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 "3.52.0"
150#define SQLITE_VERSION_NUMBER 3052000
151#define SQLITE_SOURCE_ID "2026-03-06 16:01:44 557aeb43869d3585137b17690cb3b64f7de6921774daae9e56403c3717dcalt1"
152#define SQLITE_SCM_BRANCH "trunk"
153#define SQLITE_SCM_TAGS "release major-release version-3.52.0"
154#define SQLITE_SCM_DATETIME "2026-03-06T16:01:44.367Z"
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 xNextSystemCall() 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 run-time performance statistics
2572** used by [sqlite3_stmt_scanstatus_v2()] and the [nexec and ncycle]
2573** columns of the [bytecode virtual table].
2574** For statistics to be collected, the flag must be set on
2575** the database handle both when the SQL statement is
2576** [sqlite3_prepare|prepared] and when it is [sqlite3_step|stepped].
2577** The flag is set (collection of statistics is enabled) by default.
2578** <p>This option takes two arguments: an integer and a pointer to
2579** an integer. The first argument is 1, 0, or -1 to enable, disable, or
2580** leave unchanged the statement scanstatus option. If the second argument
2581** is not NULL, then the value of the statement scanstatus setting after
2582** processing the first argument is written into the integer that the second
2583** argument points to.
2584** </dd>
2585**
2586** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2587** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2588** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2589** in which tables and indexes are scanned so that the scans start at the end
2590** and work toward the beginning rather than starting at the beginning and
2591** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2592** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2593** two arguments which are an integer and a pointer to an integer. The first
2594** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2595** reverse scan order flag, respectively. If the second argument is not NULL,
2596** then 0 or 1 is written into the integer that the second argument points to
2597** depending on if the reverse scan order flag is set after processing the
2598** first argument.
2599** </dd>
2600**
2601** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2602** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2603** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2604** the ability of the [ATTACH DATABASE] SQL command to create a new database
2605** file if the database filed named in the ATTACH command does not already
2606** exist. This ability of ATTACH to create a new database is enabled by
2607** default. Applications can disable or reenable the ability for ATTACH to
2608** create new database files using this DBCONFIG option.<p>
2609** This option takes two arguments which are an integer and a pointer
2610** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2611** leave unchanged the attach-create flag, respectively. If the second
2612** argument is not NULL, then 0 or 1 is written into the integer that the
2613** second argument points to depending on if the attach-create flag is set
2614** after processing the first argument.
2615** </dd>
2616**
2617** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2618** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2619** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2620** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2621** This capability is enabled by default. Applications can disable or
2622** reenable this capability using the current DBCONFIG option. If
2623** this capability is disabled, the [ATTACH] command will still work,
2624** but the database will be opened read-only. If this option is disabled,
2625** then the ability to create a new database using [ATTACH] is also disabled,
2626** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2627** option.<p>
2628** This option takes two arguments which are an integer and a pointer
2629** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2630** leave unchanged the ability to ATTACH another database for writing,
2631** respectively. If the second argument is not NULL, then 0 or 1 is written
2632** into the integer to which the second argument points, depending on whether
2633** the ability to ATTACH a read/write database is enabled or disabled
2634** after processing the first argument.
2635** </dd>
2636**
2637** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2638** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2639** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2640** ability to include comments in SQL text. Comments are enabled by default.
2641** An application can disable or reenable comments in SQL text using this
2642** DBCONFIG option.<p>
2643** This option takes two arguments which are an integer and a pointer
2644** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2645** leave unchanged the ability to use comments in SQL text,
2646** respectively. If the second argument is not NULL, then 0 or 1 is written
2647** into the integer that the second argument points to depending on if
2648** comments are allowed in SQL text after processing the first argument.
2649** </dd>
2650**
2651** [[SQLITE_DBCONFIG_FP_DIGITS]]
2652** <dt>SQLITE_DBCONFIG_FP_DIGITS</dt>
2653** <dd>The SQLITE_DBCONFIG_FP_DIGITS setting is a small integer that determines
2654** the number of significant digits that SQLite will attempt to preserve when
2655** converting floating point numbers (IEEE 754 "doubles") into text. The
2656** default value 17, as of SQLite version 3.52.0. The value was 15 in all
2657** prior versions.<p>
2658** This option takes two arguments which are an integer and a pointer
2659** to an integer. The first argument is a small integer, between 3 and 23, or
2660** zero. The FP_DIGITS setting is changed to that small integer, or left
2661** altered if the first argument is zero or out of range. The second argument
2662** is a pointer to an integer. If the pointer is not NULL, then the value of
2663** the FP_DIGITS setting, after possibly being modified by the first
2664** arguments, is written into the integer to which the second argument points.
2665** </dd>
2666**
2667** </dl>
2668**
2669** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2670**
2671** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2672** overall call to [sqlite3_db_config()] has a total of four parameters.
2673** The first argument (the third parameter to sqlite3_db_config()) is an integer.
2674** The second argument is a pointer to an integer. If the first argument is 1,
2675** then the option becomes enabled. If the first integer argument is 0, then the
2676** option is disabled. If the first argument is -1, then the option setting
2677** is unchanged. The second argument, the pointer to an integer, may be NULL.
2678** If the second argument is not NULL, then a value of 0 or 1 is written into
2679** the integer to which the second argument points, depending on whether the
2680** setting is disabled or enabled after applying any changes specified by
2681** the first argument.
2682**
2683** <p>While most SQLITE_DBCONFIG options use the argument format
2684** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME],
2685** [SQLITE_DBCONFIG_LOOKASIDE], and [SQLITE_DBCONFIG_FP_DIGITS] options
2686** are different. See the documentation of those exceptional options for
2687** details.
2688*/
2689#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2690#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2691#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2692#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2693#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2694#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2695#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2696#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2697#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2698#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2699#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2700#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2701#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2702#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2703#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2704#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2705#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2706#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2707#define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2708#define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2709#define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2710#define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2711#define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2712#define SQLITE_DBCONFIG_FP_DIGITS 1023 /* int int* */
2713#define SQLITE_DBCONFIG_MAX 1023 /* Largest DBCONFIG */
2714
2715/*
2716** CAPI3REF: Enable Or Disable Extended Result Codes
2717** METHOD: sqlite3
2718**
2719** ^The sqlite3_extended_result_codes() routine enables or disables the
2720** [extended result codes] feature of SQLite. ^The extended result
2721** codes are disabled by default for historical compatibility.
2722*/
2723SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2724
2725/*
2726** CAPI3REF: Last Insert Rowid
2727** METHOD: sqlite3
2728**
2729** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2730** has a unique 64-bit signed
2731** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2732** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2733** names are not also used by explicitly declared columns. ^If
2734** the table has a column of type [INTEGER PRIMARY KEY] then that column
2735** is another alias for the rowid.
2736**
2737** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2738** the most recent successful [INSERT] into a rowid table or [virtual table]
2739** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2740** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2741** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2742** zero.
2743**
2744** As well as being set automatically as rows are inserted into database
2745** tables, the value returned by this function may be set explicitly by
2746** [sqlite3_set_last_insert_rowid()]
2747**
2748** Some virtual table implementations may INSERT rows into rowid tables as
2749** part of committing a transaction (e.g. to flush data accumulated in memory
2750** to disk). In this case subsequent calls to this function return the rowid
2751** associated with these internal INSERT operations, which leads to
2752** unintuitive results. Virtual table implementations that do write to rowid
2753** tables in this way can avoid this problem by restoring the original
2754** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2755** control to the user.
2756**
2757** ^(If an [INSERT] occurs within a trigger then this routine will
2758** return the [rowid] of the inserted row as long as the trigger is
2759** running. Once the trigger program ends, the value returned
2760** by this routine reverts to what it was before the trigger was fired.)^
2761**
2762** ^An [INSERT] that fails due to a constraint violation is not a
2763** successful [INSERT] and does not change the value returned by this
2764** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2765** and INSERT OR ABORT make no changes to the return value of this
2766** routine when their insertion fails. ^(When INSERT OR REPLACE
2767** encounters a constraint violation, it does not fail. The
2768** INSERT continues to completion after deleting rows that caused
2769** the constraint problem so INSERT OR REPLACE will always change
2770** the return value of this interface.)^
2771**
2772** ^For the purposes of this routine, an [INSERT] is considered to
2773** be successful even if it is subsequently rolled back.
2774**
2775** This function is accessible to SQL statements via the
2776** [last_insert_rowid() SQL function].
2777**
2778** If a separate thread performs a new [INSERT] on the same
2779** database connection while the [sqlite3_last_insert_rowid()]
2780** function is running and thus changes the last insert [rowid],
2781** then the value returned by [sqlite3_last_insert_rowid()] is
2782** unpredictable and might not equal either the old or the new
2783** last insert [rowid].
2784*/
2785SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2786
2787/*
2788** CAPI3REF: Set the Last Insert Rowid value.
2789** METHOD: sqlite3
2790**
2791** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2792** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2793** without inserting a row into the database.
2794*/
2795SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2796
2797/*
2798** CAPI3REF: Count The Number Of Rows Modified
2799** METHOD: sqlite3
2800**
2801** ^These functions return the number of rows modified, inserted or
2802** deleted by the most recently completed INSERT, UPDATE or DELETE
2803** statement on the database connection specified by the only parameter.
2804** The two functions are identical except for the type of the return value
2805** and that if the number of rows modified by the most recent INSERT, UPDATE,
2806** or DELETE is greater than the maximum value supported by type "int", then
2807** the return value of sqlite3_changes() is undefined. ^Executing any other
2808** type of SQL statement does not modify the value returned by these functions.
2809** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2810** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2811** added to the new table by the CREATE TABLE AS SELECT statement are not
2812** counted.
2813**
2814** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2815** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2816** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2817**
2818** Changes to a view that are intercepted by
2819** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2820** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2821** DELETE statement run on a view is always zero. Only changes made to real
2822** tables are counted.
2823**
2824** Things are more complicated if the sqlite3_changes() function is
2825** executed while a trigger program is running. This may happen if the
2826** program uses the [changes() SQL function], or if some other callback
2827** function invokes sqlite3_changes() directly. Essentially:
2828**
2829** <ul>
2830** <li> ^(Before entering a trigger program the value returned by
2831** sqlite3_changes() function is saved. After the trigger program
2832** has finished, the original value is restored.)^
2833**
2834** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2835** statement sets the value returned by sqlite3_changes()
2836** upon completion as normal. Of course, this value will not include
2837** any changes performed by sub-triggers, as the sqlite3_changes()
2838** value will be saved and restored after each sub-trigger has run.)^
2839** </ul>
2840**
2841** ^This means that if the changes() SQL function (or similar) is used
2842** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2843** returns the value as set when the calling statement began executing.
2844** ^If it is used by the second or subsequent such statement within a trigger
2845** program, the value returned reflects the number of rows modified by the
2846** previous INSERT, UPDATE or DELETE statement within the same trigger.
2847**
2848** If a separate thread makes changes on the same database connection
2849** while [sqlite3_changes()] is running then the value returned
2850** is unpredictable and not meaningful.
2851**
2852** See also:
2853** <ul>
2854** <li> the [sqlite3_total_changes()] interface
2855** <li> the [count_changes pragma]
2856** <li> the [changes() SQL function]
2857** <li> the [data_version pragma]
2858** </ul>
2859*/
2860SQLITE_API int sqlite3_changes(sqlite3*);
2861SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2862
2863/*
2864** CAPI3REF: Total Number Of Rows Modified
2865** METHOD: sqlite3
2866**
2867** ^These functions return the total number of rows inserted, modified or
2868** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2869** since the database connection was opened, including those executed as
2870** part of trigger programs. The two functions are identical except for the
2871** type of the return value and that if the number of rows modified by the
2872** connection exceeds the maximum value supported by type "int", then
2873** the return value of sqlite3_total_changes() is undefined. ^Executing
2874** any other type of SQL statement does not affect the value returned by
2875** sqlite3_total_changes().
2876**
2877** ^Changes made as part of [foreign key actions] are included in the
2878** count, but those made as part of REPLACE constraint resolution are
2879** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2880** are not counted.
2881**
2882** The [sqlite3_total_changes(D)] interface only reports the number
2883** of rows that changed due to SQL statement run against database
2884** connection D. Any changes by other database connections are ignored.
2885** To detect changes against a database file from other database
2886** connections use the [PRAGMA data_version] command or the
2887** [SQLITE_FCNTL_DATA_VERSION] [file control].
2888**
2889** If a separate thread makes changes on the same database connection
2890** while [sqlite3_total_changes()] is running then the value
2891** returned is unpredictable and not meaningful.
2892**
2893** See also:
2894** <ul>
2895** <li> the [sqlite3_changes()] interface
2896** <li> the [count_changes pragma]
2897** <li> the [changes() SQL function]
2898** <li> the [data_version pragma]
2899** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2900** </ul>
2901*/
2902SQLITE_API int sqlite3_total_changes(sqlite3*);
2903SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2904
2905/*
2906** CAPI3REF: Interrupt A Long-Running Query
2907** METHOD: sqlite3
2908**
2909** ^This function causes any pending database operation to abort and
2910** return at its earliest opportunity. This routine is typically
2911** called in response to a user action such as pressing "Cancel"
2912** or Ctrl-C where the user wants a long query operation to halt
2913** immediately.
2914**
2915** ^It is safe to call this routine from a thread different from the
2916** thread that is currently running the database operation. But it
2917** is not safe to call this routine with a [database connection] that
2918** is closed or might close before sqlite3_interrupt() returns.
2919**
2920** ^If an SQL operation is very nearly finished at the time when
2921** sqlite3_interrupt() is called, then it might not have an opportunity
2922** to be interrupted and might continue to completion.
2923**
2924** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2925** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2926** that is inside an explicit transaction, then the entire transaction
2927** will be rolled back automatically.
2928**
2929** ^The sqlite3_interrupt(D) call is in effect until all currently running
2930** SQL statements on [database connection] D complete. ^Any new SQL statements
2931** that are started after the sqlite3_interrupt() call and before the
2932** running statement count reaches zero are interrupted as if they had been
2933** running prior to the sqlite3_interrupt() call. ^New SQL statements
2934** that are started after the running statement count reaches zero are
2935** not effected by the sqlite3_interrupt().
2936** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2937** SQL statements is a no-op and has no effect on SQL statements
2938** that are started after the sqlite3_interrupt() call returns.
2939**
2940** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2941** or not an interrupt is currently in effect for [database connection] D.
2942** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2943*/
2944SQLITE_API void sqlite3_interrupt(sqlite3*);
2945SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2946
2947/*
2948** CAPI3REF: Determine If An SQL Statement Is Complete
2949**
2950** These routines are useful during command-line input to determine if the
2951** currently entered text seems to form a complete SQL statement or
2952** if additional input is needed before sending the text into
2953** SQLite for parsing. ^These routines return 1 if the input string
2954** appears to be a complete SQL statement. ^A statement is judged to be
2955** complete if it ends with a semicolon token and is not a prefix of a
2956** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2957** string literals or quoted identifier names or comments are not
2958** independent tokens (they are part of the token in which they are
2959** embedded) and thus do not count as a statement terminator. ^Whitespace
2960** and comments that follow the final semicolon are ignored.
2961**
2962** ^These routines return 0 if the statement is incomplete. ^If a
2963** memory allocation fails, then SQLITE_NOMEM is returned.
2964**
2965** ^These routines do not parse the SQL statements and thus
2966** will not detect syntactically incorrect SQL.
2967**
2968** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2969** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2970** automatically by sqlite3_complete16(). If that initialization fails,
2971** then the return value from sqlite3_complete16() will be non-zero
2972** regardless of whether or not the input SQL is complete.)^
2973**
2974** The input to [sqlite3_complete()] must be a zero-terminated
2975** UTF-8 string.
2976**
2977** The input to [sqlite3_complete16()] must be a zero-terminated
2978** UTF-16 string in native byte order.
2979*/
2980SQLITE_API int sqlite3_complete(const char *sql);
2981SQLITE_API int sqlite3_complete16(const void *sql);
2982
2983/*
2984** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2985** KEYWORDS: {busy-handler callback} {busy handler}
2986** METHOD: sqlite3
2987**
2988** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2989** that might be invoked with argument P whenever
2990** an attempt is made to access a database table associated with
2991** [database connection] D when another thread
2992** or process has the table locked.
2993** The sqlite3_busy_handler() interface is used to implement
2994** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2995**
2996** ^If the busy callback is NULL, then [SQLITE_BUSY]
2997** is returned immediately upon encountering the lock. ^If the busy callback
2998** is not NULL, then the callback might be invoked with two arguments.
2999**
3000** ^The first argument to the busy handler is a copy of the void* pointer which
3001** is the third argument to sqlite3_busy_handler(). ^The second argument to
3002** the busy handler callback is the number of times that the busy handler has
3003** been invoked previously for the same locking event. ^If the
3004** busy callback returns 0, then no additional attempts are made to
3005** access the database and [SQLITE_BUSY] is returned
3006** to the application.
3007** ^If the callback returns non-zero, then another attempt
3008** is made to access the database and the cycle repeats.
3009**
3010** The presence of a busy handler does not guarantee that it will be invoked
3011** when there is lock contention. ^If SQLite determines that invoking the busy
3012** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
3013** to the application instead of invoking the
3014** busy handler.
3015** Consider a scenario where one process is holding a read lock that
3016** it is trying to promote to a reserved lock and
3017** a second process is holding a reserved lock that it is trying
3018** to promote to an exclusive lock. The first process cannot proceed
3019** because it is blocked by the second and the second process cannot
3020** proceed because it is blocked by the first. If both processes
3021** invoke the busy handlers, neither will make any progress. Therefore,
3022** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
3023** will induce the first process to release its read lock and allow
3024** the second process to proceed.
3025**
3026** ^The default busy callback is NULL.
3027**
3028** ^(There can only be a single busy handler defined for each
3029** [database connection]. Setting a new busy handler clears any
3030** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
3031** or evaluating [PRAGMA busy_timeout=N] will change the
3032** busy handler and thus clear any previously set busy handler.
3033**
3034** The busy callback should not take any actions which modify the
3035** database connection that invoked the busy handler. In other words,
3036** the busy handler is not reentrant. Any such actions
3037** result in undefined behavior.
3038**
3039** A busy handler must not close the database connection
3040** or [prepared statement] that invoked the busy handler.
3041*/
3042SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3043
3044/*
3045** CAPI3REF: Set A Busy Timeout
3046** METHOD: sqlite3
3047**
3048** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3049** for a specified amount of time when a table is locked. ^The handler
3050** will sleep multiple times until at least "ms" milliseconds of sleeping
3051** have accumulated. ^After at least "ms" milliseconds of sleeping,
3052** the handler returns 0 which causes [sqlite3_step()] to return
3053** [SQLITE_BUSY].
3054**
3055** ^Calling this routine with an argument less than or equal to zero
3056** turns off all busy handlers.
3057**
3058** ^(There can only be a single busy handler for a particular
3059** [database connection] at any given moment. If another busy handler
3060** was defined (using [sqlite3_busy_handler()]) prior to calling
3061** this routine, that other busy handler is cleared.)^
3062**
3063** See also: [PRAGMA busy_timeout]
3064*/
3065SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3066
3067/*
3068** CAPI3REF: Set the Setlk Timeout
3069** METHOD: sqlite3
3070**
3071** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3072** the VFS supports blocking locks, it sets the timeout in ms used by
3073** eligible locks taken on wal mode databases by the specified database
3074** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3075** not support blocking locks, this function is a no-op.
3076**
3077** Passing 0 to this function disables blocking locks altogether. Passing
3078** -1 to this function requests that the VFS blocks for a long time -
3079** indefinitely if possible. The results of passing any other negative value
3080** are undefined.
3081**
3082** Internally, each SQLite database handle stores two timeout values - the
3083** busy-timeout (used for rollback mode databases, or if the VFS does not
3084** support blocking locks) and the setlk-timeout (used for blocking locks
3085** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3086** values, this function sets only the setlk-timeout value. Therefore,
3087** to configure separate busy-timeout and setlk-timeout values for a single
3088** database handle, call sqlite3_busy_timeout() followed by this function.
3089**
3090** Whenever the number of connections to a wal mode database falls from
3091** 1 to 0, the last connection takes an exclusive lock on the database,
3092** then checkpoints and deletes the wal file. While it is doing this, any
3093** new connection that tries to read from the database fails with an
3094** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3095** passed to this API, the new connection blocks until the exclusive lock
3096** has been released.
3097*/
3098SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3099
3100/*
3101** CAPI3REF: Flags for sqlite3_setlk_timeout()
3102*/
3103#define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3104
3105/*
3106** CAPI3REF: Convenience Routines For Running Queries
3107** METHOD: sqlite3
3108**
3109** This is a legacy interface that is preserved for backwards compatibility.
3110** Use of this interface is not recommended.
3111**
3112** Definition: A <b>result table</b> is a memory data structure created by the
3113** [sqlite3_get_table()] interface. A result table records the
3114** complete query results from one or more queries.
3115**
3116** The table conceptually has a number of rows and columns. But
3117** these numbers are not part of the result table itself. These
3118** numbers are obtained separately. Let N be the number of rows
3119** and M be the number of columns.
3120**
3121** A result table is an array of pointers to zero-terminated UTF-8 strings.
3122** There are (N+1)*M elements in the array. The first M pointers point
3123** to zero-terminated strings that contain the names of the columns.
3124** The remaining entries all point to query results. NULL values result
3125** in NULL pointers. All other values are in their UTF-8 zero-terminated
3126** string representation as returned by [sqlite3_column_text()].
3127**
3128** A result table might consist of one or more memory allocations.
3129** It is not safe to pass a result table directly to [sqlite3_free()].
3130** A result table should be deallocated using [sqlite3_free_table()].
3131**
3132** ^(As an example of the result table format, suppose a query result
3133** is as follows:
3134**
3135** <blockquote><pre>
3136** Name | Age
3137** -----------------------
3138** Alice | 43
3139** Bob | 28
3140** Cindy | 21
3141** </pre></blockquote>
3142**
3143** There are two columns (M==2) and three rows (N==3). Thus the
3144** result table has 8 entries. Suppose the result table is stored
3145** in an array named azResult. Then azResult holds this content:
3146**
3147** <blockquote><pre>
3148** azResult&#91;0] = "Name";
3149** azResult&#91;1] = "Age";
3150** azResult&#91;2] = "Alice";
3151** azResult&#91;3] = "43";
3152** azResult&#91;4] = "Bob";
3153** azResult&#91;5] = "28";
3154** azResult&#91;6] = "Cindy";
3155** azResult&#91;7] = "21";
3156** </pre></blockquote>)^
3157**
3158** ^The sqlite3_get_table() function evaluates one or more
3159** semicolon-separated SQL statements in the zero-terminated UTF-8
3160** string of its 2nd parameter and returns a result table to the
3161** pointer given in its 3rd parameter.
3162**
3163** After the application has finished with the result from sqlite3_get_table(),
3164** it must pass the result table pointer to sqlite3_free_table() in order to
3165** release the memory that was malloced. Because of the way the
3166** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3167** function must not try to call [sqlite3_free()] directly. Only
3168** [sqlite3_free_table()] is able to release the memory properly and safely.
3169**
3170** The sqlite3_get_table() interface is implemented as a wrapper around
3171** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3172** to any internal data structures of SQLite. It uses only the public
3173** interface defined here. As a consequence, errors that occur in the
3174** wrapper layer outside of the internal [sqlite3_exec()] call are not
3175** reflected in subsequent calls to [sqlite3_errcode()] or
3176** [sqlite3_errmsg()].
3177*/
3178SQLITE_API int sqlite3_get_table(
3179 sqlite3 *db, /* An open database */
3180 const char *zSql, /* SQL to be evaluated */
3181 char ***pazResult, /* Results of the query */
3182 int *pnRow, /* Number of result rows written here */
3183 int *pnColumn, /* Number of result columns written here */
3184 char **pzErrmsg /* Error msg written here */
3185);
3186SQLITE_API void sqlite3_free_table(char **result);
3187
3188/*
3189** CAPI3REF: Formatted String Printing Functions
3190**
3191** These routines are work-alikes of the "printf()" family of functions
3192** from the standard C library.
3193** These routines understand most of the common formatting options from
3194** the standard library printf()
3195** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3196** See the [built-in printf()] documentation for details.
3197**
3198** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3199** results into memory obtained from [sqlite3_malloc64()].
3200** The strings returned by these two routines should be
3201** released by [sqlite3_free()]. ^Both routines return a
3202** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3203** memory to hold the resulting string.
3204**
3205** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3206** the standard C library. The result is written into the
3207** buffer supplied as the second parameter whose size is given by
3208** the first parameter. Note that the order of the
3209** first two parameters is reversed from snprintf().)^ This is an
3210** historical accident that cannot be fixed without breaking
3211** backwards compatibility. ^(Note also that sqlite3_snprintf()
3212** returns a pointer to its buffer instead of the number of
3213** characters actually written into the buffer.)^ We admit that
3214** the number of characters written would be a more useful return
3215** value but we cannot change the implementation of sqlite3_snprintf()
3216** now without breaking compatibility.
3217**
3218** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3219** guarantees that the buffer is always zero-terminated. ^The first
3220** parameter "n" is the total size of the buffer, including space for
3221** the zero terminator. So the longest string that can be completely
3222** written will be n-1 characters.
3223**
3224** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3225**
3226** See also: [built-in printf()], [printf() SQL function]
3227*/
3228SQLITE_API char *sqlite3_mprintf(const char*,...);
3229SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3230SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3231SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3232
3233/*
3234** CAPI3REF: Memory Allocation Subsystem
3235**
3236** The SQLite core uses these three routines for all of its own
3237** internal memory allocation needs. "Core" in the previous sentence
3238** does not include operating-system specific [VFS] implementation. The
3239** Windows VFS uses native malloc() and free() for some operations.
3240**
3241** ^The sqlite3_malloc() routine returns a pointer to a block
3242** of memory at least N bytes in length, where N is the parameter.
3243** ^If sqlite3_malloc() is unable to obtain sufficient free
3244** memory, it returns a NULL pointer. ^If the parameter N to
3245** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3246** a NULL pointer.
3247**
3248** ^The sqlite3_malloc64(N) routine works just like
3249** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3250** of a signed 32-bit integer.
3251**
3252** ^Calling sqlite3_free() with a pointer previously returned
3253** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3254** that it might be reused. ^The sqlite3_free() routine is
3255** a no-op if it is called with a NULL pointer. Passing a NULL pointer
3256** to sqlite3_free() is harmless. After being freed, memory
3257** should neither be read nor written. Even reading previously freed
3258** memory might result in a segmentation fault or other severe error.
3259** Memory corruption, a segmentation fault, or other severe error
3260** might result if sqlite3_free() is called with a non-NULL pointer that
3261** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3262**
3263** ^The sqlite3_realloc(X,N) interface attempts to resize a
3264** prior memory allocation X to be at least N bytes.
3265** ^If the X parameter to sqlite3_realloc(X,N)
3266** is a NULL pointer then its behavior is identical to calling
3267** sqlite3_malloc(N).
3268** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3269** negative then the behavior is exactly the same as calling
3270** sqlite3_free(X).
3271** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3272** of at least N bytes in size or NULL if insufficient memory is available.
3273** ^If M is the size of the prior allocation, then min(N,M) bytes of the
3274** prior allocation are copied into the beginning of the buffer returned
3275** by sqlite3_realloc(X,N) and the prior allocation is freed.
3276** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3277** prior allocation is not freed.
3278**
3279** ^The sqlite3_realloc64(X,N) interface works the same as
3280** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3281** of a 32-bit signed integer.
3282**
3283** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3284** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3285** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3286** ^The value returned by sqlite3_msize(X) might be larger than the number
3287** of bytes requested when X was allocated. ^If X is a NULL pointer then
3288** sqlite3_msize(X) returns zero. If X points to something that is not
3289** the beginning of memory allocation, or if it points to a formerly
3290** valid memory allocation that has now been freed, then the behavior
3291** of sqlite3_msize(X) is undefined and possibly harmful.
3292**
3293** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3294** sqlite3_malloc64(), and sqlite3_realloc64()
3295** is always aligned to at least an 8 byte boundary, or to a
3296** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3297** option is used.
3298**
3299** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3300** must be either NULL or else pointers obtained from a prior
3301** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3302** not yet been released.
3303**
3304** The application must not read or write any part of
3305** a block of memory after it has been released using
3306** [sqlite3_free()] or [sqlite3_realloc()].
3307*/
3308SQLITE_API void *sqlite3_malloc(int);
3309SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3310SQLITE_API void *sqlite3_realloc(void*, int);
3311SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3312SQLITE_API void sqlite3_free(void*);
3313SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3314
3315/*
3316** CAPI3REF: Memory Allocator Statistics
3317**
3318** SQLite provides these two interfaces for reporting on the status
3319** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3320** routines, which form the built-in memory allocation subsystem.
3321**
3322** ^The [sqlite3_memory_used()] routine returns the number of bytes
3323** of memory currently outstanding (malloced but not freed).
3324** ^The [sqlite3_memory_highwater()] routine returns the maximum
3325** value of [sqlite3_memory_used()] since the high-water mark
3326** was last reset. ^The values returned by [sqlite3_memory_used()] and
3327** [sqlite3_memory_highwater()] include any overhead
3328** added by SQLite in its implementation of [sqlite3_malloc()],
3329** but not overhead added by any underlying system library
3330** routines that [sqlite3_malloc()] may call.
3331**
3332** ^The memory high-water mark is reset to the current value of
3333** [sqlite3_memory_used()] if and only if the parameter to
3334** [sqlite3_memory_highwater()] is true. ^The value returned
3335** by [sqlite3_memory_highwater(1)] is the high-water mark
3336** prior to the reset.
3337*/
3338SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3339SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3340
3341/*
3342** CAPI3REF: Pseudo-Random Number Generator
3343**
3344** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3345** select random [ROWID | ROWIDs] when inserting new records into a table that
3346** already uses the largest possible [ROWID]. The PRNG is also used for
3347** the built-in random() and randomblob() SQL functions. This interface allows
3348** applications to access the same PRNG for other purposes.
3349**
3350** ^A call to this routine stores N bytes of randomness into buffer P.
3351** ^The P parameter can be a NULL pointer.
3352**
3353** ^If this routine has not been previously called or if the previous
3354** call had N less than one or a NULL pointer for P, then the PRNG is
3355** seeded using randomness obtained from the xRandomness method of
3356** the default [sqlite3_vfs] object.
3357** ^If the previous call to this routine had an N of 1 or more and a
3358** non-NULL P then the pseudo-randomness is generated
3359** internally and without recourse to the [sqlite3_vfs] xRandomness
3360** method.
3361*/
3362SQLITE_API void sqlite3_randomness(int N, void *P);
3363
3364/*
3365** CAPI3REF: Compile-Time Authorization Callbacks
3366** METHOD: sqlite3
3367** KEYWORDS: {authorizer callback}
3368**
3369** ^This routine registers an authorizer callback with a particular
3370** [database connection], supplied in the first argument.
3371** ^The authorizer callback is invoked as SQL statements are being compiled
3372** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3373** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3374** and [sqlite3_prepare16_v3()]. ^At various
3375** points during the compilation process, as logic is being created
3376** to perform various actions, the authorizer callback is invoked to
3377** see if those actions are allowed. ^The authorizer callback should
3378** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3379** specific action but allow the SQL statement to continue to be
3380** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3381** rejected with an error. ^If the authorizer callback returns
3382** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3383** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3384** the authorizer will fail with an error message.
3385**
3386** When the callback returns [SQLITE_OK], that means the operation
3387** requested is ok. ^When the callback returns [SQLITE_DENY], the
3388** [sqlite3_prepare_v2()] or equivalent call that triggered the
3389** authorizer will fail with an error message explaining that
3390** access is denied.
3391**
3392** ^The first parameter to the authorizer callback is a copy of the third
3393** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3394** to the callback is an integer [SQLITE_COPY | action code] that specifies
3395** the particular action to be authorized. ^The third through sixth parameters
3396** to the callback are either NULL pointers or zero-terminated strings
3397** that contain additional details about the action to be authorized.
3398** Applications must always be prepared to encounter a NULL pointer in any
3399** of the third through the sixth parameters of the authorization callback.
3400**
3401** ^If the action code is [SQLITE_READ]
3402** and the callback returns [SQLITE_IGNORE] then the
3403** [prepared statement] statement is constructed to substitute
3404** a NULL value in place of the table column that would have
3405** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3406** return can be used to deny an untrusted user access to individual
3407** columns of a table.
3408** ^When a table is referenced by a [SELECT] but no column values are
3409** extracted from that table (for example in a query like
3410** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3411** is invoked once for that table with a column name that is an empty string.
3412** ^If the action code is [SQLITE_DELETE] and the callback returns
3413** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3414** [truncate optimization] is disabled and all rows are deleted individually.
3415**
3416** An authorizer is used when [sqlite3_prepare | preparing]
3417** SQL statements from an untrusted source, to ensure that the SQL statements
3418** do not try to access data they are not allowed to see, or that they do not
3419** try to execute malicious statements that damage the database. For
3420** example, an application may allow a user to enter arbitrary
3421** SQL queries for evaluation by a database. But the application does
3422** not want the user to be able to make arbitrary changes to the
3423** database. An authorizer could then be put in place while the
3424** user-entered SQL is being [sqlite3_prepare | prepared] that
3425** disallows everything except [SELECT] statements.
3426**
3427** Applications that need to process SQL from untrusted sources
3428** might also consider lowering resource limits using [sqlite3_limit()]
3429** and limiting database size using the [max_page_count] [PRAGMA]
3430** in addition to using an authorizer.
3431**
3432** ^(Only a single authorizer can be in place on a database connection
3433** at a time. Each call to sqlite3_set_authorizer overrides the
3434** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3435** The authorizer is disabled by default.
3436**
3437** The authorizer callback must not do anything that will modify
3438** the database connection that invoked the authorizer callback.
3439** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3440** database connections for the meaning of "modify" in this paragraph.
3441**
3442** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3443** statement might be re-prepared during [sqlite3_step()] due to a
3444** schema change. Hence, the application should ensure that the
3445** correct authorizer callback remains in place during the [sqlite3_step()].
3446**
3447** ^Note that the authorizer callback is invoked only during
3448** [sqlite3_prepare()] or its variants. Authorization is not
3449** performed during statement evaluation in [sqlite3_step()], unless
3450** as stated in the previous paragraph, sqlite3_step() invokes
3451** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3452*/
3453SQLITE_API int sqlite3_set_authorizer(
3454 sqlite3*,
3455 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3456 void *pUserData
3457);
3458
3459/*
3460** CAPI3REF: Authorizer Return Codes
3461**
3462** The [sqlite3_set_authorizer | authorizer callback function] must
3463** return either [SQLITE_OK] or one of these two constants in order
3464** to signal SQLite whether or not the action is permitted. See the
3465** [sqlite3_set_authorizer | authorizer documentation] for additional
3466** information.
3467**
3468** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3469** returned from the [sqlite3_vtab_on_conflict()] interface.
3470*/
3471#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3472#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3473
3474/*
3475** CAPI3REF: Authorizer Action Codes
3476**
3477** The [sqlite3_set_authorizer()] interface registers a callback function
3478** that is invoked to authorize certain SQL statement actions. The
3479** second parameter to the callback is an integer code that specifies
3480** what action is being authorized. These are the integer action codes that
3481** the authorizer callback may be passed.
3482**
3483** These action code values signify what kind of operation is to be
3484** authorized. The 3rd and 4th parameters to the authorization
3485** callback function will be parameters or NULL depending on which of these
3486** codes is used as the second parameter. ^(The 5th parameter to the
3487** authorizer callback is the name of the database ("main", "temp",
3488** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3489** is the name of the inner-most trigger or view that is responsible for
3490** the access attempt or NULL if this access attempt is directly from
3491** top-level SQL code.
3492*/
3493/******************************************* 3rd ************ 4th ***********/
3494#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3495#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3496#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3497#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3498#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3499#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3500#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3501#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3502#define SQLITE_DELETE 9 /* Table Name NULL */
3503#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3504#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3505#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3506#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3507#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3508#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3509#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3510#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3511#define SQLITE_INSERT 18 /* Table Name NULL */
3512#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3513#define SQLITE_READ 20 /* Table Name Column Name */
3514#define SQLITE_SELECT 21 /* NULL NULL */
3515#define SQLITE_TRANSACTION 22 /* Operation NULL */
3516#define SQLITE_UPDATE 23 /* Table Name Column Name */
3517#define SQLITE_ATTACH 24 /* Filename NULL */
3518#define SQLITE_DETACH 25 /* Database Name NULL */
3519#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3520#define SQLITE_REINDEX 27 /* Index Name NULL */
3521#define SQLITE_ANALYZE 28 /* Table Name NULL */
3522#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3523#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3524#define SQLITE_FUNCTION 31 /* NULL Function Name */
3525#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3526#define SQLITE_COPY 0 /* No longer used */
3527#define SQLITE_RECURSIVE 33 /* NULL NULL */
3528
3529/*
3530** CAPI3REF: Deprecated Tracing And Profiling Functions
3531** DEPRECATED
3532**
3533** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3534** instead of the routines described here.
3535**
3536** These routines register callback functions that can be used for
3537** tracing and profiling the execution of SQL statements.
3538**
3539** ^The callback function registered by sqlite3_trace() is invoked at
3540** various times when an SQL statement is being run by [sqlite3_step()].
3541** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3542** SQL statement text as the statement first begins executing.
3543** ^(Additional sqlite3_trace() callbacks might occur
3544** as each triggered subprogram is entered. The callbacks for triggers
3545** contain a UTF-8 SQL comment that identifies the trigger.)^
3546**
3547** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3548** the length of [bound parameter] expansion in the output of sqlite3_trace().
3549**
3550** ^The callback function registered by sqlite3_profile() is invoked
3551** as each SQL statement finishes. ^The profile callback contains
3552** the original statement text and an estimate of wall-clock time
3553** of how long that statement took to run. ^The profile callback
3554** time is in units of nanoseconds, however the current implementation
3555** is only capable of millisecond resolution so the six least significant
3556** digits in the time are meaningless. Future versions of SQLite
3557** might provide greater resolution on the profiler callback. Invoking
3558** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3559** profile callback.
3560*/
3561SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3562 void(*xTrace)(void*,const char*), void*);
3563SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3564 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3565
3566/*
3567** CAPI3REF: SQL Trace Event Codes
3568** KEYWORDS: SQLITE_TRACE
3569**
3570** These constants identify classes of events that can be monitored
3571** using the [sqlite3_trace_v2()] tracing logic. The M argument
3572** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3573** the following constants. ^The first argument to the trace callback
3574** is one of the following constants.
3575**
3576** New tracing constants may be added in future releases.
3577**
3578** ^A trace callback has four arguments: xCallback(T,C,P,X).
3579** ^The T argument is one of the integer type codes above.
3580** ^The C argument is a copy of the context pointer passed in as the
3581** fourth argument to [sqlite3_trace_v2()].
3582** The P and X arguments are pointers whose meanings depend on T.
3583**
3584** <dl>
3585** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3586** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3587** first begins running and possibly at other times during the
3588** execution of the prepared statement, such as at the start of each
3589** trigger subprogram. ^The P argument is a pointer to the
3590** [prepared statement]. ^The X argument is a pointer to a string which
3591** is the unexpanded SQL text of the prepared statement or an SQL comment
3592** that indicates the invocation of a trigger. ^The callback can compute
3593** the same text that would have been returned by the legacy [sqlite3_trace()]
3594** interface by using the X argument when X begins with "--" and invoking
3595** [sqlite3_expanded_sql(P)] otherwise.
3596**
3597** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3598** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3599** information as is provided by the [sqlite3_profile()] callback.
3600** ^The P argument is a pointer to the [prepared statement] and the
3601** X argument points to a 64-bit integer which is approximately
3602** the number of nanoseconds that the prepared statement took to run.
3603** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3604**
3605** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3606** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3607** statement generates a single row of result.
3608** ^The P argument is a pointer to the [prepared statement] and the
3609** X argument is unused.
3610**
3611** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3612** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3613** connection closes.
3614** ^The P argument is a pointer to the [database connection] object
3615** and the X argument is unused.
3616** </dl>
3617*/
3618#define SQLITE_TRACE_STMT 0x01
3619#define SQLITE_TRACE_PROFILE 0x02
3620#define SQLITE_TRACE_ROW 0x04
3621#define SQLITE_TRACE_CLOSE 0x08
3622
3623/*
3624** CAPI3REF: SQL Trace Hook
3625** METHOD: sqlite3
3626**
3627** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3628** function X against [database connection] D, using property mask M
3629** and context pointer P. ^If the X callback is
3630** NULL or if the M mask is zero, then tracing is disabled. The
3631** M argument should be the bitwise OR-ed combination of
3632** zero or more [SQLITE_TRACE] constants.
3633**
3634** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3635** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3636** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3637** database connection may have at most one trace callback.
3638**
3639** ^The X callback is invoked whenever any of the events identified by
3640** mask M occur. ^The integer return value from the callback is currently
3641** ignored, though this may change in future releases. Callback
3642** implementations should return zero to ensure future compatibility.
3643**
3644** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3645** ^The T argument is one of the [SQLITE_TRACE]
3646** constants to indicate why the callback was invoked.
3647** ^The C argument is a copy of the context pointer.
3648** The P and X arguments are pointers whose meanings depend on T.
3649**
3650** The sqlite3_trace_v2() interface is intended to replace the legacy
3651** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3652** are deprecated.
3653*/
3654SQLITE_API int sqlite3_trace_v2(
3655 sqlite3*,
3656 unsigned uMask,
3657 int(*xCallback)(unsigned,void*,void*,void*),
3658 void *pCtx
3659);
3660
3661/*
3662** CAPI3REF: Query Progress Callbacks
3663** METHOD: sqlite3
3664**
3665** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3666** function X to be invoked periodically during long running calls to
3667** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3668** database connection D. An example use for this
3669** interface is to keep a GUI updated during a large query.
3670**
3671** ^The parameter P is passed through as the only parameter to the
3672** callback function X. ^The parameter N is the approximate number of
3673** [virtual machine instructions] that are evaluated between successive
3674** invocations of the callback X. ^If N is less than one then the progress
3675** handler is disabled.
3676**
3677** ^Only a single progress handler may be defined at one time per
3678** [database connection]; setting a new progress handler cancels the
3679** old one. ^Setting parameter X to NULL disables the progress handler.
3680** ^The progress handler is also disabled by setting N to a value less
3681** than 1.
3682**
3683** ^If the progress callback returns non-zero, the operation is
3684** interrupted. This feature can be used to implement a
3685** "Cancel" button on a GUI progress dialog box.
3686**
3687** The progress handler callback must not do anything that will modify
3688** the database connection that invoked the progress handler.
