIs are left in the database
12470** handle.
12471**
12472** The fourth argument (xFilter) passed to these functions is the "filter
12473** callback". This may be passed NULL, in which case all changes in the
12474** changeset are applied to the database. For sqlite3changeset_apply() and
12475** sqlite3_changeset_apply_v2(), if it is not NULL, then it is invoked once
12476** for each table affected by at least one change in the changeset. In this
12477** case the table name is passed as the second argument, and a copy of
12478** the context pointer passed as the sixth argument to apply() or apply_v2()
12479** as the first. If the "filter callback" returns zero, then no attempt is
12480** made to apply any changes to the table. Otherwise, if the return value is
12481** non-zero, all changes related to the table are attempted.
12482**
12483** For sqlite3_changeset_apply_v3(), the xFilter callback is invoked once
12484** per change. The second argument in this case is an sqlite3_changeset_iter
12485** that may be queried using the usual APIs for the details of the current
12486** change. If the "filter callback" returns zero in this case, then no attempt
12487** is made to apply the current change. If it returns non-zero, the change
12488** is applied.
12489**
12490** For each table that is not excluded by the filter callback, this function
12491** tests that the target database contains a compatible table. A table is
12492** considered compatible if all of the following are true:
12493**
12494** <ul>
12495** <li> The table has the same name as the name recorded in the
12496** changeset, and
12497** <li> The table has at least as many columns as recorded in the
12498** changeset, and
12499** <li> The table has primary key columns in the same position as
12500** recorded in the changeset.
12501** </ul>
12502**
12503** If there is no compatible table, it is not an error, but none of the
12504** changes associated with the table are applied. A warning message is issued
12505** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12506** one such warning is issued for each table in the changeset.
12507**
12508** For each change for which there is a compatible table, an attempt is made
12509** to modify the table contents according to each UPDATE, INSERT or DELETE
12510** change that is not excluded by a filter callback. If a change cannot be
12511** applied cleanly, the conflict handler function passed as the fifth argument
12512** to sqlite3changeset_apply() may be invoked. A description of exactly when
12513** the conflict handler is invoked for each type of change is below.
12514**
12515** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12516** of passing anything other than a valid function pointer as the xConflict
12517** argument are undefined.
12518**
12519** Each time the conflict handler function is invoked, it must return one
12520** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12521** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12522** if the second argument passed to the conflict handler is either
12523** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12524** returns an illegal value, any changes already made are rolled back and
12525** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12526** actions are taken by sqlite3changeset_apply() depending on the value
12527** returned by each invocation of the conflict-handler function. Refer to
12528** the documentation for the three
12529** [SQLITE_CHANGESET_OMIT|available return values] for details.
12530**
12531** <dl>
12532** <dt>DELETE Changes<dd>
12533** For each DELETE change, the function checks if the target database
12534** contains a row with the same primary key value (or values) as the
12535** original row values stored in the changeset. If it does, and the values
12536** stored in all non-primary key columns also match the values stored in
12537** the changeset the row is deleted from the target database.
12538**
12539** If a row with matching primary key values is found, but one or more of
12540** the non-primary key fields contains a value different from the original
12541** row value stored in the changeset, the conflict-handler function is
12542** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12543** database table has more columns than are recorded in the changeset,
12544** only the values of those non-primary key fields are compared against
12545** the current database contents - any trailing database table columns
12546** are ignored.
12547**
12548** If no row with matching primary key values is found in the database,
12549** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12550** passed as the second argument.
12551**
12552** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12553** (which can only happen if a foreign key constraint is violated), the
12554** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12555** passed as the second argument. This includes the case where the DELETE
12556** operation is attempted because an earlier call to the conflict handler
12557** function returned [SQLITE_CHANGESET_REPLACE].
12558**
12559** <dt>INSERT Changes<dd>
12560** For each INSERT change, an attempt is made to insert the new row into
12561** the database. If the changeset row contains fewer fields than the
12562** database table, the trailing fields are populated with their default
12563** values.
12564**
12565** If the attempt to insert the row fails because the database already
12566** contains a row with the same primary key values, the conflict handler
12567** function is invoked with the second argument set to
12568** [SQLITE_CHANGESET_CONFLICT].
12569**
12570** If the attempt to insert the row fails because of some other constraint
12571** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12572** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12573** This includes the case where the INSERT operation is re-attempted because
12574** an earlier call to the conflict handler function returned
12575** [SQLITE_CHANGESET_REPLACE].
12576**
12577** <dt>UPDATE Changes<dd>
12578** For each UPDATE change, the function checks if the target database
12579** contains a row with the same primary key value (or values) as the
12580** original row values stored in the changeset. If it does, and the values
12581** stored in all modified non-primary key columns also match the values
12582** stored in the changeset the row is updated within the target database.
12583**
12584** If a row with matching primary key values is found, but one or more of
12585** the modified non-primary key fields contains a value different from an
12586** original row value stored in the changeset, the conflict-handler function
12587** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12588** UPDATE changes only contain values for non-primary key fields that are
12589** to be modified, only those fields need to match the original values to
12590** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12591**
12592** If no row with matching primary key values is found in the database,
12593** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12594** passed as the second argument.
12595**
12596** If the UPDATE operation is attempted, but SQLite returns
12597** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12598** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12599** This includes the case where the UPDATE operation is attempted after
12600** an earlier call to the conflict handler function returned
12601** [SQLITE_CHANGESET_REPLACE].
12602** </dl>
12603**
12604** It is safe to execute SQL statements, including those that write to the
12605** table that the callback related to, from within the xConflict callback.
12606** This can be used to further customize the application's conflict
12607** resolution strategy.
12608**
12609** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12610** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12611** may set (*ppRebase) to point to a "rebase" that may be used with the
12612** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12613** is set to the size of the buffer in bytes. It is the responsibility of the
12614** caller to eventually free any such buffer using sqlite3_free(). The buffer
12615** is only allocated and populated if one or more conflicts were encountered
12616** while applying the patchset. See comments surrounding the sqlite3_rebaser
12617** APIs for further details.
12618**
12619** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12620** may be modified by passing a combination of
12621** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12622**
12623** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12624** and therefore subject to change.
12625*/
12626SQLITE_API int sqlite3changeset_apply(
12627 sqlite3 *db, /* Apply change to "main" db of this handle */
12628 int nChangeset, /* Size of changeset in bytes */
12629 void *pChangeset, /* Changeset blob */
12630 int(*xFilter)(
12631 void *pCtx, /* Copy of sixth arg to _apply() */
12632 const char *zTab /* Table name */
12633 ),
12634 int(*xConflict)(
12635 void *pCtx, /* Copy of sixth arg to _apply() */
12636 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12637 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12638 ),
12639 void *pCtx /* First argument passed to xConflict */
12640);
12641SQLITE_API int sqlite3changeset_apply_v2(
12642 sqlite3 *db, /* Apply change to "main" db of this handle */
12643 int nChangeset, /* Size of changeset in bytes */
12644 void *pChangeset, /* Changeset blob */
12645 int(*xFilter)(
12646 void *pCtx, /* Copy of sixth arg to _apply() */
12647 const char *zTab /* Table name */
12648 ),
12649 int(*xConflict)(
12650 void *pCtx, /* Copy of sixth arg to _apply() */
12651 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12652 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12653 ),
12654 void *pCtx, /* First argument passed to xConflict */
12655 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12656 int flags /* SESSION_CHANGESETAPPLY_* flags */
12657);
12658SQLITE_API int sqlite3changeset_apply_v3(
12659 sqlite3 *db, /* Apply change to "main" db of this handle */
12660 int nChangeset, /* Size of changeset in bytes */
12661 void *pChangeset, /* Changeset blob */
12662 int(*xFilter)(
12663 void *pCtx, /* Copy of sixth arg to _apply() */
12664 sqlite3_changeset_iter *p /* Handle describing change */
12665 ),
12666 int(*xConflict)(
12667 void *pCtx, /* Copy of sixth arg to _apply() */
12668 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12669 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12670 ),
12671 void *pCtx, /* First argument passed to xConflict */
12672 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12673 int flags /* SESSION_CHANGESETAPPLY_* flags */
12674);
12675
12676/*
12677** CAPI3REF: Flags for sqlite3changeset_apply_v2
12678**
12679** The following flags may passed via the 9th parameter to
12680** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12681**
12682** <dl>
12683** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12684** Usually, the sessions module encloses all operations performed by
12685** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12686** SAVEPOINT is committed if the changeset or patchset is successfully
12687** applied, or rolled back if an error occurs. Specifying this flag
12688** causes the sessions module to omit this savepoint. In this case, if the
12689** caller has an open transaction or savepoint when apply_v2() is called,
12690** it may revert the partially applied changeset by rolling it back.
12691**
12692** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12693** Invert the changeset before applying it. This is equivalent to inverting
12694** a changeset using sqlite3changeset_invert() before applying it. It is
12695** an error to specify this flag with a patchset.
12696**
12697** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12698** Do not invoke the conflict handler callback for any changes that
12699** would not actually modify the database even if they were applied.
12700** Specifically, this means that the conflict handler is not invoked
12701** for:
12702** <ul>
12703** <li>a delete change if the row being deleted cannot be found,
12704** <li>an update change if the modified fields are already set to
12705** their new values in the conflicting row, or
12706** <li>an insert change if all fields of the conflicting row match
12707** the row being inserted.
12708** </ul>
12709**
12710** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12711** If this flag it set, then all foreign key constraints in the target
12712** database behave as if they were declared with "ON UPDATE NO ACTION ON
12713** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12714** or SET DEFAULT.
12715*/
12716#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12717#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12718#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12719#define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12720
12721/*
12722** CAPI3REF: Constants Passed To The Conflict Handler
12723**
12724** Values that may be passed as the second argument to a conflict-handler.
12725**
12726** <dl>
12727** <dt>SQLITE_CHANGESET_DATA<dd>
12728** The conflict handler is invoked with CHANGESET_DATA as the second argument
12729** when processing a DELETE or UPDATE change if a row with the required
12730** PRIMARY KEY fields is present in the database, but one or more other
12731** (non primary-key) fields modified by the update do not contain the
12732** expected "before" values.
12733**
12734** The conflicting row, in this case, is the database row with the matching
12735** primary key.
12736**
12737** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12738** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12739** argument when processing a DELETE or UPDATE change if a row with the
12740** required PRIMARY KEY fields is not present in the database.
12741**
12742** There is no conflicting row in this case. The results of invoking the
12743** sqlite3changeset_conflict() API are undefined.
12744**
12745** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12746** CHANGESET_CONFLICT is passed as the second argument to the conflict
12747** handler while processing an INSERT change if the operation would result
12748** in duplicate primary key values.
12749**
12750** The conflicting row in this case is the database row with the matching
12751** primary key.
12752**
12753** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12754** If foreign key handling is enabled, and applying a changeset leaves the
12755** database in a state containing foreign key violations, the conflict
12756** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12757** exactly once before the changeset is committed. If the conflict handler
12758** returns CHANGESET_OMIT, the changes, including those that caused the
12759** foreign key constraint violation, are committed. Or, if it returns
12760** CHANGESET_ABORT, the changeset is rolled back.
12761**
12762** No current or conflicting row information is provided. The only function
12763** it is possible to call on the supplied sqlite3_changeset_iter handle
12764** is sqlite3changeset_fk_conflicts().
12765**
12766** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12767** If any other constraint violation occurs while applying a change (i.e.
12768** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12769** invoked with CHANGESET_CONSTRAINT as the second argument.
12770**
12771** There is no conflicting row in this case. The results of invoking the
12772** sqlite3changeset_conflict() API are undefined.
12773**
12774** </dl>
12775*/
12776#define SQLITE_CHANGESET_DATA 1
12777#define SQLITE_CHANGESET_NOTFOUND 2
12778#define SQLITE_CHANGESET_CONFLICT 3
12779#define SQLITE_CHANGESET_CONSTRAINT 4
12780#define SQLITE_CHANGESET_FOREIGN_KEY 5
12781
12782/*
12783** CAPI3REF: Constants Returned By The Conflict Handler
12784**
12785** A conflict handler callback must return one of the following three values.
12786**
12787** <dl>
12788** <dt>SQLITE_CHANGESET_OMIT<dd>
12789** If a conflict handler returns this value no special action is taken. The
12790** change that caused the conflict is not applied. The session module
12791** continues to the next change in the changeset.
12792**
12793** <dt>SQLITE_CHANGESET_REPLACE<dd>
12794** This value may only be returned if the second argument to the conflict
12795** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12796** is not the case, any changes applied so far are rolled back and the
12797** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12798**
12799** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12800** handler, then the conflicting row is either updated or deleted, depending
12801** on the type of change.
12802**
12803** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12804** handler, then the conflicting row is removed from the database and a
12805** second attempt to apply the change is made. If this second attempt fails,
12806** the original row is restored to the database before continuing.
12807**
12808** <dt>SQLITE_CHANGESET_ABORT<dd>
12809** If this value is returned, any changes applied so far are rolled back
12810** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12811** </dl>
12812*/
12813#define SQLITE_CHANGESET_OMIT 0
12814#define SQLITE_CHANGESET_REPLACE 1
12815#define SQLITE_CHANGESET_ABORT 2
12816
12817/*
12818** CAPI3REF: Rebasing changesets
12819** EXPERIMENTAL
12820**
12821** Suppose there is a site hosting a database in state S0. And that
12822** modifications are made that move that database to state S1 and a
12823** changeset recorded (the "local" changeset). Then, a changeset based
12824** on S0 is received from another site (the "remote" changeset) and
12825** applied to the database. The database is then in state
12826** (S1+"remote"), where the exact state depends on any conflict
12827** resolution decisions (OMIT or REPLACE) made while applying "remote".
12828** Rebasing a changeset is to update it to take those conflict
12829** resolution decisions into account, so that the same conflicts
12830** do not have to be resolved elsewhere in the network.