3689** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3690** database connections for the meaning of "modify" in this paragraph.
3691**
3692** The progress handler callback would originally only be invoked from the
3693** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3694** and similar because those routines might force a reparse of the schema
3695** which involves running the bytecode engine. However, beginning with
3696** SQLite version 3.41.0, the progress handler callback might also be
3697** invoked directly from [sqlite3_prepare()] while analyzing and generating
3698** code for complex queries.
3699*/
3700SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3701
3702/*
3703** CAPI3REF: Opening A New Database Connection
3704** CONSTRUCTOR: sqlite3
3705**
3706** ^These routines open an SQLite database file as specified by the
3707** filename argument. ^The filename argument is interpreted as UTF-8 for
3708** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3709** order for sqlite3_open16(). ^(A [database connection] handle is usually
3710** returned in *ppDb, even if an error occurs. The only exception is that
3711** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3712** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3713** object.)^ ^(If the database is opened (and/or created) successfully, then
3714** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3715** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3716** an English language description of the error following a failure of any
3717** of the sqlite3_open() routines.
3718**
3719** ^The default encoding will be UTF-8 for databases created using
3720** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3721** created using sqlite3_open16() will be UTF-16 in the native byte order.
3722**
3723** Whether or not an error occurs when it is opened, resources
3724** associated with the [database connection] handle should be released by
3725** passing it to [sqlite3_close()] when it is no longer required.
3726**
3727** The sqlite3_open_v2() interface works like sqlite3_open()
3728** except that it accepts two additional parameters for additional control
3729** over the new database connection. ^(The flags parameter to
3730** sqlite3_open_v2() must include, at a minimum, one of the following
3731** three flag combinations:)^
3732**
3733** <dl>
3734** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3735** <dd>The database is opened in read-only mode. If the database does
3736** not already exist, an error is returned.</dd>)^
3737**
3738** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3739** <dd>The database is opened for reading and writing if possible, or
3740** reading only if the file is write protected by the operating
3741** system. In either case the database must already exist, otherwise
3742** an error is returned. For historical reasons, if opening in
3743** read-write mode fails due to OS-level permissions, an attempt is
3744** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3745** used to determine whether the database is actually
3746** read-write.</dd>)^
3747**
3748** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3749** <dd>The database is opened for reading and writing, and is created if
3750** it does not already exist. This is the behavior that is always used for
3751** sqlite3_open() and sqlite3_open16().</dd>)^
3752** </dl>
3753**
3754** In addition to the required flags, the following optional flags are
3755** also supported:
3756**
3757** <dl>
3758** ^(<dt>[SQLITE_OPEN_URI]</dt>
3759** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3760**
3761** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3762** <dd>The database will be opened as an in-memory database. The database
3763** is named by the "filename" argument for the purposes of cache-sharing,
3764** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3765** </dd>)^
3766**
3767** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3768** <dd>The new database connection will use the "multi-thread"
3769** [threading mode].)^ This means that separate threads are allowed
3770** to use SQLite at the same time, as long as each thread is using
3771** a different [database connection].
3772**
3773** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3774** <dd>The new database connection will use the "serialized"
3775** [threading mode].)^ This means the multiple threads can safely
3776** attempt to use the same database connection at the same time.
3777** (Mutexes will block any actual concurrency, but in this mode
3778** there is no harm in trying.)
3779**
3780** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3781** <dd>The database is opened with [shared cache] enabled, overriding
3782** the default shared cache setting provided by
3783** [sqlite3_enable_shared_cache()].)^
3784** The [use of shared cache mode is discouraged] and hence shared cache
3785** capabilities may be omitted from many builds of SQLite. In such cases,
3786** this option is a no-op.
3787**
3788** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3789** <dd>The database is opened with [shared cache] disabled, overriding
3790** the default shared cache setting provided by
3791** [sqlite3_enable_shared_cache()].)^
3792**
3793** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3794** <dd>The database connection comes up in "extended result code mode".
3795** In other words, the database behaves as if
3796** [sqlite3_extended_result_codes(db,1)] were called on the database
3797** connection as soon as the connection is created. In addition to setting
3798** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3799** to return an extended result code.</dd>
3800**
3801** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3802** <dd>The database filename is not allowed to contain a symbolic link</dd>
3803** </dl>)^
3804**
3805** If the 3rd parameter to sqlite3_open_v2() is not one of the
3806** required combinations shown above optionally combined with other
3807** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3808** then the behavior is undefined. Historic versions of SQLite
3809** have silently ignored surplus bits in the flags parameter to
3810** sqlite3_open_v2(), however that behavior might not be carried through
3811** into future versions of SQLite and so applications should not rely
3812** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3813** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3814** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3815** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3816** by sqlite3_open_v2().
3817**
3818** ^The fourth parameter to sqlite3_open_v2() is the name of the
3819** [sqlite3_vfs] object that defines the operating system interface that
3820** the new database connection should use. ^If the fourth parameter is
3821** a NULL pointer then the default [sqlite3_vfs] object is used.
3822**
3823** ^If the filename is ":memory:", then a private, temporary in-memory database
3824** is created for the connection. ^This in-memory database will vanish when
3825** the database connection is closed. Future versions of SQLite might
3826** make use of additional special filenames that begin with the ":" character.
3827** It is recommended that when a database filename actually does begin with
3828** a ":" character you should prefix the filename with a pathname such as
3829** "./" to avoid ambiguity.
3830**
3831** ^If the filename is an empty string, then a private, temporary
3832** on-disk database will be created. ^This private database will be
3833** automatically deleted as soon as the database connection is closed.
3834**
3835** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3836**
3837** ^If [URI filename] interpretation is enabled, and the filename argument
3838** begins with "file:", then the filename is interpreted as a URI. ^URI
3839** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3840** set in the third argument to sqlite3_open_v2(), or if it has
3841** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3842** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3843** URI filename interpretation is turned off
3844** by default, but future releases of SQLite might enable URI filename
3845** interpretation by default. See "[URI filenames]" for additional
3846** information.
3847**
3848** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3849** authority, then it must be either an empty string or the string
3850** "localhost". ^If the authority is not an empty string or "localhost", an
3851** error is returned to the caller. ^The fragment component of a URI, if
3852** present, is ignored.
3853**
3854** ^SQLite uses the path component of the URI as the name of the disk file
3855** which contains the database. ^If the path begins with a '/' character,
3856** then it is interpreted as an absolute path. ^If the path does not begin
3857** with a '/' (meaning that the authority section is omitted from the URI)
3858** then the path is interpreted as a relative path.
3859** ^(On windows, the first component of an absolute path
3860** is a drive specification (e.g. "C:").)^
3861**
3862** [[core URI query parameters]]
3863** The query component of a URI may contain parameters that are interpreted
3864** either by SQLite itself, or by a [VFS | custom VFS implementation].
3865** SQLite and its built-in [VFSes] interpret the
3866** following query parameters:
3867**
3868** <ul>
3869** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3870** a VFS object that provides the operating system interface that should
3871** be used to access the database file on disk. ^If this option is set to
3872** an empty string the default VFS object is used. ^Specifying an unknown
3873** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3874** present, then the VFS specified by the option takes precedence over
3875** the value passed as the fourth parameter to sqlite3_open_v2().
3876**
3877** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3878** "rwc", or "memory". Attempting to set it to any other value is
3879** an error)^.
3880** ^If "ro" is specified, then the database is opened for read-only
3881** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3882** third argument to sqlite3_open_v2(). ^If the mode option is set to
3883** "rw", then the database is opened for read-write (but not create)
3884** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3885** been set. ^Value "rwc" is equivalent to setting both
3886** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3887** set to "memory" then a pure [in-memory database] that never reads
3888** or writes from disk is used. ^It is an error to specify a value for
3889** the mode parameter that is less restrictive than that specified by
3890** the flags passed in the third parameter to sqlite3_open_v2().
3891**
3892** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3893** "private". ^Setting it to "shared" is equivalent to setting the
3894** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3895** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3896** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3897** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3898** a URI filename, its value overrides any behavior requested by setting
3899** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3900**
3901** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3902** [powersafe overwrite] property does or does not apply to the
3903** storage media on which the database file resides.
3904**
3905** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3906** which if set disables file locking in rollback journal modes. This
3907** is useful for accessing a database on a filesystem that does not
3908** support locking. Caution: Database corruption might result if two
3909** or more processes write to the same database and any one of those
3910** processes uses nolock=1.
3911**
3912** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3913** parameter that indicates that the database file is stored on
3914** read-only media. ^When immutable is set, SQLite assumes that the
3915** database file cannot be changed, even by a process with higher
3916** privilege, and so the database is opened read-only and all locking
3917** and change detection is disabled. Caution: Setting the immutable
3918** property on a database file that does in fact change can result
3919** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3920** See also: [SQLITE_IOCAP_IMMUTABLE].
3921**
3922** </ul>
3923**
3924** ^Specifying an unknown parameter in the query component of a URI is not an
3925** error. Future versions of SQLite might understand additional query
3926** parameters. See "[query parameters with special meaning to SQLite]" for
3927** additional information.
3928**
3929** [[URI filename examples]] <h3>URI filename examples</h3>
3930**
3931** <table border="1" align=center cellpadding=5>
3932** <tr><th> URI filenames <th> Results
3933** <tr><td> file:data.db <td>
3934** Open the file "data.db" in the current directory.
3935** <tr><td> file:/home/fred/data.db<br>
3936** file:///home/fred/data.db <br>
3937** file://localhost/home/fred/data.db <br> <td>
3938** Open the database file "/home/fred/data.db".
3939** <tr><td> file://darkstar/home/fred/data.db <td>
3940** An error. "darkstar" is not a recognized authority.
3941** <tr><td style="white-space:nowrap">
3942** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3943** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3944** C:. Note that the %20 escaping in this example is not strictly
3945** necessary - space characters can be used literally
3946** in URI filenames.
3947** <tr><td> file:data.db?mode=ro&cache=private <td>
3948** Open file "data.db" in the current directory for read-only access.
3949** Regardless of whether or not shared-cache mode is enabled by
3950** default, use a private cache.
3951** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3952** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3953** that uses dot-files in place of posix advisory locking.
3954** <tr><td> file:data.db?mode=readonly <td>
3955** An error. "readonly" is not a valid option for the "mode" parameter.
3956** Use "ro" instead: "file:data.db?mode=ro".
3957** </table>
3958**
3959** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3960** query components of a URI. A hexadecimal escape sequence consists of a
3961** percent sign - "%" - followed by exactly two hexadecimal digits
3962** specifying an octet value. ^Before the path or query components of a
3963** URI filename are interpreted, they are encoded using UTF-8 and all
3964** hexadecimal escape sequences replaced by a single byte containing the
3965** corresponding octet. If this process generates an invalid UTF-8 encoding,
3966** the results are undefined.
3967**
3968** <b>Note to Windows users:</b> The encoding used for the filename argument
3969** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3970** codepage is currently defined. Filenames containing international
3971** characters must be converted to UTF-8 prior to passing them into
3972** sqlite3_open() or sqlite3_open_v2().
3973**
3974** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3975** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3976** features that require the use of temporary files may fail.
3977**
3978** See also: [sqlite3_temp_directory]
3979*/
3980SQLITE_API int sqlite3_open(
3981 const char *filename, /* Database filename (UTF-8) */
3982 sqlite3 **ppDb /* OUT: SQLite db handle */
3983);
3984SQLITE_API int sqlite3_open16(
3985 const void *filename, /* Database filename (UTF-16) */
3986 sqlite3 **ppDb /* OUT: SQLite db handle */
3987);
3988SQLITE_API int sqlite3_open_v2(
3989 const char *filename, /* Database filename (UTF-8) */
3990 sqlite3 **ppDb, /* OUT: SQLite db handle */
3991 int flags, /* Flags */
3992 const char *zVfs /* Name of VFS module to use */
3993);
3994
3995/*
3996** CAPI3REF: Obtain Values For URI Parameters
3997**
3998** These are utility routines, useful to [VFS|custom VFS implementations],
3999** that check if a database file was a URI that contained a specific query
4000** parameter, and if so obtains the value of that query parameter.
4001**
4002** The first parameter to these interfaces (hereafter referred to
4003** as F) must be one of:
4004** <ul>
4005** <li> A database filename pointer created by the SQLite core and
4006** passed into the xOpen() method of a VFS implementation, or
4007** <li> A filename obtained from [sqlite3_db_filename()], or
4008** <li> A new filename constructed using [sqlite3_create_filename()].
4009** </ul>
4010** If the F parameter is not one of the above, then the behavior is
4011** undefined and probably undesirable. Older versions of SQLite were
4012** more tolerant of invalid F parameters than newer versions.
4013**
4014** If F is a suitable filename (as described in the previous paragraph)
4015** and if P is the name of the query parameter, then
4016** sqlite3_uri_parameter(F,P) returns the value of the P
4017** parameter if it exists or a NULL pointer if P does not appear as a
4018** query parameter on F. If P is a query parameter of F and it
4019** has no explicit value, then sqlite3_uri_parameter(F,P) returns
4020** a pointer to an empty string.
4021**
4022** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
4023** parameter and returns true (1) or false (0) according to the value
4024** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
4025** value of query parameter P is one of "yes", "true", or "on" in any
4026** case or if the value begins with a non-zero number. The
4027** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
4028** query parameter P is one of "no", "false", or "off" in any case or
4029** if the value begins with a numeric zero. If P is not a query
4030** parameter on F or if the value of P does not match any of the
4031** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
4032**
4033** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
4034** 64-bit signed integer and returns that integer, or D if P does not
4035** exist. If the value of P is something other than an integer, then
4036** zero is returned.
4037**
4038** The sqlite3_uri_key(F,N) returns a pointer to the name (not
4039** the value) of the N-th query parameter for filename F, or a NULL
4040** pointer if N is less than zero or greater than the number of query
4041** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4042** the name of the first query parameter, 1 for the second parameter, and
4043** so forth.
4044**
4045** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4046** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4047** is not a database file pathname pointer that the SQLite core passed
4048** into the xOpen VFS method, then the behavior of this routine is undefined
4049** and probably undesirable.
4050**
4051** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4052** parameter can also be the name of a rollback journal file or WAL file
4053** in addition to the main database file. Prior to version 3.31.0, these
4054** routines would only work if F was the name of the main database file.
4055** When the F parameter is the name of the rollback journal or WAL file,
4056** it has access to all the same query parameters as were found on the
4057** main database file.
4058**
4059** See the [URI filename] documentation for additional information.
4060*/
4061SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4062SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4063SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4064SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4065
4066/*
4067** CAPI3REF: Translate filenames
4068**
4069** These routines are available to [VFS|custom VFS implementations] for
4070** translating filenames between the main database file, the journal file,
4071** and the WAL file.
4072**
4073** If F is the name of an sqlite database file, journal file, or WAL file
4074** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4075** returns the name of the corresponding database file.
4076**
4077** If F is the name of an sqlite database file, journal file, or WAL file
4078** passed by the SQLite core into the VFS, or if F is a database filename
4079** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4080** returns the name of the corresponding rollback journal file.
4081**
4082** If F is the name of an sqlite database file, journal file, or WAL file
4083** that was passed by the SQLite core into the VFS, or if F is a database
4084** filename obtained from [sqlite3_db_filename()], then
4085** sqlite3_filename_wal(F) returns the name of the corresponding
4086** WAL file.
4087**
4088** In all of the above, if F is not the name of a database, journal or WAL
4089** filename passed into the VFS from the SQLite core and F is not the
4090** return value from [sqlite3_db_filename()], then the result is
4091** undefined and is likely a memory access violation.
4092*/
4093SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4094SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4095SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4096
4097/*
4098** CAPI3REF: Database File Corresponding To A Journal
4099**
4100** ^If X is the name of a rollback or WAL-mode journal file that is
4101** passed into the xOpen method of [sqlite3_vfs], then
4102** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4103** object that represents the main database file.
4104**
4105** This routine is intended for use in custom [VFS] implementations
4106** only. It is not a general-purpose interface.
4107** The argument sqlite3_file_object(X) must be a filename pointer that
4108** has been passed into [sqlite3_vfs].xOpen method where the
4109** flags parameter to xOpen contains one of the bits
4110** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4111** of this routine results in undefined and probably undesirable
4112** behavior.
4113*/
4114SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4115
4116/*
4117** CAPI3REF: Create and Destroy VFS Filenames
4118**
4119** These interfaces are provided for use by [VFS shim] implementations and
4120** are not useful outside of that context.
4121**
4122** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4123** database filename D with corresponding journal file J and WAL file W and
4124** an array P of N URI Key/Value pairs. The result from
4125** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4126** is safe to pass to routines like:
4127** <ul>
4128** <li> [sqlite3_uri_parameter()],
4129** <li> [sqlite3_uri_boolean()],
4130** <li> [sqlite3_uri_int64()],
4131** <li> [sqlite3_uri_key()],
4132** <li> [sqlite3_filename_database()],
4133** <li> [sqlite3_filename_journal()], or
4134** <li> [sqlite3_filename_wal()].
4135** </ul>
4136** If a memory allocation error occurs, sqlite3_create_filename() might
4137** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4138** must be released by a corresponding call to sqlite3_free_filename(Y).
4139**
4140** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4141** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4142** to a key and value for a query parameter. The P parameter may be a NULL
4143** pointer if N is zero. None of the 2*N pointers in the P array may be
4144** NULL pointers and key pointers should not be empty strings.
4145** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4146** be NULL pointers, though they can be empty strings.
4147**
4148** The sqlite3_free_filename(Y) routine releases a memory allocation
4149** previously obtained from sqlite3_create_filename(). Invoking
4150** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4151**
4152** If the Y parameter to sqlite3_free_filename(Y) is anything other
4153** than a NULL pointer or a pointer previously acquired from
4154** sqlite3_create_filename(), then bad things such as heap
4155** corruption or segfaults may occur. The value Y should not be
4156** used again after sqlite3_free_filename(Y) has been called. This means
4157** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4158** then the corresponding [sqlite3_module.xClose() method should also be
4159** invoked prior to calling sqlite3_free_filename(Y).
4160*/
4161SQLITE_API sqlite3_filename sqlite3_create_filename(
4162 const char *zDatabase,
4163 const char *zJournal,
4164 const char *zWal,
4165 int nParam,
4166 const char **azParam
4167);
4168SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4169
4170/*
4171** CAPI3REF: Error Codes And Messages
4172** METHOD: sqlite3
4173**
4174** ^If the most recent sqlite3_* API call associated with
4175** [database connection] D failed, then the sqlite3_errcode(D) interface
4176** returns the numeric [result code] or [extended result code] for that
4177** API call.
4178** ^The sqlite3_extended_errcode()
4179** interface is the same except that it always returns the
4180** [extended result code] even when extended result codes are
4181** disabled.
4182**
4183** The values returned by sqlite3_errcode() and/or
4184** sqlite3_extended_errcode() might change with each API call.
4185** Except, there are some interfaces that are guaranteed to never
4186** change the value of the error code. The error-code preserving
4187** interfaces include the following:
4188**
4189** <ul>
4190** <li> sqlite3_errcode()
4191** <li> sqlite3_extended_errcode()
4192** <li> sqlite3_errmsg()
4193** <li> sqlite3_errmsg16()
4194** <li> sqlite3_error_offset()
4195** <li> sqlite3_db_handle()
4196** </ul>
4197**
4198** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4199** text that describes the error, as either UTF-8 or UTF-16 respectively,
4200** or NULL if no error message is available.
4201** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4202** ^(Memory to hold the error message string is managed internally.
4203** The application does not need to worry about freeing the result.
4204** However, the error string might be overwritten or deallocated by
4205** subsequent calls to other SQLite interface functions.)^
4206**
4207** ^The sqlite3_errstr(E) interface returns the English-language text
4208** that describes the [result code] E, as UTF-8, or NULL if E is not a
4209** result code for which a text error message is available.
4210** ^(Memory to hold the error message string is managed internally
4211** and must not be freed by the application)^.
4212**
4213** ^If the most recent error references a specific token in the input
4214** SQL, the sqlite3_error_offset() interface returns the byte offset
4215** of the start of that token. ^The byte offset returned by
4216** sqlite3_error_offset() assumes that the input SQL is UTF-8.
4217** ^If the most recent error does not reference a specific token in the input
4218** SQL, then the sqlite3_error_offset() function returns -1.
4219**
4220** When the serialized [threading mode] is in use, it might be the
4221** case that a second error occurs on a separate thread in between
4222** the time of the first error and the call to these interfaces.
4223** When that happens, the second error will be reported since these
4224** interfaces always report the most recent result. To avoid
4225** this, each thread can obtain exclusive use of the [database connection] D
4226** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4227** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4228** all calls to the interfaces listed here are completed.
4229**
4230** If an interface fails with SQLITE_MISUSE, that means the interface
4231** was invoked incorrectly by the application. In that case, the
4232** error code and message may or may not be set.
4233*/
4234SQLITE_API int sqlite3_errcode(sqlite3 *db);
4235SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4236SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4237SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4238SQLITE_API const char *sqlite3_errstr(int);
4239SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4240
4241/*
4242** CAPI3REF: Set Error Code And Message
4243** METHOD: sqlite3
4244**
4245** Set the error code of the database handle passed as the first argument
4246** to errcode, and the error message to a copy of nul-terminated string
4247** zErrMsg. If zErrMsg is passed NULL, then the error message is set to
4248** the default message associated with the supplied error code. Subsequent
4249** calls to [sqlite3_errcode()] and [sqlite3_errmsg()] and similar will
4250** return the values set by this routine in place of what was previously
4251** set by SQLite itself.
4252**
4253** This function returns SQLITE_OK if the error code and error message are
4254** successfully set, SQLITE_NOMEM if an OOM occurs, and SQLITE_MISUSE if
4255** the database handle is NULL or invalid.
4256**
4257** The error code and message set by this routine remains in effect until
4258** they are changed, either by another call to this routine or until they are
4259** changed to by SQLite itself to reflect the result of some subsquent
4260** API call.
4261**
4262** This function is intended for use by SQLite extensions or wrappers. The
4263** idea is that an extension or wrapper can use this routine to set error
4264** messages and error codes and thus behave more like a core SQLite
4265** feature from the point of view of an application.
4266*/
4267SQLITE_API int sqlite3_set_errmsg(sqlite3 *db, int errcode, const char *zErrMsg);
4268
4269/*
4270** CAPI3REF: Prepared Statement Object
4271** KEYWORDS: {prepared statement} {prepared statements}
4272**
4273** An instance of this object represents a single SQL statement that
4274** has been compiled into binary form and is ready to be evaluated.
4275**
4276** Think of each SQL statement as a separate computer program. The
4277** original SQL text is source code. A prepared statement object
4278** is the compiled object code. All SQL must be converted into a
4279** prepared statement before it can be run.
4280**
4281** The life-cycle of a prepared statement object usually goes like this:
4282**
4283** <ol>
4284** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4285** <li> Bind values to [parameters] using the sqlite3_bind_*()
4286** interfaces.
4287** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4288** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4289** to step 2. Do this zero or more times.
4290** <li> Destroy the object using [sqlite3_finalize()].
4291** </ol>
4292*/
4293typedef struct sqlite3_stmt sqlite3_stmt;
4294
4295/*
4296** CAPI3REF: Run-time Limits
4297** METHOD: sqlite3
4298**
4299** ^(This interface allows the size of various constructs to be limited
4300** on a connection by connection basis. The first parameter is the
4301** [database connection] whose limit is to be set or queried. The
4302** second parameter is one of the [limit categories] that define a
4303** class of constructs to be size limited. The third parameter is the
4304** new limit for that construct.)^
4305**
4306** ^If the new limit is a negative number, the limit is unchanged.
4307** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4308** [limits | hard upper bound]
4309** set at compile-time by a C preprocessor macro called
4310** [limits | SQLITE_MAX_<i>NAME</i>].
4311** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4312** ^Attempts to increase a limit above its hard upper bound are
4313** silently truncated to the hard upper bound.
4314**
4315** ^Regardless of whether or not the limit was changed, the
4316** [sqlite3_limit()] interface returns the prior value of the limit.
4317** ^Hence, to find the current value of a limit without changing it,
4318** simply invoke this interface with the third parameter set to -1.
4319**
4320** Run-time limits are intended for use in applications that manage
4321** both their own internal database and also databases that are controlled
4322** by untrusted external sources. An example application might be a
4323** web browser that has its own databases for storing history and
4324** separate databases controlled by JavaScript applications downloaded
4325** off the Internet. The internal databases can be given the
4326** large, default limits. Databases managed by external sources can
4327** be given much smaller limits designed to prevent a denial of service
4328** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4329** interface to further control untrusted SQL. The size of the database
4330** created by an untrusted script can be contained using the
4331** [max_page_count] [PRAGMA].
4332**
4333** New run-time limit categories may be added in future releases.
4334*/
4335SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4336
4337/*
4338** CAPI3REF: Run-Time Limit Categories
4339** KEYWORDS: {limit category} {*limit categories}
4340**
4341** These constants define various performance limits
4342** that can be lowered at run-time using [sqlite3_limit()].
4343** A concise description of these limits follows, and additional information
4344** is available at [limits | Limits in SQLite].
4345**
4346** <dl>
4347** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4348** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4349**
4350** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4351** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4352**
4353** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4354** <dd>The maximum number of columns in a table definition or in the
4355** result set of a [SELECT] or the maximum number of columns in an index
4356** or in an ORDER BY or GROUP BY clause.</dd>)^
4357**
4358** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4359** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4360**
4361** [[SQLITE_LIMIT_PARSER_DEPTH]] ^(<dt>SQLITE_LIMIT_PARSER_DEPTH</dt>
4362** <dd>The maximum depth of the LALR(1) parser stack used to analyze
4363** input SQL statements.</dd>)^
4364**
4365** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4366** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4367**
4368** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4369** <dd>The maximum number of instructions in a virtual machine program
4370** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4371** the equivalent tries to allocate space for more than this many opcodes
4372** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4373**
4374** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4375** <dd>The maximum number of arguments on a function.</dd>)^
4376**
4377** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4378** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4379**
4380** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4381** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4382** <dd>The maximum length of the pattern argument to the [LIKE] or
4383** [GLOB] operators.</dd>)^
4384**
4385** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4386** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4387** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4388**
4389** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4390** <dd>The maximum depth of recursion for triggers.</dd>)^
4391**
4392** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4393** <dd>The maximum number of auxiliary worker threads that a single
4394** [prepared statement] may start.</dd>)^
4395** </dl>
4396*/
4397#define SQLITE_LIMIT_LENGTH 0
4398#define SQLITE_LIMIT_SQL_LENGTH 1
4399#define SQLITE_LIMIT_COLUMN 2
4400#define SQLITE_LIMIT_EXPR_DEPTH 3
4401#define SQLITE_LIMIT_COMPOUND_SELECT 4
4402#define SQLITE_LIMIT_VDBE_OP 5
4403#define SQLITE_LIMIT_FUNCTION_ARG 6
4404#define SQLITE_LIMIT_ATTACHED 7
4405#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4406#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4407#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4408#define SQLITE_LIMIT_WORKER_THREADS 11
4409#define SQLITE_LIMIT_PARSER_DEPTH 12
4410
4411/*
4412** CAPI3REF: Prepare Flags
4413**
4414** These constants define various flags that can be passed into the
4415** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4416** [sqlite3_prepare16_v3()] interfaces.
4417**
4418** New flags may be added in future releases of SQLite.
4419**
4420** <dl>
4421** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4422** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4423** that the prepared statement will be retained for a long time and
4424** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4425** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4426** be used just once or at most a few times and then destroyed using
4427** [sqlite3_finalize()] relatively soon. The current implementation acts
4428** on this hint by avoiding the use of [lookaside memory] so as not to
4429** deplete the limited store of lookaside memory. Future versions of
4430** SQLite may act on this hint differently.
4431**
4432** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4433** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4434** to be required for any prepared statement that wanted to use the
4435** [sqlite3_normalized_sql()] interface. However, the
4436** [sqlite3_normalized_sql()] interface is now available to all
4437** prepared statements, regardless of whether or not they use this
4438** flag.
4439**
4440** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4441** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4442** to return an error (error code SQLITE_ERROR) if the statement uses
4443** any virtual tables.
4444**
4445** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4446** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4447** errors from being sent to the error log defined by
4448** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4449** compiles to see if some SQL syntax is well-formed, without generating
4450** messages on the global error log when it is not. If the test compile
4451** fails, the sqlite3_prepare_v3() call returns the same error indications
4452** with or without this flag; it just omits the call to [sqlite3_log()] that
4453** logs the error.
4454**
4455** [[SQLITE_PREPARE_FROM_DDL]] <dt>SQLITE_PREPARE_FROM_DDL</dt>
4456** <dd>The SQLITE_PREPARE_FROM_DDL flag causes the SQL compiler to enforce
4457** security constraints that would otherwise only be enforced when parsing
4458** the database schema. In other words, the SQLITE_PREPARE_FROM_DDL flag
4459** causes the SQL compiler to treat the SQL statement being prepared as if
4460** it had come from an attacker. When SQLITE_PREPARE_FROM_DDL is used and
4461** [SQLITE_DBCONFIG_TRUSTED_SCHEMA] is off, SQL functions may only be called
4462** if they are tagged with [SQLITE_INNOCUOUS] and virtual tables may only
4463** be used if they are tagged with [SQLITE_VTAB_INNOCUOUS]. Best practice
4464** is to use the SQLITE_PREPARE_FROM_DDL option when preparing any SQL that
4465** is derived from parts of the database schema. In particular, virtual
4466** table implementations that run SQL statements that are derived from
4467** arguments to their CREATE VIRTUAL TABLE statement should always use
4468** [sqlite3_prepare_v3()] and set the SQLITE_PREPARE_FROM_DDL flag to
4469** prevent bypass of the [SQLITE_DBCONFIG_TRUSTED_SCHEMA] security checks.
4470** </dl>
4471*/
4472#define SQLITE_PREPARE_PERSISTENT 0x01
4473#define SQLITE_PREPARE_NORMALIZE 0x02
4474#define SQLITE_PREPARE_NO_VTAB 0x04
4475#define SQLITE_PREPARE_DONT_LOG 0x10
4476#define SQLITE_PREPARE_FROM_DDL 0x20
4477
4478/*
4479** CAPI3REF: Compiling An SQL Statement
4480** KEYWORDS: {SQL statement compiler}
4481** METHOD: sqlite3
4482** CONSTRUCTOR: sqlite3_stmt
4483**
4484** To execute an SQL statement, it must first be compiled into a byte-code
4485** program using one of these routines. Or, in other words, these routines
4486** are constructors for the [prepared statement] object.
4487**
4488** The preferred routine to use is [sqlite3_prepare_v2()]. The
4489** [sqlite3_prepare()] interface is legacy and should be avoided.
4490** [sqlite3_prepare_v3()] has an extra
4491** [SQLITE_PREPARE_FROM_DDL|"prepFlags" option] that is some times
4492** needed for special purpose or to pass along security restrictions.
4493**
4494** The use of the UTF-8 interfaces is preferred, as SQLite currently
4495** does all parsing using UTF-8. The UTF-16 interfaces are provided
4496** as a convenience. The UTF-16 interfaces work by converting the
4497** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4498**
4499** The first argument, "db", is a [database connection] obtained from a
4500** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4501** [sqlite3_open16()]. The database connection must not have been closed.
4502**
4503** The second argument, "zSql", is the statement to be compiled, encoded
4504** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4505** and sqlite3_prepare_v3()
4506** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4507** and sqlite3_prepare16_v3() use UTF-16.
4508**
4509** ^If the nByte argument is negative, then zSql is read up to the
4510** first zero terminator. ^If nByte is positive, then it is the maximum
4511** number of bytes read from zSql. When nByte is positive, zSql is read
4512** up to the first zero terminator or until the nByte bytes have been read,
4513** whichever comes first. ^If nByte is zero, then no prepared
4514** statement is generated.
4515** If the caller knows that the supplied string is nul-terminated, then
4516** there is a small performance advantage to passing an nByte parameter that
4517** is the number of bytes in the input string <i>including</i>
4518** the nul-terminator.
4519** Note that nByte measures the length of the input in bytes, not
4520** characters, even for the UTF-16 interfaces.
4521**
4522** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4523** past the end of the first SQL statement in zSql. These routines only
4524** compile the first statement in zSql, so *pzTail is left pointing to
4525** what remains uncompiled.
4526**
4527** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4528** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4529** to NULL. ^If the input text contains no SQL (if the input is an empty
4530** string or a comment) then *ppStmt is set to NULL.
4531** The calling procedure is responsible for deleting the compiled
4532** SQL statement using [sqlite3_finalize()] after it has finished with it.
4533** ppStmt may not be NULL.
4534**
4535** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4536** otherwise an [error code] is returned.
4537**
4538** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4539** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4540** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4541** are retained for backwards compatibility, but their use is discouraged.
4542** ^In the "vX" interfaces, the prepared statement
4543** that is returned (the [sqlite3_stmt] object) contains a copy of the
4544** original SQL text. This causes the [sqlite3_step()] interface to
4545** behave differently in three ways:
4546**
4547** <ol>
4548** <li>
4549** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4550** always used to do, [sqlite3_step()] will automatically recompile the SQL
4551** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4552** retries will occur before sqlite3_step() gives up and returns an error.
4553** </li>
4554**
4555** <li>
4556** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4557** [error codes] or [extended error codes]. ^The legacy behavior was that
4558** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4559** and the application would have to make a second call to [sqlite3_reset()]
4560** in order to find the underlying cause of the problem. With the "v2" prepare
4561** interfaces, the underlying reason for the error is returned immediately.
4562** </li>
4563**
4564** <li>
4565** ^If the specific value bound to a [parameter | host parameter] in the
4566** WHERE clause might influence the choice of query plan for a statement,
4567** then the statement will be automatically recompiled, as if there had been
4568** a schema change, on the first [sqlite3_step()] call following any change
4569** to the [sqlite3_bind_text | bindings] of that [parameter].
4570** ^The specific value of a WHERE-clause [parameter] might influence the
4571** choice of query plan if the parameter is the left-hand side of a [LIKE]
4572** or [GLOB] operator or if the parameter is compared to an indexed column
4573** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4574** </li>
4575** </ol>
4576**
4577** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4578** the extra prepFlags parameter, which is a bit array consisting of zero or
4579** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4580** sqlite3_prepare_v2() interface works exactly the same as
4581** sqlite3_prepare_v3() with a zero prepFlags parameter.
4582*/
4583SQLITE_API int sqlite3_prepare(
4584 sqlite3 *db, /* Database handle */
4585 const char *zSql, /* SQL statement, UTF-8 encoded */
4586 int nByte, /* Maximum length of zSql in bytes. */
4587 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4588 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4589);
4590SQLITE_API int sqlite3_prepare_v2(
4591 sqlite3 *db, /* Database handle */
4592 const char *zSql, /* SQL statement, UTF-8 encoded */
4593 int nByte, /* Maximum length of zSql in bytes. */
4594 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4595 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4596);
4597SQLITE_API int sqlite3_prepare_v3(
4598 sqlite3 *db, /* Database handle */
4599 const char *zSql, /* SQL statement, UTF-8 encoded */
4600 int nByte, /* Maximum length of zSql in bytes. */
4601 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4602 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4603 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4604);
4605SQLITE_API int sqlite3_prepare16(
4606 sqlite3 *db, /* Database handle */
4607 const void *zSql, /* SQL statement, UTF-16 encoded */
4608 int nByte, /* Maximum length of zSql in bytes. */
4609 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4610 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4611);
4612SQLITE_API int sqlite3_prepare16_v2(
4613 sqlite3 *db, /* Database handle */
4614 const void *zSql, /* SQL statement, UTF-16 encoded */
4615 int nByte, /* Maximum length of zSql in bytes. */
4616 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4617 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4618);
4619SQLITE_API int sqlite3_prepare16_v3(
4620 sqlite3 *db, /* Database handle */
4621 const void *zSql, /* SQL statement, UTF-16 encoded */
4622 int nByte, /* Maximum length of zSql in bytes. */
4623 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4624 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4625 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4626);
4627
4628/*
4629** CAPI3REF: Retrieving Statement SQL
4630** METHOD: sqlite3_stmt
4631**
4632** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4633** SQL text used to create [prepared statement] P if P was
4634** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4635** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4636** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4637** string containing the SQL text of prepared statement P with
4638** [bound parameters] expanded.
4639** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4640** string containing the normalized SQL text of prepared statement P. The
4641** semantics used to normalize a SQL statement are unspecified and subject
4642** to change. At a minimum, literal values will be replaced with suitable
4643** placeholders.
4644**
4645** ^(For example, if a prepared statement is created using the SQL
4646** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4647** and parameter :xyz is unbound, then sqlite3_sql() will return
4648** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4649** will return "SELECT 2345,NULL".)^
4650**
4651** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4652** is available to hold the result, or if the result would exceed the
4653** maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4654**
4655** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4656** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4657** option causes sqlite3_expanded_sql() to always return NULL.
4658**
4659** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4660** are managed by SQLite and are automatically freed when the prepared
4661** statement is finalized.
4662** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4663** is obtained from [sqlite3_malloc()] and must be freed by the application
4664** by passing it to [sqlite3_free()].
4665**
4666** ^The sqlite3_normalized_sql() interface is only available if
4667** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4668*/
4669SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4670SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4671#ifdef SQLITE_ENABLE_NORMALIZE
4672SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4673#endif
4674
4675/*
4676** CAPI3REF: Determine If An SQL Statement Writes The Database
4677** METHOD: sqlite3_stmt
4678**
4679** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4680** and only if the [prepared statement] X makes no direct changes to
4681** the content of the database file.
4682**
4683** Note that [application-defined SQL functions] or
4684** [virtual tables] might change the database indirectly as a side effect.
4685** ^(For example, if an application defines a function "eval()" that
4686** calls [sqlite3_exec()], then the following SQL statement would
4687** change the database file through side-effects:
4688**
4689** <blockquote><pre>
4690** SELECT eval('DELETE FROM t1') FROM t2;
4691** </pre></blockquote>
4692**
4693** But because the [SELECT] statement does not change the database file
4694** directly, sqlite3_stmt_readonly() would still return true.)^
4695**
4696** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4697** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4698** since the statements themselves do not actually modify the database but
4699** rather they control the timing of when other statements modify the
4700** database. ^The [ATTACH] and [DETACH] statements also cause
4701** sqlite3_stmt_readonly() to return true since, while those statements
4702** change the configuration of a database connection, they do not make
4703** changes to the content of the database files on disk.
4704** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4705** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4706** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4707** sqlite3_stmt_readonly() returns false for those commands.
4708**
4709** ^This routine returns false if there is any possibility that the
4710** statement might change the database file. ^A false return does
4711** not guarantee that the statement will change the database file.
4712** ^For example, an UPDATE statement might have a WHERE clause that
4713** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4714** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4715** read-only no-op if the table already exists, but
4716** sqlite3_stmt_readonly() still returns false for such a statement.
4717**
4718** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4719** statement, then sqlite3_stmt_readonly(X) returns the same value as
4720** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4721*/
4722SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4723
4724/*
4725** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4726** METHOD: sqlite3_stmt
4727**
4728** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4729** prepared statement S is an EXPLAIN statement, or 2 if the
4730** statement S is an EXPLAIN QUERY PLAN.
4731** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4732** an ordinary statement or a NULL pointer.
4733*/
4734SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4735
4736/*
4737** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4738** METHOD: sqlite3_stmt
4739**
4740** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4741** setting for [prepared statement] S. If E is zero, then S becomes
4742** a normal prepared statement. If E is 1, then S behaves as if
4743** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4744** its SQL text began with "[EXPLAIN QUERY PLAN]".
4745**
4746** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4747** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4748** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4749**
4750** Because of the potential need to reprepare, a call to
4751** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4752** reprepared because it was created using [sqlite3_prepare()] instead of
4753** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4754** hence has no saved SQL text with which to reprepare.
4755**
4756** Changing the explain setting for a prepared statement does not change
4757** the original SQL text for the statement. Hence, if the SQL text originally
4758** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4759** is called to convert the statement into an ordinary statement, the EXPLAIN
4760** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4761** output, even though the statement now acts like a normal SQL statement.
4762**
4763** This routine returns SQLITE_OK if the explain mode is successfully
4764** changed, or an error code if the explain mode could not be changed.
4765** The explain mode cannot be changed while a statement is active.
4766** Hence, it is good practice to call [sqlite3_reset(S)]
4767** immediately prior to calling sqlite3_stmt_explain(S,E).
4768*/
4769SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4770
4771/*
4772** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4773** METHOD: sqlite3_stmt
4774**
4775** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4776** [prepared statement] S has been stepped at least once using
4777** [sqlite3_step(S)] but has neither run to completion (returned
4778** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4779** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4780** interface returns false if S is a NULL pointer. If S is not a
4781** NULL pointer and is not a pointer to a valid [prepared statement]
4782** object, then the behavior is undefined and probably undesirable.
4783**
4784** This interface can be used in combination [sqlite3_next_stmt()]
4785** to locate all prepared statements associated with a database
4786** connection that are in need of being reset. This can be used,
4787** for example, in diagnostic routines to search for prepared
4788** statements that are holding a transaction open.
4789*/
4790SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4791
4792/*
4793** CAPI3REF: Dynamically Typed Value Object
4794** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4795**
4796** SQLite uses the sqlite3_value object to represent all values
4797** that can be stored in a database table. SQLite uses dynamic typing
4798** for the values it stores. ^Values stored in sqlite3_value objects
4799** can be integers, floating point values, strings, BLOBs, or NULL.
4800**
4801** An sqlite3_value object may be either "protected" or "unprotected".
4802** Some interfaces require a protected sqlite3_value. Other interfaces
4803** will accept either a protected or an unprotected sqlite3_value.
4804** Every interface that accepts sqlite3_value arguments specifies
4805** whether or not it requires a protected sqlite3_value. The
4806** [sqlite3_value_dup()] interface can be used to construct a new
4807** protected sqlite3_value from an unprotected sqlite3_value.
4808**
4809** The terms "protected" and "unprotected" refer to whether or not
4810** a mutex is held. An internal mutex is held for a protected
4811** sqlite3_value object but no mutex is held for an unprotected
4812** sqlite3_value object. If SQLite is compiled to be single-threaded
4813** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4814** or if SQLite is run in one of reduced mutex modes
4815** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4816** then there is no distinction between protected and unprotected
4817** sqlite3_value objects and they can be used interchangeably. However,
4818** for maximum code portability it is recommended that applications
4819** still make the distinction between protected and unprotected
4820** sqlite3_value objects even when not strictly required.
4821**
4822** ^The sqlite3_value objects that are passed as parameters into the
4823** implementation of [application-defined SQL functions] are protected.