12831**
12832** For example, if both the local and remote changesets contain an
12833** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12834**
12835** local: INSERT INTO t1 VALUES(1, 'v1');
12836** remote: INSERT INTO t1 VALUES(1, 'v2');
12837**
12838** and the conflict resolution is REPLACE, then the INSERT change is
12839** removed from the local changeset (it was overridden). Or, if the
12840** conflict resolution was "OMIT", then the local changeset is modified
12841** to instead contain:
12842**
12843** UPDATE t1 SET b = 'v2' WHERE a=1;
12844**
12845** Changes within the local changeset are rebased as follows:
12846**
12847** <dl>
12848** <dt>Local INSERT<dd>
12849** This may only conflict with a remote INSERT. If the conflict
12850** resolution was OMIT, then add an UPDATE change to the rebased
12851** changeset. Or, if the conflict resolution was REPLACE, add
12852** nothing to the rebased changeset.
12853**
12854** <dt>Local DELETE<dd>
12855** This may conflict with a remote UPDATE or DELETE. In both cases the
12856** only possible resolution is OMIT. If the remote operation was a
12857** DELETE, then add no change to the rebased changeset. If the remote
12858** operation was an UPDATE, then the old.* fields of change are updated
12859** to reflect the new.* values in the UPDATE.
12860**
12861** <dt>Local UPDATE<dd>
12862** This may conflict with a remote UPDATE or DELETE. If it conflicts
12863** with a DELETE, and the conflict resolution was OMIT, then the update
12864** is changed into an INSERT. Any undefined values in the new.* record
12865** from the update change are filled in using the old.* values from
12866** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12867** the UPDATE change is simply omitted from the rebased changeset.
12868**
12869** If conflict is with a remote UPDATE and the resolution is OMIT, then
12870** the old.* values are rebased using the new.* values in the remote
12871** change. Or, if the resolution is REPLACE, then the change is copied
12872** into the rebased changeset with updates to columns also updated by
12873** the conflicting remote UPDATE removed. If this means no columns would
12874** be updated, the change is omitted.
12875** </dl>
12876**
12877** A local change may be rebased against multiple remote changes
12878** simultaneously. If a single key is modified by multiple remote
12879** changesets, they are combined as follows before the local changeset
12880** is rebased:
12881**
12882** <ul>
12883** <li> If there has been one or more REPLACE resolutions on a
12884** key, it is rebased according to a REPLACE.
12885**
12886** <li> If there have been no REPLACE resolutions on a key, then
12887** the local changeset is rebased according to the most recent
12888** of the OMIT resolutions.
12889** </ul>
12890**
12891** Note that conflict resolutions from multiple remote changesets are
12892** combined on a per-field basis, not per-row. This means that in the
12893** case of multiple remote UPDATE operations, some fields of a single
12894** local change may be rebased for REPLACE while others are rebased for
12895** OMIT.
12896**
12897** In order to rebase a local changeset, the remote changeset must first
12898** be applied to the local database using sqlite3changeset_apply_v2() and
12899** the buffer of rebase information captured. Then:
12900**
12901** <ol>
12902** <li> An sqlite3_rebaser object is created by calling
12903** sqlite3rebaser_create().
12904** <li> The new object is configured with the rebase buffer obtained from
12905** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12906** If the local changeset is to be rebased against multiple remote
12907** changesets, then sqlite3rebaser_configure() should be called
12908** multiple times, in the same order that the multiple
12909** sqlite3changeset_apply_v2() calls were made.
12910** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12911** <li> The sqlite3_rebaser object is deleted by calling
12912** sqlite3rebaser_delete().
12913** </ol>
12914*/
12915typedef struct sqlite3_rebaser sqlite3_rebaser;
12916
12917/*
12918** CAPI3REF: Create a changeset rebaser object.
12919** EXPERIMENTAL
12920**
12921** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12922** point to the new object and return SQLITE_OK. Otherwise, if an error
12923** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12924** to NULL.
12925*/
12926SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12927
12928/*
12929** CAPI3REF: Configure a changeset rebaser object.
12930** EXPERIMENTAL
12931**
12932** Configure the changeset rebaser object to rebase changesets according
12933** to the conflict resolutions described by buffer pRebase (size nRebase
12934** bytes), which must have been obtained from a previous call to
12935** sqlite3changeset_apply_v2().
12936*/
12937SQLITE_API int sqlite3rebaser_configure(
12938 sqlite3_rebaser*,
12939 int nRebase, const void *pRebase
12940);
12941
12942/*
12943** CAPI3REF: Rebase a changeset
12944** EXPERIMENTAL
12945**
12946** Argument pIn must point to a buffer containing a changeset nIn bytes
12947** in size. This function allocates and populates a buffer with a copy
12948** of the changeset rebased according to the configuration of the
12949** rebaser object passed as the first argument. If successful, (*ppOut)
12950** is set to point to the new buffer containing the rebased changeset and
12951** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12952** responsibility of the caller to eventually free the new buffer using
12953** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12954** are set to zero and an SQLite error code returned.
12955*/
12956SQLITE_API int sqlite3rebaser_rebase(
12957 sqlite3_rebaser*,
12958 int nIn, const void *pIn,
12959 int *pnOut, void **ppOut
12960);
12961
12962/*
12963** CAPI3REF: Delete a changeset rebaser object.
12964** EXPERIMENTAL
12965**
12966** Delete the changeset rebaser object and all associated resources. There
12967** should be one call to this function for each successful invocation
12968** of sqlite3rebaser_create().
12969*/
12970SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12971
12972/*
12973** CAPI3REF: Streaming Versions of API functions.
12974**
12975** The six streaming API xxx_strm() functions serve similar purposes to the
12976** corresponding non-streaming API functions:
12977**
12978** <table border=1 style="margin-left:8ex;margin-right:8ex">
12979** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12980** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12981** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12982** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12983** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12984** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12985** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12986** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12987** </table>
12988**
12989** Non-streaming functions that accept changesets (or patchsets) as input
12990** require that the entire changeset be stored in a single buffer in memory.
12991** Similarly, those that return a changeset or patchset do so by returning
12992** a pointer to a single large buffer allocated using sqlite3_malloc().
12993** Normally this is convenient. However, if an application running in a
12994** low-memory environment is required to handle very large changesets, the
12995** large contiguous memory allocations required can become onerous.
12996**
12997** In order to avoid this problem, instead of a single large buffer, input
12998** is passed to a streaming API functions by way of a callback function that
12999** the sessions module invokes to incrementally request input data as it is
13000** required. In all cases, a pair of API function parameters such as
13001**
13002** <pre>
13003** &nbsp; int nChangeset,
13004** &nbsp; void *pChangeset,
13005** </pre>
13006**
13007** Is replaced by:
13008**
13009** <pre>
13010** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
13011** &nbsp; void *pIn,
13012** </pre>
13013**
13014** Each time the xInput callback is invoked by the sessions module, the first
13015** argument passed is a copy of the supplied pIn context pointer. The second
13016** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
13017** error occurs the xInput method should copy up to (*pnData) bytes of data
13018** into the buffer and set (*pnData) to the actual number of bytes copied
13019** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
13020** should be set to zero to indicate this. Or, if an error occurs, an SQLite
13021** error code should be returned. In all cases, if an xInput callback returns
13022** an error, all processing is abandoned and the streaming API function
13023** returns a copy of the error code to the caller.
13024**
13025** In the case of sqlite3changeset_start_strm(), the xInput callback may be
13026** invoked by the sessions module at any point during the lifetime of the
13027** iterator. If such an xInput callback returns an error, the iterator enters
13028** an error state, whereby all subsequent calls to iterator functions
13029** immediately fail with the same error code as returned by xInput.