4824** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4825** are protected.
4826** ^The sqlite3_value object returned by
4827** [sqlite3_column_value()] is unprotected.
4828** Unprotected sqlite3_value objects may only be used as arguments
4829** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4830** [sqlite3_value_dup()].
4831** The [sqlite3_value_blob | sqlite3_value_type()] family of
4832** interfaces require protected sqlite3_value objects.
4833*/
4834typedef struct sqlite3_value sqlite3_value;
4835
4836/*
4837** CAPI3REF: SQL Function Context Object
4838**
4839** The context in which an SQL function executes is stored in an
4840** sqlite3_context object. ^A pointer to an sqlite3_context object
4841** is always the first parameter to [application-defined SQL functions].
4842** The application-defined SQL function implementation will pass this
4843** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4844** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4845** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4846** and/or [sqlite3_set_auxdata()].
4847*/
4848typedef struct sqlite3_context sqlite3_context;
4849
4850/*
4851** CAPI3REF: Binding Values To Prepared Statements
4852** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4853** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4854** METHOD: sqlite3_stmt
4855**
4856** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4857** literals may be replaced by a [parameter] that matches one of the following
4858** templates:
4859**
4860** <ul>
4861** <li> ?
4862** <li> ?NNN
4863** <li> :VVV
4864** <li> @VVV
4865** <li> $VVV
4866** </ul>
4867**
4868** In the templates above, NNN represents an integer literal,
4869** and VVV represents an alphanumeric identifier.)^ ^The values of these
4870** parameters (also called "host parameter names" or "SQL parameters")
4871** can be set using the sqlite3_bind_*() routines defined here.
4872**
4873** ^The first argument to the sqlite3_bind_*() routines is always
4874** a pointer to the [sqlite3_stmt] object returned from
4875** [sqlite3_prepare_v2()] or its variants.
4876**
4877** ^The second argument is the index of the SQL parameter to be set.
4878** ^The leftmost SQL parameter has an index of 1. ^When the same named
4879** SQL parameter is used more than once, second and subsequent
4880** occurrences have the same index as the first occurrence.
4881** ^The index for named parameters can be looked up using the
4882** [sqlite3_bind_parameter_index()] API if desired. ^The index
4883** for "?NNN" parameters is the value of NNN.
4884** ^The NNN value must be between 1 and the [sqlite3_limit()]
4885** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4886**
4887** ^The third argument is the value to bind to the parameter.
4888** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4889** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4890** is ignored and the end result is the same as sqlite3_bind_null().
4891** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4892** it should be a pointer to well-formed UTF8 text.
4893** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4894** it should be a pointer to well-formed UTF16 text.
4895** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4896** it should be a pointer to a well-formed unicode string that is
4897** either UTF8 if the sixth parameter is SQLITE_UTF8 or SQLITE_UTF8_ZT,
4898** or UTF16 otherwise.
4899**
4900** [[byte-order determination rules]] ^The byte-order of
4901** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4902** found in the first character, which is removed, or in the absence of a BOM
4903** the byte order is the native byte order of the host
4904** machine for sqlite3_bind_text16() or the byte order specified in
4905** the 6th parameter for sqlite3_bind_text64().)^
4906** ^If UTF16 input text contains invalid unicode
4907** characters, then SQLite might change those invalid characters
4908** into the unicode replacement character: U+FFFD.
4909**
4910** ^(In those routines that have a fourth argument, its value is the
4911** number of bytes in the parameter. To be clear: the value is the
4912** number of <u>bytes</u> in the value, not the number of characters.)^
4913** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4914** is negative, then the length of the string is
4915** the number of bytes up to the first zero terminator.
4916** If the fourth parameter to sqlite3_bind_blob() is negative, then
4917** the behavior is undefined.
4918** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4919** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4920** that parameter must be the byte offset
4921** where the NUL terminator would occur assuming the string were NUL
4922** terminated. If any NUL characters occur at byte offsets less than
4923** the value of the fourth parameter then the resulting string value will
4924** contain embedded NULs. The result of expressions involving strings
4925** with embedded NULs is undefined.
4926**
4927** ^The fifth argument to the BLOB and string binding interfaces controls
4928** or indicates the lifetime of the object referenced by the third parameter.
4929** These three options exist:
4930** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4931** with it may be passed. ^It is called to dispose of the BLOB or string even
4932** if the call to the bind API fails, except the destructor is not called if
4933** the third parameter is a NULL pointer or the fourth parameter is negative.
4934** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4935** the application remains responsible for disposing of the object. ^In this
4936** case, the object and the provided pointer to it must remain valid until
4937** either the prepared statement is finalized or the same SQL parameter is
4938** bound to something else, whichever occurs sooner.
4939** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4940** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4941** object and pointer to it must remain valid until then. ^SQLite will then
4942** manage the lifetime of its private copy.
4943**
4944** ^The sixth argument (the E argument)
4945** to sqlite3_bind_text64(S,K,Z,N,D,E) must be one of
4946** [SQLITE_UTF8], [SQLITE_UTF8_ZT], [SQLITE_UTF16], [SQLITE_UTF16BE],
4947** or [SQLITE_UTF16LE] to specify the encoding of the text in the
4948** third parameter, Z. The special value [SQLITE_UTF8_ZT] means that the
4949** string argument is both UTF-8 encoded and is zero-terminated. In other
4950** words, SQLITE_UTF8_ZT means that the Z array is allocated to hold at
4951** least N+1 bytes and that the Z&#91;N&#93; byte is zero. If
4952** the E argument to sqlite3_bind_text64(S,K,Z,N,D,E) is not one of the
4953** allowed values shown above, or if the text encoding is different
4954** from the encoding specified by the sixth parameter, then the behavior
4955** is undefined.
4956**
4957** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4958** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4959** (just an integer to hold its size) while it is being processed.
4960** Zeroblobs are intended to serve as placeholders for BLOBs whose
4961** content is later written using
4962** [sqlite3_blob_open | incremental BLOB I/O] routines.
4963** ^A negative value for the zeroblob results in a zero-length BLOB.
4964**
4965** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4966** [prepared statement] S to have an SQL value of NULL, but to also be
4967** associated with the pointer P of type T. ^D is either a NULL pointer or
4968** a pointer to a destructor function for P. ^SQLite will invoke the
4969** destructor D with a single argument of P when it is finished using
4970** P, even if the call to sqlite3_bind_pointer() fails. Due to a
4971** historical design quirk, results are undefined if D is
4972** SQLITE_TRANSIENT. The T parameter should be a static string,
4973** preferably a string literal. The sqlite3_bind_pointer() routine is
4974** part of the [pointer passing interface] added for SQLite 3.20.0.
4975**
4976** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4977** for the [prepared statement] or with a prepared statement for which
4978** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4979** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4980** routine is passed a [prepared statement] that has been finalized, the
4981** result is undefined and probably harmful.
4982**
4983** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4984** ^Unbound parameters are interpreted as NULL.
4985**
4986** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4987** [error code] if anything goes wrong.
4988** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4989** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4990** [SQLITE_MAX_LENGTH].
4991** ^[SQLITE_RANGE] is returned if the parameter
4992** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4993**
4994** See also: [sqlite3_bind_parameter_count()],
4995** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4996*/
4997SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4998SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4999 void(*)(void*));
5000SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
5001SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
5002SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
5003SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
5004SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
5005SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
5006SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
5007 void(*)(void*), unsigned char encoding);
5008SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
5009SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
5010SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
5011SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
5012
5013/*
5014** CAPI3REF: Number Of SQL Parameters
5015** METHOD: sqlite3_stmt
5016**
5017** ^This routine can be used to find the number of [SQL parameters]
5018** in a [prepared statement]. SQL parameters are tokens of the
5019** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
5020** placeholders for values that are [sqlite3_bind_blob | bound]
5021** to the parameters at a later time.
5022**
5023** ^(This routine actually returns the index of the largest (rightmost)
5024** parameter. For all forms except ?NNN, this will correspond to the
5025** number of unique parameters. If parameters of the ?NNN form are used,
5026** there may be gaps in the list.)^
5027**
5028** See also: [sqlite3_bind_blob|sqlite3_bind()],
5029** [sqlite3_bind_parameter_name()], and
5030** [sqlite3_bind_parameter_index()].
5031*/
5032SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
5033
5034/*
5035** CAPI3REF: Name Of A Host Parameter
5036** METHOD: sqlite3_stmt
5037**
5038** ^The sqlite3_bind_parameter_name(P,N) interface returns
5039** the name of the N-th [SQL parameter] in the [prepared statement] P.
5040** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
5041** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
5042** respectively.
5043** In other words, the initial ":" or "$" or "@" or "?"
5044** is included as part of the name.)^
5045** ^Parameters of the form "?" without a following integer have no name
5046** and are referred to as "nameless" or "anonymous parameters".
5047**
5048** ^The first host parameter has an index of 1, not 0.
5049**
5050** ^If the value N is out of range or if the N-th parameter is
5051** nameless, then NULL is returned. ^The returned string is
5052** always in UTF-8 encoding even if the named parameter was
5053** originally specified as UTF-16 in [sqlite3_prepare16()],
5054** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
5055**
5056** See also: [sqlite3_bind_blob|sqlite3_bind()],
5057** [sqlite3_bind_parameter_count()], and
5058** [sqlite3_bind_parameter_index()].
5059*/
5060SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
5061
5062/*
5063** CAPI3REF: Index Of A Parameter With A Given Name
5064** METHOD: sqlite3_stmt
5065**
5066** ^Return the index of an SQL parameter given its name. ^The
5067** index value returned is suitable for use as the second
5068** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
5069** is returned if no matching parameter is found. ^The parameter
5070** name must be given in UTF-8 even if the original statement
5071** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
5072** [sqlite3_prepare16_v3()].
5073**
5074** See also: [sqlite3_bind_blob|sqlite3_bind()],
5075** [sqlite3_bind_parameter_count()], and
5076** [sqlite3_bind_parameter_name()].
5077*/
5078SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
5079
5080/*
5081** CAPI3REF: Reset All Bindings On A Prepared Statement
5082** METHOD: sqlite3_stmt
5083**
5084** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
5085** the [sqlite3_bind_blob | bindings] on a [prepared statement].
5086** ^Use this routine to reset all host parameters to NULL.
5087*/
5088SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
5089
5090/*
5091** CAPI3REF: Number Of Columns In A Result Set
5092** METHOD: sqlite3_stmt
5093**
5094** ^Return the number of columns in the result set returned by the
5095** [prepared statement]. ^If this routine returns 0, that means the
5096** [prepared statement] returns no data (for example an [UPDATE]).
5097** ^However, just because this routine returns a positive number does not
5098** mean that one or more rows of data will be returned. ^A SELECT statement
5099** will always have a positive sqlite3_column_count() but depending on the
5100** WHERE clause constraints and the table content, it might return no rows.
5101**
5102** See also: [sqlite3_data_count()]
5103*/
5104SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
5105
5106/*
5107** CAPI3REF: Column Names In A Result Set
5108** METHOD: sqlite3_stmt
5109**
5110** ^These routines return the name assigned to a particular column
5111** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
5112** interface returns a pointer to a zero-terminated UTF-8 string
5113** and sqlite3_column_name16() returns a pointer to a zero-terminated
5114** UTF-16 string. ^The first parameter is the [prepared statement]
5115** that implements the [SELECT] statement. ^The second parameter is the
5116** column number. ^The leftmost column is number 0.
5117**
5118** ^The returned string pointer is valid until either the [prepared statement]
5119** is destroyed by [sqlite3_finalize()] or until the statement is automatically
5120** reprepared by the first call to [sqlite3_step()] for a particular run
5121** or until the next call to
5122** sqlite3_column_name() or sqlite3_column_name16() on the same column.
5123**
5124** ^If sqlite3_malloc() fails during the processing of either routine
5125** (for example during a conversion from UTF-8 to UTF-16) then a
5126** NULL pointer is returned.
5127**
5128** ^The name of a result column is the value of the "AS" clause for
5129** that column, if there is an AS clause. If there is no AS clause
5130** then the name of the column is unspecified and may change from
5131** one release of SQLite to the next.
5132*/
5133SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
5134SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
5135
5136/*
5137** CAPI3REF: Source Of Data In A Query Result
5138** METHOD: sqlite3_stmt
5139**
5140** ^These routines provide a means to determine the database, table, and
5141** table column that is the origin of a particular result column in a
5142** [SELECT] statement.
5143** ^The name of the database or table or column can be returned as
5144** either a UTF-8 or UTF-16 string. ^The _database_ routines return
5145** the database name, the _table_ routines return the table name, and
5146** the origin_ routines return the column name.
5147** ^The returned string is valid until the [prepared statement] is destroyed
5148** using [sqlite3_finalize()] or until the statement is automatically
5149** reprepared by the first call to [sqlite3_step()] for a particular run
5150** or until the same information is requested
5151** again in a different encoding.
5152**
5153** ^The names returned are the original un-aliased names of the
5154** database, table, and column.
5155**
5156** ^The first argument to these interfaces is a [prepared statement].
5157** ^These functions return information about the Nth result column returned by
5158** the statement, where N is the second function argument.
5159** ^The left-most column is column 0 for these routines.
5160**
5161** ^If the Nth column returned by the statement is an expression or
5162** subquery and is not a column value, then all of these functions return
5163** NULL. ^These routines might also return NULL if a memory allocation error
5164** occurs. ^Otherwise, they return the name of the attached database, table,
5165** or column that query result column was extracted from.
5166**
5167** ^As with all other SQLite APIs, those whose names end with "16" return
5168** UTF-16 encoded strings and the other functions return UTF-8.
5169**
5170** ^These APIs are only available if the library was compiled with the
5171** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
5172**
5173** If two or more threads call one or more
5174** [sqlite3_column_database_name | column metadata interfaces]
5175** for the same [prepared statement] and result column
5176** at the same time then the results are undefined.
5177*/
5178SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
5179SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
5180SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
5181SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
5182SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
5183SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
5184
5185/*
5186** CAPI3REF: Declared Datatype Of A Query Result
5187** METHOD: sqlite3_stmt
5188**
5189** ^(The first parameter is a [prepared statement].
5190** If this statement is a [SELECT] statement and the Nth column of the
5191** returned result set of that [SELECT] is a table column (not an
5192** expression or subquery) then the declared type of the table
5193** column is returned.)^ ^If the Nth column of the result set is an
5194** expression or subquery, then a NULL pointer is returned.
5195** ^The returned string is always UTF-8 encoded.
5196**
5197** ^(For example, given the database schema:
5198**
5199** CREATE TABLE t1(c1 VARIANT);
5200**
5201** and the following statement to be compiled:
5202**
5203** SELECT c1 + 1, c1 FROM t1;
5204**
5205** this routine would return the string "VARIANT" for the second result
5206** column (i==1), and a NULL pointer for the first result column (i==0).)^
5207**
5208** ^SQLite uses dynamic run-time typing. ^So just because a column
5209** is declared to contain a particular type does not mean that the
5210** data stored in that column is of the declared type. SQLite is
5211** strongly typed, but the typing is dynamic not static. ^Type
5212** is associated with individual values, not with the containers
5213** used to hold those values.
5214*/
5215SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
5216SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
5217
5218/*
5219** CAPI3REF: Evaluate An SQL Statement
5220** METHOD: sqlite3_stmt
5221**
5222** After a [prepared statement] has been prepared using any of
5223** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
5224** or [sqlite3_prepare16_v3()] or one of the legacy
5225** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
5226** must be called one or more times to evaluate the statement.
5227**
5228** The details of the behavior of the sqlite3_step() interface depend
5229** on whether the statement was prepared using the newer "vX" interfaces
5230** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
5231** [sqlite3_prepare16_v2()] or the older legacy
5232** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
5233** new "vX" interface is recommended for new applications but the legacy
5234** interface will continue to be supported.
5235**
5236** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
5237** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
5238** ^With the "v2" interface, any of the other [result codes] or
5239** [extended result codes] might be returned as well.
5240**
5241** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
5242** database locks it needs to do its job. ^If the statement is a [COMMIT]
5243** or occurs outside of an explicit transaction, then you can retry the
5244** statement. If the statement is not a [COMMIT] and occurs within an
5245** explicit transaction then you should rollback the transaction before
5246** continuing.
5247**
5248** ^[SQLITE_DONE] means that the statement has finished executing
5249** successfully. sqlite3_step() should not be called again on this virtual
5250** machine without first calling [sqlite3_reset()] to reset the virtual
5251** machine back to its initial state.
5252**
5253** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
5254** is returned each time a new row of data is ready for processing by the
5255** caller. The values may be accessed using the [column access functions].
5256** sqlite3_step() is called again to retrieve the next row of data.
5257**
5258** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
5259** violation) has occurred. sqlite3_step() should not be called again on
5260** the VM. More information may be found by calling [sqlite3_errmsg()].
5261** ^With the legacy interface, a more specific error code (for example,
5262** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
5263** can be obtained by calling [sqlite3_reset()] on the
5264** [prepared statement]. ^In the "v2" interface,
5265** the more specific error code is returned directly by sqlite3_step().
5266**
5267** [SQLITE_MISUSE] means that the this routine was called inappropriately.
5268** Perhaps it was called on a [prepared statement] that has
5269** already been [sqlite3_finalize | finalized] or on one that had
5270** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
5271** be the case that the same database connection is being used by two or
5272** more threads at the same moment in time.
5273**
5274** For all versions of SQLite up to and including 3.6.23.1, a call to
5275** [sqlite3_reset()] was required after sqlite3_step() returned anything
5276** other than [SQLITE_ROW] before any subsequent invocation of
5277** sqlite3_step(). Failure to reset the prepared statement using
5278** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
5279** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]),
5280** sqlite3_step() began
5281** calling [sqlite3_reset()] automatically in this circumstance rather
5282** than returning [SQLITE_MISUSE]. This is not considered a compatibility
5283** break because any application that ever receives an SQLITE_MISUSE error
5284** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
5285** can be used to restore the legacy behavior.
5286**
5287** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
5288** API always returns a generic error code, [SQLITE_ERROR], following any
5289** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
5290** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
5291** specific [error codes] that better describes the error.
5292** We admit that this is a goofy design. The problem has been fixed
5293** with the "v2" interface. If you prepare all of your SQL statements
5294** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
5295** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5296** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5297** then the more specific [error codes] are returned directly
5298** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5299*/
5300SQLITE_API int sqlite3_step(sqlite3_stmt*);
5301
5302/*
5303** CAPI3REF: Number of columns in a result set
5304** METHOD: sqlite3_stmt
5305**
5306** ^The sqlite3_data_count(P) interface returns the number of columns in the
5307** current row of the result set of [prepared statement] P.
5308** ^If prepared statement P does not have results ready to return
5309** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5310** interfaces) then sqlite3_data_count(P) returns 0.
5311** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5312** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5313** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5314** will return non-zero if previous call to [sqlite3_step](P) returned
5315** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5316** where it always returns zero since each step of that multi-step
5317** pragma returns 0 columns of data.
5318**
5319** See also: [sqlite3_column_count()]
5320*/
5321SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5322
5323/*
5324** CAPI3REF: Fundamental Datatypes
5325** KEYWORDS: SQLITE_TEXT
5326**
5327** ^(Every value in SQLite has one of five fundamental datatypes:
5328**
5329** <ul>
5330** <li> 64-bit signed integer
5331** <li> 64-bit IEEE floating point number
5332** <li> string
5333** <li> BLOB
5334** <li> NULL
5335** </ul>)^
5336**
5337** These constants are codes for each of those types.
5338**
5339** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5340** for a completely different meaning. Software that links against both
5341** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5342** SQLITE_TEXT.
5343*/
5344#define SQLITE_INTEGER 1
5345#define SQLITE_FLOAT 2
5346#define SQLITE_BLOB 4
5347#define SQLITE_NULL 5
5348#ifdef SQLITE_TEXT
5349# undef SQLITE_TEXT
5350#else
5351# define SQLITE_TEXT 3
5352#endif
5353#define SQLITE3_TEXT 3
5354
5355/*
5356** CAPI3REF: Result Values From A Query
5357** KEYWORDS: {column access functions}
5358** METHOD: sqlite3_stmt
5359**
5360** <b>Summary:</b>
5361** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5362** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
5363** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
5364** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
5365** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
5366** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
5367** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
5368** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
5369** [sqlite3_value|unprotected sqlite3_value] object.
5370** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5371** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
5372** or a UTF-8 TEXT result in bytes
5373** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
5374** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5375** TEXT in bytes
5376** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
5377** datatype of the result
5378** </table></blockquote>
5379**
5380** <b>Details:</b>
5381**
5382** ^These routines return information about a single column of the current
5383** result row of a query. ^In every case the first argument is a pointer
5384** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5385** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5386** and the second argument is the index of the column for which information
5387** should be returned. ^The leftmost column of the result set has the index 0.
5388** ^The number of columns in the result can be determined using
5389** [sqlite3_column_count()].
5390**
5391** If the SQL statement does not currently point to a valid row, or if the
5392** column index is out of range, the result is undefined.
5393** These routines may only be called when the most recent call to
5394** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5395** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5396** If any of these routines are called after [sqlite3_reset()] or
5397** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5398** something other than [SQLITE_ROW], the results are undefined.
5399** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5400** are called from a different thread while any of these routines
5401** are pending, then the results are undefined.
5402**
5403** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5404** each return the value of a result column in a specific data format. If
5405** the result column is not initially in the requested format (for example,
5406** if the query returns an integer but the sqlite3_column_text() interface
5407** is used to extract the value) then an automatic type conversion is performed.
5408**
5409** ^The sqlite3_column_type() routine returns the
5410** [SQLITE_INTEGER | datatype code] for the initial data type
5411** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5412** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5413** The return value of sqlite3_column_type() can be used to decide which
5414** of the first six interface should be used to extract the column value.
5415** The value returned by sqlite3_column_type() is only meaningful if no
5416** automatic type conversions have occurred for the value in question.
5417** After a type conversion, the result of calling sqlite3_column_type()
5418** is undefined, though harmless. Future
5419** versions of SQLite may change the behavior of sqlite3_column_type()
5420** following a type conversion.
5421**
5422** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5423** or sqlite3_column_bytes16() interfaces can be used to determine the size
5424** of that BLOB or string.
5425**
5426** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5427** routine returns the number of bytes in that BLOB or string.
5428** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5429** the string to UTF-8 and then returns the number of bytes.
5430** ^If the result is a numeric value then sqlite3_column_bytes() uses
5431** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5432** the number of bytes in that string.
5433** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5434**
5435** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5436** routine returns the number of bytes in that BLOB or string.
5437** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5438** the string to UTF-16 and then returns the number of bytes.
5439** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5440** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5441** the number of bytes in that string.
5442** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5443**
5444** ^The values returned by [sqlite3_column_bytes()] and
5445** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5446** of the string. ^For clarity: the values returned by
5447** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5448** bytes in the string, not the number of characters.
5449**
5450** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5451** even empty strings, are always zero-terminated. ^The return
5452** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5453**
5454** ^Strings returned by sqlite3_column_text16() always have the endianness
5455** which is native to the platform, regardless of the text encoding set
5456** for the database.
5457**
5458** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5459** [unprotected sqlite3_value] object. In a multithreaded environment,
5460** an unprotected sqlite3_value object may only be used safely with
5461** [sqlite3_bind_value()] and [sqlite3_result_value()].
5462** If the [unprotected sqlite3_value] object returned by
5463** [sqlite3_column_value()] is used in any other way, including calls
5464** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5465** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5466** Hence, the sqlite3_column_value() interface
5467** is normally only useful within the implementation of
5468** [application-defined SQL functions] or [virtual tables], not within
5469** top-level application code.
5470**
5471** These routines may attempt to convert the datatype of the result.
5472** ^For example, if the internal representation is FLOAT and a text result
5473** is requested, [sqlite3_snprintf()] is used internally to perform the
5474** conversion automatically. ^(The following table details the conversions
5475** that are applied:
5476**
5477** <blockquote>
5478** <table border="1">
5479** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5480**
5481** <tr><td> NULL <td> INTEGER <td> Result is 0
5482** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5483** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5484** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5485** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5486** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5487** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5488** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5489** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5490** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5491** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5492** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5493** <tr><td> TEXT <td> BLOB <td> No change
5494** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5495** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5496** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5497** </table>
5498** </blockquote>)^
5499**
5500** Note that when type conversions occur, pointers returned by prior
5501** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5502** sqlite3_column_text16() may be invalidated.
5503** Type conversions and pointer invalidations might occur
5504** in the following cases:
5505**
5506** <ul>
5507** <li> The initial content is a BLOB and sqlite3_column_text() or
5508** sqlite3_column_text16() is called. A zero-terminator might
5509** need to be added to the string.</li>
5510** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5511** sqlite3_column_text16() is called. The content must be converted
5512** to UTF-16.</li>
5513** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5514** sqlite3_column_text() is called. The content must be converted
5515** to UTF-8.</li>
5516** </ul>
5517**
5518** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5519** not invalidate a prior pointer, though of course the content of the buffer
5520** that the prior pointer references will have been modified. Other kinds
5521** of conversion are done in place when it is possible, but sometimes they
5522** are not possible and in those cases prior pointers are invalidated.
5523**
5524** The safest policy is to invoke these routines
5525** in one of the following ways:
5526**
5527** <ul>
5528** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5529** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5530** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5531** </ul>
5532**
5533** In other words, you should call sqlite3_column_text(),
5534** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5535** into the desired format, then invoke sqlite3_column_bytes() or
5536** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5537** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5538** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5539** with calls to sqlite3_column_bytes().
5540**
5541** ^The pointers returned are valid until a type conversion occurs as
5542** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5543** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5544** and BLOBs is freed automatically. Do not pass the pointers returned
5545** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5546** [sqlite3_free()].
5547**
5548** As long as the input parameters are correct, these routines will only
5549** fail if an out-of-memory error occurs during a format conversion.
5550** Only the following subset of interfaces are subject to out-of-memory
5551** errors:
5552**
5553** <ul>
5554** <li> sqlite3_column_blob()
5555** <li> sqlite3_column_text()
5556** <li> sqlite3_column_text16()
5557** <li> sqlite3_column_bytes()
5558** <li> sqlite3_column_bytes16()
5559** </ul>
5560**
5561** If an out-of-memory error occurs, then the return value from these
5562** routines is the same as if the column had contained an SQL NULL value.
5563** Valid SQL NULL returns can be distinguished from out-of-memory errors
5564** by invoking the [sqlite3_errcode()] immediately after the suspect
5565** return value is obtained and before any
5566** other SQLite interface is called on the same [database connection].
5567*/
5568SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5569SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5570SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5571SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5572SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5573SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5574SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5575SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5576SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5577SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5578
5579/*
5580** CAPI3REF: Destroy A Prepared Statement Object
5581** DESTRUCTOR: sqlite3_stmt
5582**
5583** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5584** ^If the most recent evaluation of the statement encountered no errors
5585** or if the statement has never been evaluated, then sqlite3_finalize() returns
5586** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5587** sqlite3_finalize(S) returns the appropriate [error code] or
5588** [extended error code].
5589**
5590** ^The sqlite3_finalize(S) routine can be called at any point during
5591** the life cycle of [prepared statement] S:
5592** before statement S is ever evaluated, after
5593** one or more calls to [sqlite3_reset()], or after any call
5594** to [sqlite3_step()] regardless of whether or not the statement has
5595** completed execution.
5596**
5597** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5598**
5599** The application must finalize every [prepared statement] in order to avoid
5600** resource leaks. It is a grievous error for the application to try to use
5601** a prepared statement after it has been finalized. Any use of a prepared
5602** statement after it has been finalized can result in undefined and
5603** undesirable behavior such as segfaults and heap corruption.
5604*/
5605SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5606
5607/*
5608** CAPI3REF: Reset A Prepared Statement Object
5609** METHOD: sqlite3_stmt
5610**
5611** The sqlite3_reset() function is called to reset a [prepared statement]
5612** object back to its initial state, ready to be re-executed.
5613** ^Any SQL statement variables that had values bound to them using
5614** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5615** Use [sqlite3_clear_bindings()] to reset the bindings.
5616**
5617** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5618** back to the beginning of its program.
5619**
5620** ^The return code from [sqlite3_reset(S)] indicates whether or not
5621** the previous evaluation of prepared statement S completed successfully.
5622** ^If [sqlite3_step(S)] has never before been called on S or if
5623** [sqlite3_step(S)] has not been called since the previous call
5624** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5625** [SQLITE_OK].
5626**
5627** ^If the most recent call to [sqlite3_step(S)] for the
5628** [prepared statement] S indicated an error, then
5629** [sqlite3_reset(S)] returns an appropriate [error code].
5630** ^The [sqlite3_reset(S)] interface might also return an [error code]
5631** if there were no prior errors but the process of resetting
5632** the prepared statement caused a new error. ^For example, if an
5633** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5634** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5635** the overall statement might still fail and the [sqlite3_reset(S)] call
5636** might return SQLITE_BUSY if locking constraints prevent the
5637** database change from committing. Therefore, it is important that
5638** applications check the return code from [sqlite3_reset(S)] even if
5639** no prior call to [sqlite3_step(S)] indicated a problem.
5640**
5641** ^The [sqlite3_reset(S)] interface does not change the values
5642** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5643*/
5644SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5645
5646
5647/*
5648** CAPI3REF: Create Or Redefine SQL Functions
5649** KEYWORDS: {function creation routines}
5650** METHOD: sqlite3
5651**
5652** ^These functions (collectively known as "function creation routines")
5653** are used to add SQL functions or aggregates or to redefine the behavior
5654** of existing SQL functions or aggregates. The only differences between
5655** the three "sqlite3_create_function*" routines are the text encoding
5656** expected for the second parameter (the name of the function being
5657** created) and the presence or absence of a destructor callback for
5658** the application data pointer. Function sqlite3_create_window_function()
5659** is similar, but allows the user to supply the extra callback functions
5660** needed by [aggregate window functions].
5661**
5662** ^The first parameter is the [database connection] to which the SQL
5663** function is to be added. ^If an application uses more than one database
5664** connection then application-defined SQL functions must be added
5665** to each database connection separately.
5666**
5667** ^The second parameter is the name of the SQL function to be created or
5668** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5669** representation, exclusive of the zero-terminator. ^Note that the name
5670** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5671** ^Any attempt to create a function with a longer name
5672** will result in [SQLITE_MISUSE] being returned.
5673**
5674** ^The third parameter (nArg)
5675** is the number of arguments that the SQL function or
5676** aggregate takes. ^If this parameter is -1, then the SQL function or
5677** aggregate may take any number of arguments between 0 and the limit
5678** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5679** parameter is less than -1 or greater than 127 then the behavior is
5680** undefined.
5681**
5682** ^The fourth parameter, eTextRep, specifies what
5683** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5684** its parameters. The application should set this parameter to
5685** [SQLITE_UTF16LE] if the function implementation invokes
5686** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5687** implementation invokes [sqlite3_value_text16be()] on an input, or
5688** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5689** otherwise. ^The same SQL function may be registered multiple times using
5690** different preferred text encodings, with different implementations for
5691** each encoding.
5692** ^When multiple implementations of the same function are available, SQLite
5693** will pick the one that involves the least amount of data conversion.
5694**
5695** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5696** to signal that the function will always return the same result given
5697** the same inputs within a single SQL statement. Most SQL functions are
5698** deterministic. The built-in [random()] SQL function is an example of a
5699** function that is not deterministic. The SQLite query planner is able to
5700** perform additional optimizations on deterministic functions, so use
5701** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5702**
5703** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5704** flag, which if present prevents the function from being invoked from
5705** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5706** index expressions, or the WHERE clause of partial indexes.
5707**
5708** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5709** all application-defined SQL functions that do not need to be
5710** used inside of triggers, views, CHECK constraints, or other elements of
5711** the database schema. This flag is especially recommended for SQL
5712** functions that have side effects or reveal internal application state.
5713** Without this flag, an attacker might be able to modify the schema of
5714** a database file to include invocations of the function with parameters
5715** chosen by the attacker, which the application will then execute when
5716** the database file is opened and read.
5717**
5718** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5719** function can gain access to this pointer using [sqlite3_user_data()].)^
5720**
5721** ^The sixth, seventh and eighth parameters passed to the three
5722** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5723** pointers to C-language functions that implement the SQL function or
5724** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5725** callback only; NULL pointers must be passed as the xStep and xFinal
5726** parameters. ^An aggregate SQL function requires an implementation of xStep
5727** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5728** SQL function or aggregate, pass NULL pointers for all three function
5729** callbacks.
5730**
5731** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5732** and xInverse) passed to sqlite3_create_window_function are pointers to
5733** C-language callbacks that implement the new function. xStep and xFinal
5734** must both be non-NULL. xValue and xInverse may either both be NULL, in
5735** which case a regular aggregate function is created, or must both be
5736** non-NULL, in which case the new function may be used as either an aggregate
5737** or aggregate window function. More details regarding the implementation
5738** of aggregate window functions are
5739** [user-defined window functions|available here].
5740**
5741** ^(If the final parameter to sqlite3_create_function_v2() or
5742** sqlite3_create_window_function() is not NULL, then it is the destructor for
5743** the application data pointer. The destructor is invoked when the function
5744** is deleted, either by being overloaded or when the database connection
5745** closes.)^ ^The destructor is also invoked if the call to
5746** sqlite3_create_function_v2() fails. ^When the destructor callback is
5747** invoked, it is passed a single argument which is a copy of the application
5748** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5749**
5750** ^It is permitted to register multiple implementations of the same
5751** functions with the same name but with either differing numbers of
5752** arguments or differing preferred text encodings. ^SQLite will use
5753** the implementation that most closely matches the way in which the
5754** SQL function is used. ^A function implementation with a non-negative
5755** nArg parameter is a better match than a function implementation with
5756** a negative nArg. ^A function where the preferred text encoding
5757** matches the database encoding is a better
5758** match than a function where the encoding is different.
5759** ^A function where the encoding difference is between UTF16le and UTF16be
5760** is a closer match than a function where the encoding difference is
5761** between UTF8 and UTF16.
5762**
5763** ^Built-in functions may be overloaded by new application-defined functions.
5764**
5765** ^An application-defined function is permitted to call other
5766** SQLite interfaces. However, such calls must not
5767** close the database connection nor finalize or reset the prepared
5768** statement in which the function is running.
5769*/
5770SQLITE_API int sqlite3_create_function(
5771 sqlite3 *db,
5772 const char *zFunctionName,
5773 int nArg,
5774 int eTextRep,
5775 void *pApp,
5776 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5777 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5778 void (*xFinal)(sqlite3_context*)
5779);
5780SQLITE_API int sqlite3_create_function16(
5781 sqlite3 *db,
5782 const void *zFunctionName,
5783 int nArg,
5784 int eTextRep,
5785 void *pApp,
5786 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5787 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5788 void (*xFinal)(sqlite3_context*)
5789);
5790SQLITE_API int sqlite3_create_function_v2(
5791 sqlite3 *db,
5792 const char *zFunctionName,
5793 int nArg,
5794 int eTextRep,
5795 void *pApp,
5796 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5797 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5798 void (*xFinal)(sqlite3_context*),
5799 void(*xDestroy)(void*)
5800);
5801SQLITE_API int sqlite3_create_window_function(
5802 sqlite3 *db,
5803 const char *zFunctionName,
5804 int nArg,
5805 int eTextRep,
5806 void *pApp,
5807 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5808 void (*xFinal)(sqlite3_context*),
5809 void (*xValue)(sqlite3_context*),
5810 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5811 void(*xDestroy)(void*)
5812);
5813
5814/*
5815** CAPI3REF: Text Encodings
5816**
5817** These constants define integer codes that represent the various
5818** text encodings supported by SQLite.
5819**
5820** <dl>
5821** [[SQLITE_UTF8]] <dt>SQLITE_UTF8</dt><dd>Text is encoding as UTF-8</dd>
5822**
5823** [[SQLITE_UTF16LE]] <dt>SQLITE_UTF16LE</dt><dd>Text is encoding as UTF-16
5824** with each code point being expressed "little endian" - the least significant
5825** byte first. This is the usual encoding, for example on Windows.</dd>
5826**
5827** [[SQLITE_UTF16BE]] <dt>SQLITE_UTF16BE</dt><dd>Text is encoding as UTF-16
5828** with each code point being expressed "big endian" - the most significant
5829** byte first. This encoding is less common, but is still sometimes seen,
5830** specially on older systems.
5831**
5832** [[SQLITE_UTF16]] <dt>SQLITE_UTF16</dt><dd>Text is encoding as UTF-16
5833** with each code point being expressed either little endian or as big
5834** endian, according to the native endianness of the host computer.
5835**
5836** [[SQLITE_ANY]] <dt>SQLITE_ANY</dt><dd>This encoding value may only be used
5837** to declare the preferred text for [application-defined SQL functions]
5838** created using [sqlite3_create_function()] and similar. If the preferred
5839** encoding (the 4th parameter to sqlite3_create_function() - the eTextRep
5840** parameter) is SQLITE_ANY, that indicates that the function does not have
5841** a preference regarding the text encoding of its parameters and can take
5842** any text encoding that the SQLite core find convenient to supply. This
5843** option is deprecated. Please do not use it in new applications.
5844**
5845** [[SQLITE_UTF16_ALIGNED]] <dt>SQLITE_UTF16_ALIGNED</dt><dd>This encoding
5846** value may be used as the 3rd parameter (the eTextRep parameter) to
5847** [sqlite3_create_collation()] and similar. This encoding value means
5848** that the application-defined collating sequence created expects its
5849** input strings to be in UTF16 in native byte order, and that the start
5850** of the strings must be aligned to a 2-byte boundary.
5851**
5852** [[SQLITE_UTF8_ZT]] <dt>SQLITE_UTF8_ZT</dt><dd>This option can only be
5853** used to specify the text encoding to strings input to [sqlite3_result_text64()]
5854** and [sqlite3_bind_text64()]. It means that the input string (call it "z")
5855** is UTF-8 encoded and that it is zero-terminated. If the length parameter
5856** (call it "n") is non-negative, this encoding option means that the caller
5857** guarantees that z array contains at least n+1 bytes and that the z&#91;n&#93;
5858** byte has a value of zero.
5859** This option gives the same output as SQLITE_UTF8, but can be more efficient
5860** by avoiding the need to make a copy of the input string, in some cases.
5861** However, if z is allocated to hold fewer than n+1 bytes or if the
5862** z&#91;n&#93; byte is not zero, undefined behavior may result.
5863** </dl>
5864*/
5865#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5866#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5867#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5868#define SQLITE_UTF16 4 /* Use native byte order */
5869#define SQLITE_ANY 5 /* Deprecated */
5870#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5871#define SQLITE_UTF8_ZT 16 /* Zero-terminated UTF8 */
5872
5873/*
5874** CAPI3REF: Function Flags
5875**
5876** These constants may be ORed together with the
5877** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5878** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5879** [sqlite3_create_function_v2()].
5880**
5881** <dl>
5882** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5883** The SQLITE_DETERMINISTIC flag means that the new function always gives
5884** the same output when the input parameters are the same.
5885** The [abs|abs() function] is deterministic, for example, but
5886** [randomblob|randomblob()] is not. Functions must
5887** be deterministic in order to be used in certain contexts such as
5888** with the WHERE clause of [partial indexes] or in [generated columns].
5889** SQLite might also optimize deterministic functions by factoring them
5890** out of inner loops.
5891** </dd>
5892**
5893** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5894** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5895** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5896** schema structures such as [CHECK constraints], [DEFAULT clauses],
5897** [expression indexes], [partial indexes], or [generated columns].
5898** <p>
5899** The SQLITE_DIRECTONLY flag is recommended for any
5900** [application-defined SQL function]
5901** that has side-effects or that could potentially leak sensitive information.
5902** This will prevent attacks in which an application is tricked
5903** into using a database file that has had its schema surreptitiously
5904** modified to invoke the application-defined function in ways that are
5905** harmful.
5906** <p>
5907** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5908** [application-defined SQL functions], regardless of whether or not they
5909** are security sensitive, as doing so prevents those functions from being used
5910** inside of the database schema, and thus ensures that the database
5911** can be inspected and modified using generic tools (such as the [CLI])
5912** that do not have access to the application-defined functions.
5913** </dd>
5914**
5915** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5916** The SQLITE_INNOCUOUS flag means that the function is unlikely
5917** to cause problems even if misused. An innocuous function should have
5918** no side effects and should not depend on any values other than its
5919** input parameters. The [abs|abs() function] is an example of an
5920** innocuous function.
5921** The [load_extension() SQL function] is not innocuous because of its
5922** side effects.
5923** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5924** exactly the same. The [random|random() function] is an example of a
5925** function that is innocuous but not deterministic.
5926** <p>Some heightened security settings
5927** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5928** disable the use of SQL functions inside views and triggers and in
5929** schema structures such as [CHECK constraints], [DEFAULT clauses],
5930** [expression indexes], [partial indexes], and [generated columns] unless
5931** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5932** are innocuous. Developers are advised to avoid using the
5933** SQLITE_INNOCUOUS flag for application-defined functions unless the
5934** function has been carefully audited and found to be free of potentially
5935** security-adverse side-effects and information-leaks.
5936** </dd>
5937**
5938** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5939** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5940** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5941** This flag instructs SQLite to omit some corner-case optimizations that
5942** might disrupt the operation of the [sqlite3_value_subtype()] function,
5943** causing it to return zero rather than the correct subtype().
5944** All SQL functions that invoke [sqlite3_value_subtype()] should have this
5945** property. If the SQLITE_SUBTYPE property is omitted, then the return
5946** value from [sqlite3_value_subtype()] might sometimes be zero even though
5947** a non-zero subtype was specified by the function argument expression.
5948**
5949** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5950** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5951** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5952** result.
5953** Every function that invokes [sqlite3_result_subtype()] should have this
5954** property. If it does not, then the call to [sqlite3_result_subtype()]
5955** might become a no-op if the function is used as a term in an
5956** [expression index]. On the other hand, SQL functions that never invoke
5957** [sqlite3_result_subtype()] should avoid setting this property, as the
5958** purpose of this property is to disable certain optimizations that are
5959** incompatible with subtypes.
5960**
5961** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
5962** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
5963** that internally orders the values provided to the first argument. The
5964** ordered-set aggregate SQL notation with a single ORDER BY term can be
5965** used to invoke this function. If the ordered-set aggregate notation is
5966** used on a function that lacks this flag, then an error is raised. Note
5967** that the ordered-set aggregate syntax is only available if SQLite is
5968** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
5969** </dd>
5970** </dl>
5971*/
5972#define SQLITE_DETERMINISTIC 0x000000800
5973#define SQLITE_DIRECTONLY 0x000080000
5974#define SQLITE_SUBTYPE 0x000100000
5975#define SQLITE_INNOCUOUS 0x000200000
5976#define SQLITE_RESULT_SUBTYPE 0x001000000
5977#define SQLITE_SELFORDER1 0x002000000
5978
5979/*
5980** CAPI3REF: Deprecated Functions
5981** DEPRECATED
5982**
5983** These functions are [deprecated]. In order to maintain
5984** backwards compatibility with older code, these functions continue
5985** to be supported. However, new applications should avoid
5986** the use of these functions. To encourage programmers to avoid
5987** these functions, we will not explain what they do.
5988*/
5989#ifndef SQLITE_OMIT_DEPRECATED
5990SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5991SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5992SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5993SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5994SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5995SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5996 void*,sqlite3_int64);
5997#endif
5998
5999/*
6000** CAPI3REF: Obtaining SQL Values
6001** METHOD: sqlite3_value
6002**
6003** <b>Summary:</b>
6004** <blockquote><table border=0 cellpadding=0 cellspacing=0>
6005** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
6006** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
6007** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
6008** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
6009** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
6010** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
6011** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
6012** the native byteorder
6013** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
6014** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
6015** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
6016** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
6017** or a UTF-8 TEXT in bytes
6018** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
6019** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
6020** TEXT in bytes
6021** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
6022** datatype of the value
6023** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
6024** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
6025** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
6026** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
6027** against a virtual table.
6028** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
6029** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
6030** </table></blockquote>
6031**
6032** <b>Details:</b>
6033**
6034** These routines extract type, size, and content information from
6035** [protected sqlite3_value] objects. Protected sqlite3_value objects
6036** are used to pass parameter information into the functions that
6037** implement [application-defined SQL functions] and [virtual tables].
6038**
6039** These routines work only with [protected sqlite3_value] objects.
6040** Any attempt to use these routines on an [unprotected sqlite3_value]
6041** is not threadsafe.
6042**
6043** ^These routines work just like the corresponding [column access functions]
6044** except that these routines take a single [protected sqlite3_value] object
6045** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
6046**
6047** ^The sqlite3_value_text16() interface extracts a UTF-16 string
6048** in the native byte-order of the host machine. ^The
6049** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
6050** extract UTF-16 strings as big-endian and little-endian respectively.
6051**
6052** ^If [sqlite3_value] object V was initialized
6053** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
6054** and if X and Y are strings that compare equal according to strcmp(X,Y),
6055** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
6056** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
6057** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6058**
6059** ^(The sqlite3_value_type(V) interface returns the
6060** [SQLITE_INTEGER | datatype code] for the initial datatype of the
6061** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
6062** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
6063** Other interfaces might change the datatype for an sqlite3_value object.
6064** For example, if the datatype is initially SQLITE_INTEGER and
6065** sqlite3_value_text(V) is called to extract a text value for that
6066** integer, then subsequent calls to sqlite3_value_type(V) might return
6067** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
6068** occurs is undefined and may change from one release of SQLite to the next.
6069**
6070** ^(The sqlite3_value_numeric_type() interface attempts to apply
6071** numeric affinity to the value. This means that an attempt is
6072** made to convert the value to an integer or floating point. If
6073** such a conversion is possible without loss of information (in other
6074** words, if the value is a string that looks like a number)
6075** then the conversion is performed. Otherwise no conversion occurs.
6076** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
6077**
6078** ^Within the [xUpdate] method of a [virtual table], the
6079** sqlite3_value_nochange(X) interface returns true if and only if
6080** the column corresponding to X is unchanged by the UPDATE operation
6081** that the xUpdate method call was invoked to implement and if
6082** the prior [xColumn] method call that was invoked to extract
6083** the value for that column returned without setting a result (probably
6084** because it queried [sqlite3_vtab_nochange()] and found that the column
6085** was unchanging). ^Within an [xUpdate] method, any value for which
6086** sqlite3_value_nochange(X) is true will in all other respects appear
6087** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
6088** than within an [xUpdate] method call for an UPDATE statement, then
6089** the return value is arbitrary and meaningless.
6090**
6091** ^The sqlite3_value_frombind(X) interface returns non-zero if the
6092** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
6093** interfaces. ^If X comes from an SQL literal value, or a table column,
6094** or an expression, then sqlite3_value_frombind(X) returns zero.
6095**
6096** Please pay particular attention to the fact that the pointer returned
6097** from [sqlite3_value_blob()], [sqlite3_value_text()], or
6098** [sqlite3_value_text16()] can be invalidated by a subsequent call to
6099** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
6100** or [sqlite3_value_text16()].
6101**
6102** These routines must be called from the same thread as
6103** the SQL function that supplied the [sqlite3_value*] parameters.
6104**
6105** As long as the input parameter is correct, these routines can only
6106** fail if an out-of-memory error occurs during a format conversion.
6107** Only the following subset of interfaces are subject to out-of-memory
6108** errors:
6109**
6110** <ul>
6111** <li> sqlite3_value_blob()
6112** <li> sqlite3_value_text()
6113** <li> sqlite3_value_text16()
6114** <li> sqlite3_value_text16le()
6115** <li> sqlite3_value_text16be()
6116** <li> sqlite3_value_bytes()
6117** <li> sqlite3_value_bytes16()
6118** </ul>
6119**
6120** If an out-of-memory error occurs, then the return value from these
6121** routines is the same as if the column had contained an SQL NULL value.
6122** Valid SQL NULL returns can be distinguished from out-of-memory errors
6123** by invoking the [sqlite3_errcode()] immediately after the suspect
6124** return value is obtained and before any
6125** other SQLite interface is called on the same [database connection].
6126*/
6127SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
6128SQLITE_API double sqlite3_value_double(sqlite3_value*);
6129SQLITE_API int sqlite3_value_int(sqlite3_value*);
6130SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
6131SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
6132SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
6133SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
6134SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
6135SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
6136SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
6137SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
6138SQLITE_API int sqlite3_value_type(sqlite3_value*);
6139SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
6140SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
6141SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
6142
6143/*
6144** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
6145** METHOD: sqlite3_value
6146**
6147** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
6148** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
6149** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
6150** returns something other than SQLITE_TEXT, then the return value from
6151** sqlite3_value_encoding(X) is meaningless. ^Calls to
6152** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
6153** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
6154** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
6155** thus change the return from subsequent calls to sqlite3_value_encoding(X).
6156**
6157** This routine is intended for used by applications that test and validate
6158** the SQLite implementation. This routine is inquiring about the opaque
6159** internal state of an [sqlite3_value] object. Ordinary applications should
6160** not need to know what the internal state of an sqlite3_value object is and
6161** hence should not need to use this interface.
6162*/
6163SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
6164
6165/*
6166** CAPI3REF: Finding The Subtype Of SQL Values
6167** METHOD: sqlite3_value
6168**
6169** The sqlite3_value_subtype(V) function returns the subtype for
6170** an [application-defined SQL function] argument V. The subtype
6171** information can be used to pass a limited amount of context from
6172** one SQL function to another. Use the [sqlite3_result_subtype()]
6173** routine to set the subtype for the return value of an SQL function.
6174**
6175** Every [application-defined SQL function] that invokes this interface
6176** should include the [SQLITE_SUBTYPE] property in the text
6177** encoding argument when the function is [sqlite3_create_function|registered].
6178** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
6179** might return zero instead of the upstream subtype in some corner cases.
6180*/
6181SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
6182
6183/*
6184** CAPI3REF: Copy And Free SQL Values
6185** METHOD: sqlite3_value
6186**
6187** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
6188** object V and returns a pointer to that copy. ^The [sqlite3_value] returned
6189** is a [protected sqlite3_value] object even if the input is not.
6190** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
6191** memory allocation fails. ^If V is a [pointer value], then the result
6192** of sqlite3_value_dup(V) is a NULL value.
6193**
6194** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
6195** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
6196** then sqlite3_value_free(V) is a harmless no-op.
6197*/
6198SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
6199SQLITE_API void sqlite3_value_free(sqlite3_value*);
6200
6201/*
6202** CAPI3REF: Obtain Aggregate Function Context
6203** METHOD: sqlite3_context
6204**
6205** Implementations of aggregate SQL functions use this
6206** routine to allocate memory for storing their state.
6207**
6208** ^The first time the sqlite3_aggregate_context(C,N) routine is called
6209** for a particular aggregate function, SQLite allocates
6210** N bytes of memory, zeroes out that memory, and returns a pointer
6211** to the new memory. ^On second and subsequent calls to
6212** sqlite3_aggregate_context() for the same aggregate function instance,
6213** the same buffer is returned. Sqlite3_aggregate_context() is normally
6214** called once for each invocation of the xStep callback and then one
6215** last time when the xFinal callback is invoked. ^(When no rows match
6216** an aggregate query, the xStep() callback of the aggregate function
6217** implementation is never called and xFinal() is called exactly once.
6218** In those cases, sqlite3_aggregate_context() might be called for the
6219** first time from within xFinal().)^
6220**
6221** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
6222** when first called if N is less than or equal to zero or if a memory
6223** allocation error occurs.
6224**
6225** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
6226** determined by the N parameter on the first successful call. Changing the
6227** value of N in any subsequent call to sqlite3_aggregate_context() within
6228** the same aggregate function instance will not resize the memory
6229** allocation.)^ Within the xFinal callback, it is customary to set
6230** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
6231** pointless memory allocations occur.
6232**
6233** ^SQLite automatically frees the memory allocated by
6234** sqlite3_aggregate_context() when the aggregate query concludes.
6235**
6236** The first parameter must be a copy of the
6237** [sqlite3_context | SQL function context] that is the first parameter
6238** to the xStep or xFinal callback routine that implements the aggregate
6239** function.
6240**
6241** This routine must be called from the same thread in which
6242** the aggregate SQL function is running.
6243*/
6244SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
6245
6246/*
6247** CAPI3REF: User Data For Functions
6248** METHOD: sqlite3_context
6249**
6250** ^The sqlite3_user_data() interface returns a copy of
6251** the pointer that was the pUserData parameter (the 5th parameter)
6252** of the [sqlite3_create_function()]
6253** and [sqlite3_create_function16()] routines that originally
6254** registered the application defined function.
6255**
6256** This routine must be called from the same thread in which
6257** the application-defined function is running.
6258*/
6259SQLITE_API void *sqlite3_user_data(sqlite3_context*);
6260
6261/*
6262** CAPI3REF: Database Connection For Functions
6263** METHOD: sqlite3_context
6264**
6265** ^The sqlite3_context_db_handle() interface returns a copy of
6266** the pointer to the [database connection] (the 1st parameter)
6267** of the [sqlite3_create_function()]
6268** and [sqlite3_create_function16()] routines that originally
6269** registered the application defined function.
6270*/
6271SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
6272
6273/*
6274** CAPI3REF: Function Auxiliary Data
6275** METHOD: sqlite3_context
6276**
6277** These functions may be used by (non-aggregate) SQL functions to
6278** associate auxiliary data with argument values. If the same argument
6279** value is passed to multiple invocations of the same SQL function during
6280** query execution, under some circumstances the associated auxiliary data
6281** might be preserved. An example of where this might be useful is in a
6282** regular-expression matching function. The compiled version of the regular
6283** expression can be stored as auxiliary data associated with the pattern string.
6284** Then as long as the pattern string remains the same,
6285** the compiled regular expression can be reused on multiple
6286** invocations of the same function.
6287**
6288** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
6289** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
6290** value to the application-defined function. ^N is zero for the left-most
6291** function argument. ^If there is no auxiliary data
6292** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
6293** returns a NULL pointer.
6294**
6295** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
6296** N-th argument of the application-defined function. ^Subsequent
6297** calls to sqlite3_get_auxdata(C,N) return P from the most recent
6298** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
6299** NULL if the auxiliary data has been discarded.
6300** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
6301** SQLite will invoke the destructor function X with parameter P exactly
6302** once, when the auxiliary data is discarded.
6303** SQLite is free to discard the auxiliary data at any time, including: <ul>
6304** <li> ^(when the corresponding function parameter changes)^, or
6305** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
6306** SQL statement)^, or
6307** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
6308** parameter)^, or
6309** <li> ^(during the original sqlite3_set_auxdata() call when a memory
6310** allocation error occurs.)^
6311** <li> ^(during the original sqlite3_set_auxdata() call if the function
6312** is evaluated during query planning instead of during query execution,
6313** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
6314**
6315** Note the last two bullets in particular. The destructor X in
6316** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
6317** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
6318** should be called near the end of the function implementation and the
6319** function implementation should not make any use of P after
6320** sqlite3_set_auxdata() has been called. Furthermore, a call to
6321** sqlite3_get_auxdata() that occurs immediately after a corresponding call
6322** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
6323** condition occurred during the sqlite3_set_auxdata() call or if the
6324** function is being evaluated during query planning rather than during
6325** query execution.
6326**
6327** ^(In practice, auxiliary data is preserved between function calls for
6328** function parameters that are compile-time constants, including literal
6329** values and [parameters] and expressions composed from the same.)^
6330**
6331** The value of the N parameter to these interfaces should be non-negative.
6332** Future enhancements may make use of negative N values to define new
6333** kinds of function caching behavior.
6334**
6335** These routines must be called from the same thread in which
6336** the SQL function is running.
6337**
6338** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
6339*/
6340SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
6341SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
6342
6343/*
6344** CAPI3REF: Database Connection Client Data
6345** METHOD: sqlite3
6346**
6347** These functions are used to associate one or more named pointers
6348** with a [database connection].
6349** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
6350** to be attached to [database connection] D using name N. Subsequent
6351** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6352** or a NULL pointer if there were no prior calls to
6353** sqlite3_set_clientdata() with the same values of D and N.
6354** Names are compared using strcmp() and are thus case sensitive.
6355** It returns 0 on success and SQLITE_NOMEM on allocation failure.
6356**
6357** If P and X are both non-NULL, then the destructor X is invoked with
6358** argument P on the first of the following occurrences:
6359** <ul>
6360** <li> An out-of-memory error occurs during the call to
6361** sqlite3_set_clientdata() which attempts to register pointer P.
6362** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6363** with the same D and N parameters.
6364** <li> The database connection closes. SQLite does not make any guarantees
6365** about the order in which destructors are called, only that all
6366** destructors will be called exactly once at some point during the
6367** database connection closing process.
6368** </ul>
6369**
6370** SQLite does not do anything with client data other than invoke
6371** destructors on the client data at the appropriate time. The intended
6372** use for client data is to provide a mechanism for wrapper libraries
6373** to store additional information about an SQLite database connection.
6374**
6375** There is no limit (other than available memory) on the number of different
6376** client data pointers (with different names) that can be attached to a
6377** single database connection. However, the current implementation stores
6378** the content on a linked list. Insert and retrieval performance will
6379** be proportional to the number of entries. The design use case, and
6380** the use case for which the implementation is optimized, is
6381** that an application will store only small number of client data names,
6382** typically just one or two. This interface is not intended to be a
6383** generalized key/value store for thousands or millions of keys. It
6384** will work for that, but performance might be disappointing.
6385**
6386** There is no way to enumerate the client data pointers
6387** associated with a database connection. The N parameter can be thought
6388** of as a secret key such that only code that knows the secret key is able
6389** to access the associated data.
6390**
6391** Security Warning: These interfaces should not be exposed in scripting
6392** languages or in other circumstances where it might be possible for an
6393** attacker to invoke them. Any agent that can invoke these interfaces
6394** can probably also take control of the process.
6395**
6396** Database connection client data is only available for SQLite
6397** version 3.44.0 ([dateof:3.44.0]) and later.
6398**
6399** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6400*/
6401SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6402SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6403
6404/*
6405** CAPI3REF: Constants Defining Special Destructor Behavior
6406**
6407** These are special values for the destructor that is passed in as the
6408** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6409** argument is SQLITE_STATIC, it means that the content pointer is constant
6410** and will never change. It does not need to be destroyed. ^The
6411** SQLITE_TRANSIENT value means that the content will likely change in
6412** the near future and that SQLite should make its own private copy of
6413** the content before returning.
6414**
6415** The typedef is necessary to work around problems in certain
6416** C++ compilers.
6417*/
6418typedef void (*sqlite3_destructor_type)(void*);
6419#define SQLITE_STATIC ((sqlite3_destructor_type)0)
6420#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6421
6422/*
6423** CAPI3REF: Setting The Result Of An SQL Function
6424** METHOD: sqlite3_context
6425**
6426** These routines are used by the xFunc or xFinal callbacks that
6427** implement SQL functions and aggregates. See
6428** [sqlite3_create_function()] and [sqlite3_create_function16()]
6429** for additional information.
6430**
6431** These functions work very much like the [parameter binding] family of
6432** functions used to bind values to host parameters in prepared statements.
6433** Refer to the [SQL parameter] documentation for additional information.
6434**
6435** ^The sqlite3_result_blob() interface sets the result from
6436** an application-defined function to be the BLOB whose content is pointed
6437** to by the second parameter and which is N bytes long where N is the
6438** third parameter.
6439**
6440** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6441** interfaces set the result of the application-defined function to be
6442** a BLOB containing all zero bytes and N bytes in size.
6443**
6444** ^The sqlite3_result_double() interface sets the result from
6445** an application-defined function to be a floating point value specified
6446** by its 2nd argument.
6447**
6448** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6449** cause the implemented SQL function to throw an exception.
6450** ^SQLite uses the string pointed to by the
6451** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6452** as the text of an error message. ^SQLite interprets the error
6453** message string from sqlite3_result_error() as UTF-8. ^SQLite
6454** interprets the string from sqlite3_result_error16() as UTF-16 using
6455** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6456** ^If the third parameter to sqlite3_result_error()
6457** or sqlite3_result_error16() is negative then SQLite takes as the error
6458** message all text up through the first zero character.
6459** ^If the third parameter to sqlite3_result_error() or
6460** sqlite3_result_error16() is non-negative then SQLite takes that many
6461** bytes (not characters) from the 2nd parameter as the error message.
6462** ^The sqlite3_result_error() and sqlite3_result_error16()
6463** routines make a private copy of the error message text before
6464** they return. Hence, the calling function can deallocate or
6465** modify the text after they return without harm.
6466** ^The sqlite3_result_error_code() function changes the error code
6467** returned by SQLite as a result of an error in a function. ^By default,
6468** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6469** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6470**
6471** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6472** error indicating that a string or BLOB is too long to represent.
6473**
6474** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6475** error indicating that a memory allocation failed.
6476**
6477** ^The sqlite3_result_int() interface sets the return value
6478** of the application-defined function to be the 32-bit signed integer
6479** value given in the 2nd argument.
6480** ^The sqlite3_result_int64() interface sets the return value
6481** of the application-defined function to be the 64-bit signed integer
6482** value given in the 2nd argument.
6483**
6484** ^The sqlite3_result_null() interface sets the return value
6485** of the application-defined function to be NULL.
6486**
6487** ^The sqlite3_result_text(), sqlite3_result_text16(),
6488** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6489** set the return value of the application-defined function to be
6490** a text string which is represented as UTF-8, UTF-16 native byte order,
6491** UTF-16 little endian, or UTF-16 big endian, respectively.
6492** ^The sqlite3_result_text64(C,Z,N,D,E) interface sets the return value of an
6493** application-defined function to be a text string in an encoding
6494** specified the E parameter, which must be one
6495** of [SQLITE_UTF8], [SQLITE_UTF8_ZT], [SQLITE_UTF16], [SQLITE_UTF16BE],
6496** or [SQLITE_UTF16LE]. ^The special value [SQLITE_UTF8_ZT] means that
6497** the result text is both UTF-8 and zero-terminated. In other words,
6498** SQLITE_UTF8_ZT means that the Z array holds at least N+1 byes and that
6499** the Z&#91;N&#93; is zero.
6500** ^SQLite takes the text result from the application from
6501** the 2nd parameter of the sqlite3_result_text* interfaces.
6502** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6503** other than sqlite3_result_text64() is negative, then SQLite computes
6504** the string length itself by searching the 2nd parameter for the first
6505** zero character.
6506** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6507** is non-negative, then as many bytes (not characters) of the text
6508** pointed to by the 2nd parameter are taken as the application-defined
6509** function result. If the 3rd parameter is non-negative, then it
6510** must be the byte offset into the string where the NUL terminator would
6511** appear if the string were NUL terminated. If any NUL characters occur
6512** in the string at a byte offset that is less than the value of the 3rd
6513** parameter, then the resulting string will contain embedded NULs and the
6514** result of expressions operating on strings with embedded NULs is undefined.
6515** ^If the 4th parameter to the sqlite3_result_text* interfaces
6516** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6517** function as the destructor on the text or BLOB result when it has
6518** finished using that result.
6519** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6520** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6521** assumes that the text or BLOB result is in constant space and does not
6522** copy the content of the parameter nor call a destructor on the content
6523** when it has finished using that result.
6524** ^If the 4th parameter to the sqlite3_result_text* interfaces
6525** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6526** then SQLite makes a copy of the result into space obtained
6527** from [sqlite3_malloc()] before it returns.
6528**
6529** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6530** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6531** when the encoding is not UTF8, if the input UTF16 begins with a
6532** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6533** string and the rest of the string is interpreted according to the
6534** byte-order specified by the BOM. ^The byte-order specified by
6535** the BOM at the beginning of the text overrides the byte-order
6536** specified by the interface procedure. ^So, for example, if
6537** sqlite3_result_text16le() is invoked with text that begins
6538** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6539** first two bytes of input are skipped and the remaining input
6540** is interpreted as UTF16BE text.
6541**
6542** ^For UTF16 input text to the sqlite3_result_text16(),
6543** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6544** sqlite3_result_text64() routines, if the text contains invalid
6545** UTF16 characters, the invalid characters might be converted
6546** into the unicode replacement character, U+FFFD.
6547**
6548** ^The sqlite3_result_value() interface sets the result of
6549** the application-defined function to be a copy of the
6550** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6551** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6552** so that the [sqlite3_value] specified in the parameter may change or
6553** be deallocated after sqlite3_result_value() returns without harm.
6554** ^A [protected sqlite3_value] object may always be used where an
6555** [unprotected sqlite3_value] object is required, so either
6556** kind of [sqlite3_value] object can be used with this interface.
6557**
6558** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6559** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6560** also associates the host-language pointer P or type T with that
6561** NULL value such that the pointer can be retrieved within an
6562** [application-defined SQL function] using [sqlite3_value_pointer()].
6563** ^If the D parameter is not NULL, then it is a pointer to a destructor
6564** for the P parameter. ^SQLite invokes D with P as its only argument
6565** when SQLite is finished with P. The T parameter should be a static
6566** string and preferably a string literal. The sqlite3_result_pointer()
6567** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6568**
6569** If these routines are called from within a different thread
6570** than the one containing the application-defined function that received
6571** the [sqlite3_context] pointer, the results are undefined.
6572*/
6573SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6574SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6575 sqlite3_uint64,void(*)(void*));
6576SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6577SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6578SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6579SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6580SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6581SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6582SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6583SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6584SQLITE_API void sqlite3_result_null(sqlite3_context*);
6585SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6586SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char *z, sqlite3_uint64 n,
6587 void(*)(void*), unsigned char encoding);
6588SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6589SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6590SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6591SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6592SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6593SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6594SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6595
6596
6597/*
6598** CAPI3REF: Setting The Subtype Of An SQL Function
6599** METHOD: sqlite3_context
6600**
6601** The sqlite3_result_subtype(C,T) function causes the subtype of
6602** the result from the [application-defined SQL function] with
6603** [sqlite3_context] C to be the value T. Only the lower 8 bits
6604** of the subtype T are preserved in current versions of SQLite;
6605** higher order bits are discarded.
6606** The number of subtype bytes preserved by SQLite might increase
6607** in future releases of SQLite.
6608**
6609** Every [application-defined SQL function] that invokes this interface
6610** should include the [SQLITE_RESULT_SUBTYPE] property in its
6611** text encoding argument when the SQL function is
6612** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6613** property is omitted from the function that invokes sqlite3_result_subtype(),
6614** then in some cases the sqlite3_result_subtype() might fail to set
6615** the result subtype.
6616**
6617** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6618** SQL function that invokes the sqlite3_result_subtype() interface
6619** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6620** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6621** by default.
6622*/
6623SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6624
6625/*
6626** CAPI3REF: Define New Collating Sequences
6627** METHOD: sqlite3
6628**
6629** ^These functions add, remove, or modify a [collation] associated
6630** with the [database connection] specified as the first argument.
6631**
6632** ^The name of the collation is a UTF-8 string
6633** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6634** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6635** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6636** considered to be the same name.
6637**
6638** ^(The third argument (eTextRep) must be one of the constants:
6639** <ul>
6640** <li> [SQLITE_UTF8],
6641** <li> [SQLITE_UTF16LE],
6642** <li> [SQLITE_UTF16BE],
6643** <li> [SQLITE_UTF16], or
6644** <li> [SQLITE_UTF16_ALIGNED].
6645** </ul>)^
6646** ^The eTextRep argument determines the encoding of strings passed
6647** to the collating function callback, xCompare.
6648** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6649** force strings to be UTF16 with native byte order.
6650** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6651** on an even byte address.
6652**
6653** ^The fourth argument, pArg, is an application data pointer that is passed
6654** through as the first argument to the collating function callback.
6655**
6656** ^The fifth argument, xCompare, is a pointer to the collating function.
6657** ^Multiple collating functions can be registered using the same name but
6658** with different eTextRep parameters and SQLite will use whichever
6659** function requires the least amount of data transformation.
6660** ^If the xCompare argument is NULL then the collating function is
6661** deleted. ^When all collating functions having the same name are deleted,
6662** that collation is no longer usable.
6663**
6664** ^The collating function callback is invoked with a copy of the pArg
6665** application data pointer and with two strings in the encoding specified
6666** by the eTextRep argument. The two integer parameters to the collating
6667** function callback are the length of the two strings, in bytes. The collating
6668** function must return an integer that is negative, zero, or positive
6669** if the first string is less than, equal to, or greater than the second,
6670** respectively. A collating function must always return the same answer
6671** given the same inputs. If two or more collating functions are registered
6672** to the same collation name (using different eTextRep values) then all
6673** must give an equivalent answer when invoked with equivalent strings.
6674** The collating function must obey the following properties for all
6675** strings A, B, and C:
6676**
6677** <ol>
6678** <li> If A==B then B==A.
6679** <li> If A==B and B==C then A==C.
6680** <li> If A&lt;B THEN B&gt;A.
6681** <li> If A&lt;B and B&lt;C then A&lt;C.
6682** </ol>
6683**
6684** If a collating function fails any of the above constraints and that
6685** collating function is registered and used, then the behavior of SQLite
6686** is undefined.
6687**
6688** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6689** with the addition that the xDestroy callback is invoked on pArg when
6690** the collating function is deleted.
6691** ^Collating functions are deleted when they are overridden by later
6692** calls to the collation creation functions or when the
6693** [database connection] is closed using [sqlite3_close()].
6694**
6695** ^The xDestroy callback is <u>not</u> called if the
6696** sqlite3_create_collation_v2() function fails. Applications that invoke
6697** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6698** check the return code and dispose of the application data pointer
6699** themselves rather than expecting SQLite to deal with it for them.
6700** This is different from every other SQLite interface. The inconsistency
6701** is unfortunate but cannot be changed without breaking backwards
6702** compatibility.
6703**
6704** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6705*/
6706SQLITE_API int sqlite3_create_collation(
6707 sqlite3*,
6708 const char *zName,
6709 int eTextRep,
6710 void *pArg,
6711 int(*xCompare)(void*,int,const void*,int,const void*)
6712);
6713SQLITE_API int sqlite3_create_collation_v2(
6714 sqlite3*,
6715 const char *zName,
6716 int eTextRep,
6717 void *pArg,
6718 int(*xCompare)(void*,int,const void*,int,const void*),
6719 void(*xDestroy)(void*)
6720);
6721SQLITE_API int sqlite3_create_collation16(
6722 sqlite3*,
6723 const void *zName,
6724 int eTextRep,
6725 void *pArg,
6726 int(*xCompare)(void*,int,const void*,int,const void*)
6727);
6728
6729/*
6730** CAPI3REF: Collation Needed Callbacks
6731** METHOD: sqlite3
6732**
6733** ^To avoid having to register all collation sequences before a database
6734** can be used, a single callback function may be registered with the
6735** [database connection] to be invoked whenever an undefined collation
6736** sequence is required.
6737**
6738** ^If the function is registered using the sqlite3_collation_needed() API,
6739** then it is passed the names of undefined collation sequences as strings
6740** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6741** the names are passed as UTF-16 in machine native byte order.
6742** ^A call to either function replaces the existing collation-needed callback.
6743**
6744** ^(When the callback is invoked, the first argument passed is a copy
6745** of the second argument to sqlite3_collation_needed() or
6746** sqlite3_collation_needed16(). The second argument is the database
6747** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6748** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6749** sequence function required. The fourth parameter is the name of the
6750** required collation sequence.)^
6751**
6752** The callback function should register the desired collation using
6753** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6754** [sqlite3_create_collation_v2()].
6755*/
6756SQLITE_API int sqlite3_collation_needed(
6757 sqlite3*,
6758 void*,
6759 void(*)(void*,sqlite3*,int eTextRep,const char*)
6760);
6761SQLITE_API int sqlite3_collation_needed16(
6762 sqlite3*,
6763 void*,
6764 void(*)(void*,sqlite3*,int eTextRep,const void*)
6765);
6766
6767#ifdef SQLITE_ENABLE_CEROD
6768/*
6769** Specify the activation key for a CEROD database. Unless
6770** activated, none of the CEROD routines will work.
6771*/
6772SQLITE_API void sqlite3_activate_cerod(
6773 const char *zPassPhrase /* Activation phrase */
6774);
6775#endif
6776
6777/*
6778** CAPI3REF: Suspend Execution For A Short Time
6779**
6780** The sqlite3_sleep() function causes the current thread to suspend execution
6781** for at least a number of milliseconds specified in its parameter.
6782**
6783** If the operating system does not support sleep requests with
6784** millisecond time resolution, then the time will be rounded up to
6785** the nearest second. The number of milliseconds of sleep actually
6786** requested from the operating system is returned.
6787**
6788** ^SQLite implements this interface by calling the xSleep()
6789** method of the default [sqlite3_vfs] object. If the xSleep() method
6790** of the default VFS is not implemented correctly, or not implemented at
6791** all, then the behavior of sqlite3_sleep() may deviate from the description
6792** in the previous paragraphs.
6793**
6794** If a negative argument is passed to sqlite3_sleep() the results vary by
6795** VFS and operating system. Some system treat a negative argument as an
6796** instruction to sleep forever. Others understand it to mean do not sleep
6797** at all. ^In SQLite version 3.42.0 and later, a negative
6798** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6799** down into the xSleep method of the VFS.
6800*/
6801SQLITE_API int sqlite3_sleep(int);
6802
6803/*
6804** CAPI3REF: Name Of The Folder Holding Temporary Files
6805**
6806** ^(If this global variable is made to point to a string which is
6807** the name of a folder (a.k.a. directory), then all temporary files
6808** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6809** will be placed in that directory.)^ ^If this variable
6810** is a NULL pointer, then SQLite performs a search for an appropriate
6811** temporary file directory.
6812**
6813** Applications are strongly discouraged from using this global variable.
6814** It is required to set a temporary folder on Windows Runtime (WinRT).
6815** But for all other platforms, it is highly recommended that applications
6816** neither read nor write this variable. This global variable is a relic
6817** that exists for backwards compatibility of legacy applications and should
6818** be avoided in new projects.
6819**
6820** It is not safe to read or modify this variable in more than one
6821** thread at a time. It is not safe to read or modify this variable
6822** if a [database connection] is being used at the same time in a separate
6823** thread.
6824** It is intended that this variable be set once
6825** as part of process initialization and before any SQLite interface
6826** routines have been called and that this variable remain unchanged
6827** thereafter.
6828**
6829** ^The [temp_store_directory pragma] may modify this variable and cause
6830** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6831** the [temp_store_directory pragma] always assumes that any string
6832** that this variable points to is held in memory obtained from
6833** [sqlite3_malloc] and the pragma may attempt to free that memory
6834** using [sqlite3_free].
6835** Hence, if this variable is modified directly, either it should be
6836** made NULL or made to point to memory obtained from [sqlite3_malloc]
6837** or else the use of the [temp_store_directory pragma] should be avoided.
6838** Except when requested by the [temp_store_directory pragma], SQLite
6839** does not free the memory that sqlite3_temp_directory points to. If
6840** the application wants that memory to be freed, it must do
6841** so itself, taking care to only do so after all [database connection]
6842** objects have been destroyed.
6843**
6844** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6845** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6846** features that require the use of temporary files may fail. Here is an
6847** example of how to do this using C++ with the Windows Runtime:
6848**
6849** <blockquote><pre>
6850** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6851** &nbsp; TemporaryFolder->Path->Data();
6852** char zPathBuf&#91;MAX_PATH + 1&#93;;
6853** memset(zPathBuf, 0, sizeof(zPathBuf));
6854** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6855** &nbsp; NULL, NULL);
6856** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6857** </pre></blockquote>
6858*/
6859SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6860
6861/*
6862** CAPI3REF: Name Of The Folder Holding Database Files
6863**
6864** ^(If this global variable is made to point to a string which is
6865** the name of a folder (a.k.a. directory), then all database files
6866** specified with a relative pathname and created or accessed by
6867** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6868** to be relative to that directory.)^ ^If this variable is a NULL
6869** pointer, then SQLite assumes that all database files specified
6870** with a relative pathname are relative to the current directory
6871** for the process. Only the windows VFS makes use of this global
6872** variable; it is ignored by the unix VFS.
6873**
6874** Changing the value of this variable while a database connection is
6875** open can result in a corrupt database.
6876**
6877** It is not safe to read or modify this variable in more than one
6878** thread at a time. It is not safe to read or modify this variable
6879** if a [database connection] is being used at the same time in a separate
6880** thread.
6881** It is intended that this variable be set once
6882** as part of process initialization and before any SQLite interface
6883** routines have been called and that this variable remain unchanged
6884** thereafter.
6885**
6886** ^The [data_store_directory pragma] may modify this variable and cause
6887** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6888** the [data_store_directory pragma] always assumes that any string
6889** that this variable points to is held in memory obtained from
6890** [sqlite3_malloc] and the pragma may attempt to free that memory
6891** using [sqlite3_free].
6892** Hence, if this variable is modified directly, either it should be
6893** made NULL or made to point to memory obtained from [sqlite3_malloc]
6894** or else the use of the [data_store_directory pragma] should be avoided.
6895*/
6896SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6897
6898/*
6899** CAPI3REF: Win32 Specific Interface
6900**
6901** These interfaces are available only on Windows. The
6902** [sqlite3_win32_set_directory] interface is used to set the value associated
6903** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6904** zValue, depending on the value of the type parameter. The zValue parameter
6905** should be NULL to cause the previous value to be freed via [sqlite3_free];
6906** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6907** prior to being used. The [sqlite3_win32_set_directory] interface returns
6908** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6909** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6910** [sqlite3_data_directory] variable is intended to act as a replacement for
6911** the current directory on the sub-platforms of Win32 where that concept is
6912** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6913** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6914** sqlite3_win32_set_directory interface except the string parameter must be
6915** UTF-8 or UTF-16, respectively.
6916*/
6917SQLITE_API int sqlite3_win32_set_directory(
6918 unsigned long type, /* Identifier for directory being set or reset */
6919 void *zValue /* New value for directory being set or reset */
6920);
6921SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6922SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6923
6924/*
6925** CAPI3REF: Win32 Directory Types
6926**
6927** These macros are only available on Windows. They define the allowed values
6928** for the type argument to the [sqlite3_win32_set_directory] interface.
6929*/
6930#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6931#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6932
6933/*
6934** CAPI3REF: Test For Auto-Commit Mode
6935** KEYWORDS: {autocommit mode}
6936** METHOD: sqlite3
6937**
6938** ^The sqlite3_get_autocommit() interface returns non-zero or
6939** zero if the given database connection is or is not in autocommit mode,
6940** respectively. ^Autocommit mode is on by default.
6941** ^Autocommit mode is disabled by a [BEGIN] statement.
6942** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6943**
6944** If certain kinds of errors occur on a statement within a multi-statement
6945** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6946** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6947** transaction might be rolled back automatically. The only way to
6948** find out whether SQLite automatically rolled back the transaction after
6949** an error is to use this function.
6950**
6951** If another thread changes the autocommit status of the database
6952** connection while this routine is running, then the return value
6953** is undefined.
6954*/
6955SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6956
6957/*
6958** CAPI3REF: Find The Database Handle Of A Prepared Statement
6959** METHOD: sqlite3_stmt
6960**
6961** ^The sqlite3_db_handle interface returns the [database connection] handle
6962** to which a [prepared statement] belongs. ^The [database connection]
6963** returned by sqlite3_db_handle is the same [database connection]
6964** that was the first argument
6965** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6966** create the statement in the first place.
6967*/
6968SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6969
6970/*
6971** CAPI3REF: Return The Schema Name For A Database Connection
6972** METHOD: sqlite3
6973**
6974** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6975** for the N-th database on database connection D, or a NULL pointer if N is
6976** out of range. An N value of 0 means the main database file. An N of 1 is
6977** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6978** databases.
6979**
6980** Space to hold the string that is returned by sqlite3_db_name() is managed
6981** by SQLite itself. The string might be deallocated by any operation that
6982** changes the schema, including [ATTACH] or [DETACH] or calls to
6983** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6984** occur on a different thread. Applications that need to
6985** remember the string long-term should make their own copy. Applications that
6986** are accessing the same database connection simultaneously on multiple
6987** threads should mutex-protect calls to this API and should make their own
6988** private copy of the result prior to releasing the mutex.
6989*/
6990SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6991
6992/*
6993** CAPI3REF: Return The Filename For A Database Connection
6994** METHOD: sqlite3
6995**
6996** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6997** associated with database N of connection D.
6998** ^If there is no attached database N on the database
6999** connection D, or if database N is a temporary or in-memory database, then
7000** this function will return either a NULL pointer or an empty string.
7001**
7002** ^The string value returned by this routine is owned and managed by
7003** the database connection. ^The value will be valid until the database N
7004** is [DETACH]-ed or until the database connection closes.
7005**
7006** ^The filename returned by this function is the output of the
7007** xFullPathname method of the [VFS]. ^In other words, the filename
7008** will be an absolute pathname, even if the filename used
7009** to open the database originally was a URI or relative pathname.
7010**
7011** If the filename pointer returned by this routine is not NULL, then it
7012** can be used as the filename input parameter to these routines:
7013** <ul>
7014** <li> [sqlite3_uri_parameter()]
7015** <li> [sqlite3_uri_boolean()]
7016** <li> [sqlite3_uri_int64()]
7017** <li> [sqlite3_filename_database()]
7018** <li> [sqlite3_filename_journal()]
7019** <li> [sqlite3_filename_wal()]
7020** </ul>
7021*/
7022SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
7023
7024/*
7025** CAPI3REF: Determine if a database is read-only
7026** METHOD: sqlite3
7027**
7028** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
7029** of connection D is read-only, 0 if it is read/write, or -1 if N is not
7030** the name of a database on connection D.
7031*/
7032SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
7033
7034/*
7035** CAPI3REF: Determine the transaction state of a database
7036** METHOD: sqlite3
7037**
7038** ^The sqlite3_txn_state(D,S) interface returns the current
7039** [transaction state] of schema S in database connection D. ^If S is NULL,
7040** then the highest transaction state of any schema on database connection D
7041** is returned. Transaction states are (in order of lowest to highest):
7042** <ol>
7043** <li value="0"> SQLITE_TXN_NONE
7044** <li value="1"> SQLITE_TXN_READ
7045** <li value="2"> SQLITE_TXN_WRITE
7046** </ol>
7047** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
7048** a valid schema, then -1 is returned.
7049*/
7050SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
7051
7052/*
7053** CAPI3REF: Allowed return values from sqlite3_txn_state()
7054** KEYWORDS: {transaction state}
7055**
7056** These constants define the current transaction state of a database file.
7057** ^The [sqlite3_txn_state(D,S)] interface returns one of these
7058** constants in order to describe the transaction state of schema S
7059** in [database connection] D.
7060**
7061** <dl>
7062** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
7063** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
7064** pending.</dd>
7065**
7066** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
7067** <dd>The SQLITE_TXN_READ state means that the database is currently
7068** in a read transaction. Content has been read from the database file
7069** but nothing in the database file has changed. The transaction state
7070** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
7071** no other conflicting concurrent write transactions. The transaction
7072** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
7073** [COMMIT].</dd>
7074**
7075** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
7076** <dd>The SQLITE_TXN_WRITE state means that the database is currently
7077** in a write transaction. Content has been written to the database file
7078** but has not yet committed. The transaction state will change to
7079** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
7080*/
7081#define SQLITE_TXN_NONE 0
7082#define SQLITE_TXN_READ 1
7083#define SQLITE_TXN_WRITE 2
7084
7085/*
7086** CAPI3REF: Find the next prepared statement
7087** METHOD: sqlite3
7088**
7089** ^This interface returns a pointer to the next [prepared statement] after
7090** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
7091** then this interface returns a pointer to the first prepared statement
7092** associated with the database connection pDb. ^If no prepared statement
7093** satisfies the conditions of this routine, it returns NULL.
7094**
7095** The [database connection] pointer D in a call to
7096** [sqlite3_next_stmt(D,S)] must refer to an open database
7097** connection and in particular must not be a NULL pointer.
7098*/
7099SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
7100
7101/*
7102** CAPI3REF: Commit And Rollback Notification Callbacks
7103** METHOD: sqlite3
7104**
7105** ^The sqlite3_commit_hook() interface registers a callback
7106** function to be invoked whenever a transaction is [COMMIT | committed].
7107** ^Any callback set by a previous call to sqlite3_commit_hook()
7108** for the same database connection is overridden.
7109** ^The sqlite3_rollback_hook() interface registers a callback
7110** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
7111** ^Any callback set by a previous call to sqlite3_rollback_hook()
7112** for the same database connection is overridden.
7113** ^The pArg argument is passed through to the callback.
7114** ^If the callback on a commit hook function returns non-zero,
7115** then the commit is converted into a rollback.
7116**
7117** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
7118** return the P argument from the previous call of the same function
7119** on the same [database connection] D, or NULL for
7120** the first call for each function on D.
7121**
7122** The commit and rollback hook callbacks are not reentrant.
7123** The callback implementation must not do anything that will modify
7124** the database connection that invoked the callback. Any actions
7125** to modify the database connection must be deferred until after the
7126** completion of the [sqlite3_step()] call that triggered the commit
7127** or rollback hook in the first place.
7128** Note that running any other SQL statements, including SELECT statements,
7129** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
7130** the database connections for the meaning of "modify" in this paragraph.
7131**
7132** ^Registering a NULL function disables the callback.