13030**
13031** Similarly, streaming API functions that return changesets (or patchsets)
13032** return them in chunks by way of a callback function instead of via a
13033** pointer to a single large buffer. In this case, a pair of parameters such
13034** as:
13035**
13036** <pre>
13037** &nbsp; int *pnChangeset,
13038** &nbsp; void **ppChangeset,
13039** </pre>
13040**
13041** Is replaced by:
13042**
13043** <pre>
13044** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
13045** &nbsp; void *pOut
13046** </pre>
13047**
13048** The xOutput callback is invoked zero or more times to return data to
13049** the application. The first parameter passed to each call is a copy of the
13050** pOut pointer supplied by the application. The second parameter, pData,
13051** points to a buffer nData bytes in size containing the chunk of output
13052** data being returned. If the xOutput callback successfully processes the
13053** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
13054** it should return some other SQLite error code. In this case processing
13055** is immediately abandoned and the streaming API function returns a copy
13056** of the xOutput error code to the application.
13057**
13058** The sessions module never invokes an xOutput callback with the third
13059** parameter set to a value less than or equal to zero. Other than this,
13060** no guarantees are made as to the size of the chunks of data returned.
13061*/
13062SQLITE_API int sqlite3changeset_apply_strm(
13063 sqlite3 *db, /* Apply change to "main" db of this handle */
13064 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13065 void *pIn, /* First arg for xInput */
13066 int(*xFilter)(
13067 void *pCtx, /* Copy of sixth arg to _apply() */
13068 const char *zTab /* Table name */
13069 ),
13070 int(*xConflict)(
13071 void *pCtx, /* Copy of sixth arg to _apply() */
13072 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13073 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13074 ),
13075 void *pCtx /* First argument passed to xConflict */
13076);
13077SQLITE_API int sqlite3changeset_apply_v2_strm(
13078 sqlite3 *db, /* Apply change to "main" db of this handle */
13079 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13080 void *pIn, /* First arg for xInput */
13081 int(*xFilter)(
13082 void *pCtx, /* Copy of sixth arg to _apply() */
13083 const char *zTab /* Table name */
13084 ),
13085 int(*xConflict)(
13086 void *pCtx, /* Copy of sixth arg to _apply() */
13087 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13088 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13089 ),
13090 void *pCtx, /* First argument passed to xConflict */
13091 void **ppRebase, int *pnRebase,
13092 int flags
13093);
13094SQLITE_API int sqlite3changeset_apply_v3_strm(
13095 sqlite3 *db, /* Apply change to "main" db of this handle */
13096 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13097 void *pIn, /* First arg for xInput */
13098 int(*xFilter)(
13099 void *pCtx, /* Copy of sixth arg to _apply() */
13100 sqlite3_changeset_iter *p
13101 ),
13102 int(*xConflict)(
13103 void *pCtx, /* Copy of sixth arg to _apply() */
13104 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13105 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13106 ),
13107 void *pCtx, /* First argument passed to xConflict */
13108 void **ppRebase, int *pnRebase,
13109 int flags
13110);
13111SQLITE_API int sqlite3changeset_concat_strm(
13112 int (*xInputA)(void *pIn, void *pData, int *pnData),
13113 void *pInA,
13114 int (*xInputB)(void *pIn, void *pData, int *pnData),
13115 void *pInB,
13116 int (*xOutput)(void *pOut, const void *pData, int nData),
13117 void *pOut
13118);
13119SQLITE_API int sqlite3changeset_invert_strm(
13120 int (*xInput)(void *pIn, void *pData, int *pnData),
13121 void *pIn,
13122 int (*xOutput)(void *pOut, const void *pData, int nData),
13123 void *pOut
13124);
13125SQLITE_API int sqlite3changeset_start_strm(
13126 sqlite3_changeset_iter **pp,
13127 int (*xInput)(void *pIn, void *pData, int *pnData),
13128 void *pIn
13129);
13130SQLITE_API int sqlite3changeset_start_v2_strm(
13131 sqlite3_changeset_iter **pp,
13132 int (*xInput)(void *pIn, void *pData, int *pnData),
13133 void *pIn,
13134 int flags
13135);
13136SQLITE_API int sqlite3session_changeset_strm(
13137 sqlite3_session *pSession,
13138 int (*xOutput)(void *pOut, const void *pData, int nData),
13139 void *pOut
13140);
13141SQLITE_API int sqlite3session_patchset_strm(
13142 sqlite3_session *pSession,
13143 int (*xOutput)(void *pOut, const void *pData, int nData),
13144 void *pOut
13145);
13146SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
13147 int (*xInput)(void *pIn, void *pData, int *pnData),
13148 void *pIn
13149);
13150SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
13151 int (*xOutput)(void *pOut, const void *pData, int nData),
13152 void *pOut
13153);
13154SQLITE_API int sqlite3rebaser_rebase_strm(
13155 sqlite3_rebaser *pRebaser,
13156 int (*xInput)(void *pIn, void *pData, int *pnData),
13157 void *pIn,
13158 int (*xOutput)(void *pOut, const void *pData, int nData),
13159 void *pOut
13160);
13161
13162/*
13163** CAPI3REF: Configure global parameters
13164**
13165** The sqlite3session_config() interface is used to make global configuration
13166** changes to the sessions module in order to tune it to the specific needs
13167** of the application.
13168**
13169** The sqlite3session_config() interface is not threadsafe. If it is invoked
13170** while any other thread is inside any other sessions method then the
13171** results are undefined. Furthermore, if it is invoked after any sessions
13172** related objects have been created, the results are also undefined.
13173**
13174** The first argument to the sqlite3session_config() function must be one
13175** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
13176** interpretation of the (void*) value passed as the second parameter and
13177** the effect of calling this function depends on the value of the first
13178** parameter.
13179**
13180** <dl>
13181** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
13182** By default, the sessions module streaming interfaces attempt to input
13183** and output data in approximately 1 KiB chunks. This operand may be used
13184** to set and query the value of this configuration setting. The pointer
13185** passed as the second argument must point to a value of type (int).
13186** If this value is greater than 0, it is used as the new streaming data
13187** chunk size for both input and output. Before returning, the (int) value
13188** pointed to by pArg is set to the final value of the streaming interface
13189** chunk size.
13190** </dl>
13191**
13192** This function returns SQLITE_OK if successful, or an SQLite error code
13193** otherwise.
13194*/
13195SQLITE_API int sqlite3session_config(int op, void *pArg);
13196
13197/*
13198** CAPI3REF: Values for sqlite3session_config().
13199*/
13200#define SQLITE_SESSION_CONFIG_STRMSIZE 1
13201
13202/*
13203** Make sure we can call this stuff from C++.
13204*/
13205#ifdef __cplusplus
13206}
13207#endif
13208
13209#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
13210
13211/******** End of sqlite3session.h *********/
13212/******** Begin file fts5.h *********/
13213/*
13214** 2014 May 31
13215**
13216** The author disclaims copyright to this source code. In place of
13217** a legal notice, here is a blessing:
13218**
13219** May you do good and not evil.
13220** May you find forgiveness for yourself and forgive others.
13221** May you share freely, never taking more than you give.
13222**
13223******************************************************************************
13224**
13225** Interfaces to extend FTS5. Using the interfaces defined in this file,
13226** FTS5 may be extended with:
13227**
13228** * custom tokenizers, and
13229** * custom auxiliary functions.
13230*/
13231
13232
13233#ifndef _FTS5_H
13234#define _FTS5_H
13235
13236
13237#ifdef __cplusplus
13238extern "C" {
13239#endif
13240
13241/*************************************************************************
13242** CUSTOM AUXILIARY FUNCTIONS
13243**
13244** Virtual table implementations may overload SQL functions by implementing
13245** the sqlite3_module.xFindFunction() method.
13246*/
13247
13248typedef struct Fts5ExtensionApi Fts5ExtensionApi;
13249typedef struct Fts5Context Fts5Context;
13250typedef struct Fts5PhraseIter Fts5PhraseIter;
13251
13252typedef void (*fts5_extension_function)(
13253 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
13254 Fts5Context *pFts, /* First arg to pass to pApi functions */
13255 sqlite3_context *pCtx, /* Context for returning result/error */
13256 int nVal, /* Number of values in apVal[] array */
13257 sqlite3_value **apVal /* Array of trailing arguments */
13258);
13259
13260struct Fts5PhraseIter {
13261 const unsigned char *a;
13262 const unsigned char *b;
13263};
13264
13265/*
13266** EXTENSION API FUNCTIONS
13267**
13268** xUserData(pFts):
13269** Return a copy of the pUserData pointer passed to the xCreateFunction()
13270** API when the extension function was registered.
13271**
13272** xColumnTotalSize(pFts, iCol, pnToken):
13273** If parameter iCol is less than zero, set output variable *pnToken
13274** to the total number of tokens in the FTS5 table. Or, if iCol is
13275** non-negative but less than the number of columns in the table, return
13276** the total number of tokens in column iCol, considering all rows in
13277** the FTS5 table.
13278**
13279** If parameter iCol is greater than or equal to the number of columns
13280** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13281** an OOM condition or IO error), an appropriate SQLite error code is
13282** returned.
13283**
13284** xColumnCount(pFts):
13285** Return the number of columns in the table.
13286**
13287** xColumnSize(pFts, iCol, pnToken):
13288** If parameter iCol is less than zero, set output variable *pnToken
13289** to the total number of tokens in the current row. Or, if iCol is
13290** non-negative but less than the number of columns in the table, set
13291** *pnToken to the number of tokens in column iCol of the current row.
13292**
13293** If parameter iCol is greater than or equal to the number of columns
13294** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13295** an OOM condition or IO error), an appropriate SQLite error code is
13296** returned.
13297**
13298** This function may be quite inefficient if used with an FTS5 table
13299** created with the "columnsize=0" option.
13300**
13301** xColumnText:
13302** If parameter iCol is less than zero, or greater than or equal to the
13303** number of columns in the table, SQLITE_RANGE is returned.
13304**
13305** Otherwise, this function attempts to retrieve the text of column iCol of
13306** the current document. If successful, (*pz) is set to point to a buffer
13307** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
13308** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
13309** if an error occurs, an SQLite error code is returned and the final values
13310** of (*pz) and (*pn) are undefined.
13311**
13312** xPhraseCount:
13313** Returns the number of phrases in the current query expression.
13314**
13315** xPhraseSize:
13316** If parameter iCol is less than zero, or greater than or equal to the
13317** number of phrases in the current query, as returned by xPhraseCount,
13318** 0 is returned. Otherwise, this function returns the number of tokens in
13319** phrase iPhrase of the query. Phrases are numbered starting from zero.
13320**
13321** xInstCount:
13322** Set *pnInst to the total number of occurrences of all phrases within
13323** the query within the current row. Return SQLITE_OK if successful, or
13324** an error code (i.e. SQLITE_NOMEM) if an error occurs.
13325**
13326** This API can be quite slow if used with an FTS5 table created with the
13327** "detail=none" or "detail=column" option. If the FTS5 table is created
13328** with either "detail=none" or "detail=column" and "content=" option
13329** (i.e. if it is a contentless table), then this API always returns 0.
13330**
13331** xInst:
13332** Query for the details of phrase match iIdx within the current row.
13333** Phrase matches are numbered starting from zero, so the iIdx argument
13334** should be greater than or equal to zero and smaller than the value
13335** output by xInstCount(). If iIdx is less than zero or greater than
13336** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
13337**
13338** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
13339** to the column in which it occurs and *piOff the token offset of the
13340** first token of the phrase. SQLITE_OK is returned if successful, or an
13341** error code (i.e. SQLITE_NOMEM) if an error occurs.
13342**
13343** This API can be quite slow if used with an FTS5 table created with the
13344** "detail=none" or "detail=column" option.
13345**
13346** xRowid:
13347** Returns the rowid of the current row.
13348**
13349** xTokenize:
13350** Tokenize text using the tokenizer belonging to the FTS5 table.
13351**
13352** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
13353** This API function is used to query the FTS table for phrase iPhrase
13354** of the current query. Specifically, a query equivalent to:
13355**
13356** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
13357**
13358** with $p set to a phrase equivalent to the phrase iPhrase of the
13359** current query is executed. Any column filter that applies to
13360** phrase iPhrase of the current query is included in $p. For each
13361** row visited, the callback function passed as the fourth argument
13362** is invoked. The context and API objects passed to the callback
13363** function may be used to access the properties of each matched row.
13364** Invoking Api.xUserData() returns a copy of the pointer passed as
13365** the third argument to pUserData.
13366**
13367** If parameter iPhrase is less than zero, or greater than or equal to
13368** the number of phrases in the query, as returned by xPhraseCount(),
13369** this function returns SQLITE_RANGE.
13370**
13371** If the callback function returns any value other than SQLITE_OK, the
13372** query is abandoned and the xQueryPhrase function returns immediately.
13373** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
13374** Otherwise, the error code is propagated upwards.
13375**
13376** If the query runs to completion without incident, SQLITE_OK is returned.
13377** Or, if some error occurs before the query completes or is aborted by
13378** the callback, an SQLite error code is returned.
13379**
13380**
13381** xSetAuxdata(pFts5, pAux, xDelete)
13382**
13383** Save the pointer passed as the second argument as the extension function's
13384** "auxiliary data". The pointer may then be retrieved by the current or any
13385** future invocation of the same fts5 extension function made as part of
13386** the same MATCH query using the xGetAuxdata() API.
13387**
13388** Each extension function is allocated a single auxiliary data slot for
13389** each FTS query (MATCH expression). If the extension function is invoked
13390** more than once for a single FTS query, then all invocations share a
13391** single auxiliary data context.
13392**
13393** If there is already an auxiliary data pointer when this function is
13394** invoked, then it is replaced by the new pointer. If an xDelete callback
13395** was specified along with the original pointer, it is invoked at this
13396** point.
13397**
13398** The xDelete callback, if one is specified, is also invoked on the
13399** auxiliary data pointer after the FTS5 query has finished.
13400**
13401** If an error (e.g. an OOM condition) occurs within this function,
13402** the auxiliary data is set to NULL and an error code returned. If the
13403** xDelete parameter was not NULL, it is invoked on the auxiliary data
13404** pointer before returning.