7133**
7134** ^When the commit hook callback routine returns zero, the [COMMIT]
7135** operation is allowed to continue normally. ^If the commit hook
7136** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
7137** ^The rollback hook is invoked on a rollback that results from a commit
7138** hook returning non-zero, just as it would be with any other rollback.
7139**
7140** ^For the purposes of this API, a transaction is said to have been
7141** rolled back if an explicit "ROLLBACK" statement is executed, or
7142** an error or constraint causes an implicit rollback to occur.
7143** ^The rollback callback is not invoked if a transaction is
7144** automatically rolled back because the database connection is closed.
7145**
7146** See also the [sqlite3_update_hook()] interface.
7147*/
7148SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
7149SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
7150
7151/*
7152** CAPI3REF: Autovacuum Compaction Amount Callback
7153** METHOD: sqlite3
7154**
7155** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
7156** function C that is invoked prior to each autovacuum of the database
7157** file. ^The callback is passed a copy of the generic data pointer (P),
7158** the schema-name of the attached database that is being autovacuumed,
7159** the size of the database file in pages, the number of free pages,
7160** and the number of bytes per page, respectively. The callback should
7161** return the number of free pages that should be removed by the
7162** autovacuum. ^If the callback returns zero, then no autovacuum happens.
7163** ^If the value returned is greater than or equal to the number of
7164** free pages, then a complete autovacuum happens.
7165**
7166** <p>^If there are multiple ATTACH-ed database files that are being
7167** modified as part of a transaction commit, then the autovacuum pages
7168** callback is invoked separately for each file.
7169**
7170** <p><b>The callback is not reentrant.</b> The callback function should
7171** not attempt to invoke any other SQLite interface. If it does, bad
7172** things may happen, including segmentation faults and corrupt database
7173** files. The callback function should be a simple function that
7174** does some arithmetic on its input parameters and returns a result.
7175**
7176** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
7177** destructor for the P parameter. ^If X is not NULL, then X(P) is
7178** invoked whenever the database connection closes or when the callback
7179** is overwritten by another invocation of sqlite3_autovacuum_pages().
7180**
7181** <p>^There is only one autovacuum pages callback per database connection.
7182** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
7183** previous invocations for that database connection. ^If the callback
7184** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
7185** then the autovacuum steps callback is canceled. The return value
7186** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
7187** be some other error code if something goes wrong. The current
7188** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
7189** return codes might be added in future releases.
7190**
7191** <p>If no autovacuum pages callback is specified (the usual case) or
7192** a NULL pointer is provided for the callback,
7193** then the default behavior is to vacuum all free pages. So, in other
7194** words, the default behavior is the same as if the callback function
7195** were something like this:
7196**
7197** <blockquote><pre>
7198** &nbsp; unsigned int demonstration_autovac_pages_callback(
7199** &nbsp; void *pClientData,
7200** &nbsp; const char *zSchema,
7201** &nbsp; unsigned int nDbPage,
7202** &nbsp; unsigned int nFreePage,
7203** &nbsp; unsigned int nBytePerPage
7204** &nbsp; ){
7205** &nbsp; return nFreePage;
7206** &nbsp; }
7207** </pre></blockquote>
7208*/
7209SQLITE_API int sqlite3_autovacuum_pages(
7210 sqlite3 *db,
7211 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
7212 void*,
7213 void(*)(void*)
7214);
7215
7216
7217/*
7218** CAPI3REF: Data Change Notification Callbacks
7219** METHOD: sqlite3
7220**
7221** ^The sqlite3_update_hook() interface registers a callback function
7222** with the [database connection] identified by the first argument
7223** to be invoked whenever a row is updated, inserted or deleted in
7224** a [rowid table].
7225** ^Any callback set by a previous call to this function
7226** for the same database connection is overridden.
7227**
7228** ^The second argument is a pointer to the function to invoke when a
7229** row is updated, inserted or deleted in a rowid table.
7230** ^The update hook is disabled by invoking sqlite3_update_hook()
7231** with a NULL pointer as the second parameter.
7232** ^The first argument to the callback is a copy of the third argument
7233** to sqlite3_update_hook().
7234** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
7235** or [SQLITE_UPDATE], depending on the operation that caused the callback
7236** to be invoked.
7237** ^The third and fourth arguments to the callback contain pointers to the
7238** database and table name containing the affected row.
7239** ^The final callback parameter is the [rowid] of the row.
7240** ^In the case of an update, this is the [rowid] after the update takes place.
7241**
7242** ^(The update hook is not invoked when internal system tables are
7243** modified (i.e. sqlite_sequence).)^
7244** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
7245**
7246** ^In the current implementation, the update hook
7247** is not invoked when conflicting rows are deleted because of an
7248** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
7249** invoked when rows are deleted using the [truncate optimization].
7250** The exceptions defined in this paragraph might change in a future
7251** release of SQLite.
7252**
7253** Whether the update hook is invoked before or after the
7254** corresponding change is currently unspecified and may differ
7255** depending on the type of change. Do not rely on the order of the
7256** hook call with regards to the final result of the operation which
7257** triggers the hook.
7258**
7259** The update hook implementation must not do anything that will modify
7260** the database connection that invoked the update hook. Any actions
7261** to modify the database connection must be deferred until after the
7262** completion of the [sqlite3_step()] call that triggered the update hook.
7263** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
7264** database connections for the meaning of "modify" in this paragraph.
7265**
7266** ^The sqlite3_update_hook(D,C,P) function
7267** returns the P argument from the previous call
7268** on the same [database connection] D, or NULL for
7269** the first call on D.
7270**
7271** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
7272** and [sqlite3_preupdate_hook()] interfaces.
7273*/
7274SQLITE_API void *sqlite3_update_hook(
7275 sqlite3*,
7276 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
7277 void*
7278);
7279
7280/*
7281** CAPI3REF: Enable Or Disable Shared Pager Cache
7282**
7283** ^(This routine enables or disables the sharing of the database cache
7284** and schema data structures between [database connection | connections]
7285** to the same database. Sharing is enabled if the argument is true
7286** and disabled if the argument is false.)^
7287**
7288** This interface is omitted if SQLite is compiled with
7289** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
7290** compile-time option is recommended because the
7291** [use of shared cache mode is discouraged].
7292**
7293** ^Cache sharing is enabled and disabled for an entire process.
7294** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
7295** In prior versions of SQLite,
7296** sharing was enabled or disabled for each thread separately.
7297**
7298** ^(The cache sharing mode set by this interface effects all subsequent
7299** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
7300** Existing database connections continue to use the sharing mode
7301** that was in effect at the time they were opened.)^
7302**
7303** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
7304** successfully. An [error code] is returned otherwise.)^
7305**
7306** ^Shared cache is disabled by default. It is recommended that it stay
7307** that way. In other words, do not use this routine. This interface
7308** continues to be provided for historical compatibility, but its use is
7309** discouraged. Any use of shared cache is discouraged. If shared cache
7310** must be used, it is recommended that shared cache only be enabled for
7311** individual database connections using the [sqlite3_open_v2()] interface
7312** with the [SQLITE_OPEN_SHAREDCACHE] flag.
7313**
7314** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
7315** and will always return SQLITE_MISUSE. On those systems,
7316** shared cache mode should be enabled per-database connection via
7317** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
7318**
7319** This interface is threadsafe on processors where writing a
7320** 32-bit integer is atomic.
7321**
7322** See Also: [SQLite Shared-Cache Mode]
7323*/
7324SQLITE_API int sqlite3_enable_shared_cache(int);
7325
7326/*
7327** CAPI3REF: Attempt To Free Heap Memory
7328**
7329** ^The sqlite3_release_memory() interface attempts to free N bytes
7330** of heap memory by deallocating non-essential memory allocations
7331** held by the database library. Memory used to cache database
7332** pages to improve performance is an example of non-essential memory.
7333** ^sqlite3_release_memory() returns the number of bytes actually freed,
7334** which might be more or less than the amount requested.
7335** ^The sqlite3_release_memory() routine is a no-op returning zero
7336** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
7337**
7338** See also: [sqlite3_db_release_memory()]
7339*/
7340SQLITE_API int sqlite3_release_memory(int);
7341
7342/*
7343** CAPI3REF: Free Memory Used By A Database Connection
7344** METHOD: sqlite3
7345**
7346** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
7347** memory as possible from database connection D. Unlike the
7348** [sqlite3_release_memory()] interface, this interface is in effect even
7349** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
7350** omitted.
7351**
7352** See also: [sqlite3_release_memory()]
7353*/
7354SQLITE_API int sqlite3_db_release_memory(sqlite3*);
7355
7356/*
7357** CAPI3REF: Impose A Limit On Heap Size
7358**
7359** These interfaces impose limits on the amount of heap memory that will be
7360** used by all database connections within a single process.
7361**
7362** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7363** soft limit on the amount of heap memory that may be allocated by SQLite.
7364** ^SQLite strives to keep heap memory utilization below the soft heap
7365** limit by reducing the number of pages held in the page cache
7366** as heap memory usages approaches the limit.
7367** ^The soft heap limit is "soft" because even though SQLite strives to stay
7368** below the limit, it will exceed the limit rather than generate
7369** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7370** is advisory only.
7371**
7372** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7373** N bytes on the amount of memory that will be allocated. ^The
7374** sqlite3_hard_heap_limit64(N) interface is similar to
7375** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7376** when the hard heap limit is reached.
7377**
7378** ^The return value from both sqlite3_soft_heap_limit64() and
7379** sqlite3_hard_heap_limit64() is the size of
7380** the heap limit prior to the call, or negative in the case of an
7381** error. ^If the argument N is negative
7382** then no change is made to the heap limit. Hence, the current
7383** size of heap limits can be determined by invoking
7384** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7385**
7386** ^Setting the heap limits to zero disables the heap limiter mechanism.
7387**
7388** ^The soft heap limit may not be greater than the hard heap limit.
7389** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7390** is invoked with a value of N that is greater than the hard heap limit,
7391** the soft heap limit is set to the value of the hard heap limit.
7392** ^The soft heap limit is automatically enabled whenever the hard heap
7393** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7394** the soft heap limit is outside the range of 1..N, then the soft heap
7395** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7396** hard heap limit is enabled makes the soft heap limit equal to the
7397** hard heap limit.
7398**
7399** The memory allocation limits can also be adjusted using
7400** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7401**
7402** ^(The heap limits are not enforced in the current implementation
7403** if one or more of following conditions are true:
7404**
7405** <ul>
7406** <li> The limit value is set to zero.
7407** <li> Memory accounting is disabled using a combination of the
7408** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7409** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7410** <li> An alternative page cache implementation is specified using
7411** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7412** <li> The page cache allocates from its own memory pool supplied
7413** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7414** from the heap.
7415** </ul>)^
7416**
7417** The circumstances under which SQLite will enforce the heap limits may
7418** change in future releases of SQLite.
7419*/
7420SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7421SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7422
7423/*
7424** CAPI3REF: Deprecated Soft Heap Limit Interface
7425** DEPRECATED
7426**
7427** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7428** interface. This routine is provided for historical compatibility
7429** only. All new applications should use the
7430** [sqlite3_soft_heap_limit64()] interface rather than this one.
7431*/
7432SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7433
7434
7435/*
7436** CAPI3REF: Extract Metadata About A Column Of A Table
7437** METHOD: sqlite3
7438**
7439** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7440** information about column C of table T in database D
7441** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7442** interface returns SQLITE_OK and fills in the non-NULL pointers in
7443** the final five arguments with appropriate values if the specified
7444** column exists. ^The sqlite3_table_column_metadata() interface returns
7445** SQLITE_ERROR if the specified column does not exist.
7446** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7447** NULL pointer, then this routine simply checks for the existence of the
7448** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7449** does not. If the table name parameter T in a call to
7450** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7451** undefined behavior.
7452**
7453** ^The column is identified by the second, third and fourth parameters to
7454** this function. ^(The second parameter is either the name of the database
7455** (i.e. "main", "temp", or an attached database) containing the specified
7456** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7457** for the table using the same algorithm used by the database engine to
7458** resolve unqualified table references.
7459**
7460** ^The third and fourth parameters to this function are the table and column
7461** name of the desired column, respectively.
7462**
7463** ^Metadata is returned by writing to the memory locations passed as the 5th
7464** and subsequent parameters to this function. ^Any of these arguments may be
7465** NULL, in which case the corresponding element of metadata is omitted.
7466**
7467** ^(<blockquote>
7468** <table border="1">
7469** <tr><th> Parameter <th> Output<br>Type <th> Description
7470**
7471** <tr><td> 5th <td> const char* <td> Data type
7472** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7473** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7474** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7475** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7476** </table>
7477** </blockquote>)^
7478**
7479** ^The memory pointed to by the character pointers returned for the
7480** declaration type and collation sequence is valid until the next
7481** call to any SQLite API function.
7482**
7483** ^If the specified table is actually a view, an [error code] is returned.
7484**
7485** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7486** is not a [WITHOUT ROWID] table and an
7487** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7488** parameters are set for the explicitly declared column. ^(If there is no
7489** [INTEGER PRIMARY KEY] column, then the outputs
7490** for the [rowid] are set as follows:
7491**
7492** <pre>
7493** data type: "INTEGER"
7494** collation sequence: "BINARY"
7495** not null: 0
7496** primary key: 1
7497** auto increment: 0
7498** </pre>)^
7499**
7500** ^This function causes all database schemas to be read from disk and
7501** parsed, if that has not already been done, and returns an error if
7502** any errors are encountered while loading the schema.
7503*/
7504SQLITE_API int sqlite3_table_column_metadata(
7505 sqlite3 *db, /* Connection handle */
7506 const char *zDbName, /* Database name or NULL */
7507 const char *zTableName, /* Table name */
7508 const char *zColumnName, /* Column name */
7509 char const **pzDataType, /* OUTPUT: Declared data type */
7510 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7511 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7512 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7513 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7514);
7515
7516/*
7517** CAPI3REF: Load An Extension
7518** METHOD: sqlite3
7519**
7520** ^This interface loads an SQLite extension library from the named file.
7521**
7522** ^The sqlite3_load_extension() interface attempts to load an
7523** [SQLite extension] library contained in the file zFile. If
7524** the file cannot be loaded directly, attempts are made to load
7525** with various operating-system specific filename extensions added.
7526** So for example, if "samplelib" cannot be loaded, then names like
7527** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7528** be tried also.
7529**
7530** ^The entry point is zProc.
7531** ^(zProc may be 0, in which case SQLite will try to come up with an
7532** entry point name on its own. It first tries "sqlite3_extension_init".
7533** If that does not work, it tries names of the form "sqlite3_X_init"
7534** where X consists of the lower-case equivalent of all ASCII alphabetic
7535** characters or all ASCII alphanumeric characters in the filename from
7536** the last "/" to the first following "." and omitting any initial "lib".)^
7537** ^The sqlite3_load_extension() interface returns
7538** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7539** ^If an error occurs and pzErrMsg is not 0, then the
7540** [sqlite3_load_extension()] interface shall attempt to
7541** fill *pzErrMsg with error message text stored in memory
7542** obtained from [sqlite3_malloc()]. The calling function
7543** should free this memory by calling [sqlite3_free()].
7544**
7545** ^Extension loading must be enabled using
7546** [sqlite3_enable_load_extension()] or
7547** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7548** prior to calling this API,
7549** otherwise an error will be returned.
7550**
7551** <b>Security warning:</b> It is recommended that the
7552** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7553** interface. The use of the [sqlite3_enable_load_extension()] interface
7554** should be avoided. This will keep the SQL function [load_extension()]
7555** disabled and prevent SQL injections from giving attackers
7556** access to extension loading capabilities.
7557**
7558** See also the [load_extension() SQL function].
7559*/
7560SQLITE_API int sqlite3_load_extension(
7561 sqlite3 *db, /* Load the extension into this database connection */
7562 const char *zFile, /* Name of the shared library containing extension */
7563 const char *zProc, /* Entry point. Derived from zFile if 0 */
7564 char **pzErrMsg /* Put error message here if not 0 */
7565);
7566
7567/*
7568** CAPI3REF: Enable Or Disable Extension Loading
7569** METHOD: sqlite3
7570**
7571** ^So as not to open security holes in older applications that are
7572** unprepared to deal with [extension loading], and as a means of disabling
7573** [extension loading] while evaluating user-entered SQL, the following API
7574** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7575**
7576** ^Extension loading is off by default.
7577** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7578** to turn extension loading on and call it with onoff==0 to turn
7579** it back off again.
7580**
7581** ^This interface enables or disables both the C-API
7582** [sqlite3_load_extension()] and the SQL function [load_extension()].
7583** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7584** to enable or disable only the C-API.)^
7585**
7586** <b>Security warning:</b> It is recommended that extension loading
7587** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7588** rather than this interface, so the [load_extension()] SQL function
7589** remains disabled. This will prevent SQL injections from giving attackers
7590** access to extension loading capabilities.
7591*/
7592SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7593
7594/*
7595** CAPI3REF: Automatically Load Statically Linked Extensions
7596**
7597** ^This interface causes the xEntryPoint() function to be invoked for
7598** each new [database connection] that is created. The idea here is that
7599** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7600** that is to be automatically loaded into all new database connections.
7601**
7602** ^(Even though the function prototype shows that xEntryPoint() takes
7603** no arguments and returns void, SQLite invokes xEntryPoint() with three
7604** arguments and expects an integer result as if the signature of the
7605** entry point were as follows:
7606**
7607** <blockquote><pre>
7608** &nbsp; int xEntryPoint(
7609** &nbsp; sqlite3 *db,
7610** &nbsp; const char **pzErrMsg,
7611** &nbsp; const struct sqlite3_api_routines *pThunk
7612** &nbsp; );
7613** </pre></blockquote>)^
7614**
7615** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7616** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7617** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7618** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7619** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7620** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7621** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7622**
7623** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7624** on the list of automatic extensions is a harmless no-op. ^No entry point
7625** will be called more than once for each database connection that is opened.
7626**
7627** See also: [sqlite3_reset_auto_extension()]
7628** and [sqlite3_cancel_auto_extension()]
7629*/
7630SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7631
7632/*
7633** CAPI3REF: Cancel Automatic Extension Loading
7634**
7635** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7636** initialization routine X that was registered using a prior call to
7637** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7638** routine returns 1 if initialization routine X was successfully
7639** unregistered and it returns 0 if X was not on the list of initialization
7640** routines.
7641*/
7642SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7643
7644/*
7645** CAPI3REF: Reset Automatic Extension Loading
7646**
7647** ^This interface disables all automatic extensions previously
7648** registered using [sqlite3_auto_extension()].
7649*/
7650SQLITE_API void sqlite3_reset_auto_extension(void);
7651
7652/*
7653** Structures used by the virtual table interface
7654*/
7655typedef struct sqlite3_vtab sqlite3_vtab;
7656typedef struct sqlite3_index_info sqlite3_index_info;
7657typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7658typedef struct sqlite3_module sqlite3_module;
7659
7660/*
7661** CAPI3REF: Virtual Table Object
7662** KEYWORDS: sqlite3_module {virtual table module}
7663**
7664** This structure, sometimes called a "virtual table module",
7665** defines the implementation of a [virtual table].
7666** This structure consists mostly of methods for the module.
7667**
7668** ^A virtual table module is created by filling in a persistent
7669** instance of this structure and passing a pointer to that instance
7670** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7671** ^The registration remains valid until it is replaced by a different
7672** module or until the [database connection] closes. The content
7673** of this structure must not change while it is registered with
7674** any database connection.
7675*/
7676struct sqlite3_module {
7677 int iVersion;
7678 int (*xCreate)(sqlite3*, void *pAux,
7679 int argc, const char *const*argv,
7680 sqlite3_vtab **ppVTab, char**);
7681 int (*xConnect)(sqlite3*, void *pAux,
7682 int argc, const char *const*argv,
7683 sqlite3_vtab **ppVTab, char**);
7684 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7685 int (*xDisconnect)(sqlite3_vtab *pVTab);
7686 int (*xDestroy)(sqlite3_vtab *pVTab);
7687 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7688 int (*xClose)(sqlite3_vtab_cursor*);
7689 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7690 int argc, sqlite3_value **argv);
7691 int (*xNext)(sqlite3_vtab_cursor*);
7692 int (*xEof)(sqlite3_vtab_cursor*);
7693 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7694 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7695 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7696 int (*xBegin)(sqlite3_vtab *pVTab);
7697 int (*xSync)(sqlite3_vtab *pVTab);
7698 int (*xCommit)(sqlite3_vtab *pVTab);
7699 int (*xRollback)(sqlite3_vtab *pVTab);
7700 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7701 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7702 void **ppArg);
7703 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7704 /* The methods above are in version 1 of the sqlite_module object. Those
7705 ** below are for version 2 and greater. */
7706 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7707 int (*xRelease)(sqlite3_vtab *pVTab, int);
7708 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7709 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7710 ** Those below are for version 3 and greater. */
7711 int (*xShadowName)(const char*);
7712 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7713 ** Those below are for version 4 and greater. */
7714 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7715 const char *zTabName, int mFlags, char **pzErr);
7716};
7717
7718/*
7719** CAPI3REF: Virtual Table Indexing Information
7720** KEYWORDS: sqlite3_index_info
7721**
7722** The sqlite3_index_info structure and its substructures is used as part
7723** of the [virtual table] interface to
7724** pass information into and receive the reply from the [xBestIndex]
7725** method of a [virtual table module]. The fields under **Inputs** are the
7726** inputs to xBestIndex and are read-only. xBestIndex inserts its
7727** results into the **Outputs** fields.
7728**
7729** ^(The aConstraint[] array records WHERE clause constraints of the form:
7730**
7731** <blockquote>column OP expr</blockquote>
7732**
7733** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7734** stored in aConstraint[].op using one of the
7735** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7736** ^(The index of the column is stored in
7737** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7738** expr on the right-hand side can be evaluated (and thus the constraint
7739** is usable) and false if it cannot.)^
7740**
7741** ^The optimizer automatically inverts terms of the form "expr OP column"
7742** and makes other simplifications to the WHERE clause in an attempt to
7743** get as many WHERE clause terms into the form shown above as possible.
7744** ^The aConstraint[] array only reports WHERE clause terms that are
7745** relevant to the particular virtual table being queried.
7746**
7747** ^Information about the ORDER BY clause is stored in aOrderBy[].
7748** ^Each term of aOrderBy records a column of the ORDER BY clause.
7749**
7750** The colUsed field indicates which columns of the virtual table may be
7751** required by the current scan. Virtual table columns are numbered from
7752** zero in the order in which they appear within the CREATE TABLE statement
7753** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7754** the corresponding bit is set within the colUsed mask if the column may be
7755** required by SQLite. If the table has at least 64 columns and any column
7756** to the right of the first 63 is required, then bit 63 of colUsed is also
7757** set. In other words, column iCol may be required if the expression
7758** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7759** non-zero.
7760**
7761** The [xBestIndex] method must fill aConstraintUsage[] with information
7762** about what parameters to pass to xFilter. ^If argvIndex>0 then
7763** the right-hand side of the corresponding aConstraint[] is evaluated
7764** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7765** is true, then the constraint is assumed to be fully handled by the
7766** virtual table and might not be checked again by the byte code.)^ ^(The
7767** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7768** is left in its default setting of false, the constraint will always be
7769** checked separately in byte code. If the omit flag is changed to true, then
7770** the constraint may or may not be checked in byte code. In other words,
7771** when the omit flag is true there is no guarantee that the constraint will
7772** not be checked again using byte code.)^
7773**
7774** ^The idxNum and idxStr values are recorded and passed into the
7775** [xFilter] method.
7776** ^[sqlite3_free()] is used to free idxStr if and only if
7777** needToFreeIdxStr is true.
7778**
7779** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7780** the correct order to satisfy the ORDER BY clause so that no separate
7781** sorting step is required.
7782**
7783** ^The estimatedCost value is an estimate of the cost of a particular
7784** strategy. A cost of N indicates that the cost of the strategy is similar
7785** to a linear scan of an SQLite table with N rows. A cost of log(N)
7786** indicates that the expense of the operation is similar to that of a
7787** binary search on a unique indexed field of an SQLite table with N rows.
7788**
7789** ^The estimatedRows value is an estimate of the number of rows that
7790** will be returned by the strategy.
7791**
7792** The xBestIndex method may optionally populate the idxFlags field with a
7793** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
7794** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
7795** output to show the idxNum as hex instead of as decimal. Another flag is
7796** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
7797** return at most one row.
7798**
7799** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7800** SQLite also assumes that if a call to the xUpdate() method is made as
7801** part of the same statement to delete or update a virtual table row and the
7802** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7803** any database changes. In other words, if the xUpdate() returns
7804** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7805** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7806** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7807** the xUpdate method are automatically rolled back by SQLite.
7808**
7809** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7810** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7811** If a virtual table extension is
7812** used with an SQLite version earlier than 3.8.2, the results of attempting
7813** to read or write the estimatedRows field are undefined (but are likely
7814** to include crashing the application). The estimatedRows field should
7815** therefore only be used if [sqlite3_libversion_number()] returns a
7816** value greater than or equal to 3008002. Similarly, the idxFlags field
7817** was added for [version 3.9.0] ([dateof:3.9.0]).
7818** It may therefore only be used if
7819** sqlite3_libversion_number() returns a value greater than or equal to
7820** 3009000.
7821*/
7822struct sqlite3_index_info {
7823 /* Inputs */
7824 int nConstraint; /* Number of entries in aConstraint */
7825 struct sqlite3_index_constraint {
7826 int iColumn; /* Column constrained. -1 for ROWID */
7827 unsigned char op; /* Constraint operator */
7828 unsigned char usable; /* True if this constraint is usable */
7829 int iTermOffset; /* Used internally - xBestIndex should ignore */
7830 } *aConstraint; /* Table of WHERE clause constraints */
7831 int nOrderBy; /* Number of terms in the ORDER BY clause */
7832 struct sqlite3_index_orderby {
7833 int iColumn; /* Column number */
7834 unsigned char desc; /* True for DESC. False for ASC. */
7835 } *aOrderBy; /* The ORDER BY clause */
7836 /* Outputs */
7837 struct sqlite3_index_constraint_usage {
7838 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7839 unsigned char omit; /* Do not code a test for this constraint */
7840 } *aConstraintUsage;
7841 int idxNum; /* Number used to identify the index */
7842 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7843 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7844 int orderByConsumed; /* True if output is already ordered */
7845 double estimatedCost; /* Estimated cost of using this index */
7846 /* Fields below are only available in SQLite 3.8.2 and later */
7847 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7848 /* Fields below are only available in SQLite 3.9.0 and later */
7849 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7850 /* Fields below are only available in SQLite 3.10.0 and later */
7851 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7852};
7853
7854/*
7855** CAPI3REF: Virtual Table Scan Flags
7856**
7857** Virtual table implementations are allowed to set the
7858** [sqlite3_index_info].idxFlags field to some combination of
7859** these bits.
7860*/
7861#define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
7862#define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */
7863 /* in EXPLAIN QUERY PLAN */
7864
7865/*
7866** CAPI3REF: Virtual Table Constraint Operator Codes
7867**
7868** These macros define the allowed values for the
7869** [sqlite3_index_info].aConstraint[].op field. Each value represents
7870** an operator that is part of a constraint term in the WHERE clause of
7871** a query that uses a [virtual table].
7872**
7873** ^The left-hand operand of the operator is given by the corresponding
7874** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7875** operand is the rowid.
7876** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7877** operators have no left-hand operand, and so for those operators the
7878** corresponding aConstraint[].iColumn is meaningless and should not be
7879** used.
7880**
7881** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7882** value 255 are reserved to represent functions that are overloaded
7883** by the [xFindFunction|xFindFunction method] of the virtual table
7884** implementation.
7885**
7886** The right-hand operands for each constraint might be accessible using
7887** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7888** operand is only available if it appears as a single constant literal
7889** in the input SQL. If the right-hand operand is another column or an
7890** expression (even a constant expression) or a parameter, then the
7891** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7892** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7893** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7894** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7895** always return SQLITE_NOTFOUND.
7896**
7897** The collating sequence to be used for comparison can be found using
7898** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7899** tables, the collating sequence of constraints does not matter (for example
7900** because the constraints are numeric) and so the sqlite3_vtab_collation()
7901** interface is not commonly needed.
7902*/
7903#define SQLITE_INDEX_CONSTRAINT_EQ 2
7904#define SQLITE_INDEX_CONSTRAINT_GT 4
7905#define SQLITE_INDEX_CONSTRAINT_LE 8
7906#define SQLITE_INDEX_CONSTRAINT_LT 16
7907#define SQLITE_INDEX_CONSTRAINT_GE 32
7908#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7909#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7910#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7911#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7912#define SQLITE_INDEX_CONSTRAINT_NE 68
7913#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7914#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7915#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7916#define SQLITE_INDEX_CONSTRAINT_IS 72
7917#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7918#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7919#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7920
7921/*
7922** CAPI3REF: Register A Virtual Table Implementation
7923** METHOD: sqlite3
7924**
7925** ^These routines are used to register a new [virtual table module] name.
7926** ^Module names must be registered before
7927** creating a new [virtual table] using the module and before using a
7928** preexisting [virtual table] for the module.
7929**
7930** ^The module name is registered on the [database connection] specified
7931** by the first parameter. ^The name of the module is given by the
7932** second parameter. ^The third parameter is a pointer to
7933** the implementation of the [virtual table module]. ^The fourth
7934** parameter is an arbitrary client data pointer that is passed through
7935** into the [xCreate] and [xConnect] methods of the virtual table module
7936** when a new virtual table is being created or reinitialized.
7937**
7938** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7939** is a pointer to a destructor for the pClientData. ^SQLite will
7940** invoke the destructor function (if it is not NULL) when SQLite
7941** no longer needs the pClientData pointer. ^The destructor will also
7942** be invoked if the call to sqlite3_create_module_v2() fails.
7943** ^The sqlite3_create_module()
7944** interface is equivalent to sqlite3_create_module_v2() with a NULL
7945** destructor.
7946**
7947** ^If the third parameter (the pointer to the sqlite3_module object) is
7948** NULL then no new module is created and any existing modules with the
7949** same name are dropped.
7950**
7951** See also: [sqlite3_drop_modules()]
7952*/
7953SQLITE_API int sqlite3_create_module(
7954 sqlite3 *db, /* SQLite connection to register module with */
7955 const char *zName, /* Name of the module */
7956 const sqlite3_module *p, /* Methods for the module */
7957 void *pClientData /* Client data for xCreate/xConnect */
7958);
7959SQLITE_API int sqlite3_create_module_v2(
7960 sqlite3 *db, /* SQLite connection to register module with */
7961 const char *zName, /* Name of the module */
7962 const sqlite3_module *p, /* Methods for the module */
7963 void *pClientData, /* Client data for xCreate/xConnect */
7964 void(*xDestroy)(void*) /* Module destructor function */
7965);
7966
7967/*
7968** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7969** METHOD: sqlite3
7970**
7971** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7972** table modules from database connection D except those named on list L.
7973** The L parameter must be either NULL or a pointer to an array of pointers
7974** to strings where the array is terminated by a single NULL pointer.
7975** ^If the L parameter is NULL, then all virtual table modules are removed.
7976**
7977** See also: [sqlite3_create_module()]
7978*/
7979SQLITE_API int sqlite3_drop_modules(
7980 sqlite3 *db, /* Remove modules from this connection */
7981 const char **azKeep /* Except, do not remove the ones named here */
7982);
7983
7984/*
7985** CAPI3REF: Virtual Table Instance Object
7986** KEYWORDS: sqlite3_vtab
7987**
7988** Every [virtual table module] implementation uses a subclass
7989** of this object to describe a particular instance
7990** of the [virtual table]. Each subclass will
7991** be tailored to the specific needs of the module implementation.
7992** The purpose of this superclass is to define certain fields that are
7993** common to all module implementations.
7994**
7995** ^Virtual tables methods can set an error message by assigning a
7996** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7997** take care that any prior string is freed by a call to [sqlite3_free()]
7998** prior to assigning a new string to zErrMsg. ^After the error message
7999** is delivered up to the client application, the string will be automatically
8000** freed by sqlite3_free() and the zErrMsg field will be zeroed.
8001*/
8002struct sqlite3_vtab {
8003 const sqlite3_module *pModule; /* The module for this virtual table */
8004 int nRef; /* Number of open cursors */
8005 char *zErrMsg; /* Error message from sqlite3_mprintf() */
8006 /* Virtual table implementations will typically add additional fields */
8007};
8008
8009/*
8010** CAPI3REF: Virtual Table Cursor Object
8011** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
8012**
8013** Every [virtual table module] implementation uses a subclass of the
8014** following structure to describe cursors that point into the
8015** [virtual table] and are used
8016** to loop through the virtual table. Cursors are created using the
8017** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
8018** by the [sqlite3_module.xClose | xClose] method. Cursors are used
8019** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
8020** of the module. Each module implementation will define
8021** the content of a cursor structure to suit its own needs.
8022**
8023** This superclass exists in order to define fields of the cursor that
8024** are common to all implementations.
8025*/
8026struct sqlite3_vtab_cursor {
8027 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
8028 /* Virtual table implementations will typically add additional fields */
8029};
8030
8031/*
8032** CAPI3REF: Declare The Schema Of A Virtual Table
8033**
8034** ^The [xCreate] and [xConnect] methods of a
8035** [virtual table module] call this interface
8036** to declare the format (the names and datatypes of the columns) of
8037** the virtual tables they implement.
8038*/
8039SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
8040
8041/*
8042** CAPI3REF: Overload A Function For A Virtual Table
8043** METHOD: sqlite3
8044**
8045** ^(Virtual tables can provide alternative implementations of functions
8046** using the [xFindFunction] method of the [virtual table module].
8047** But global versions of those functions
8048** must exist in order to be overloaded.)^
8049**
8050** ^(This API makes sure a global version of a function with a particular
8051** name and number of parameters exists. If no such function exists
8052** before this API is called, a new function is created.)^ ^The implementation
8053** of the new function always causes an exception to be thrown. So
8054** the new function is not good for anything by itself. Its only
8055** purpose is to be a placeholder function that can be overloaded
8056** by a [virtual table].
8057*/
8058SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
8059
8060/*
8061** CAPI3REF: A Handle To An Open BLOB
8062** KEYWORDS: {BLOB handle} {BLOB handles}
8063**
8064** An instance of this object represents an open BLOB on which
8065** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
8066** ^Objects of this type are created by [sqlite3_blob_open()]
8067** and destroyed by [sqlite3_blob_close()].
8068** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
8069** can be used to read or write small subsections of the BLOB.
8070** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
8071*/
8072typedef struct sqlite3_blob sqlite3_blob;
8073
8074/*
8075** CAPI3REF: Open A BLOB For Incremental I/O
8076** METHOD: sqlite3
8077** CONSTRUCTOR: sqlite3_blob
8078**
8079** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
8080** in row iRow, column zColumn, table zTable in database zDb;
8081** in other words, the same BLOB that would be selected by:
8082**
8083** <pre>
8084** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
8085** </pre>)^
8086**
8087** ^(Parameter zDb is not the filename that contains the database, but
8088** rather the symbolic name of the database. For attached databases, this is
8089** the name that appears after the AS keyword in the [ATTACH] statement.
8090** For the main database file, the database name is "main". For TEMP
8091** tables, the database name is "temp".)^
8092**
8093** ^If the flags parameter is non-zero, then the BLOB is opened for read
8094** and write access. ^If the flags parameter is zero, the BLOB is opened for
8095** read-only access.
8096**
8097** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
8098** in *ppBlob. Otherwise an [error code] is returned and, unless the error
8099** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
8100** the API is not misused, it is always safe to call [sqlite3_blob_close()]
8101** on *ppBlob after this function returns.
8102**
8103** This function fails with SQLITE_ERROR if any of the following are true:
8104** <ul>
8105** <li> ^(Database zDb does not exist)^,
8106** <li> ^(Table zTable does not exist within database zDb)^,
8107** <li> ^(Table zTable is a WITHOUT ROWID table)^,
8108** <li> ^(Column zColumn does not exist)^,
8109** <li> ^(Row iRow is not present in the table)^,
8110** <li> ^(The specified column of row iRow contains a value that is not
8111** a TEXT or BLOB value)^,
8112** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
8113** constraint and the blob is being opened for read/write access)^,
8114** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
8115** column zColumn is part of a [child key] definition and the blob is
8116** being opened for read/write access)^.
8117** </ul>
8118**
8119** ^Unless it returns SQLITE_MISUSE, this function sets the
8120** [database connection] error code and message accessible via
8121** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8122**
8123** A BLOB referenced by sqlite3_blob_open() may be read using the
8124** [sqlite3_blob_read()] interface and modified by using
8125** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
8126** different row of the same table using the [sqlite3_blob_reopen()]
8127** interface. However, the column, table, or database of a [BLOB handle]
8128** cannot be changed after the [BLOB handle] is opened.
8129**
8130** ^(If the row that a BLOB handle points to is modified by an
8131** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
8132** then the BLOB handle is marked as "expired".
8133** This is true if any column of the row is changed, even a column
8134** other than the one the BLOB handle is open on.)^
8135** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
8136** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
8137** ^(Changes written into a BLOB prior to the BLOB expiring are not
8138** rolled back by the expiration of the BLOB. Such changes will eventually
8139** commit if the transaction continues to completion.)^
8140**
8141** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
8142** the opened blob. ^The size of a blob may not be changed by this
8143** interface. Use the [UPDATE] SQL command to change the size of a
8144** blob.
8145**
8146** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
8147** and the built-in [zeroblob] SQL function may be used to create a
8148** zero-filled blob to read or write using the incremental-blob interface.
8149**
8150** To avoid a resource leak, every open [BLOB handle] should eventually
8151** be released by a call to [sqlite3_blob_close()].
8152**
8153** See also: [sqlite3_blob_close()],
8154** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
8155** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
8156*/
8157SQLITE_API int sqlite3_blob_open(
8158 sqlite3*,
8159 const char *zDb,
8160 const char *zTable,
8161 const char *zColumn,
8162 sqlite3_int64 iRow,
8163 int flags,
8164 sqlite3_blob **ppBlob
8165);
8166
8167/*
8168** CAPI3REF: Move a BLOB Handle to a New Row
8169** METHOD: sqlite3_blob
8170**
8171** ^This function is used to move an existing [BLOB handle] so that it points
8172** to a different row of the same database table. ^The new row is identified
8173** by the rowid value passed as the second argument. Only the row can be
8174** changed. ^The database, table and column on which the blob handle is open
8175** remain the same. Moving an existing [BLOB handle] to a new row is
8176** faster than closing the existing handle and opening a new one.
8177**
8178** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
8179** it must exist and there must be either a blob or text value stored in
8180** the nominated column.)^ ^If the new row is not present in the table, or if
8181** it does not contain a blob or text value, or if another error occurs, an
8182** SQLite error code is returned and the blob handle is considered aborted.
8183** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
8184** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
8185** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
8186** always returns zero.
8187**
8188** ^This function sets the database handle error code and message.
8189*/
8190SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
8191
8192/*
8193** CAPI3REF: Close A BLOB Handle
8194** DESTRUCTOR: sqlite3_blob
8195**
8196** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
8197** unconditionally. Even if this routine returns an error code, the
8198** handle is still closed.)^
8199**
8200** ^If the blob handle being closed was opened for read-write access, and if
8201** the database is in auto-commit mode and there are no other open read-write
8202** blob handles or active write statements, the current transaction is
8203** committed. ^If an error occurs while committing the transaction, an error
8204** code is returned and the transaction rolled back.
8205**
8206** Calling this function with an argument that is not a NULL pointer or an
8207** open blob handle results in undefined behavior. ^Calling this routine
8208** with a null pointer (such as would be returned by a failed call to
8209** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
8210** is passed a valid open blob handle, the values returned by the
8211** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
8212*/
8213SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
8214
8215/*
8216** CAPI3REF: Return The Size Of An Open BLOB
8217** METHOD: sqlite3_blob
8218**
8219** ^Returns the size in bytes of the BLOB accessible via the
8220** successfully opened [BLOB handle] in its only argument. ^The
8221** incremental blob I/O routines can only read or overwrite existing
8222** blob content; they cannot change the size of a blob.
8223**
8224** This routine only works on a [BLOB handle] which has been created
8225** by a prior successful call to [sqlite3_blob_open()] and which has not
8226** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8227** to this routine results in undefined and probably undesirable behavior.
8228*/
8229SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
8230
8231/*
8232** CAPI3REF: Read Data From A BLOB Incrementally
8233** METHOD: sqlite3_blob
8234**
8235** ^(This function is used to read data from an open [BLOB handle] into a
8236** caller-supplied buffer. N bytes of data are copied into buffer Z
8237** from the open BLOB, starting at offset iOffset.)^
8238**
8239** ^If offset iOffset is less than N bytes from the end of the BLOB,
8240** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
8241** less than zero, [SQLITE_ERROR] is returned and no data is read.
8242** ^The size of the blob (and hence the maximum value of N+iOffset)
8243** can be determined using the [sqlite3_blob_bytes()] interface.
8244**
8245** ^An attempt to read from an expired [BLOB handle] fails with an
8246** error code of [SQLITE_ABORT].
8247**
8248** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
8249** Otherwise, an [error code] or an [extended error code] is returned.)^
8250**
8251** This routine only works on a [BLOB handle] which has been created
8252** by a prior successful call to [sqlite3_blob_open()] and which has not
8253** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8254** to this routine results in undefined and probably undesirable behavior.
8255**
8256** See also: [sqlite3_blob_write()].
8257*/
8258SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
8259
8260/*
8261** CAPI3REF: Write Data Into A BLOB Incrementally
8262** METHOD: sqlite3_blob
8263**
8264** ^(This function is used to write data into an open [BLOB handle] from a
8265** caller-supplied buffer. N bytes of data are copied from the buffer Z
8266** into the open BLOB, starting at offset iOffset.)^
8267**
8268** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
8269** Otherwise, an [error code] or an [extended error code] is returned.)^
8270** ^Unless SQLITE_MISUSE is returned, this function sets the
8271** [database connection] error code and message accessible via
8272** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8273**
8274** ^If the [BLOB handle] passed as the first argument was not opened for
8275** writing (the flags parameter to [sqlite3_blob_open()] was zero),
8276** this function returns [SQLITE_READONLY].
8277**
8278** This function may only modify the contents of the BLOB; it is
8279** not possible to increase the size of a BLOB using this API.
8280** ^If offset iOffset is less than N bytes from the end of the BLOB,
8281** [SQLITE_ERROR] is returned and no data is written. The size of the
8282** BLOB (and hence the maximum value of N+iOffset) can be determined
8283** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
8284** than zero [SQLITE_ERROR] is returned and no data is written.