13405**
13406**
13407** xGetAuxdata(pFts5, bClear)
13408**
13409** Returns the current auxiliary data pointer for the fts5 extension
13410** function. See the xSetAuxdata() method for details.
13411**
13412** If the bClear argument is non-zero, then the auxiliary data is cleared
13413** (set to NULL) before this function returns. In this case the xDelete,
13414** if any, is not invoked.
13415**
13416**
13417** xRowCount(pFts5, pnRow)
13418**
13419** This function is used to retrieve the total number of rows in the table.
13420** In other words, the same value that would be returned by:
13421**
13422** SELECT count(*) FROM ftstable;
13423**
13424** xPhraseFirst()
13425** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13426** method, to iterate through all instances of a single query phrase within
13427** the current row. This is the same information as is accessible via the
13428** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13429** to use, this API may be faster under some circumstances. To iterate
13430** through instances of phrase iPhrase, use the following code:
13431**
13432** Fts5PhraseIter iter;
13433** int iCol, iOff;
13434** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13435** iCol>=0;
13436** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13437** ){
13438** // An instance of phrase iPhrase at offset iOff of column iCol
13439** }
13440**
13441** The Fts5PhraseIter structure is defined above. Applications should not
13442** modify this structure directly - it should only be used as shown above
13443** with the xPhraseFirst() and xPhraseNext() API methods (and by
13444** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13445**
13446** This API can be quite slow if used with an FTS5 table created with the
13447** "detail=none" or "detail=column" option. If the FTS5 table is created
13448** with either "detail=none" or "detail=column" and "content=" option
13449** (i.e. if it is a contentless table), then this API always iterates
13450** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13451**
13452** In all cases, matches are visited in (column ASC, offset ASC) order.
13453** i.e. all those in column 0, sorted by offset, followed by those in
13454** column 1, etc.
13455**
13456** xPhraseNext()
13457** See xPhraseFirst above.
13458**
13459** xPhraseFirstColumn()
13460** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13461** and xPhraseNext() APIs described above. The difference is that instead
13462** of iterating through all instances of a phrase in the current row, these
13463** APIs are used to iterate through the set of columns in the current row
13464** that contain one or more instances of a specified phrase. For example:
13465**
13466** Fts5PhraseIter iter;
13467** int iCol;
13468** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13469** iCol>=0;
13470** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13471** ){
13472** // Column iCol contains at least one instance of phrase iPhrase
13473** }
13474**
13475** This API can be quite slow if used with an FTS5 table created with the
13476** "detail=none" option. If the FTS5 table is created with either
13477** "detail=none" "content=" option (i.e. if it is a contentless table),
13478** then this API always iterates through an empty set (all calls to
13479** xPhraseFirstColumn() set iCol to -1).
13480**
13481** The information accessed using this API and its companion
13482** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13483** (or xInst/xInstCount). The chief advantage of this API is that it is
13484** significantly more efficient than those alternatives when used with
13485** "detail=column" tables.
13486**
13487** xPhraseNextColumn()
13488** See xPhraseFirstColumn above.
13489**
13490** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13491** This is used to access token iToken of phrase iPhrase of the current
13492** query. Before returning, output parameter *ppToken is set to point
13493** to a buffer containing the requested token, and *pnToken to the
13494** size of this buffer in bytes.
13495**
13496** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13497** or equal to the number of phrases in the query as reported by
13498** xPhraseCount(), or if iToken is equal to or greater than the number of
13499** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13500 are both zeroed.
13501**
13502** The output text is not a copy of the query text that specified the
13503** token. It is the output of the tokenizer module. For tokendata=1
13504** tables, this includes any embedded 0x00 and trailing data.
13505**
13506** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13507** This is used to access token iToken of phrase hit iIdx within the
13508** current row. If iIdx is less than zero or greater than or equal to the
13509** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13510** output variable (*ppToken) is set to point to a buffer containing the
13511** matching document token, and (*pnToken) to the size of that buffer in
13512** bytes.
13513**
13514** The output text is not a copy of the document text that was tokenized.
13515** It is the output of the tokenizer module. For tokendata=1 tables, this
13516** includes any embedded 0x00 and trailing data.
13517**
13518** This API may be slow in some cases if the token identified by parameters
13519** iIdx and iToken matched a prefix token in the query. In most cases, the
13520** first call to this API for each prefix token in the query is forced
13521** to scan the portion of the full-text index that matches the prefix
13522** token to collect the extra data required by this API. If the prefix
13523** token matches a large number of token instances in the document set,
13524** this may be a performance problem.
13525**
13526** If the user knows in advance that a query may use this API for a
13527** prefix token, FTS5 may be configured to collect all required data as part
13528** of the initial querying of the full-text index, avoiding the second scan
13529** entirely. This also causes prefix queries that do not use this API to
13530** run more slowly and use more memory. FTS5 may be configured in this way
13531** either on a per-table basis using the [FTS5 insttoken | 'insttoken']
13532** option, or on a per-query basis using the
13533** [fts5_insttoken | fts5_insttoken()] user function.
13534**
13535** This API can be quite slow if used with an FTS5 table created with the
13536** "detail=none" or "detail=column" option.
13537**
13538** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
13539** If parameter iCol is less than zero, or greater than or equal to the
13540** number of columns in the table, SQLITE_RANGE is returned.
13541**
13542** Otherwise, this function attempts to retrieve the locale associated
13543** with column iCol of the current row. Usually, there is no associated
13544** locale, and output parameters (*pzLocale) and (*pnLocale) are set
13545** to NULL and 0, respectively. However, if the fts5_locale() function
13546** was used to associate a locale with the value when it was inserted
13547** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
13548** buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
13549** is set to the size in bytes of the buffer, not including the
13550** nul-terminator.
13551**
13552** If successful, SQLITE_OK is returned. Or, if an error occurs, an
13553** SQLite error code is returned. The final value of the output parameters
13554** is undefined in this case.
13555**
13556** xTokenize_v2:
13557** Tokenize text using the tokenizer belonging to the FTS5 table. This
13558** API is the same as the xTokenize() API, except that it allows a tokenizer
13559** locale to be specified.
13560*/
13561struct Fts5ExtensionApi {
13562 int iVersion; /* Currently always set to 4 */
13563
13564 void *(*xUserData)(Fts5Context*);
13565
13566 int (*xColumnCount)(Fts5Context*);
13567 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13568 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13569
13570 int (*xTokenize)(Fts5Context*,
13571 const char *pText, int nText, /* Text to tokenize */
13572 void *pCtx, /* Context passed to xToken() */
13573 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13574 );
13575
13576 int (*xPhraseCount)(Fts5Context*);
13577 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13578
13579 int (*xInstCount)(Fts5Context*, int *pnInst);
13580 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13581
13582 sqlite3_int64 (*xRowid)(Fts5Context*);
13583 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13584 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13585
13586 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13587 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13588 );
13589 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13590 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13591
13592 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13593 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13594
13595 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13596 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13597
13598 /* Below this point are iVersion>=3 only */
13599 int (*xQueryToken)(Fts5Context*,
13600 int iPhrase, int iToken,
13601 const char **ppToken, int *pnToken
13602 );
13603 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13604
13605 /* Below this point are iVersion>=4 only */
13606 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
13607 int (*xTokenize_v2)(Fts5Context*,
13608 const char *pText, int nText, /* Text to tokenize */
13609 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */
13610 void *pCtx, /* Context passed to xToken() */
13611 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13612 );
13613};
13614
13615/*
13616** CUSTOM AUXILIARY FUNCTIONS
13617*************************************************************************/
13618
13619/*************************************************************************
13620** CUSTOM TOKENIZERS
13621**
13622** Applications may also register custom tokenizer types. A tokenizer
13623** is registered by providing fts5 with a populated instance of the
13624** following structure. All structure methods must be defined, setting
13625** any member of the fts5_tokenizer struct to NULL leads to undefined
13626** behaviour. The structure methods are expected to function as follows:
13627**
13628** xCreate:
13629** This function is used to allocate and initialize a tokenizer instance.
13630** A tokenizer instance is required to actually tokenize text.
13631**
13632** The first argument passed to this function is a copy of the (void*)
13633** pointer provided by the application when the fts5_tokenizer_v2 object
13634** was registered with FTS5 (the third argument to xCreateTokenizer()).
13635** The second and third arguments are an array of nul-terminated strings
13636** containing the tokenizer arguments, if any, specified following the
13637** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13638** to create the FTS5 table.
13639**
13640** The final argument is an output variable. If successful, (*ppOut)
13641** should be set to point to the new tokenizer handle and SQLITE_OK
13642** returned. If an error occurs, some value other than SQLITE_OK should
13643** be returned. In this case, fts5 assumes that the final value of *ppOut
13644** is undefined.
13645**
13646** xDelete:
13647** This function is invoked to delete a tokenizer handle previously
13648** allocated using xCreate(). Fts5 guarantees that this function will
13649** be invoked exactly once for each successful call to xCreate().
13650**
13651** xTokenize:
13652** This function is expected to tokenize the nText byte string indicated
13653** by argument pText. pText may or may not be nul-terminated. The first
13654** argument passed to this function is a pointer to an Fts5Tokenizer object
13655** returned by an earlier call to xCreate().
13656**
13657** The third argument indicates the reason that FTS5 is requesting
13658** tokenization of the supplied text. This is always one of the following
13659** four values:
13660**
13661** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13662** or removed from the FTS table. The tokenizer is being invoked to
13663** determine the set of tokens to add to (or delete from) the
13664** FTS index.
13665**
13666** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13667** against the FTS index. The tokenizer is being called to tokenize
13668** a bareword or quoted string specified as part of the query.
13669**
13670** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13671** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13672** followed by a "*" character, indicating that the last token
13673** returned by the tokenizer will be treated as a token prefix.
13674**
13675** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13676** satisfy an fts5_api.xTokenize() request made by an auxiliary
13677** function. Or an fts5_api.xColumnSize() request made by the same
13678** on a columnsize=0 database.
13679** </ul>
13680**
13681** The sixth and seventh arguments passed to xTokenize() - pLocale and
13682** nLocale - are a pointer to a buffer containing the locale to use for
13683** tokenization (e.g. "en_US") and its size in bytes, respectively. The
13684** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
13685** which case nLocale is always 0) to indicate that the tokenizer should
13686** use its default locale.
13687**
13688** For each token in the input string, the supplied callback xToken() must
13689** be invoked. The first argument to it should be a copy of the pointer
13690** passed as the second argument to xTokenize(). The third and fourth
13691** arguments are a pointer to a buffer containing the token text, and the
13692** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13693** of the first byte of and first byte immediately following the text from
13694** which the token is derived within the input.
13695**
13696** The second argument passed to the xToken() callback ("tflags") should
13697** normally be set to 0. The exception is if the tokenizer supports
13698** synonyms. In this case see the discussion below for details.
13699**
13700** FTS5 assumes the xToken() callback is invoked for each token in the
13701** order that they occur within the input text.
13702**
13703** If an xToken() callback returns any value other than SQLITE_OK, then
13704** the tokenization should be abandoned and the xTokenize() method should
13705** immediately return a copy of the xToken() return value. Or, if the
13706** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13707** if an error occurs with the xTokenize() implementation itself, it
13708** may abandon the tokenization and return any error code other than
13709** SQLITE_OK or SQLITE_DONE.
13710**
13711** If the tokenizer is registered using an fts5_tokenizer_v2 object,
13712** then the xTokenize() method has two additional arguments - pLocale
13713** and nLocale. These specify the locale that the tokenizer should use
13714** for the current request. If pLocale and nLocale are both 0, then the
13715** tokenizer should use its default locale. Otherwise, pLocale points to
13716** an nLocale byte buffer containing the name of the locale to use as utf-8
13717** text. pLocale is not nul-terminated.
13718**
13719** FTS5_TOKENIZER
13720**
13721** There is also an fts5_tokenizer object. This is an older, deprecated,
13722** version of fts5_tokenizer_v2. It is similar except that:
13723**
13724** <ul>
13725** <li> There is no "iVersion" field, and
13726** <li> The xTokenize() method does not take a locale argument.
13727** </ul>
13728**
13729** Legacy fts5_tokenizer tokenizers must be registered using the
13730** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
13731**
13732** Tokenizer implementations registered using either API may be retrieved
13733** using both xFindTokenizer() and xFindTokenizer_v2().
13734**
13735** SYNONYM SUPPORT
13736**
13737** Custom tokenizers may also support synonyms. Consider a case in which a
13738** user wishes to query for a phrase such as "first place". Using the
13739** built-in tokenizers, the FTS5 query 'first + place' will match instances
13740** of "first place" within the document set, but not alternative forms
13741** such as "1st place". In some applications, it would be better to match
13742** all instances of "first place" or "1st place" regardless of which form
13743** the user specified in the MATCH query text.
13744**
13745** There are several ways to approach this in FTS5:
13746**
13747** <ol><li> By mapping all synonyms to a single token. In this case, using
13748** the above example, this means that the tokenizer returns the
13749** same token for inputs "first" and "1st". Say that token is in
13750** fact "first", so that when the user inserts the document "I won
13751** 1st place" entries are added to the index for tokens "i", "won",
13752** "first" and "place". If the user then queries for '1st + place',
13753** the tokenizer substitutes "first" for "1st" and the query works
13754** as expected.
13755**
13756** <li> By querying the index for all synonyms of each query term
13757** separately. In this case, when tokenizing query text, the
13758** tokenizer may provide multiple synonyms for a single term
13759** within the document. FTS5 then queries the index for each
13760** synonym individually. For example, faced with the query:
13761**
13762** <codeblock>
13763** ... MATCH 'first place'</codeblock>
13764**
13765** the tokenizer offers both "1st" and "first" as synonyms for the
13766** first token in the MATCH query and FTS5 effectively runs a query
13767** similar to:
13768**
13769** <codeblock>
13770** ... MATCH '(first OR 1st) place'</codeblock>
13771**
13772** except that, for the purposes of auxiliary functions, the query
13773** still appears to contain just two phrases - "(first OR 1st)"
13774** being treated as a single phrase.
13775**
13776** <li> By adding multiple synonyms for a single term to the FTS index.