8285**
8286** ^An attempt to write to an expired [BLOB handle] fails with an
8287** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
8288** before the [BLOB handle] expired are not rolled back by the
8289** expiration of the handle, though of course those changes might
8290** have been overwritten by the statement that expired the BLOB handle
8291** or by other independent statements.
8292**
8293** This routine only works on a [BLOB handle] which has been created
8294** by a prior successful call to [sqlite3_blob_open()] and which has not
8295** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8296** to this routine results in undefined and probably undesirable behavior.
8297**
8298** See also: [sqlite3_blob_read()].
8299*/
8300SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
8301
8302/*
8303** CAPI3REF: Virtual File System Objects
8304**
8305** A virtual filesystem (VFS) is an [sqlite3_vfs] object
8306** that SQLite uses to interact
8307** with the underlying operating system. Most SQLite builds come with a
8308** single default VFS that is appropriate for the host computer.
8309** New VFSes can be registered and existing VFSes can be unregistered.
8310** The following interfaces are provided.
8311**
8312** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
8313** ^Names are case sensitive.
8314** ^Names are zero-terminated UTF-8 strings.
8315** ^If there is no match, a NULL pointer is returned.
8316** ^If zVfsName is NULL then the default VFS is returned.
8317**
8318** ^New VFSes are registered with sqlite3_vfs_register().
8319** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
8320** ^The same VFS can be registered multiple times without injury.
8321** ^To make an existing VFS into the default VFS, register it again
8322** with the makeDflt flag set. If two different VFSes with the
8323** same name are registered, the behavior is undefined. If a
8324** VFS is registered with a name that is NULL or an empty string,
8325** then the behavior is undefined.
8326**
8327** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
8328** ^(If the default VFS is unregistered, another VFS is chosen as
8329** the default. The choice for the new VFS is arbitrary.)^
8330*/
8331SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
8332SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
8333SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
8334
8335/*
8336** CAPI3REF: Mutexes
8337**
8338** The SQLite core uses these routines for thread
8339** synchronization. Though they are intended for internal
8340** use by SQLite, code that links against SQLite is
8341** permitted to use any of these routines.
8342**
8343** The SQLite source code contains multiple implementations
8344** of these mutex routines. An appropriate implementation
8345** is selected automatically at compile-time. The following
8346** implementations are available in the SQLite core:
8347**
8348** <ul>
8349** <li> SQLITE_MUTEX_PTHREADS
8350** <li> SQLITE_MUTEX_W32
8351** <li> SQLITE_MUTEX_NOOP
8352** </ul>
8353**
8354** The SQLITE_MUTEX_NOOP implementation is a set of routines
8355** that does no real locking and is appropriate for use in
8356** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
8357** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
8358** and Windows.
8359**
8360** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
8361** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
8362** implementation is included with the library. In this case the
8363** application must supply a custom mutex implementation using the
8364** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
8365** before calling sqlite3_initialize() or any other public sqlite3_
8366** function that calls sqlite3_initialize().
8367**
8368** ^The sqlite3_mutex_alloc() routine allocates a new
8369** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8370** routine returns NULL if it is unable to allocate the requested
8371** mutex. The argument to sqlite3_mutex_alloc() must be one of these
8372** integer constants:
8373**
8374** <ul>
8375** <li> SQLITE_MUTEX_FAST
8376** <li> SQLITE_MUTEX_RECURSIVE
8377** <li> SQLITE_MUTEX_STATIC_MAIN
8378** <li> SQLITE_MUTEX_STATIC_MEM
8379** <li> SQLITE_MUTEX_STATIC_OPEN
8380** <li> SQLITE_MUTEX_STATIC_PRNG
8381** <li> SQLITE_MUTEX_STATIC_LRU
8382** <li> SQLITE_MUTEX_STATIC_PMEM
8383** <li> SQLITE_MUTEX_STATIC_APP1
8384** <li> SQLITE_MUTEX_STATIC_APP2
8385** <li> SQLITE_MUTEX_STATIC_APP3
8386** <li> SQLITE_MUTEX_STATIC_VFS1
8387** <li> SQLITE_MUTEX_STATIC_VFS2
8388** <li> SQLITE_MUTEX_STATIC_VFS3
8389** </ul>
8390**
8391** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8392** cause sqlite3_mutex_alloc() to create
8393** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8394** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8395** The mutex implementation does not need to make a distinction
8396** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8397** not want to. SQLite will only request a recursive mutex in
8398** cases where it really needs one. If a faster non-recursive mutex
8399** implementation is available on the host platform, the mutex subsystem
8400** might return such a mutex in response to SQLITE_MUTEX_FAST.
8401**
8402** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8403** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8404** a pointer to a static preexisting mutex. ^Nine static mutexes are
8405** used by the current version of SQLite. Future versions of SQLite
8406** may add additional static mutexes. Static mutexes are for internal
8407** use by SQLite only. Applications that use SQLite mutexes should
8408** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8409** SQLITE_MUTEX_RECURSIVE.
8410**
8411** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8412** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8413** returns a different mutex on every call. ^For the static
8414** mutex types, the same mutex is returned on every call that has
8415** the same type number.
8416**
8417** ^The sqlite3_mutex_free() routine deallocates a previously
8418** allocated dynamic mutex. Attempting to deallocate a static
8419** mutex results in undefined behavior.
8420**
8421** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8422** to enter a mutex. ^If another thread is already within the mutex,
8423** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8424** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8425** upon successful entry. ^(Mutexes created using
8426** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8427** In such cases, the
8428** mutex must be exited an equal number of times before another thread
8429** can enter.)^ If the same thread tries to enter any mutex other
8430** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8431**
8432** ^(Some systems (for example, Windows 95) do not support the operation
8433** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8434** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8435** sqlite3_mutex_try() as an optimization, so this is acceptable
8436** behavior. The exceptions are unix builds that set the
8437** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8438** sqlite3_mutex_try() is required.)^
8439**
8440** ^The sqlite3_mutex_leave() routine exits a mutex that was
8441** previously entered by the same thread. The behavior
8442** is undefined if the mutex is not currently entered by the
8443** calling thread or is not currently allocated.
8444**
8445** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8446** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8447** then any of the four routines behaves as a no-op.
8448**
8449** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8450*/
8451SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8452SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8453SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8454SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8455SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8456
8457/*
8458** CAPI3REF: Mutex Methods Object
8459**
8460** An instance of this structure defines the low-level routines
8461** used to allocate and use mutexes.
8462**
8463** Usually, the default mutex implementations provided by SQLite are
8464** sufficient, however the application has the option of substituting a custom
8465** implementation for specialized deployments or systems for which SQLite
8466** does not provide a suitable implementation. In this case, the application
8467** creates and populates an instance of this structure to pass
8468** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8469** Additionally, an instance of this structure can be used as an
8470** output variable when querying the system for the current mutex
8471** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8472**
8473** ^The xMutexInit method defined by this structure is invoked as
8474** part of system initialization by the sqlite3_initialize() function.
8475** ^The xMutexInit routine is called by SQLite exactly once for each
8476** effective call to [sqlite3_initialize()].
8477**
8478** ^The xMutexEnd method defined by this structure is invoked as
8479** part of system shutdown by the sqlite3_shutdown() function. The
8480** implementation of this method is expected to release all outstanding
8481** resources obtained by the mutex methods implementation, especially
8482** those obtained by the xMutexInit method. ^The xMutexEnd()
8483** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8484**
8485** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8486** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8487** xMutexNotheld) implement the following interfaces (respectively):
8488**
8489** <ul>
8490** <li> [sqlite3_mutex_alloc()] </li>
8491** <li> [sqlite3_mutex_free()] </li>
8492** <li> [sqlite3_mutex_enter()] </li>
8493** <li> [sqlite3_mutex_try()] </li>
8494** <li> [sqlite3_mutex_leave()] </li>
8495** <li> [sqlite3_mutex_held()] </li>
8496** <li> [sqlite3_mutex_notheld()] </li>
8497** </ul>)^
8498**
8499** The only difference is that the public sqlite3_XXX functions enumerated
8500** above silently ignore any invocations that pass a NULL pointer instead
8501** of a valid mutex handle. The implementations of the methods defined
8502** by this structure are not required to handle this case. The results
8503** of passing a NULL pointer instead of a valid mutex handle are undefined
8504** (i.e. it is acceptable to provide an implementation that segfaults if
8505** it is passed a NULL pointer).
8506**
8507** The xMutexInit() method must be threadsafe. It must be harmless to
8508** invoke xMutexInit() multiple times within the same process and without
8509** intervening calls to xMutexEnd(). Second and subsequent calls to
8510** xMutexInit() must be no-ops.
8511**
8512** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8513** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8514** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8515** memory allocation for a fast or recursive mutex.
8516**
8517** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8518** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8519** If xMutexInit fails in any way, it is expected to clean up after itself
8520** prior to returning.
8521*/
8522typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8523struct sqlite3_mutex_methods {
8524 int (*xMutexInit)(void);
8525 int (*xMutexEnd)(void);
8526 sqlite3_mutex *(*xMutexAlloc)(int);
8527 void (*xMutexFree)(sqlite3_mutex *);
8528 void (*xMutexEnter)(sqlite3_mutex *);
8529 int (*xMutexTry)(sqlite3_mutex *);
8530 void (*xMutexLeave)(sqlite3_mutex *);
8531 int (*xMutexHeld)(sqlite3_mutex *);
8532 int (*xMutexNotheld)(sqlite3_mutex *);
8533};
8534
8535/*
8536** CAPI3REF: Mutex Verification Routines
8537**
8538** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8539** are intended for use inside assert() statements. The SQLite core
8540** never uses these routines except inside an assert() and applications
8541** are advised to follow the lead of the core. The SQLite core only
8542** provides implementations for these routines when it is compiled
8543** with the SQLITE_DEBUG flag. External mutex implementations
8544** are only required to provide these routines if SQLITE_DEBUG is
8545** defined and if NDEBUG is not defined.
8546**
8547** These routines should return true if the mutex in their argument
8548** is held or not held, respectively, by the calling thread.
8549**
8550** The implementation is not required to provide versions of these
8551** routines that actually work. If the implementation does not provide working
8552** versions of these routines, it should at least provide stubs that always
8553** return true so that one does not get spurious assertion failures.
8554**
8555** If the argument to sqlite3_mutex_held() is a NULL pointer then
8556** the routine should return 1. This seems counter-intuitive since
8557** clearly the mutex cannot be held if it does not exist. But
8558** the reason the mutex does not exist is because the build is not
8559** using mutexes. And we do not want the assert() containing the
8560** call to sqlite3_mutex_held() to fail, so a non-zero return is
8561** the appropriate thing to do. The sqlite3_mutex_notheld()
8562** interface should also return 1 when given a NULL pointer.
8563*/
8564#ifndef NDEBUG
8565SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8566SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8567#endif
8568
8569/*
8570** CAPI3REF: Mutex Types
8571**
8572** The [sqlite3_mutex_alloc()] interface takes a single argument
8573** which is one of these integer constants.
8574**
8575** The set of static mutexes may change from one SQLite release to the
8576** next. Applications that override the built-in mutex logic must be
8577** prepared to accommodate additional static mutexes.
8578*/
8579#define SQLITE_MUTEX_FAST 0
8580#define SQLITE_MUTEX_RECURSIVE 1
8581#define SQLITE_MUTEX_STATIC_MAIN 2
8582#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8583#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8584#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8585#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8586#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8587#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8588#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8589#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8590#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8591#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8592#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8593#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8594#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8595
8596/* Legacy compatibility: */
8597#define SQLITE_MUTEX_STATIC_MASTER 2
8598
8599
8600/*
8601** CAPI3REF: Retrieve the mutex for a database connection
8602** METHOD: sqlite3
8603**
8604** ^This interface returns a pointer to the [sqlite3_mutex] object that
8605** serializes access to the [database connection] given in the argument
8606** when the [threading mode] is Serialized.
8607** ^If the [threading mode] is Single-thread or Multi-thread then this
8608** routine returns a NULL pointer.
8609*/
8610SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8611
8612/*
8613** CAPI3REF: Low-Level Control Of Database Files
8614** METHOD: sqlite3
8615** KEYWORDS: {file control}
8616**
8617** ^The [sqlite3_file_control()] interface makes a direct call to the
8618** xFileControl method for the [sqlite3_io_methods] object associated
8619** with a particular database identified by the second argument. ^The
8620** name of the database is "main" for the main database or "temp" for the
8621** TEMP database, or the name that appears after the AS keyword for
8622** databases that are added using the [ATTACH] SQL command.
8623** ^A NULL pointer can be used in place of "main" to refer to the
8624** main database file.
8625** ^The third and fourth parameters to this routine
8626** are passed directly through to the second and third parameters of
8627** the xFileControl method. ^The return value of the xFileControl
8628** method becomes the return value of this routine.
8629**
8630** A few opcodes for [sqlite3_file_control()] are handled directly
8631** by the SQLite core and never invoke the
8632** sqlite3_io_methods.xFileControl method.
8633** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8634** a pointer to the underlying [sqlite3_file] object to be written into
8635** the space pointed to by the 4th parameter. The
8636** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8637** the [sqlite3_file] object associated with the journal file instead of
8638** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8639** a pointer to the underlying [sqlite3_vfs] object for the file.
8640** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8641** from the pager.
8642**
8643** ^If the second parameter (zDbName) does not match the name of any
8644** open database file, then SQLITE_ERROR is returned. ^This error
8645** code is not remembered and will not be recalled by [sqlite3_errcode()]
8646** or [sqlite3_errmsg()]. The underlying xFileControl method might
8647** also return SQLITE_ERROR. There is no way to distinguish between
8648** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8649** xFileControl method.
8650**
8651** See also: [file control opcodes]
8652*/
8653SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8654
8655/*
8656** CAPI3REF: Testing Interface
8657**
8658** ^The sqlite3_test_control() interface is used to read out internal
8659** state of SQLite and to inject faults into SQLite for testing
8660** purposes. ^The first parameter is an operation code that determines
8661** the number, meaning, and operation of all subsequent parameters.
8662**
8663** This interface is not for use by applications. It exists solely
8664** for verifying the correct operation of the SQLite library. Depending
8665** on how the SQLite library is compiled, this interface might not exist.
8666**
8667** The details of the operation codes, their meanings, the parameters
8668** they take, and what they do are all subject to change without notice.
8669** Unlike most of the SQLite API, this function is not guaranteed to
8670** operate consistently from one release to the next.
8671*/
8672SQLITE_API int sqlite3_test_control(int op, ...);
8673
8674/*
8675** CAPI3REF: Testing Interface Operation Codes
8676**
8677** These constants are the valid operation code parameters used
8678** as the first argument to [sqlite3_test_control()].
8679**
8680** These parameters and their meanings are subject to change
8681** without notice. These values are for testing purposes only.
8682** Applications should not use any of these parameters or the
8683** [sqlite3_test_control()] interface.
8684*/
8685#define SQLITE_TESTCTRL_FIRST 5
8686#define SQLITE_TESTCTRL_PRNG_SAVE 5
8687#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8688#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8689#define SQLITE_TESTCTRL_FK_NO_ACTION 7
8690#define SQLITE_TESTCTRL_BITVEC_TEST 8
8691#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8692#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8693#define SQLITE_TESTCTRL_PENDING_BYTE 11
8694#define SQLITE_TESTCTRL_ASSERT 12
8695#define SQLITE_TESTCTRL_ALWAYS 13
8696#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8697#define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8698#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8699#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8700#define SQLITE_TESTCTRL_GETOPT 16
8701#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8702#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8703#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8704#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8705#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8706#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8707#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8708#define SQLITE_TESTCTRL_BYTEORDER 22
8709#define SQLITE_TESTCTRL_ISINIT 23
8710#define SQLITE_TESTCTRL_SORTER_MMAP 24
8711#define SQLITE_TESTCTRL_IMPOSTER 25
8712#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8713#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8714#define SQLITE_TESTCTRL_PRNG_SEED 28
8715#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8716#define SQLITE_TESTCTRL_SEEK_COUNT 30
8717#define SQLITE_TESTCTRL_TRACEFLAGS 31
8718#define SQLITE_TESTCTRL_TUNE 32
8719#define SQLITE_TESTCTRL_LOGEST 33
8720#define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */
8721#define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8722
8723/*
8724** CAPI3REF: SQL Keyword Checking
8725**
8726** These routines provide access to the set of SQL language keywords
8727** recognized by SQLite. Applications can use these routines to determine
8728** whether or not a specific identifier needs to be escaped (for example,
8729** by enclosing in double-quotes) so as not to confuse the parser.
8730**
8731** The sqlite3_keyword_count() interface returns the number of distinct
8732** keywords understood by SQLite.
8733**
8734** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8735** makes *Z point to that keyword expressed as UTF8 and writes the number
8736** of bytes in the keyword into *L. The string that *Z points to is not
8737** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8738** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8739** or L are NULL or invalid pointers then calls to
8740** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8741**
8742** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8743** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8744** if it is and zero if not.
8745**
8746** The parser used by SQLite is forgiving. It is often possible to use
8747** a keyword as an identifier as long as such use does not result in a
8748** parsing ambiguity. For example, the statement
8749** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8750** creates a new table named "BEGIN" with three columns named
8751** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8752** using keywords as identifiers. Common techniques used to avoid keyword
8753** name collisions include:
8754** <ul>
8755** <li> Put all identifier names inside double-quotes. This is the official
8756** SQL way to escape identifier names.
8757** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8758** but it is what SQL Server does and so lots of programmers use this
8759** technique.
8760** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8761** with "Z".
8762** <li> Include a digit somewhere in every identifier name.
8763** </ul>
8764**
8765** Note that the number of keywords understood by SQLite can depend on
8766** compile-time options. For example, "VACUUM" is not a keyword if
8767** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8768** new keywords may be added to future releases of SQLite.
8769*/
8770SQLITE_API int sqlite3_keyword_count(void);
8771SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8772SQLITE_API int sqlite3_keyword_check(const char*,int);
8773
8774/*
8775** CAPI3REF: Dynamic String Object
8776** KEYWORDS: {dynamic string}
8777**
8778** An instance of the sqlite3_str object contains a dynamically-sized
8779** string under construction.
8780**
8781** The lifecycle of an sqlite3_str object is as follows:
8782** <ol>
8783** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8784** <li> ^Text is appended to the sqlite3_str object using various
8785** methods, such as [sqlite3_str_appendf()].
8786** <li> ^The sqlite3_str object is destroyed and the string it created
8787** is returned using the [sqlite3_str_finish()] interface.
8788** </ol>
8789*/
8790typedef struct sqlite3_str sqlite3_str;
8791
8792/*
8793** CAPI3REF: Create A New Dynamic String Object
8794** CONSTRUCTOR: sqlite3_str
8795**
8796** ^The [sqlite3_str_new(D)] interface allocates and initializes
8797** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8798** [sqlite3_str_new()] must be freed by a subsequent call to
8799** [sqlite3_str_finish(X)].
8800**
8801** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8802** valid [sqlite3_str] object, though in the event of an out-of-memory
8803** error the returned object might be a special singleton that will
8804** silently reject new text, always return SQLITE_NOMEM from
8805** [sqlite3_str_errcode()], always return 0 for
8806** [sqlite3_str_length()], and always return NULL from
8807** [sqlite3_str_finish(X)]. It is always safe to use the value
8808** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8809** to any of the other [sqlite3_str] methods.
8810**
8811** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8812** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8813** length of the string contained in the [sqlite3_str] object will be
8814** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8815** of [SQLITE_MAX_LENGTH].
8816*/
8817SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8818
8819/*
8820** CAPI3REF: Finalize A Dynamic String
8821** DESTRUCTOR: sqlite3_str
8822**
8823** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8824** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8825** that contains the constructed string. The calling application should
8826** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8827** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8828** errors were encountered during construction of the string. ^The
8829** [sqlite3_str_finish(X)] interface might also return a NULL pointer if the
8830** string in [sqlite3_str] object X is zero bytes long.
8831**
8832** ^The [sqlite3_str_free(X)] interface destroys both the sqlite3_str object
8833** X and the string content it contains. Calling sqlite3_str_free(X) is
8834** the equivalent of calling [sqlite3_free](sqlite3_str_finish(X)).
8835*/
8836SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8837SQLITE_API void sqlite3_str_free(sqlite3_str*);
8838
8839/*
8840** CAPI3REF: Add Content To A Dynamic String
8841** METHOD: sqlite3_str
8842**
8843** These interfaces add or remove content to an sqlite3_str object
8844** previously obtained from [sqlite3_str_new()].
8845**
8846** ^The [sqlite3_str_appendf(X,F,...)] and
8847** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8848** functionality of SQLite to append formatted text onto the end of
8849** [sqlite3_str] object X.
8850**
8851** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8852** onto the end of the [sqlite3_str] object X. N must be non-negative.
8853** S must contain at least N non-zero bytes of content. To append a
8854** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8855** method instead.
8856**
8857** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8858** zero-terminated string S onto the end of [sqlite3_str] object X.
8859**
8860** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8861** single-byte character C onto the end of [sqlite3_str] object X.
8862** ^This method can be used, for example, to add whitespace indentation.
8863**
8864** ^The [sqlite3_str_reset(X)] method resets the string under construction
8865** inside [sqlite3_str] object X back to zero bytes in length.
8866**
8867** ^The [sqlite3_str_truncate(X,N)] method changes the length of the string
8868** under construction to be N bytes are less. This routine is a no-op if
8869** N is negative or if the string is already N bytes or smaller in size.
8870**
8871** These methods do not return a result code. ^If an error occurs, that fact
8872** is recorded in the [sqlite3_str] object and can be recovered by a
8873** subsequent call to [sqlite3_str_errcode(X)].
8874*/
8875SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8876SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8877SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8878SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8879SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8880SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8881SQLITE_API void sqlite3_str_truncate(sqlite3_str*,int N);
8882
8883/*
8884** CAPI3REF: Status Of A Dynamic String
8885** METHOD: sqlite3_str
8886**
8887** These interfaces return the current status of an [sqlite3_str] object.
8888**
8889** ^If any prior errors have occurred while constructing the dynamic string
8890** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8891** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8892** [SQLITE_NOMEM] following any out-of-memory error, or
8893** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8894** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8895**
8896** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8897** of the dynamic string under construction in [sqlite3_str] object X.
8898** ^The length returned by [sqlite3_str_length(X)] does not include the
8899** zero-termination byte.
8900**
8901** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8902** content of the dynamic string under construction in X. The value
8903** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8904** and might be freed or altered by any subsequent method on the same
8905** [sqlite3_str] object. Applications must not use the pointer returned by
8906** [sqlite3_str_value(X)] after any subsequent method call on the same
8907** object. ^Applications may change the content of the string returned
8908** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8909** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8910** write any byte after any subsequent sqlite3_str method call.
8911*/
8912SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8913SQLITE_API int sqlite3_str_length(sqlite3_str*);
8914SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8915
8916/*
8917** CAPI3REF: SQLite Runtime Status
8918**
8919** ^These interfaces are used to retrieve runtime status information
8920** about the performance of SQLite, and optionally to reset various
8921** highwater marks. ^The first argument is an integer code for
8922** the specific parameter to measure. ^(Recognized integer codes
8923** are of the form [status parameters | SQLITE_STATUS_...].)^
8924** ^The current value of the parameter is returned into *pCurrent.
8925** ^The highest recorded value is returned in *pHighwater. ^If the
8926** resetFlag is true, then the highest record value is reset after
8927** *pHighwater is written. ^(Some parameters do not record the highest
8928** value. For those parameters
8929** nothing is written into *pHighwater and the resetFlag is ignored.)^
8930** ^(Other parameters record only the highwater mark and not the current
8931** value. For these latter parameters nothing is written into *pCurrent.)^
8932**
8933** ^The sqlite3_status() and sqlite3_status64() routines return
8934** SQLITE_OK on success and a non-zero [error code] on failure.
8935**
8936** If either the current value or the highwater mark is too large to
8937** be represented by a 32-bit integer, then the values returned by
8938** sqlite3_status() are undefined.
8939**
8940** See also: [sqlite3_db_status()]
8941*/
8942SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8943SQLITE_API int sqlite3_status64(
8944 int op,
8945 sqlite3_int64 *pCurrent,
8946 sqlite3_int64 *pHighwater,
8947 int resetFlag
8948);
8949
8950
8951/*
8952** CAPI3REF: Status Parameters
8953** KEYWORDS: {status parameters}
8954**
8955** These integer constants designate various run-time status parameters
8956** that can be returned by [sqlite3_status()].
8957**
8958** <dl>
8959** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8960** <dd>This parameter is the current amount of memory checked out
8961** using [sqlite3_malloc()], either directly or indirectly. The
8962** figure includes calls made to [sqlite3_malloc()] by the application
8963** and internal memory usage by the SQLite library. Auxiliary page-cache
8964** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8965** this parameter. The amount returned is the sum of the allocation
8966** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8967**
8968** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8969** <dd>This parameter records the largest memory allocation request
8970** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8971** internal equivalents). Only the value returned in the
8972** *pHighwater parameter to [sqlite3_status()] is of interest.
8973** The value written into the *pCurrent parameter is undefined.</dd>)^
8974**
8975** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8976** <dd>This parameter records the number of separate memory allocations
8977** currently checked out.</dd>)^
8978**
8979** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8980** <dd>This parameter returns the number of pages used out of the
8981** [pagecache memory allocator] that was configured using
8982** [SQLITE_CONFIG_PAGECACHE]. The
8983** value returned is in pages, not in bytes.</dd>)^
8984**
8985** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8986** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8987** <dd>This parameter returns the number of bytes of page cache
8988** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8989** buffer and where forced to overflow to [sqlite3_malloc()]. The
8990** returned value includes allocations that overflowed because they
8991** were too large (they were larger than the "sz" parameter to
8992** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8993** no space was left in the page cache.</dd>)^
8994**
8995** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8996** <dd>This parameter records the largest memory allocation request
8997** handed to the [pagecache memory allocator]. Only the value returned in the
8998** *pHighwater parameter to [sqlite3_status()] is of interest.
8999** The value written into the *pCurrent parameter is undefined.</dd>)^
9000**
9001** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
9002** <dd>No longer used.</dd>
9003**
9004** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
9005** <dd>No longer used.</dd>
9006**
9007** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
9008** <dd>No longer used.</dd>
9009**
9010** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
9011** <dd>The *pHighwater parameter records the deepest parser stack.
9012** The *pCurrent value is undefined. The *pHighwater value is only
9013** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
9014** </dl>
9015**
9016** New status parameters may be added from time to time.
9017*/
9018#define SQLITE_STATUS_MEMORY_USED 0
9019#define SQLITE_STATUS_PAGECACHE_USED 1
9020#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
9021#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
9022#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
9023#define SQLITE_STATUS_MALLOC_SIZE 5
9024#define SQLITE_STATUS_PARSER_STACK 6
9025#define SQLITE_STATUS_PAGECACHE_SIZE 7
9026#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
9027#define SQLITE_STATUS_MALLOC_COUNT 9
9028
9029/*
9030** CAPI3REF: Database Connection Status
9031** METHOD: sqlite3
9032**
9033** ^This interface is used to retrieve runtime status information
9034** about a single [database connection]. ^The first argument is the
9035** database connection object to be interrogated. ^The second argument
9036** is an integer constant, taken from the set of
9037** [SQLITE_DBSTATUS options], that
9038** determines the parameter to interrogate. The set of
9039** [SQLITE_DBSTATUS options] is likely
9040** to grow in future releases of SQLite.
9041**
9042** ^The current value of the requested parameter is written into *pCur
9043** and the highest instantaneous value is written into *pHiwtr. ^If
9044** the resetFlg is true, then the highest instantaneous value is
9045** reset back down to the current value.
9046**
9047** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
9048** non-zero [error code] on failure.
9049**
9050** ^The sqlite3_db_status64(D,O,C,H,R) routine works exactly the same
9051** way as sqlite3_db_status(D,O,C,H,R) routine except that the C and H
9052** parameters are pointer to 64-bit integers (type: sqlite3_int64) instead
9053** of pointers to 32-bit integers, which allows larger status values
9054** to be returned. If a status value exceeds 2,147,483,647 then
9055** sqlite3_db_status() will truncate the value whereas sqlite3_db_status64()
9056** will return the full value.
9057**
9058** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
9059*/
9060SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
9061SQLITE_API int sqlite3_db_status64(sqlite3*,int,sqlite3_int64*,sqlite3_int64*,int);
9062
9063/*
9064** CAPI3REF: Status Parameters for database connections
9065** KEYWORDS: {SQLITE_DBSTATUS options}
9066**
9067** These constants are the available integer "verbs" that can be passed as
9068** the second argument to the [sqlite3_db_status()] interface.
9069**
9070** New verbs may be added in future releases of SQLite. Existing verbs
9071** might be discontinued. Applications should check the return code from
9072** [sqlite3_db_status()] to make sure that the call worked.
9073** The [sqlite3_db_status()] interface will return a non-zero error code
9074** if a discontinued or unsupported verb is invoked.
9075**
9076** <dl>
9077** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
9078** <dd>This parameter returns the number of lookaside memory slots currently
9079** checked out.</dd>)^
9080**
9081** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
9082** <dd>This parameter returns the number of malloc attempts that were
9083** satisfied using lookaside memory. Only the high-water value is meaningful;
9084** the current value is always zero.</dd>)^
9085**
9086** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
9087** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
9088** <dd>This parameter returns the number of malloc attempts that might have
9089** been satisfied using lookaside memory but failed due to the amount of
9090** memory requested being larger than the lookaside slot size.
9091** Only the high-water value is meaningful;
9092** the current value is always zero.</dd>)^
9093**
9094** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
9095** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
9096** <dd>This parameter returns the number of malloc attempts that might have
9097** been satisfied using lookaside memory but failed due to all lookaside
9098** memory already being in use.
9099** Only the high-water value is meaningful;
9100** the current value is always zero.</dd>)^
9101**
9102** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
9103** <dd>This parameter returns the approximate number of bytes of heap
9104** memory used by all pager caches associated with the database connection.)^
9105** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
9106** </dd>
9107**
9108** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
9109** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
9110** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
9111** pager cache is shared between two or more connections the bytes of heap
9112** memory used by that pager cache is divided evenly between the attached
9113** connections.)^ In other words, if none of the pager caches associated
9114** with the database connection are shared, this request returns the same
9115** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
9116** shared, the value returned by this call will be smaller than that returned
9117** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
9118** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
9119**
9120** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
9121** <dd>This parameter returns the approximate number of bytes of heap
9122** memory used to store the schema for all databases associated
9123** with the connection - main, temp, and any [ATTACH]-ed databases.)^
9124** ^The full amount of memory used by the schemas is reported, even if the
9125** schema memory is shared with other database connections due to
9126** [shared cache mode] being enabled.
9127** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
9128** </dd>
9129**
9130** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
9131** <dd>This parameter returns the approximate number of bytes of heap
9132** and lookaside memory used by all prepared statements associated with
9133** the database connection.)^
9134** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
9135** </dd>
9136**
9137** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
9138** <dd>This parameter returns the number of pager cache hits that have
9139** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
9140** is always 0.
9141** </dd>
9142**
9143** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
9144** <dd>This parameter returns the number of pager cache misses that have
9145** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
9146** is always 0.
9147** </dd>
9148**
9149** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
9150** <dd>This parameter returns the number of dirty cache entries that have
9151** been written to disk. Specifically, the number of pages written to the
9152** wal file in wal mode databases, or the number of pages written to the
9153** database file in rollback mode databases. Any pages written as part of
9154** transaction rollback or database recovery operations are not included.
9155** If an IO or other error occurs while writing a page to disk, the effect
9156** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
9157** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
9158** <p>
9159** ^(There is overlap between the quantities measured by this parameter
9160** (SQLITE_DBSTATUS_CACHE_WRITE) and SQLITE_DBSTATUS_TEMPBUF_SPILL.
9161** Resetting one will reduce the other.)^
9162** </dd>
9163**
9164** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
9165** <dd>This parameter returns the number of dirty cache entries that have
9166** been written to disk in the middle of a transaction due to the page
9167** cache overflowing. Transactions are more efficient if they are written
9168** to disk all at once. When pages spill mid-transaction, that introduces
9169** additional overhead. This parameter can be used to help identify
9170** inefficiencies that can be resolved by increasing the cache size.
9171** </dd>
9172**
9173** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
9174** <dd>This parameter returns zero for the current value if and only if
9175** all foreign key constraints (deferred or immediate) have been
9176** resolved.)^ ^The highwater mark is always 0.
9177**
9178** [[SQLITE_DBSTATUS_TEMPBUF_SPILL] ^(<dt>SQLITE_DBSTATUS_TEMPBUF_SPILL</dt>
9179** <dd>^(This parameter returns the number of bytes written to temporary
9180** files on disk that could have been kept in memory had sufficient memory
9181** been available. This value includes writes to intermediate tables that
9182** are part of complex queries, external sorts that spill to disk, and
9183** writes to TEMP tables.)^
9184** ^The highwater mark is always 0.
9185** <p>
9186** ^(There is overlap between the quantities measured by this parameter
9187** (SQLITE_DBSTATUS_TEMPBUF_SPILL) and SQLITE_DBSTATUS_CACHE_WRITE.
9188** Resetting one will reduce the other.)^
9189** </dd>
9190** </dl>
9191*/
9192#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
9193#define SQLITE_DBSTATUS_CACHE_USED 1
9194#define SQLITE_DBSTATUS_SCHEMA_USED 2
9195#define SQLITE_DBSTATUS_STMT_USED 3
9196#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
9197#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
9198#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
9199#define SQLITE_DBSTATUS_CACHE_HIT 7
9200#define SQLITE_DBSTATUS_CACHE_MISS 8
9201#define SQLITE_DBSTATUS_CACHE_WRITE 9
9202#define SQLITE_DBSTATUS_DEFERRED_FKS 10
9203#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
9204#define SQLITE_DBSTATUS_CACHE_SPILL 12
9205#define SQLITE_DBSTATUS_TEMPBUF_SPILL 13
9206#define SQLITE_DBSTATUS_MAX 13 /* Largest defined DBSTATUS */
9207
9208
9209/*
9210** CAPI3REF: Prepared Statement Status
9211** METHOD: sqlite3_stmt
9212**
9213** ^(Each prepared statement maintains various
9214** [SQLITE_STMTSTATUS counters] that measure the number
9215** of times it has performed specific operations.)^ These counters can
9216** be used to monitor the performance characteristics of the prepared
9217** statements. For example, if the number of table steps greatly exceeds
9218** the number of table searches or result rows, that would tend to indicate
9219** that the prepared statement is using a full table scan rather than
9220** an index.
9221**
9222** ^(This interface is used to retrieve and reset counter values from
9223** a [prepared statement]. The first argument is the prepared statement
9224** object to be interrogated. The second argument
9225** is an integer code for a specific [SQLITE_STMTSTATUS counter]
9226** to be interrogated.)^
9227** ^The current value of the requested counter is returned.
9228** ^If the resetFlg is true, then the counter is reset to zero after this
9229** interface call returns.
9230**
9231** See also: [sqlite3_status()] and [sqlite3_db_status()].
9232*/
9233SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
9234
9235/*
9236** CAPI3REF: Status Parameters for prepared statements
9237** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
9238**
9239** These preprocessor macros define integer codes that name counter
9240** values associated with the [sqlite3_stmt_status()] interface.
9241** The meanings of the various counters are as follows:
9242**
9243** <dl>
9244** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
9245** <dd>^This is the number of times that SQLite has stepped forward in
9246** a table as part of a full table scan. Large numbers for this counter
9247** may indicate opportunities for performance improvement through
9248** careful use of indices.</dd>
9249**
9250** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
9251** <dd>^This is the number of sort operations that have occurred.
9252** A non-zero value in this counter may indicate an opportunity to
9253** improve performance through careful use of indices.</dd>
9254**
9255** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
9256** <dd>^This is the number of rows inserted into transient indices that
9257** were created automatically in order to help joins run faster.
9258** A non-zero value in this counter may indicate an opportunity to
9259** improve performance by adding permanent indices that do not
9260** need to be reinitialized each time the statement is run.</dd>
9261**
9262** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
9263** <dd>^This is the number of virtual machine operations executed
9264** by the prepared statement if that number is less than or equal
9265** to 2147483647. The number of virtual machine operations can be
9266** used as a proxy for the total work done by the prepared statement.
9267** If the number of virtual machine operations exceeds 2147483647
9268** then the value returned by this statement status code is undefined.</dd>
9269**
9270** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
9271** <dd>^This is the number of times that the prepare statement has been
9272** automatically regenerated due to schema changes or changes to
9273** [bound parameters] that might affect the query plan.</dd>
9274**
9275** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
9276** <dd>^This is the number of times that the prepared statement has
9277** been run. A single "run" for the purposes of this counter is one
9278** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
9279** The counter is incremented on the first [sqlite3_step()] call of each
9280** cycle.</dd>
9281**
9282** [[SQLITE_STMTSTATUS_FILTER_MISS]]
9283** [[SQLITE_STMTSTATUS_FILTER HIT]]
9284** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
9285** SQLITE_STMTSTATUS_FILTER_MISS</dt>
9286** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
9287** step was bypassed because a Bloom filter returned not-found. The
9288** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
9289** times that the Bloom filter returned a find, and thus the join step
9290** had to be processed as normal.</dd>
9291**
9292** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
9293** <dd>^This is the approximate number of bytes of heap memory
9294** used to store the prepared statement. ^This value is not actually
9295** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
9296** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
9297** </dd>
9298** </dl>
9299*/
9300#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
9301#define SQLITE_STMTSTATUS_SORT 2
9302#define SQLITE_STMTSTATUS_AUTOINDEX 3
9303#define SQLITE_STMTSTATUS_VM_STEP 4
9304#define SQLITE_STMTSTATUS_REPREPARE 5
9305#define SQLITE_STMTSTATUS_RUN 6
9306#define SQLITE_STMTSTATUS_FILTER_MISS 7
9307#define SQLITE_STMTSTATUS_FILTER_HIT 8
9308#define SQLITE_STMTSTATUS_MEMUSED 99
9309
9310/*
9311** CAPI3REF: Custom Page Cache Object
9312**
9313** The sqlite3_pcache type is opaque. It is implemented by
9314** the pluggable module. The SQLite core has no knowledge of
9315** its size or internal structure and never deals with the
9316** sqlite3_pcache object except by holding and passing pointers
9317** to the object.
9318**
9319** See [sqlite3_pcache_methods2] for additional information.
9320*/
9321typedef struct sqlite3_pcache sqlite3_pcache;
9322
9323/*
9324** CAPI3REF: Custom Page Cache Object
9325**
9326** The sqlite3_pcache_page object represents a single page in the
9327** page cache. The page cache will allocate instances of this
9328** object. Various methods of the page cache use pointers to instances
9329** of this object as parameters or as their return value.
9330**
9331** See [sqlite3_pcache_methods2] for additional information.
9332*/
9333typedef struct sqlite3_pcache_page sqlite3_pcache_page;
9334struct sqlite3_pcache_page {
9335 void *pBuf; /* The content of the page */
9336 void *pExtra; /* Extra information associated with the page */
9337};
9338
9339/*
9340** CAPI3REF: Application Defined Page Cache.
9341** KEYWORDS: {page cache}
9342**
9343** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
9344** register an alternative page cache implementation by passing in an
9345** instance of the sqlite3_pcache_methods2 structure.)^
9346** In many applications, most of the heap memory allocated by
9347** SQLite is used for the page cache.
9348** By implementing a
9349** custom page cache using this API, an application can better control
9350** the amount of memory consumed by SQLite, the way in which
9351** that memory is allocated and released, and the policies used to
9352** determine exactly which parts of a database file are cached and for
9353** how long.
9354**
9355** The alternative page cache mechanism is an
9356** extreme measure that is only needed by the most demanding applications.
9357** The built-in page cache is recommended for most uses.
9358**
9359** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
9360** internal buffer by SQLite within the call to [sqlite3_config]. Hence
9361** the application may discard the parameter after the call to
9362** [sqlite3_config()] returns.)^
9363**
9364** [[the xInit() page cache method]]
9365** ^(The xInit() method is called once for each effective
9366** call to [sqlite3_initialize()])^
9367** (usually only once during the lifetime of the process). ^(The xInit()
9368** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
9369** The intent of the xInit() method is to set up global data structures
9370** required by the custom page cache implementation.
9371** ^(If the xInit() method is NULL, then the
9372** built-in default page cache is used instead of the application defined
9373** page cache.)^
9374**
9375** [[the xShutdown() page cache method]]
9376** ^The xShutdown() method is called by [sqlite3_shutdown()].
9377** It can be used to clean up
9378** any outstanding resources before process shutdown, if required.
9379** ^The xShutdown() method may be NULL.
9380**
9381** ^SQLite automatically serializes calls to the xInit method,
9382** so the xInit method need not be threadsafe. ^The
9383** xShutdown method is only called from [sqlite3_shutdown()] so it does
9384** not need to be threadsafe either. All other methods must be threadsafe
9385** in multithreaded applications.
9386**
9387** ^SQLite will never invoke xInit() more than once without an intervening
9388** call to xShutdown().
9389**
9390** [[the xCreate() page cache methods]]
9391** ^SQLite invokes the xCreate() method to construct a new cache instance.
9392** SQLite will typically create one cache instance for each open database file,
9393** though this is not guaranteed. ^The
9394** first parameter, szPage, is the size in bytes of the pages that must
9395** be allocated by the cache. ^szPage will always be a power of two. ^The
9396** second parameter szExtra is a number of bytes of extra storage
9397** associated with each page cache entry. ^The szExtra parameter will be
9398** a number less than 250. SQLite will use the
9399** extra szExtra bytes on each page to store metadata about the underlying
9400** database page on disk. The value passed into szExtra depends
9401** on the SQLite version, the target platform, and how SQLite was compiled.
9402** ^The third argument to xCreate(), bPurgeable, is true if the cache being
9403** created will be used to cache database pages of a file stored on disk, or
9404** false if it is used for an in-memory database. The cache implementation
9405** does not have to do anything special based upon the value of bPurgeable;
9406** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9407** never invoke xUnpin() except to deliberately delete a page.
9408** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9409** false will always have the "discard" flag set to true.
9410** ^Hence, a cache created with bPurgeable set to false will
9411** never contain any unpinned pages.
9412**
9413** [[the xCachesize() page cache method]]
9414** ^(The xCachesize() method may be called at any time by SQLite to set the
9415** suggested maximum cache-size (number of pages stored) for the cache
9416** instance passed as the first argument. This is the value configured using
9417** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9418** parameter, the implementation is not required to do anything with this
9419** value; it is advisory only.
9420**
9421** [[the xPagecount() page cache methods]]
9422** The xPagecount() method must return the number of pages currently
9423** stored in the cache, both pinned and unpinned.