13777** Using this method, when tokenizing document text, the tokenizer
13778** provides multiple synonyms for each token. So that when a
13779** document such as "I won first place" is tokenized, entries are
13780** added to the FTS index for "i", "won", "first", "1st" and
13781** "place".
13782**
13783** This way, even if the tokenizer does not provide synonyms
13784** when tokenizing query text (it should not - to do so would be
13785** inefficient), it doesn't matter if the user queries for
13786** 'first + place' or '1st + place', as there are entries in the
13787** FTS index corresponding to both forms of the first token.
13788** </ol>
13789**
13790** Whether it is parsing document or query text, any call to xToken that
13791** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13792** is considered to supply a synonym for the previous token. For example,
13793** when parsing the document "I won first place", a tokenizer that supports
13794** synonyms would call xToken() 5 times, as follows:
13795**
13796** <codeblock>
13797** xToken(pCtx, 0, "i", 1, 0, 1);
13798** xToken(pCtx, 0, "won", 3, 2, 5);
13799** xToken(pCtx, 0, "first", 5, 6, 11);
13800** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13801** xToken(pCtx, 0, "place", 5, 12, 17);
13802**</codeblock>
13803**
13804** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13805** xToken() is called. Multiple synonyms may be specified for a single token
13806** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13807** There is no limit to the number of synonyms that may be provided for a
13808** single token.
13809**
13810** In many cases, method (1) above is the best approach. It does not add
13811** extra data to the FTS index or require FTS5 to query for multiple terms,
13812** so it is efficient in terms of disk space and query speed. However, it
13813** does not support prefix queries very well. If, as suggested above, the
13814** token "first" is substituted for "1st" by the tokenizer, then the query:
13815**
13816** <codeblock>
13817** ... MATCH '1s*'</codeblock>
13818**
13819** will not match documents that contain the token "1st" (as the tokenizer
13820** will probably not map "1s" to any prefix of "first").
13821**
13822** For full prefix support, method (3) may be preferred. In this case,
13823** because the index contains entries for both "first" and "1st", prefix
13824** queries such as 'fi*' or '1s*' will match correctly. However, because
13825** extra entries are added to the FTS index, this method uses more space
13826** within the database.
13827**
13828** Method (2) offers a midpoint between (1) and (3). Using this method,
13829** a query such as '1s*' will match documents that contain the literal
13830** token "1st", but not "first" (assuming the tokenizer is not able to
13831** provide synonyms for prefixes). However, a non-prefix query like '1st'
13832** will match against "1st" and "first". This method does not require
13833** extra disk space, as no extra entries are added to the FTS index.
13834** On the other hand, it may require more CPU cycles to run MATCH queries,
13835** as separate queries of the FTS index are required for each synonym.
13836**
13837** When using methods (2) or (3), it is important that the tokenizer only
13838** provide synonyms when tokenizing document text (method (3)) or query
13839** text (method (2)), not both. Doing so will not cause any errors, but is
13840** inefficient.
13841*/
13842typedef struct Fts5Tokenizer Fts5Tokenizer;
13843typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
13844struct fts5_tokenizer_v2 {
13845 int iVersion; /* Currently always 2 */
13846
13847 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13848 void (*xDelete)(Fts5Tokenizer*);
13849 int (*xTokenize)(Fts5Tokenizer*,
13850 void *pCtx,
13851 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13852 const char *pText, int nText,
13853 const char *pLocale, int nLocale,
13854 int (*xToken)(
13855 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13856 int tflags, /* Mask of FTS5_TOKEN_* flags */
13857 const char *pToken, /* Pointer to buffer containing token */
13858 int nToken, /* Size of token in bytes */
13859 int iStart, /* Byte offset of token within input text */
13860 int iEnd /* Byte offset of end of token within input text */
13861 )
13862 );
13863};
13864
13865/*
13866** New code should use the fts5_tokenizer_v2 type to define tokenizer
13867** implementations. The following type is included for legacy applications
13868** that still use it.
13869*/
13870typedef struct fts5_tokenizer fts5_tokenizer;
13871struct fts5_tokenizer {
13872 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13873 void (*xDelete)(Fts5Tokenizer*);
13874 int (*xTokenize)(Fts5Tokenizer*,
13875 void *pCtx,
13876 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13877 const char *pText, int nText,
13878 int (*xToken)(
13879 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13880 int tflags, /* Mask of FTS5_TOKEN_* flags */
13881 const char *pToken, /* Pointer to buffer containing token */
13882 int nToken, /* Size of token in bytes */
13883 int iStart, /* Byte offset of token within input text */
13884 int iEnd /* Byte offset of end of token within input text */
13885 )
13886 );
13887};
13888
13889
13890/* Flags that may be passed as the third argument to xTokenize() */
13891#define FTS5_TOKENIZE_QUERY 0x0001
13892#define FTS5_TOKENIZE_PREFIX 0x0002
13893#define FTS5_TOKENIZE_DOCUMENT 0x0004
13894#define FTS5_TOKENIZE_AUX 0x0008
13895
13896/* Flags that may be passed by the tokenizer implementation back to FTS5
13897** as the third argument to the supplied xToken callback. */
13898#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13899
13900/*
13901** END OF CUSTOM TOKENIZERS
13902*************************************************************************/
13903
13904/*************************************************************************
13905** FTS5 EXTENSION REGISTRATION API
13906*/
13907typedef struct fts5_api fts5_api;
13908struct fts5_api {
13909 int iVersion; /* Currently always set to 3 */
13910
13911 /* Create a new tokenizer */
13912 int (*xCreateTokenizer)(
13913 fts5_api *pApi,
13914 const char *zName,
13915 void *pUserData,
13916 fts5_tokenizer *pTokenizer,
13917 void (*xDestroy)(void*)
13918 );
13919
13920 /* Find an existing tokenizer */
13921 int (*xFindTokenizer)(
13922 fts5_api *pApi,
13923 const char *zName,
13924 void **ppUserData,
13925 fts5_tokenizer *pTokenizer
13926 );
13927
13928 /* Create a new auxiliary function */
13929 int (*xCreateFunction)(
13930 fts5_api *pApi,
13931 const char *zName,
13932 void *pUserData,
13933 fts5_extension_function xFunction,
13934 void (*xDestroy)(void*)
13935 );
13936
13937 /* APIs below this point are only available if iVersion>=3 */
13938
13939 /* Create a new tokenizer */
13940 int (*xCreateTokenizer_v2)(
13941 fts5_api *pApi,
13942 const char *zName,
13943 void *pUserData,
13944 fts5_tokenizer_v2 *pTokenizer,
13945 void (*xDestroy)(void*)
13946 );
13947
13948 /* Find an existing tokenizer */
13949 int (*xFindTokenizer_v2)(
13950 fts5_api *pApi,
13951 const char *zName,
13952 void **ppUserData,
13953 fts5_tokenizer_v2 **ppTokenizer
13954 );
13955};
13956
13957/*
13958** END OF REGISTRATION API
13959*************************************************************************/
13960
13961#ifdef __cplusplus
13962} /* end of the 'extern "C"' block */
13963#endif
13964
13965#endif /* _FTS5_H */
13966
13967/******** End of fts5.h *********/
13968#endif /* SQLITE3_H */
13969