9424**
9425** [[the xFetch() page cache methods]]
9426** The xFetch() method locates a page in the cache and returns a pointer to
9427** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9428** The pBuf element of the returned sqlite3_pcache_page object will be a
9429** pointer to a buffer of szPage bytes used to store the content of a
9430** single database page. The pExtra element of sqlite3_pcache_page will be
9431** a pointer to the szExtra bytes of extra storage that SQLite has requested
9432** for each entry in the page cache.
9433**
9434** The page to be fetched is determined by the key. ^The minimum key value
9435** is 1. After it has been retrieved using xFetch, the page is considered
9436** to be "pinned".
9437**
9438** If the requested page is already in the page cache, then the page cache
9439** implementation must return a pointer to the page buffer with its content
9440** intact. If the requested page is not already in the cache, then the
9441** cache implementation should use the value of the createFlag
9442** parameter to help it determine what action to take:
9443**
9444** <table border=1 width=85% align=center>
9445** <tr><th> createFlag <th> Behavior when page is not already in cache
9446** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9447** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so.
9448** Otherwise return NULL.
9449** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9450** NULL if allocating a new page is effectively impossible.
9451** </table>
9452**
9453** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9454** will only use a createFlag of 2 after a prior call with a createFlag of 1
9455** failed.)^ In between the xFetch() calls, SQLite may
9456** attempt to unpin one or more cache pages by spilling the content of
9457** pinned pages to disk and synching the operating system disk cache.
9458**
9459** [[the xUnpin() page cache method]]
9460** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9461** as its second argument. If the third parameter, discard, is non-zero,
9462** then the page must be evicted from the cache.
9463** ^If the discard parameter is
9464** zero, then the page may be discarded or retained at the discretion of the
9465** page cache implementation. ^The page cache implementation
9466** may choose to evict unpinned pages at any time.
9467**
9468** The cache must not perform any reference counting. A single
9469** call to xUnpin() unpins the page regardless of the number of prior calls
9470** to xFetch().
9471**
9472** [[the xRekey() page cache methods]]
9473** The xRekey() method is used to change the key value associated with the
9474** page passed as the second argument. If the cache
9475** previously contains an entry associated with newKey, it must be
9476** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9477** to be pinned.
9478**
9479** When SQLite calls the xTruncate() method, the cache must discard all
9480** existing cache entries with page numbers (keys) greater than or equal
9481** to the value of the iLimit parameter passed to xTruncate(). If any
9482** of these pages are pinned, they become implicitly unpinned, meaning that
9483** they can be safely discarded.
9484**
9485** [[the xDestroy() page cache method]]
9486** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9487** All resources associated with the specified cache should be freed. ^After
9488** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9489** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9490** functions.
9491**
9492** [[the xShrink() page cache method]]
9493** ^SQLite invokes the xShrink() method when it wants the page cache to
9494** free up as much of heap memory as possible. The page cache implementation
9495** is not obligated to free any memory, but well-behaved implementations should
9496** do their best.
9497*/
9498typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9499struct sqlite3_pcache_methods2 {
9500 int iVersion;
9501 void *pArg;
9502 int (*xInit)(void*);
9503 void (*xShutdown)(void*);
9504 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9505 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9506 int (*xPagecount)(sqlite3_pcache*);
9507 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9508 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9509 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9510 unsigned oldKey, unsigned newKey);
9511 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9512 void (*xDestroy)(sqlite3_pcache*);
9513 void (*xShrink)(sqlite3_pcache*);
9514};
9515
9516/*
9517** This is the obsolete pcache_methods object that has now been replaced
9518** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9519** retained in the header file for backwards compatibility only.
9520*/
9521typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9522struct sqlite3_pcache_methods {
9523 void *pArg;
9524 int (*xInit)(void*);
9525 void (*xShutdown)(void*);
9526 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9527 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9528 int (*xPagecount)(sqlite3_pcache*);
9529 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9530 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9531 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9532 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9533 void (*xDestroy)(sqlite3_pcache*);
9534};
9535
9536
9537/*
9538** CAPI3REF: Online Backup Object
9539**
9540** The sqlite3_backup object records state information about an ongoing
9541** online backup operation. ^The sqlite3_backup object is created by
9542** a call to [sqlite3_backup_init()] and is destroyed by a call to
9543** [sqlite3_backup_finish()].
9544**
9545** See Also: [Using the SQLite Online Backup API]
9546*/
9547typedef struct sqlite3_backup sqlite3_backup;
9548
9549/*
9550** CAPI3REF: Online Backup API.
9551**
9552** The backup API copies the content of one database into another.
9553** It is useful either for creating backups of databases or
9554** for copying in-memory databases to or from persistent files.
9555**
9556** See Also: [Using the SQLite Online Backup API]
9557**
9558** ^SQLite holds a write transaction open on the destination database file
9559** for the duration of the backup operation.
9560** ^The source database is read-locked only while it is being read;
9561** it is not locked continuously for the entire backup operation.
9562** ^Thus, the backup may be performed on a live source database without
9563** preventing other database connections from
9564** reading or writing to the source database while the backup is underway.
9565**
9566** ^(To perform a backup operation:
9567** <ol>
9568** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9569** backup,
9570** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9571** the data between the two databases, and finally
9572** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9573** associated with the backup operation.
9574** </ol>)^
9575** There should be exactly one call to sqlite3_backup_finish() for each
9576** successful call to sqlite3_backup_init().
9577**
9578** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9579**
9580** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9581** [database connection] associated with the destination database
9582** and the database name, respectively.
9583** ^The database name is "main" for the main database, "temp" for the
9584** temporary database, or the name specified after the AS keyword in
9585** an [ATTACH] statement for an attached database.
9586** ^The S and M arguments passed to
9587** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9588** and database name of the source database, respectively.
9589** ^The source and destination [database connections] (parameters S and D)
9590** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9591** an error.
9592**
9593** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9594** there is already a read or read-write transaction open on the
9595** destination database.
9596**
9597** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9598** returned and an error code and error message are stored in the
9599** destination [database connection] D.
9600** ^The error code and message for the failed call to sqlite3_backup_init()
9601** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9602** [sqlite3_errmsg16()] functions.
9603** ^A successful call to sqlite3_backup_init() returns a pointer to an
9604** [sqlite3_backup] object.
9605** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9606** sqlite3_backup_finish() functions to perform the specified backup
9607** operation.
9608**
9609** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9610**
9611** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9612** the source and destination databases specified by [sqlite3_backup] object B.
9613** ^If N is negative, all remaining source pages are copied.
9614** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9615** are still more pages to be copied, then the function returns [SQLITE_OK].
9616** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9617** from source to destination, then it returns [SQLITE_DONE].
9618** ^If an error occurs while running sqlite3_backup_step(B,N),
9619** then an [error code] is returned. ^As well as [SQLITE_OK] and
9620** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9621** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9622** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9623**
9624** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9625** <ol>
9626** <li> the destination database was opened read-only, or
9627** <li> the destination database is using write-ahead-log journaling
9628** and the destination and source page sizes differ, or
9629** <li> the destination database is an in-memory database and the
9630** destination and source page sizes differ.
9631** </ol>)^
9632**
9633** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9634** the [sqlite3_busy_handler | busy-handler function]
9635** is invoked (if one is specified). ^If the
9636** busy-handler returns non-zero before the lock is available, then
9637** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9638** sqlite3_backup_step() can be retried later. ^If the source
9639** [database connection]
9640** is being used to write to the source database when sqlite3_backup_step()
9641** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9642** case the call to sqlite3_backup_step() can be retried later on. ^(If
9643** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9644** [SQLITE_READONLY] is returned, then
9645** there is no point in retrying the call to sqlite3_backup_step(). These
9646** errors are considered fatal.)^ The application must accept
9647** that the backup operation has failed and pass the backup operation handle
9648** to the sqlite3_backup_finish() to release associated resources.
9649**
9650** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9651** on the destination file. ^The exclusive lock is not released until either
9652** sqlite3_backup_finish() is called or the backup operation is complete
9653** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9654** sqlite3_backup_step() obtains a [shared lock] on the source database that
9655** lasts for the duration of the sqlite3_backup_step() call.
9656** ^Because the source database is not locked between calls to
9657** sqlite3_backup_step(), the source database may be modified mid-way
9658** through the backup process. ^If the source database is modified by an
9659** external process or via a database connection other than the one being
9660** used by the backup operation, then the backup will be automatically
9661** restarted by the next call to sqlite3_backup_step(). ^If the source
9662** database is modified by using the same database connection as is used
9663** by the backup operation, then the backup database is automatically
9664** updated at the same time.
9665**
9666** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9667**
9668** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9669** application wishes to abandon the backup operation, the application
9670** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9671** ^The sqlite3_backup_finish() interfaces releases all
9672** resources associated with the [sqlite3_backup] object.
9673** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9674** active write-transaction on the destination database is rolled back.
9675** The [sqlite3_backup] object is invalid
9676** and may not be used following a call to sqlite3_backup_finish().
9677**
9678** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9679** sqlite3_backup_step() errors occurred, regardless of whether or not
9680** sqlite3_backup_step() completed.
9681** ^If an out-of-memory condition or IO error occurred during any prior
9682** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9683** sqlite3_backup_finish() returns the corresponding [error code].
9684**
9685** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9686** is not a permanent error and does not affect the return value of
9687** sqlite3_backup_finish().
9688**
9689** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9690** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9691**
9692** ^The sqlite3_backup_remaining() routine returns the number of pages still
9693** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9694** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9695** in the source database at the conclusion of the most recent
9696** sqlite3_backup_step().
9697** ^(The values returned by these functions are only updated by
9698** sqlite3_backup_step(). If the source database is modified in a way that
9699** changes the size of the source database or the number of pages remaining,
9700** those changes are not reflected in the output of sqlite3_backup_pagecount()
9701** and sqlite3_backup_remaining() until after the next
9702** sqlite3_backup_step().)^
9703**
9704** <b>Concurrent Usage of Database Handles</b>
9705**
9706** ^The source [database connection] may be used by the application for other
9707** purposes while a backup operation is underway or being initialized.
9708** ^If SQLite is compiled and configured to support threadsafe database
9709** connections, then the source database connection may be used concurrently
9710** from within other threads.
9711**
9712** However, the application must guarantee that the destination
9713** [database connection] is not passed to any other API (by any thread) after
9714** sqlite3_backup_init() is called and before the corresponding call to
9715** sqlite3_backup_finish(). SQLite does not currently check to see
9716** if the application incorrectly accesses the destination [database connection]
9717** and so no error code is reported, but the operations may malfunction
9718** nevertheless. Use of the destination database connection while a
9719** backup is in progress might also cause a mutex deadlock.
9720**
9721** If running in [shared cache mode], the application must
9722** guarantee that the shared cache used by the destination database
9723** is not accessed while the backup is running. In practice this means
9724** that the application must guarantee that the disk file being
9725** backed up to is not accessed by any connection within the process,
9726** not just the specific connection that was passed to sqlite3_backup_init().
9727**
9728** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9729** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9730** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9731** APIs are not strictly speaking threadsafe. If they are invoked at the
9732** same time as another thread is invoking sqlite3_backup_step() it is
9733** possible that they return invalid values.
9734**
9735** <b>Alternatives To Using The Backup API</b>
9736**
9737** Other techniques for safely creating a consistent backup of an SQLite
9738** database include:
9739**
9740** <ul>
9741** <li> The [VACUUM INTO] command.
9742** <li> The [sqlite3_rsync] utility program.
9743** </ul>
9744*/
9745SQLITE_API sqlite3_backup *sqlite3_backup_init(
9746 sqlite3 *pDest, /* Destination database handle */
9747 const char *zDestName, /* Destination database name */
9748 sqlite3 *pSource, /* Source database handle */
9749 const char *zSourceName /* Source database name */
9750);
9751SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9752SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9753SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9754SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9755
9756/*
9757** CAPI3REF: Unlock Notification
9758** METHOD: sqlite3
9759**
9760** ^When running in shared-cache mode, a database operation may fail with
9761** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9762** individual tables within the shared-cache cannot be obtained. See
9763** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9764** ^This API may be used to register a callback that SQLite will invoke
9765** when the connection currently holding the required lock relinquishes it.
9766** ^This API is only available if the library was compiled with the
9767** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9768**
9769** See Also: [Using the SQLite Unlock Notification Feature].
9770**
9771** ^Shared-cache locks are released when a database connection concludes
9772** its current transaction, either by committing it or rolling it back.
9773**
9774** ^When a connection (known as the blocked connection) fails to obtain a
9775** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9776** identity of the database connection (the blocking connection) that
9777** has locked the required resource is stored internally. ^After an
9778** application receives an SQLITE_LOCKED error, it may call the
9779** sqlite3_unlock_notify() method with the blocked connection handle as
9780** the first argument to register for a callback that will be invoked
9781** when the blocking connection's current transaction is concluded. ^The
9782** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9783** call that concludes the blocking connection's transaction.
9784**
9785** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9786** there is a chance that the blocking connection will have already
9787** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9788** If this happens, then the specified callback is invoked immediately,
9789** from within the call to sqlite3_unlock_notify().)^
9790**
9791** ^If the blocked connection is attempting to obtain a write-lock on a
9792** shared-cache table, and more than one other connection currently holds
9793** a read-lock on the same table, then SQLite arbitrarily selects one of
9794** the other connections to use as the blocking connection.
9795**
9796** ^(There may be at most one unlock-notify callback registered by a
9797** blocked connection. If sqlite3_unlock_notify() is called when the
9798** blocked connection already has a registered unlock-notify callback,
9799** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9800** called with a NULL pointer as its second argument, then any existing
9801** unlock-notify callback is canceled. ^The blocked connection's
9802** unlock-notify callback may also be canceled by closing the blocked
9803** connection using [sqlite3_close()].
9804**
9805** The unlock-notify callback is not reentrant. If an application invokes
9806** any sqlite3_xxx API functions from within an unlock-notify callback, a
9807** crash or deadlock may be the result.
9808**
9809** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9810** returns SQLITE_OK.
9811**
9812** <b>Callback Invocation Details</b>
9813**
9814** When an unlock-notify callback is registered, the application provides a
9815** single void* pointer that is passed to the callback when it is invoked.
9816** However, the signature of the callback function allows SQLite to pass
9817** it an array of void* context pointers. The first argument passed to
9818** an unlock-notify callback is a pointer to an array of void* pointers,
9819** and the second is the number of entries in the array.
9820**
9821** When a blocking connection's transaction is concluded, there may be
9822** more than one blocked connection that has registered for an unlock-notify
9823** callback. ^If two or more such blocked connections have specified the
9824** same callback function, then instead of invoking the callback function
9825** multiple times, it is invoked once with the set of void* context pointers
9826** specified by the blocked connections bundled together into an array.
9827** This gives the application an opportunity to prioritize any actions
9828** related to the set of unblocked database connections.
9829**
9830** <b>Deadlock Detection</b>
9831**
9832** Assuming that after registering for an unlock-notify callback a
9833** database waits for the callback to be issued before taking any further
9834** action (a reasonable assumption), then using this API may cause the
9835** application to deadlock. For example, if connection X is waiting for
9836** connection Y's transaction to be concluded, and similarly connection
9837** Y is waiting on connection X's transaction, then neither connection
9838** will proceed and the system may remain deadlocked indefinitely.
9839**
9840** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9841** detection. ^If a given call to sqlite3_unlock_notify() would put the
9842** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9843** unlock-notify callback is registered. The system is said to be in
9844** a deadlocked state if connection A has registered for an unlock-notify
9845** callback on the conclusion of connection B's transaction, and connection
9846** B has itself registered for an unlock-notify callback when connection
9847** A's transaction is concluded. ^Indirect deadlock is also detected, so
9848** the system is also considered to be deadlocked if connection B has
9849** registered for an unlock-notify callback on the conclusion of connection
9850** C's transaction, where connection C is waiting on connection A. ^Any
9851** number of levels of indirection are allowed.
9852**
9853** <b>The "DROP TABLE" Exception</b>
9854**
9855** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9856** always appropriate to call sqlite3_unlock_notify(). There is however,
9857** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9858** SQLite checks if there are any currently executing SELECT statements
9859** that belong to the same connection. If there are, SQLITE_LOCKED is
9860** returned. In this case there is no "blocking connection", so invoking
9861** sqlite3_unlock_notify() results in the unlock-notify callback being
9862** invoked immediately. If the application then re-attempts the "DROP TABLE"
9863** or "DROP INDEX" query, an infinite loop might be the result.
9864**
9865** One way around this problem is to check the extended error code returned
9866** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9867** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9868** the special "DROP TABLE/INDEX" case, the extended error code is just
9869** SQLITE_LOCKED.)^
9870*/
9871SQLITE_API int sqlite3_unlock_notify(
9872 sqlite3 *pBlocked, /* Waiting connection */
9873 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9874 void *pNotifyArg /* Argument to pass to xNotify */
9875);
9876
9877
9878/*
9879** CAPI3REF: String Comparison
9880**
9881** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9882** and extensions to compare the contents of two buffers containing UTF-8
9883** strings in a case-independent fashion, using the same definition of "case
9884** independence" that SQLite uses internally when comparing identifiers.
9885*/
9886SQLITE_API int sqlite3_stricmp(const char *, const char *);
9887SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9888
9889/*
9890** CAPI3REF: String Globbing
9891*
9892** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9893** string X matches the [GLOB] pattern P.
9894** ^The definition of [GLOB] pattern matching used in
9895** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9896** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9897** is case sensitive.
9898**
9899** Note that this routine returns zero on a match and non-zero if the strings
9900** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9901**
9902** See also: [sqlite3_strlike()].
9903*/
9904SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9905
9906/*
9907** CAPI3REF: String LIKE Matching
9908*
9909** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9910** string X matches the [LIKE] pattern P with escape character E.
9911** ^The definition of [LIKE] pattern matching used in
9912** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9913** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9914** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9915** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9916** insensitive - equivalent upper and lower case ASCII characters match
9917** one another.
9918**
9919** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9920** only ASCII characters are case folded.
9921**
9922** Note that this routine returns zero on a match and non-zero if the strings
9923** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9924**
9925** See also: [sqlite3_strglob()].
9926*/
9927SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9928
9929/*
9930** CAPI3REF: Error Logging Interface
9931**
9932** ^The [sqlite3_log()] interface writes a message into the [error log]
9933** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9934** ^If logging is enabled, the zFormat string and subsequent arguments are
9935** used with [sqlite3_snprintf()] to generate the final output string.
9936**
9937** The sqlite3_log() interface is intended for use by extensions such as
9938** virtual tables, collating functions, and SQL functions. While there is
9939** nothing to prevent an application from calling sqlite3_log(), doing so
9940** is considered bad form.
9941**
9942** The zFormat string must not be NULL.
9943**
9944** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9945** will not use dynamically allocated memory. The log message is stored in
9946** a fixed-length buffer on the stack. If the log message is longer than
9947** a few hundred characters, it will be truncated to the length of the
9948** buffer.
9949*/
9950SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9951
9952/*
9953** CAPI3REF: Write-Ahead Log Commit Hook
9954** METHOD: sqlite3
9955**
9956** ^The [sqlite3_wal_hook()] function is used to register a callback that
9957** is invoked each time data is committed to a database in wal mode.
9958**
9959** ^(The callback is invoked by SQLite after the commit has taken place and
9960** the associated write-lock on the database released)^, so the implementation
9961** may read, write or [checkpoint] the database as required.
9962**
9963** ^The first parameter passed to the callback function when it is invoked
9964** is a copy of the third parameter passed to sqlite3_wal_hook() when
9965** registering the callback. ^The second is a copy of the database handle.
9966** ^The third parameter is the name of the database that was written to -
9967** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9968** is the number of pages currently in the write-ahead log file,
9969** including those that were just committed.
9970**
9971** ^The callback function should normally return [SQLITE_OK]. ^If an error
9972** code is returned, that error will propagate back up through the
9973** SQLite code base to cause the statement that provoked the callback
9974** to report an error, though the commit will have still occurred. If the
9975** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9976** that does not correspond to any valid SQLite error code, the results
9977** are undefined.
9978**
9979** ^A single database handle may have at most a single write-ahead log
9980** callback registered at one time. ^Calling [sqlite3_wal_hook()]
9981** replaces the default behavior or previously registered write-ahead
9982** log callback.
9983**
9984** ^The return value is a copy of the third parameter from the
9985** previous call, if any, or 0.
9986**
9987** ^The [sqlite3_wal_autocheckpoint()] interface and the
9988** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and
9989** will overwrite any prior [sqlite3_wal_hook()] settings.
9990**
9991** ^If a write-ahead log callback is set using this function then
9992** [sqlite3_wal_checkpoint_v2()] or [PRAGMA wal_checkpoint]
9993** should be invoked periodically to keep the write-ahead log file
9994** from growing without bound.
9995**
9996** ^Passing a NULL pointer for the callback disables automatic
9997** checkpointing entirely. To re-enable the default behavior, call
9998** sqlite3_wal_autocheckpoint(db,1000) or use [PRAGMA wal_checkpoint].
9999*/
10000SQLITE_API void *sqlite3_wal_hook(
10001 sqlite3*,
10002 int(*)(void *,sqlite3*,const char*,int),
10003 void*
10004);
10005
10006/*
10007** CAPI3REF: Configure an auto-checkpoint
10008** METHOD: sqlite3
10009**
10010** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
10011** [sqlite3_wal_hook()] that causes any database on [database connection] D
10012** to automatically [checkpoint]
10013** after committing a transaction if there are N or
10014** more frames in the [write-ahead log] file. ^Passing zero or
10015** a negative value as the N parameter disables automatic
10016** checkpoints entirely.
10017**
10018** ^The callback registered by this function replaces any existing callback
10019** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
10020** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
10021** configured by this function.
10022**
10023** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
10024** from SQL.
10025**
10026** ^Checkpoints initiated by this mechanism are
10027** [sqlite3_wal_checkpoint_v2|PASSIVE].
10028**
10029** ^Every new [database connection] defaults to having the auto-checkpoint
10030** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
10031** pages.
10032**
10033** ^The use of this interface is only necessary if the default setting
10034** is found to be suboptimal for a particular application.
10035*/
10036SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
10037
10038/*
10039** CAPI3REF: Checkpoint a database
10040** METHOD: sqlite3
10041**
10042** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
10043** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
10044**
10045** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
10046** [write-ahead log] for database X on [database connection] D to be
10047** transferred into the database file and for the write-ahead log to
10048** be reset. See the [checkpointing] documentation for addition
10049** information.
10050**
10051** This interface used to be the only way to cause a checkpoint to
10052** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
10053** interface was added. This interface is retained for backwards
10054** compatibility and as a convenience for applications that need to manually
10055** start a callback but which do not need the full power (and corresponding
10056** complication) of [sqlite3_wal_checkpoint_v2()].
10057*/
10058SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
10059
10060/*
10061** CAPI3REF: Checkpoint a database
10062** METHOD: sqlite3
10063**
10064** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
10065** operation on database X of [database connection] D in mode M. Status
10066** information is written back into integers pointed to by L and C.)^
10067** ^(The M parameter must be a valid [checkpoint mode]:)^
10068**
10069** <dl>
10070** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
10071** ^Checkpoint as many frames as possible without waiting for any database
10072** readers or writers to finish, then sync the database file if all frames
10073** in the log were checkpointed. ^The [busy-handler callback]
10074** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
10075** ^On the other hand, passive mode might leave the checkpoint unfinished
10076** if there are concurrent readers or writers.
10077**
10078** <dt>SQLITE_CHECKPOINT_FULL<dd>
10079** ^This mode blocks (it invokes the
10080** [sqlite3_busy_handler|busy-handler callback]) until there is no
10081** database writer and all readers are reading from the most recent database
10082** snapshot. ^It then checkpoints all frames in the log file and syncs the
10083** database file. ^This mode blocks new database writers while it is pending,
10084** but new database readers are allowed to continue unimpeded.
10085**
10086** <dt>SQLITE_CHECKPOINT_RESTART<dd>
10087** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
10088** that after checkpointing the log file it blocks (calls the
10089** [busy-handler callback])
10090** until all readers are reading from the database file only. ^This ensures
10091** that the next writer will restart the log file from the beginning.
10092** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
10093** database writer attempts while it is pending, but does not impede readers.
10094**
10095** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
10096** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
10097** addition that it also truncates the log file to zero bytes just prior
10098** to a successful return.
10099**
10100** <dt>SQLITE_CHECKPOINT_NOOP<dd>
10101** ^This mode always checkpoints zero frames. The only reason to invoke
10102** a NOOP checkpoint is to access the values returned by
10103** sqlite3_wal_checkpoint_v2() via output parameters *pnLog and *pnCkpt.
10104** </dl>
10105**
10106** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
10107** the log file or to -1 if the checkpoint could not run because
10108** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
10109** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
10110** log file (including any that were already checkpointed before the function
10111** was called) or to -1 if the checkpoint could not run due to an error or
10112** because the database is not in WAL mode. ^Note that upon successful
10113** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
10114** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
10115**
10116** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
10117** any other process is running a checkpoint operation at the same time, the
10118** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
10119** busy-handler configured, it will not be invoked in this case.
10120**
10121** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
10122** exclusive "writer" lock on the database file. ^If the writer lock cannot be
10123** obtained immediately, and a busy-handler is configured, it is invoked and
10124** the writer lock retried until either the busy-handler returns 0 or the lock
10125** is successfully obtained. ^The busy-handler is also invoked while waiting for
10126** database readers as described above. ^If the busy-handler returns 0 before
10127** the writer lock is obtained or while waiting for database readers, the
10128** checkpoint operation proceeds from that point in the same way as
10129** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
10130** without blocking any further. ^SQLITE_BUSY is returned in this case.
10131**
10132** ^If parameter zDb is NULL or points to a zero length string, then the
10133** specified operation is attempted on all WAL databases [attached] to
10134** [database connection] db. In this case the
10135** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
10136** an SQLITE_BUSY error is encountered when processing one or more of the
10137** attached WAL databases, the operation is still attempted on any remaining
10138** attached databases and SQLITE_BUSY is returned at the end. ^If any other
10139** error occurs while processing an attached database, processing is abandoned
10140** and the error code is returned to the caller immediately. ^If no error
10141** (SQLITE_BUSY or otherwise) is encountered while processing the attached
10142** databases, SQLITE_OK is returned.
10143**
10144** ^If database zDb is the name of an attached database that is not in WAL
10145** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
10146** zDb is not NULL (or a zero length string) and is not the name of any
10147** attached database, SQLITE_ERROR is returned to the caller.
10148**
10149** ^Unless it returns SQLITE_MISUSE,
10150** the sqlite3_wal_checkpoint_v2() interface
10151** sets the error information that is queried by
10152** [sqlite3_errcode()] and [sqlite3_errmsg()].
10153**
10154** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
10155** from SQL.
10156*/
10157SQLITE_API int sqlite3_wal_checkpoint_v2(
10158 sqlite3 *db, /* Database handle */
10159 const char *zDb, /* Name of attached database (or NULL) */
10160 int eMode, /* SQLITE_CHECKPOINT_* value */
10161 int *pnLog, /* OUT: Size of WAL log in frames */
10162 int *pnCkpt /* OUT: Total number of frames checkpointed */
10163);
10164
10165/*
10166** CAPI3REF: Checkpoint Mode Values
10167** KEYWORDS: {checkpoint mode}
10168**
10169** These constants define all valid values for the "checkpoint mode" passed
10170** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
10171** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
10172** meaning of each of these checkpoint modes.
10173*/
10174#define SQLITE_CHECKPOINT_NOOP -1 /* Do no work at all */
10175#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
10176#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
10177#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
10178#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
10179
10180/*
10181** CAPI3REF: Virtual Table Interface Configuration
10182**
10183** This function may be called by either the [xConnect] or [xCreate] method
10184** of a [virtual table] implementation to configure
10185** various facets of the virtual table interface.
10186**
10187** If this interface is invoked outside the context of an xConnect or
10188** xCreate virtual table method then the behavior is undefined.
10189**
10190** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
10191** [database connection] in which the virtual table is being created and
10192** which is passed in as the first argument to the [xConnect] or [xCreate]
10193** method that is invoking sqlite3_vtab_config(). The C parameter is one
10194** of the [virtual table configuration options]. The presence and meaning
10195** of parameters after C depend on which [virtual table configuration option]
10196** is used.
10197*/
10198SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
10199
10200/*
10201** CAPI3REF: Virtual Table Configuration Options
10202** KEYWORDS: {virtual table configuration options}
10203** KEYWORDS: {virtual table configuration option}
10204**
10205** These macros define the various options to the
10206** [sqlite3_vtab_config()] interface that [virtual table] implementations
10207** can use to customize and optimize their behavior.
10208**
10209** <dl>
10210** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
10211** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
10212** <dd>Calls of the form
10213** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
10214** where X is an integer. If X is zero, then the [virtual table] whose
10215** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
10216** support constraints. In this configuration (which is the default) if
10217** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
10218** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
10219** specified as part of the user's SQL statement, regardless of the actual
10220** ON CONFLICT mode specified.
10221**
10222** If X is non-zero, then the virtual table implementation guarantees
10223** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
10224** any modifications to internal or persistent data structures have been made.
10225** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
10226** is able to roll back a statement or database transaction, and abandon
10227** or continue processing the current SQL statement as appropriate.
10228** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
10229** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
10230** had been ABORT.
10231**
10232** Virtual table implementations that are required to handle OR REPLACE
10233** must do so within the [xUpdate] method. If a call to the
10234** [sqlite3_vtab_on_conflict()] function indicates that the current ON
10235** CONFLICT policy is REPLACE, the virtual table implementation should
10236** silently replace the appropriate rows within the xUpdate callback and
10237** return SQLITE_OK. Or, if this is not possible, it may return
10238** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
10239** constraint handling.
10240** </dd>
10241**
10242** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
10243** <dd>Calls of the form
10244** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
10245** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10246** prohibits that virtual table from being used from within triggers and
10247** views.
10248** </dd>
10249**
10250** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
10251** <dd>Calls of the form
10252** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
10253** [xConnect] or [xCreate] methods of a [virtual table] implementation
10254** identify that virtual table as being safe to use from within triggers
10255** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
10256** virtual table can do no serious harm even if it is controlled by a
10257** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
10258** flag unless absolutely necessary.
10259** </dd>
10260**
10261** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
10262** <dd>Calls of the form
10263** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
10264** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10265** instruct the query planner to begin at least a read transaction on
10266** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
10267** virtual table is used.
10268** </dd>
10269** </dl>
10270*/
10271#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
10272#define SQLITE_VTAB_INNOCUOUS 2
10273#define SQLITE_VTAB_DIRECTONLY 3
10274#define SQLITE_VTAB_USES_ALL_SCHEMAS 4
10275
10276/*
10277** CAPI3REF: Determine The Virtual Table Conflict Policy
10278**
10279** This function may only be called from within a call to the [xUpdate] method
10280** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
10281** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
10282** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
10283** of the SQL statement that triggered the call to the [xUpdate] method of the
10284** [virtual table].
10285*/
10286SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
10287
10288/*
10289** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
10290**
10291** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
10292** method of a [virtual table], then it might return true if the
10293** column is being fetched as part of an UPDATE operation during which the
10294** column value will not change. The virtual table implementation can use
10295** this hint as permission to substitute a return value that is less
10296** expensive to compute and that the corresponding
10297** [xUpdate] method understands as a "no-change" value.
10298**
10299** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
10300** the column is not changed by the UPDATE statement, then the xColumn
10301** method can optionally return without setting a result, without calling
10302** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
10303** In that case, [sqlite3_value_nochange(X)] will return true for the
10304** same column in the [xUpdate] method.
10305**
10306** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
10307** implementations should continue to give a correct answer even if the
10308** sqlite3_vtab_nochange() interface were to always return false. In the
10309** current implementation, the sqlite3_vtab_nochange() interface does always
10310** returns false for the enhanced [UPDATE FROM] statement.
10311*/
10312SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
10313
10314/*
10315** CAPI3REF: Determine The Collation For a Virtual Table Constraint
10316** METHOD: sqlite3_index_info
10317**
10318** This function may only be called from within a call to the [xBestIndex]
10319** method of a [virtual table]. This function returns a pointer to a string
10320** that is the name of the appropriate collation sequence to use for text
10321** comparisons on the constraint identified by its arguments.
10322**
10323** The first argument must be the pointer to the [sqlite3_index_info] object
10324** that is the first parameter to the xBestIndex() method. The second argument
10325** must be an index into the aConstraint[] array belonging to the
10326** sqlite3_index_info structure passed to xBestIndex.
10327**
10328** Important:
10329** The first parameter must be the same pointer that is passed into the
10330** xBestMethod() method. The first parameter may not be a pointer to a
10331** different [sqlite3_index_info] object, even an exact copy.
10332**
10333** The return value is computed as follows:
10334**
10335** <ol>
10336** <li><p> If the constraint comes from a WHERE clause expression that contains
10337** a [COLLATE operator], then the name of the collation specified by
10338** that COLLATE operator is returned.
10339** <li><p> If there is no COLLATE operator, but the column that is the subject
10340** of the constraint specifies an alternative collating sequence via
10341** a [COLLATE clause] on the column definition within the CREATE TABLE
10342** statement that was passed into [sqlite3_declare_vtab()], then the
10343** name of that alternative collating sequence is returned.
10344** <li><p> Otherwise, "BINARY" is returned.
10345** </ol>
10346*/
10347SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
10348
10349/*
10350** CAPI3REF: Determine if a virtual table query is DISTINCT
10351** METHOD: sqlite3_index_info
10352**
10353** This API may only be used from within an [xBestIndex|xBestIndex method]
10354** of a [virtual table] implementation. The result of calling this
10355** interface from outside of xBestIndex() is undefined and probably harmful.
10356**
10357** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
10358** 3. The integer returned by sqlite3_vtab_distinct()
10359** gives the virtual table additional information about how the query
10360** planner wants the output to be ordered. As long as the virtual table
10361** can meet the ordering requirements of the query planner, it may set
10362** the "orderByConsumed" flag.
10363**
10364** <ol><li value="0"><p>
10365** ^If the sqlite3_vtab_distinct() interface returns 0, that means
10366** that the query planner needs the virtual table to return all rows in the
10367** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
10368** [sqlite3_index_info] object. This is the default expectation. If the
10369** virtual table outputs all rows in sorted order, then it is always safe for
10370** the xBestIndex method to set the "orderByConsumed" flag, regardless of
10371** the return value from sqlite3_vtab_distinct().
10372** <li value="1"><p>
10373** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
10374** that the query planner does not need the rows to be returned in sorted order
10375** as long as all rows with the same values in all columns identified by the
10376** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
10377** is doing a GROUP BY.
10378** <li value="2"><p>
10379** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
10380** that the query planner does not need the rows returned in any particular
10381** order, as long as rows with the same values in all columns identified
10382** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
10383** contain the same values for all columns identified by "colUsed", all but
10384** one such row may optionally be omitted from the result.)^
10385** The virtual table is not required to omit rows that are duplicates
10386** over the "colUsed" columns, but if the virtual table can do that without
10387** too much extra effort, it could potentially help the query to run faster.
10388** This mode is used for a DISTINCT query.
10389** <li value="3"><p>
10390** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
10391** virtual table must return rows in the order defined by "aOrderBy" as
10392** if the sqlite3_vtab_distinct() interface had returned 0. However if
10393** two or more rows in the result have the same values for all columns
10394** identified by "colUsed", then all but one such row may optionally be
10395** omitted.)^ Like when the return value is 2, the virtual table
10396** is not required to omit rows that are duplicates over the "colUsed"
10397** columns, but if the virtual table can do that without
10398** too much extra effort, it could potentially help the query to run faster.
10399** This mode is used for queries
10400** that have both DISTINCT and ORDER BY clauses.
10401** </ol>
10402**
10403** <p>The following table summarizes the conditions under which the
10404** virtual table is allowed to set the "orderByConsumed" flag based on
10405** the value returned by sqlite3_vtab_distinct(). This table is a
10406** restatement of the previous four paragraphs:
10407**
10408** <table border=1 cellspacing=0 cellpadding=10 width="90%">
10409** <tr>
10410** <td valign="top">sqlite3_vtab_distinct() return value
10411** <td valign="top">Rows are returned in aOrderBy order
10412** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
10413** <td valign="top">Duplicates over all colUsed columns may be omitted
10414** <tr><td>0<td>yes<td>yes<td>no
10415** <tr><td>1<td>no<td>yes<td>no
10416** <tr><td>2<td>no<td>yes<td>yes
10417** <tr><td>3<td>yes<td>yes<td>yes
10418** </table>
10419**
10420** ^For the purposes of comparing virtual table output values to see if the
10421** values are the same value for sorting purposes, two NULL values are considered
10422** to be the same. In other words, the comparison operator is "IS"
10423** (or "IS NOT DISTINCT FROM") and not "==".
10424**
10425** If a virtual table implementation is unable to meet the requirements
10426** specified above, then it must not set the "orderByConsumed" flag in the
10427** [sqlite3_index_info] object or an incorrect answer may result.
10428**
10429** ^A virtual table implementation is always free to return rows in any order
10430** it wants, as long as the "orderByConsumed" flag is not set. ^When the
10431** "orderByConsumed" flag is unset, the query planner will add extra
10432** [bytecode] to ensure that the final results returned by the SQL query are
10433** ordered correctly. The use of the "orderByConsumed" flag and the
10434** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
10435** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10436** flag might help queries against a virtual table to run faster. Being
10437** overly aggressive and setting the "orderByConsumed" flag when it is not
10438** valid to do so, on the other hand, might cause SQLite to return incorrect
10439** results.
10440*/
10441SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10442
10443/*
10444** CAPI3REF: Identify and handle IN constraints in xBestIndex
10445**
10446** This interface may only be used from within an
10447** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10448** The result of invoking this interface from any other context is
10449** undefined and probably harmful.
10450**
10451** ^(A constraint on a virtual table of the form
10452** "[IN operator|column IN (...)]" is
10453** communicated to the xBestIndex method as a
10454** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10455** this constraint, it must set the corresponding
10456** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10457** the usual mode of handling IN operators, SQLite generates [bytecode]
10458** that invokes the [xFilter|xFilter() method] once for each value
10459** on the right-hand side of the IN operator.)^ Thus the virtual table
10460** only sees a single value from the right-hand side of the IN operator
10461** at a time.
10462**
10463** In some cases, however, it would be advantageous for the virtual
10464** table to see all values on the right-hand of the IN operator all at
10465** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10466**
10467** <ol>
10468** <li><p>
10469** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10470** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10471** is an [IN operator] that can be processed all at once. ^In other words,
10472** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10473** by which the virtual table can ask SQLite if all-at-once processing
10474** of the IN operator is even possible.
10475**
10476** <li><p>
10477** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10478** to SQLite that the virtual table does or does not want to process
10479** the IN operator all-at-once, respectively. ^Thus when the third
10480** parameter (F) is non-negative, this interface is the mechanism by
10481** which the virtual table tells SQLite how it wants to process the
10482** IN operator.
10483** </ol>
10484**
10485** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10486** within the same xBestIndex method call. ^For any given P,N pair,
10487** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10488** within the same xBestIndex call. ^If the interface returns true
10489** (non-zero), that means that the constraint is an IN operator
10490** that can be processed all-at-once. ^If the constraint is not an IN
10491** operator or cannot be processed all-at-once, then the interface returns
10492** false.
10493**
10494** ^(All-at-once processing of the IN operator is selected if both of the
10495** following conditions are met:
10496**
10497** <ol>
10498** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10499** integer. This is how the virtual table tells SQLite that it wants to
10500** use the N-th constraint.
10501**
10502** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10503** non-negative had F>=1.
10504** </ol>)^
10505**
10506** ^If either or both of the conditions above are false, then SQLite uses
10507** the traditional one-at-a-time processing strategy for the IN constraint.
10508** ^If both conditions are true, then the argvIndex-th parameter to the
10509** xFilter method will be an [sqlite3_value] that appears to be NULL,
10510** but which can be passed to [sqlite3_vtab_in_first()] and
10511** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10512** of the IN constraint.
10513*/
10514SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10515
10516/*
10517** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10518**
10519** These interfaces are only useful from within the
10520** [xFilter|xFilter() method] of a [virtual table] implementation.
10521** The result of invoking these interfaces from any other context
10522** is undefined and probably harmful.
10523**
10524** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10525** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10526** xFilter method which invokes these routines, and specifically
10527** a parameter that was previously selected for all-at-once IN constraint
10528** processing using the [sqlite3_vtab_in()] interface in the
10529** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10530** an xFilter argument that was selected for all-at-once IN constraint
10531** processing, then these routines return [SQLITE_ERROR].)^
10532**
10533** ^(Use these routines to access all values on the right-hand side
10534** of the IN constraint using code like the following:
10535**
10536** <blockquote><pre>
10537** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
10538** &nbsp; rc==SQLITE_OK && pVal;
10539** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
10540** &nbsp; ){
10541** &nbsp; // do something with pVal
10542** &nbsp; }
10543** &nbsp; if( rc!=SQLITE_DONE ){
10544** &nbsp; // an error has occurred
10545** &nbsp; }
10546** </pre></blockquote>)^
10547**
10548** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10549** routines return SQLITE_OK and set *P to point to the first or next value
10550** on the RHS of the IN constraint. ^If there are no more values on the
10551** right hand side of the IN constraint, then *P is set to NULL and these
10552** routines return [SQLITE_DONE]. ^The return value might be
10553** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10554**
10555** The *ppOut values returned by these routines are only valid until the
10556** next call to either of these routines or until the end of the xFilter
10557** method from which these routines were called. If the virtual table
10558** implementation needs to retain the *ppOut values for longer, it must make
10559** copies. The *ppOut values are [protected sqlite3_value|protected].
10560*/
10561SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10562SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10563
10564/*
10565** CAPI3REF: Constraint values in xBestIndex()
10566** METHOD: sqlite3_index_info
10567**
10568** This API may only be used from within the [xBestIndex|xBestIndex method]
10569** of a [virtual table] implementation. The result of calling this interface
10570** from outside of an xBestIndex method are undefined and probably harmful.
10571**
10572** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10573** the [xBestIndex] method of a [virtual table] implementation, with P being
10574** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10575** J being a 0-based index into P->aConstraint[], then this routine
10576** attempts to set *V to the value of the right-hand operand of
10577** that constraint if the right-hand operand is known. ^If the
10578** right-hand operand is not known, then *V is set to a NULL pointer.
10579** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10580** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10581** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10582** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10583** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if
10584** something goes wrong.
10585**
10586** The sqlite3_vtab_rhs_value() interface is usually only successful if
10587** the right-hand operand of a constraint is a literal value in the original
10588** SQL statement. If the right-hand operand is an expression or a reference
10589** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10590** will probably return [SQLITE_NOTFOUND].
10591**
10592** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10593** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10594** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10595**
10596** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10597** and remains valid for the duration of the xBestIndex method call.
10598** ^When xBestIndex returns, the sqlite3_value object returned by
10599** sqlite3_vtab_rhs_value() is automatically deallocated.
10600**
10601** The "_rhs_" in the name of this routine is an abbreviation for
10602** "Right-Hand Side".
10603*/
10604SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10605
10606/*
10607** CAPI3REF: Conflict resolution modes
10608** KEYWORDS: {conflict resolution mode}
10609**
10610** These constants are returned by [sqlite3_vtab_on_conflict()] to
10611** inform a [virtual table] implementation of the [ON CONFLICT] mode
10612** for the SQL statement being evaluated.
10613**
10614** Note that the [SQLITE_IGNORE] constant is also used as a potential
10615** return value from the [sqlite3_set_authorizer()] callback and that
10616** [SQLITE_ABORT] is also a [result code].
10617*/
10618#define SQLITE_ROLLBACK 1
10619/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10620#define SQLITE_FAIL 3
10621/* #define SQLITE_ABORT 4 // Also an error code */
10622#define SQLITE_REPLACE 5
10623
10624/*
10625** CAPI3REF: Prepared Statement Scan Status Opcodes
10626** KEYWORDS: {scanstatus options}
10627**
10628** The following constants can be used for the T parameter to the
10629** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10630** different metric for sqlite3_stmt_scanstatus() to return.
10631**
10632** When the value returned to V is a string, space to hold that string is
10633** managed by the prepared statement S and will be automatically freed when
10634** S is finalized.
10635**
10636** Not all values are available for all query elements. When a value is
10637** not available, the output variable is set to -1 if the value is numeric,
10638** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10639**
10640** <dl>
10641** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10642** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10643** set to the total number of times that the X-th loop has run.</dd>
10644**
10645** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10646** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10647** to the total number of rows examined by all iterations of the X-th loop.</dd>
10648**
10649** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10650** <dd>^The "double" variable pointed to by the V parameter will be set to the
10651** query planner's estimate for the average number of rows output from each
10652** iteration of the X-th loop. If the query planner's estimate was accurate,
10653** then this value will approximate the quotient NVISIT/NLOOP and the
10654** product of this value for all prior loops with the same SELECTID will
10655** be the NLOOP value for the current loop.</dd>
10656**
10657** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10658** <dd>^The "const char *" variable pointed to by the V parameter will be set
10659** to a zero-terminated UTF-8 string containing the name of the index or table
10660** used for the X-th loop.</dd>
10661**
10662** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10663** <dd>^The "const char *" variable pointed to by the V parameter will be set
10664** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10665** description for the X-th loop.</dd>
10666**
10667** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10668** <dd>^The "int" variable pointed to by the V parameter will be set to the
10669** id for the X-th query plan element. The id value is unique within the
10670** statement. The select-id is the same value as is output in the first
10671** column of an [EXPLAIN QUERY PLAN] query.</dd>
10672**
10673** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10674** <dd>The "int" variable pointed to by the V parameter will be set to the
10675** id of the parent of the current query element, if applicable, or
10676** to zero if the query element has no parent. This is the same value as
10677** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd>
10678**
10679** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10680** <dd>The sqlite3_int64 output value is set to the number of cycles,
10681** according to the processor time-stamp counter, that elapsed while the
10682** query element was being processed. This value is not available for
10683** all query elements - if it is unavailable the output variable is
10684** set to -1.</dd>
10685** </dl>
10686*/
10687#define SQLITE_SCANSTAT_NLOOP 0
10688#define SQLITE_SCANSTAT_NVISIT 1
10689#define SQLITE_SCANSTAT_EST 2
10690#define SQLITE_SCANSTAT_NAME 3
10691#define SQLITE_SCANSTAT_EXPLAIN 4
10692#define SQLITE_SCANSTAT_SELECTID 5
10693#define SQLITE_SCANSTAT_PARENTID 6
10694#define SQLITE_SCANSTAT_NCYCLE 7
10695
10696/*
10697** CAPI3REF: Prepared Statement Scan Status
10698** METHOD: sqlite3_stmt
10699**
10700** These interfaces return information about the predicted and measured
10701** performance for pStmt. Advanced applications can use this
10702** interface to compare the predicted and the measured performance and
10703** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10704**
10705** Since this interface is expected to be rarely used, it is only
10706** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10707** compile-time option.
10708**
10709** The "iScanStatusOp" parameter determines which status information to return.
10710** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10711** of this interface is undefined. ^The requested measurement is written into
10712** a variable pointed to by the "pOut" parameter.
10713**
10714** The "flags" parameter must be passed a mask of flags. At present only
10715** one flag is defined - [SQLITE_SCANSTAT_COMPLEX]. If SQLITE_SCANSTAT_COMPLEX
10716** is specified, then status information is available for all elements
10717** of a query plan that are reported by "[EXPLAIN QUERY PLAN]" output. If
10718** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10719** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10720** the EXPLAIN QUERY PLAN output) are available. Invoking API
10721** sqlite3_stmt_scanstatus() is equivalent to calling
10722** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10723**
10724** Parameter "idx" identifies the specific query element to retrieve statistics
10725** for. Query elements are numbered starting from zero. A value of -1 may
10726** retrieve statistics for the entire query. ^If idx is out of range
10727** - less than -1 or greater than or equal to the total number of query
10728** elements used to implement the statement - a non-zero value is returned and
10729** the variable that pOut points to is unchanged.
10730**
10731** See also: [sqlite3_stmt_scanstatus_reset()] and the
10732** [nexec and ncycle] columnes of the [bytecode virtual table].
10733*/
10734SQLITE_API int sqlite3_stmt_scanstatus(
10735 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10736 int idx, /* Index of loop to report on */
10737 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10738 void *pOut /* Result written here */
10739);
10740SQLITE_API int sqlite3_stmt_scanstatus_v2(
10741 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10742 int idx, /* Index of loop to report on */
10743 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10744 int flags, /* Mask of flags defined below */
10745 void *pOut /* Result written here */
10746);
10747
10748/*
10749** CAPI3REF: Prepared Statement Scan Status
10750** KEYWORDS: {scan status flags}
10751*/
10752#define SQLITE_SCANSTAT_COMPLEX 0x0001
10753
10754/*
10755** CAPI3REF: Zero Scan-Status Counters
10756** METHOD: sqlite3_stmt
10757**
10758** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10759**
10760** This API is only available if the library is built with pre-processor
10761** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10762*/
10763SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10764
10765/*
10766** CAPI3REF: Flush caches to disk mid-transaction
10767** METHOD: sqlite3
10768**
10769** ^If a write-transaction is open on [database connection] D when the
10770** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
10771** pages in the pager-cache that are not currently in use are written out
10772** to disk. A dirty page may be in use if a database cursor created by an
10773** active SQL statement is reading from it, or if it is page 1 of a database
10774** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10775** interface flushes caches for all schemas - "main", "temp", and
10776** any [attached] databases.
10777**
10778** ^If this function needs to obtain extra database locks before dirty pages
10779** can be flushed to disk, it does so. ^If those locks cannot be obtained
10780** immediately and there is a busy-handler callback configured, it is invoked
10781** in the usual manner. ^If the required lock still cannot be obtained, then
10782** the database is skipped and an attempt made to flush any dirty pages
10783** belonging to the next (if any) database. ^If any databases are skipped
10784** because locks cannot be obtained, but no other error occurs, this
10785** function returns SQLITE_BUSY.
10786**
10787** ^If any other error occurs while flushing dirty pages to disk (for
10788** example an IO error or out-of-memory condition), then processing is
10789** abandoned and an SQLite [error code] is returned to the caller immediately.
10790**
10791** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10792**
10793** ^This function does not set the database handle error code or message
10794** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10795*/
10796SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10797
10798/*
10799** CAPI3REF: The pre-update hook.
10800** METHOD: sqlite3
10801**
10802** ^These interfaces are only available if SQLite is compiled using the
10803** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10804**
10805** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10806** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10807** on a database table.
10808** ^At most one preupdate hook may be registered at a time on a single
10809** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10810** the previous setting.
10811** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10812** with a NULL pointer as the second parameter.
10813** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10814** the first parameter to callbacks.
10815**
10816** ^The preupdate hook only fires for changes to real database tables; the
10817** preupdate hook is not invoked for changes to [virtual tables] or to
10818** system tables like sqlite_sequence or sqlite_stat1.
10819**
10820** ^The second parameter to the preupdate callback is a pointer to
10821** the [database connection] that registered the preupdate hook.
10822** ^The third parameter to the preupdate callback is one of the constants
10823** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10824** kind of update operation that is about to occur.
10825** ^(The fourth parameter to the preupdate callback is the name of the
10826** database within the database connection that is being modified. This
10827** will be "main" for the main database or "temp" for TEMP tables or
10828** the name given after the AS keyword in the [ATTACH] statement for attached
10829** databases.)^
10830** ^The fifth parameter to the preupdate callback is the name of the
10831** table that is being modified.
10832**
10833** For an UPDATE or DELETE operation on a [rowid table], the sixth
10834** parameter passed to the preupdate callback is the initial [rowid] of the
10835** row being modified or deleted. For an INSERT operation on a rowid table,
10836** or any operation on a WITHOUT ROWID table, the value of the sixth
10837** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10838** seventh parameter is the final rowid value of the row being inserted
10839** or updated. The value of the seventh parameter passed to the callback
10840** function is not defined for operations on WITHOUT ROWID tables, or for
10841** DELETE operations on rowid tables.
10842**
10843** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10844** the previous call on the same [database connection] D, or NULL for
10845** the first call on D.
10846**
10847** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10848** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10849** provide additional information about a preupdate event. These routines
10850** may only be called from within a preupdate callback. Invoking any of
10851** these routines from outside of a preupdate callback or with a
10852** [database connection] pointer that is different from the one supplied
10853** to the preupdate callback results in undefined and probably undesirable
10854** behavior.
10855**
10856** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10857** in the row that is being inserted, updated, or deleted.
10858**
10859** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10860** a [protected sqlite3_value] that contains the value of the Nth column of
10861** the table row before it is updated. The N parameter must be between 0
10862** and one less than the number of columns or the behavior will be
10863** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10864** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10865** behavior is undefined. The [sqlite3_value] that P points to
10866** will be destroyed when the preupdate callback returns.
10867**
10868** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10869** a [protected sqlite3_value] that contains the value of the Nth column of
10870** the table row after it is updated. The N parameter must be between 0
10871** and one less than the number of columns or the behavior will be
10872** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10873** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10874** behavior is undefined. The [sqlite3_value] that P points to
10875** will be destroyed when the preupdate callback returns.
10876**
10877** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10878** callback was invoked as a result of a direct insert, update, or delete
10879** operation; or 1 for inserts, updates, or deletes invoked by top-level
10880** triggers; or 2 for changes resulting from triggers called by top-level
10881** triggers; and so forth.
10882**
10883** When the [sqlite3_blob_write()] API is used to update a blob column,
10884** the pre-update hook is invoked with SQLITE_DELETE, because
10885** the new values are not yet available. In this case, when a
10886** callback made with op==SQLITE_DELETE is actually a write using the
10887** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10888** the index of the column being written. In other cases, where the
10889** pre-update hook is being invoked for some other reason, including a
10890** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10891**
10892** See also: [sqlite3_update_hook()]
10893*/
10894#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10895SQLITE_API void *sqlite3_preupdate_hook(
10896 sqlite3 *db,
10897 void(*xPreUpdate)(
10898 void *pCtx, /* Copy of third arg to preupdate_hook() */
10899 sqlite3 *db, /* Database handle */
10900 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10901 char const *zDb, /* Database name */
10902 char const *zName, /* Table name */
10903 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10904 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10905 ),
10906 void*
10907);
10908SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10909SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10910SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10911SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10912SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10913#endif
10914
10915/*
10916** CAPI3REF: Low-level system error code
10917** METHOD: sqlite3
10918**
10919** ^Attempt to return the underlying operating system error code or error
10920** number that caused the most recent I/O error or failure to open a file.
10921** The return value is OS-dependent. For example, on unix systems, after
10922** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10923** called to get back the underlying "errno" that caused the problem, such
10924** as ENOSPC, EAUTH, EISDIR, and so forth.
10925*/
10926SQLITE_API int sqlite3_system_errno(sqlite3*);
10927
10928/*
10929** CAPI3REF: Database Snapshot
10930** KEYWORDS: {snapshot} {sqlite3_snapshot}
10931**
10932** An instance of the snapshot object records the state of a [WAL mode]
10933** database for some specific point in history.
10934**
10935** In [WAL mode], multiple [database connections] that are open on the
10936** same database file can each be reading a different historical version
10937** of the database file. When a [database connection] begins a read
10938** transaction, that connection sees an unchanging copy of the database
10939** as it existed for the point in time when the transaction first started.
10940** Subsequent changes to the database from other connections are not seen
10941** by the reader until a new read transaction is started.
10942**
10943** The sqlite3_snapshot object records state information about an historical
10944** version of the database file so that it is possible to later open a new read
10945** transaction that sees that historical version of the database rather than
10946** the most recent version.
10947*/
10948typedef struct sqlite3_snapshot {
10949 unsigned char hidden[48];
10950} sqlite3_snapshot;
10951
10952/*
10953** CAPI3REF: Record A Database Snapshot
10954** CONSTRUCTOR: sqlite3_snapshot
10955**
10956** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10957** new [sqlite3_snapshot] object that records the current state of
10958** schema S in database connection D. ^On success, the
10959** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10960** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10961** If there is not already a read-transaction open on schema S when
10962** this function is called, one is opened automatically.
10963**
10964** If a read-transaction is opened by this function, then it is guaranteed
10965** that the returned snapshot object may not be invalidated by a database
10966** writer or checkpointer until after the read-transaction is closed. This
10967** is not guaranteed if a read-transaction is already open when this
10968** function is called. In that case, any subsequent write or checkpoint
10969** operation on the database may invalidate the returned snapshot handle,
10970** even while the read-transaction remains open.
10971**
10972** The following must be true for this function to succeed. If any of
10973** the following statements are false when sqlite3_snapshot_get() is
10974** called, SQLITE_ERROR is returned. The final value of *P is undefined
10975** in this case.
10976**
10977** <ul>
10978** <li> The database handle must not be in [autocommit mode].
10979**
10980** <li> Schema S of [database connection] D must be a [WAL mode] database.
10981**
10982** <li> There must not be a write transaction open on schema S of database
10983** connection D.
10984**
10985** <li> One or more transactions must have been written to the current wal
10986** file since it was created on disk (by any connection). This means
10987** that a snapshot cannot be taken on a wal mode database with no wal
10988** file immediately after it is first opened. At least one transaction
10989** must be written to it first.
10990** </ul>
10991**
10992** This function may also return SQLITE_NOMEM. If it is called with the
10993** database handle in autocommit mode but fails for some other reason,
10994** whether or not a read transaction is opened on schema S is undefined.
10995**
10996** The [sqlite3_snapshot] object returned from a successful call to
10997** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10998** to avoid a memory leak.
10999**
11000** The [sqlite3_snapshot_get()] interface is only available when the
11001** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
11002*/
11003SQLITE_API int sqlite3_snapshot_get(
11004 sqlite3 *db,
11005 const char *zSchema,
11006 sqlite3_snapshot **ppSnapshot
11007);
11008
11009/*
11010** CAPI3REF: Start a read transaction on an historical snapshot
11011** METHOD: sqlite3_snapshot
11012**
11013** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
11014** transaction or upgrades an existing one for schema S of
11015** [database connection] D such that the read transaction refers to
11016** historical [snapshot] P, rather than the most recent change to the
11017** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
11018** on success or an appropriate [error code] if it fails.
11019**
11020** ^In order to succeed, the database connection must not be in
11021** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
11022** is already a read transaction open on schema S, then the database handle
11023** must have no active statements (SELECT statements that have been passed
11024** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
11025** SQLITE_ERROR is returned if either of these conditions is violated, or
11026** if schema S does not exist, or if the snapshot object is invalid.
11027**
11028** ^A call to sqlite3_snapshot_open() will fail to open if the specified
11029** snapshot has been overwritten by a [checkpoint]. In this case
11030** SQLITE_ERROR_SNAPSHOT is returned.
11031**
11032** If there is already a read transaction open when this function is
11033** invoked, then the same read transaction remains open (on the same
11034** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
11035** is returned. If another error code - for example SQLITE_PROTOCOL or an
11036** SQLITE_IOERR error code - is returned, then the final state of the
11037** read transaction is undefined. If SQLITE_OK is returned, then the
11038** read transaction is now open on database snapshot P.
11039**
11040** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
11041** database connection D does not know that the database file for
11042** schema S is in [WAL mode]. A database connection might not know
11043** that the database file is in [WAL mode] if there has been no prior
11044** I/O on that database connection, or if the database entered [WAL mode]
11045** after the most recent I/O on the database connection.)^
11046** (Hint: Run "[PRAGMA application_id]" against a newly opened
11047** database connection in order to make it ready to use snapshots.)
11048**
11049** The [sqlite3_snapshot_open()] interface is only available when the
11050** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
11051*/
11052SQLITE_API int sqlite3_snapshot_open(
11053 sqlite3 *db,
11054 const char *zSchema,
11055 sqlite3_snapshot *pSnapshot
11056);
11057
11058/*
11059** CAPI3REF: Destroy a snapshot
11060** DESTRUCTOR: sqlite3_snapshot
11061**
11062** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
11063** The application must eventually free every [sqlite3_snapshot] object
11064** using this routine to avoid a memory leak.
11065**
11066** The [sqlite3_snapshot_free()] interface is only available when the
11067** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
11068*/
11069SQLITE_API void sqlite3_snapshot_free(sqlite3_snapshot*);
11070
11071/*
11072** CAPI3REF: Compare the ages of two snapshot handles.
11073** METHOD: sqlite3_snapshot
11074**
11075** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
11076** of two valid snapshot handles.
11077**
11078** If the two snapshot handles are not associated with the same database
11079** file, the result of the comparison is undefined.
11080**
11081** Additionally, the result of the comparison is only valid if both of the
11082** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
11083** last time the wal file was deleted. The wal file is deleted when the
11084** database is changed back to rollback mode or when the number of database
11085** clients drops to zero. If either snapshot handle was obtained before the
11086** wal file was last deleted, the value returned by this function
11087** is undefined.
11088**
11089** Otherwise, this API returns a negative value if P1 refers to an older
11090** snapshot than P2, zero if the two handles refer to the same database
11091** snapshot, and a positive value if P1 is a newer snapshot than P2.
11092**
11093** This interface is only available if SQLite is compiled with the
11094** [SQLITE_ENABLE_SNAPSHOT] option.
11095*/
11096SQLITE_API int sqlite3_snapshot_cmp(
11097 sqlite3_snapshot *p1,
11098 sqlite3_snapshot *p2
11099);
11100
11101/*
11102** CAPI3REF: Recover snapshots from a wal file
11103** METHOD: sqlite3_snapshot
11104**
11105** If a [WAL file] remains on disk after all database connections close
11106** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
11107** or because the last process to have the database opened exited without
11108** calling [sqlite3_close()]) and a new connection is subsequently opened
11109** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
11110** will only be able to open the last transaction added to the WAL file
11111** even though the WAL file contains other valid transactions.
11112**
11113** This function attempts to scan the WAL file associated with database zDb
11114** of database handle db and make all valid snapshots available to
11115** sqlite3_snapshot_open(). It is an error if there is already a read
11116** transaction open on the database, or if the database is not a WAL mode
11117** database.
11118**
11119** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
11120**
11121** This interface is only available if SQLite is compiled with the
11122** [SQLITE_ENABLE_SNAPSHOT] option.
11123*/
11124SQLITE_API int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
11125
11126/*
11127** CAPI3REF: Serialize a database
11128**
11129** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
11130** memory that is a serialization of the S database on
11131** [database connection] D. If S is a NULL pointer, the main database is used.
11132** If P is not a NULL pointer, then the size of the database in bytes
11133** is written into *P.
11134**
11135** For an ordinary on-disk database file, the serialization is just a
11136** copy of the disk file. For an in-memory database or a "TEMP" database,
11137** the serialization is the same sequence of bytes which would be written
11138** to disk if that database were backed up to disk.
11139**
11140** The usual case is that sqlite3_serialize() copies the serialization of
11141** the database into memory obtained from [sqlite3_malloc64()] and returns
11142** a pointer to that memory. The caller is responsible for freeing the
11143** returned value to avoid a memory leak. However, if the F argument
11144** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
11145** are made, and the sqlite3_serialize() function will return a pointer
11146** to the contiguous memory representation of the database that SQLite
11147** is currently using for that database, or NULL if no such contiguous
11148** memory representation of the database exists. A contiguous memory
11149** representation of the database will usually only exist if there has
11150** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
11151** values of D and S.
11152** The size of the database is written into *P even if the
11153** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
11154** of the database exists.
11155**
11156** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
11157** the returned buffer content will remain accessible and unchanged
11158** until either the next write operation on the connection or when
11159** the connection is closed, and applications must not modify the
11160** buffer. If the bit had been clear, the returned buffer will not
11161** be accessed by SQLite after the call.
11162**
11163** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
11164** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
11165** allocation error occurs.
11166**
11167** This interface is omitted if SQLite is compiled with the
11168** [SQLITE_OMIT_DESERIALIZE] option.
11169*/
11170SQLITE_API unsigned char *sqlite3_serialize(
11171 sqlite3 *db, /* The database connection */
11172 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
11173 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
11174 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
11175);
11176
11177/*
11178** CAPI3REF: Flags for sqlite3_serialize
11179**
11180** Zero or more of the following constants can be OR-ed together for
11181** the F argument to [sqlite3_serialize(D,S,P,F)].
11182**
11183** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
11184** a pointer to contiguous in-memory database that it is currently using,
11185** without making a copy of the database. If SQLite is not currently using
11186** a contiguous in-memory database, then this option causes
11187** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
11188** using a contiguous in-memory database if it has been initialized by a
11189** prior call to [sqlite3_deserialize()].
11190*/
11191#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
11192
11193/*
11194** CAPI3REF: Deserialize a database
11195**
11196** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
11197** [database connection] D to disconnect from database S and then
11198** reopen S as an in-memory database based on the serialization
11199** contained in P. If S is a NULL pointer, the main database is
11200** used. The serialized database P is N bytes in size. M is the size
11201** of the buffer P, which might be larger than N. If M is larger than
11202** N, and the SQLITE_DESERIALIZE_READONLY bit is not set in F, then
11203** SQLite is permitted to add content to the in-memory database as
11204** long as the total size does not exceed M bytes.
11205**
11206** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
11207** invoke sqlite3_free() on the serialization buffer when the database
11208** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
11209** SQLite will try to increase the buffer size using sqlite3_realloc64()
11210** if writes on the database cause it to grow larger than M bytes.
11211**
11212** Applications must not modify the buffer P or invalidate it before
11213** the database connection D is closed.
11214**
11215** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
11216** database is currently in a read transaction or is involved in a backup
11217** operation.
11218**
11219** It is not possible to deserialize into the TEMP database. If the
11220** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
11221** function returns SQLITE_ERROR.
11222**
11223** The deserialized database should not be in [WAL mode]. If the database
11224** is in WAL mode, then any attempt to use the database file will result
11225** in an [SQLITE_CANTOPEN] error. The application can set the
11226** [file format version numbers] (bytes 18 and 19) of the input database P
11227** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
11228** database file into rollback mode and work around this limitation.
11229**
11230** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
11231** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
11232** [sqlite3_free()] is invoked on argument P prior to returning.
11233**
11234** This interface is omitted if SQLite is compiled with the
11235** [SQLITE_OMIT_DESERIALIZE] option.
11236*/
11237SQLITE_API int sqlite3_deserialize(
11238 sqlite3 *db, /* The database connection */
11239 const char *zSchema, /* Which DB to reopen with the deserialization */
11240 unsigned char *pData, /* The serialized database content */
11241 sqlite3_int64 szDb, /* Number of bytes in the deserialization */
11242 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
11243 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
11244);
11245
11246/*
11247** CAPI3REF: Flags for sqlite3_deserialize()
11248**
11249** The following are allowed values for the 6th argument (the F argument) to
11250** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
11251**
11252** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
11253** in the P argument is held in memory obtained from [sqlite3_malloc64()]
11254** and that SQLite should take ownership of this memory and automatically
11255** free it when it has finished using it. Without this flag, the caller
11256** is responsible for freeing any dynamically allocated memory.
11257**
11258** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
11259** grow the size of the database using calls to [sqlite3_realloc64()]. This
11260** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
11261** Without this flag, the deserialized database cannot increase in size beyond
11262** the number of bytes specified by the M parameter.
11263**
11264** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
11265** should be treated as read-only.
11266*/
11267#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
11268#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
11269#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
11270
11271/*
11272** CAPI3REF: Bind array values to the CARRAY table-valued function
11273**
11274** The sqlite3_carray_bind_v2(S,I,P,N,F,X,D) interface binds an array value to
11275** parameter that is the first argument of the [carray() table-valued function].
11276** The S parameter is a pointer to the [prepared statement] that uses the carray()
11277** functions. I is the parameter index to be bound. I must be the index of the
11278** parameter that is the first argument to the carray() table-valued function.
11279** P is a pointer to the array to be bound, and N is the number of elements in
11280** the array. The F argument is one of constants [SQLITE_CARRAY_INT32],
11281** [SQLITE_CARRAY_INT64], [SQLITE_CARRAY_DOUBLE], [SQLITE_CARRAY_TEXT],
11282** or [SQLITE_CARRAY_BLOB] to indicate the datatype of the array P.
11283**
11284** If the X argument is not a NULL pointer or one of the special
11285** values [SQLITE_STATIC] or [SQLITE_TRANSIENT], then SQLite will invoke
11286** the function X with argument D when it is finished using the data in P.
11287** The call to X(D) is a destructor for the array P. The destructor X(D)
11288** is invoked even if the call to sqlite3_carray_bind() fails. If the X
11289** parameter is the special-case value [SQLITE_STATIC], then SQLite assumes
11290** that the data static and the destructor is never invoked. If the X
11291** parameter is the special-case value [SQLITE_TRANSIENT], then
11292** sqlite3_carray_bind_v2() makes its own private copy of the data prior
11293** to returning and never invokes the destructor X.
11294**
11295** The sqlite3_carray_bind() function works the same as sqlite_carray_bind_v2()
11296** with a D parameter set to P. In other words,
11297** sqlite3_carray_bind(S,I,P,N,F,X) is same as
11298** sqlite3_carray_bind(S,I,P,N,F,X,P).
11299*/
11300SQLITE_API int sqlite3_carray_bind_v2(
11301 sqlite3_stmt *pStmt, /* Statement to be bound */
11302 int i, /* Parameter index */
11303 void *aData, /* Pointer to array data */
11304 int nData, /* Number of data elements */
11305 int mFlags, /* CARRAY flags */
11306 void (*xDel)(void*), /* Destructor for aData */
11307 void *pDel /* Optional argument to xDel() */
11308);
11309SQLITE_API int sqlite3_carray_bind(
11310 sqlite3_stmt *pStmt, /* Statement to be bound */
11311 int i, /* Parameter index */
11312 void *aData, /* Pointer to array data */
11313 int nData, /* Number of data elements */
11314 int mFlags, /* CARRAY flags */
11315 void (*xDel)(void*) /* Destructor for aData */
11316);
11317
11318/*
11319** CAPI3REF: Datatypes for the CARRAY table-valued function
11320**
11321** The fifth argument to the [sqlite3_carray_bind()] interface musts be
11322** one of the following constants, to specify the datatype of the array
11323** that is being bound into the [carray table-valued function].
11324*/
11325#define SQLITE_CARRAY_INT32 0 /* Data is 32-bit signed integers */
11326#define SQLITE_CARRAY_INT64 1 /* Data is 64-bit signed integers */
11327#define SQLITE_CARRAY_DOUBLE 2 /* Data is doubles */
11328#define SQLITE_CARRAY_TEXT 3 /* Data is char* */
11329#define SQLITE_CARRAY_BLOB 4 /* Data is struct iovec */
11330
11331/*
11332** Versions of the above #defines that omit the initial SQLITE_, for
11333** legacy compatibility.
11334*/
11335#define CARRAY_INT32 0 /* Data is 32-bit signed integers */
11336#define CARRAY_INT64 1 /* Data is 64-bit signed integers */
11337#define CARRAY_DOUBLE 2 /* Data is doubles */
11338#define CARRAY_TEXT 3 /* Data is char* */
11339#define CARRAY_BLOB 4 /* Data is struct iovec */
11340
11341/*
11342** Undo the hack that converts floating point types to integer for
11343** builds on processors without floating point support.
11344*/
11345#ifdef SQLITE_OMIT_FLOATING_POINT
11346# undef double
11347#endif
11348
11349#if defined(__wasi__)
11350# undef SQLITE_WASI
11351# define SQLITE_WASI 1
11352# ifndef SQLITE_OMIT_LOAD_EXTENSION
11353# define SQLITE_OMIT_LOAD_EXTENSION
11354# endif
11355# ifndef SQLITE_THREADSAFE
11356# define SQLITE_THREADSAFE 0
11357# endif
11358#endif
11359
11360#ifdef __cplusplus
11361} /* End of the 'extern "C"' block */
11362#endif
11363/* #endif for SQLITE3_H will be added by mksqlite3.tcl */
11364
11365/******** Begin file sqlite3rtree.h *********/
11366/*
11367** 2010 August 30
11368**
11369** The author disclaims copyright to this source code. In place of
11370** a legal notice, here is a blessing:
11371**
11372** May you do good and not evil.
11373** May you find forgiveness for yourself and forgive others.
11374** May you share freely, never taking more than you give.
11375**
11376*************************************************************************
11377*/
11378
11379#ifndef _SQLITE3RTREE_H_
11380#define _SQLITE3RTREE_H_
11381
11382
11383#ifdef __cplusplus
11384extern "C" {
11385#endif
11386
11387typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
11388typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
11389
11390/* The double-precision datatype used by RTree depends on the
11391** SQLITE_RTREE_INT_ONLY compile-time option.
11392*/
11393#ifdef SQLITE_RTREE_INT_ONLY
11394 typedef sqlite3_int64 sqlite3_rtree_dbl;
11395#else
11396 typedef double sqlite3_rtree_dbl;
11397#endif
11398
11399/*
11400** Register a geometry callback named zGeom that can be used as part of an
11401** R-Tree geometry query as follows:
11402**
11403** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
11404*/
11405SQLITE_API int sqlite3_rtree_geometry_callback(
11406 sqlite3 *db,
11407 const char *zGeom,
11408 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
11409 void *pContext
11410);
11411
11412
11413/*
11414** A pointer to a structure of the following type is passed as the first
11415** argument to callbacks registered using rtree_geometry_callback().
11416*/
11417struct sqlite3_rtree_geometry {
11418 void *pContext; /* Copy of pContext passed to s_r_g_c() */
11419 int nParam; /* Size of array aParam[] */
11420 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
11421 void *pUser; /* Callback implementation user data */
11422 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
11423};
11424
11425/*
11426** Register a 2nd-generation geometry callback named zScore that can be
11427** used as part of an R-Tree geometry query as follows:
11428**
11429** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
11430*/
11431SQLITE_API int sqlite3_rtree_query_callback(
11432 sqlite3 *db,
11433 const char *zQueryFunc,
11434 int (*xQueryFunc)(sqlite3_rtree_query_info*),
11435 void *pContext,
11436 void (*xDestructor)(void*)
11437);
11438
11439
11440/*
11441** A pointer to a structure of the following type is passed as the
11442** argument to scored geometry callback registered using
11443** sqlite3_rtree_query_callback().
11444**
11445** Note that the first 5 fields of this structure are identical to
11446** sqlite3_rtree_geometry. This structure is a subclass of
11447** sqlite3_rtree_geometry.
11448*/
11449struct sqlite3_rtree_query_info {
11450 void *pContext; /* pContext from when function registered */
11451 int nParam; /* Number of function parameters */
11452 sqlite3_rtree_dbl *aParam; /* value of function parameters */
11453 void *pUser; /* callback can use this, if desired */
11454 void (*xDelUser)(void*); /* function to free pUser */
11455 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
11456 unsigned int *anQueue; /* Number of pending entries in the queue */
11457 int nCoord; /* Number of coordinates */
11458 int iLevel; /* Level of current node or entry */
11459 int mxLevel; /* The largest iLevel value in the tree */
11460 sqlite3_int64 iRowid; /* Rowid for current entry */
11461 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
11462 int eParentWithin; /* Visibility of parent node */
11463 int eWithin; /* OUT: Visibility */
11464 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
11465 /* The following fields are only available in 3.8.11 and later */
11466 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
11467};
11468
11469/*
11470** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
11471*/
11472#define NOT_WITHIN 0 /* Object completely outside of query region */
11473#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
11474#define FULLY_WITHIN 2 /* Object fully contained within query region */
11475
11476
11477#ifdef __cplusplus
11478} /* end of the 'extern "C"' block */
11479#endif
11480
11481#endif /* ifndef _SQLITE3RTREE_H_ */
11482
11483/******** End of sqlite3rtree.h *********/
11484/******** Begin file sqlite3session.h *********/
11485
11486#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
11487#define __SQLITESESSION_H_ 1
11488
11489/*
11490** Make sure we can call this stuff from C++.
11491*/
11492#ifdef __cplusplus
11493extern "C" {
11494#endif
11495
11496
11497/*
11498** CAPI3REF: Session Object Handle
11499**
11500** An instance of this object is a [session] that can be used to
11501** record changes to a database.
11502*/
11503typedef struct sqlite3_session sqlite3_session;
11504
11505/*
11506** CAPI3REF: Changeset Iterator Handle
11507**
11508** An instance of this object acts as a cursor for iterating
11509** over the elements of a [changeset] or [patchset].
11510*/
11511typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
11512
11513/*
11514** CAPI3REF: Create A New Session Object
11515** CONSTRUCTOR: sqlite3_session
11516**
11517** Create a new session object attached to database handle db. If successful,
11518** a pointer to the new object is written to *ppSession and SQLITE_OK is
11519** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11520** error code (e.g. SQLITE_NOMEM) is returned.
11521**
11522** It is possible to create multiple session objects attached to a single
11523** database handle.
11524**
11525** Session objects created using this function should be deleted using the
11526** [sqlite3session_delete()] function before the database handle that they
11527** are attached to is itself closed. If the database handle is closed before
11528** the session object is deleted, then the results of calling any session
11529** module function, including [sqlite3session_delete()] on the session object
11530** are undefined.
11531**
11532** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11533** is not possible for an application to register a pre-update hook on a
11534** database handle that has one or more session objects attached. Nor is
11535** it possible to create a session object attached to a database handle for
11536** which a pre-update hook is already defined. The results of attempting
11537** either of these things are undefined.
11538**
11539** The session object will be used to create changesets for tables in
11540** database zDb, where zDb is either "main", or "temp", or the name of an
11541** attached database. It is not an error if database zDb is not attached
11542** to the database when the session object is created.
11543*/
11544SQLITE_API int sqlite3session_create(
11545 sqlite3 *db, /* Database handle */
11546 const char *zDb, /* Name of db (e.g. "main") */
11547 sqlite3_session **ppSession /* OUT: New session object */
11548);
11549
11550/*
11551** CAPI3REF: Delete A Session Object
11552** DESTRUCTOR: sqlite3_session
11553**
11554** Delete a session object previously allocated using
11555** [sqlite3session_create()]. Once a session object has been deleted, the
11556** results of attempting to use pSession with any other session module
11557** function are undefined.
11558**
11559** Session objects must be deleted before the database handle to which they
11560** are attached is closed. Refer to the documentation for
11561** [sqlite3session_create()] for details.
11562*/
11563SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11564
11565/*
11566** CAPI3REF: Configure a Session Object
11567** METHOD: sqlite3_session
11568**
11569** This method is used to configure a session object after it has been
11570** created. At present the only valid values for the second parameter are
11571** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11572**
11573*/
11574SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11575
11576/*
11577** CAPI3REF: Options for sqlite3session_object_config
11578**
11579** The following values may passed as the the 2nd parameter to
11580** sqlite3session_object_config().
11581**
11582** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11583** This option is used to set, clear or query the flag that enables
11584** the [sqlite3session_changeset_size()] API. Because it imposes some
11585** computational overhead, this API is disabled by default. Argument
11586** pArg must point to a value of type (int). If the value is initially
11587** 0, then the sqlite3session_changeset_size() API is disabled. If it
11588** is greater than 0, then the same API is enabled. Or, if the initial
11589** value is less than zero, no change is made. In all cases the (int)
11590** variable is set to 1 if the sqlite3session_changeset_size() API is
11591** enabled following the current call, or 0 otherwise.
11592**
11593** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11594** the first table has been attached to the session object.
11595**
11596** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11597** This option is used to set, clear or query the flag that enables
11598** collection of data for tables with no explicit PRIMARY KEY.
11599**
11600** Normally, tables with no explicit PRIMARY KEY are simply ignored
11601** by the sessions module. However, if this flag is set, it behaves
11602** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11603** as their leftmost columns.
11604**
11605** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11606** the first table has been attached to the session object.
11607*/
11608#define SQLITE_SESSION_OBJCONFIG_SIZE 1
11609#define SQLITE_SESSION_OBJCONFIG_ROWID 2
11610
11611/*
11612** CAPI3REF: Enable Or Disable A Session Object
11613** METHOD: sqlite3_session
11614**
11615** Enable or disable the recording of changes by a session object. When
11616** enabled, a session object records changes made to the database. When
11617** disabled - it does not. A newly created session object is enabled.
11618** Refer to the documentation for [sqlite3session_changeset()] for further
11619** details regarding how enabling and disabling a session object affects
11620** the eventual changesets.
11621**
11622** Passing zero to this function disables the session. Passing a value
11623** greater than zero enables it. Passing a value less than zero is a
11624** no-op, and may be used to query the current state of the session.
11625**
11626** The return value indicates the final state of the session object: 0 if
11627** the session is disabled, or 1 if it is enabled.
11628*/
11629SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11630
11631/*
11632** CAPI3REF: Set Or Clear the Indirect Change Flag
11633** METHOD: sqlite3_session
11634**
11635** Each change recorded by a session object is marked as either direct or
11636** indirect. A change is marked as indirect if either:
11637**
11638** <ul>
11639** <li> The session object "indirect" flag is set when the change is
11640** made, or
11641** <li> The change is made by an SQL trigger or foreign key action
11642** instead of directly as a result of a users SQL statement.
11643** </ul>
11644**
11645** If a single row is affected by more than one operation within a session,
11646** then the change is considered indirect if all operations meet the criteria
11647** for an indirect change above, or direct otherwise.
11648**
11649** This function is used to set, clear or query the session object indirect
11650** flag. If the second argument passed to this function is zero, then the
11651** indirect flag is cleared. If it is greater than zero, the indirect flag
11652** is set. Passing a value less than zero does not modify the current value
11653** of the indirect flag, and may be used to query the current state of the
11654** indirect flag for the specified session object.
11655**
11656** The return value indicates the final state of the indirect flag: 0 if
11657** it is clear, or 1 if it is set.
11658*/
11659SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11660
11661/*
11662** CAPI3REF: Attach A Table To A Session Object
11663** METHOD: sqlite3_session
11664**
11665** If argument zTab is not NULL, then it is the name of a table to attach
11666** to the session object passed as the first argument. All subsequent changes
11667** made to the table while the session object is enabled will be recorded. See
11668** documentation for [sqlite3session_changeset()] for further details.
11669**
11670** Or, if argument zTab is NULL, then changes are recorded for all tables
11671** in the database. If additional tables are added to the database (by
11672** executing "CREATE TABLE" statements) after this call is made, changes for
11673** the new tables are also recorded.
11674**
11675** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11676** defined as part of their CREATE TABLE statement. It does not matter if the
11677** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11678** KEY may consist of a single column, or may be a composite key.
11679**
11680** It is not an error if the named table does not exist in the database. Nor
11681** is it an error if the named table does not have a PRIMARY KEY. However,
11682** no changes will be recorded in either of these scenarios.
11683**
11684** Changes are not recorded for individual rows that have NULL values stored
11685** in one or more of their PRIMARY KEY columns.
11686**
11687** SQLITE_OK is returned if the call completes without error. Or, if an error
11688** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11689**
11690** <h3>Special sqlite_stat1 Handling</h3>
11691**
11692** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11693** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11694** <pre>
11695** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
11696** </pre>
11697**
11698** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11699** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11700** are recorded for rows for which (idx IS NULL) is true. However, for such
11701** rows a zero-length blob (SQL value X'') is stored in the changeset or
11702** patchset instead of a NULL value. This allows such changesets to be
11703** manipulated by legacy implementations of sqlite3changeset_invert(),
11704** concat() and similar.
11705**
11706** The sqlite3changeset_apply() function automatically converts the
11707** zero-length blob back to a NULL value when updating the sqlite_stat1
11708** table. However, if the application calls sqlite3changeset_new(),
11709** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11710** iterator directly (including on a changeset iterator passed to a
11711** conflict-handler callback) then the X'' value is returned. The application
11712** must translate X'' to NULL itself if required.
11713**
11714** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11715** changes made to the sqlite_stat1 table. Legacy versions of the
11716** sqlite3changeset_apply() function silently ignore any modifications to the
11717** sqlite_stat1 table that are part of a changeset or patchset.
11718*/
11719SQLITE_API int sqlite3session_attach(
11720 sqlite3_session *pSession, /* Session object */
11721 const char *zTab /* Table name */
11722);
11723
11724/*
11725** CAPI3REF: Set a table filter on a Session Object.
11726** METHOD: sqlite3_session
11727**
11728** The second argument (xFilter) is the "filter callback". For changes to rows
11729** in tables that are not attached to the Session object, the filter is called
11730** to determine whether changes to the table's rows should be tracked or not.
11731** If xFilter returns 0, changes are not tracked. Note that once a table is
11732** attached, xFilter will not be called again.
11733*/
11734SQLITE_API void sqlite3session_table_filter(
11735 sqlite3_session *pSession, /* Session object */
11736 int(*xFilter)(
11737 void *pCtx, /* Copy of third arg to _filter_table() */
11738 const char *zTab /* Table name */
11739 ),
11740 void *pCtx /* First argument passed to xFilter */
11741);
11742
11743/*
11744** CAPI3REF: Generate A Changeset From A Session Object
11745** METHOD: sqlite3_session
11746**
11747** Obtain a changeset containing changes to the tables attached to the
11748** session object passed as the first argument. If successful,
11749** set *ppChangeset to point to a buffer containing the changeset
11750** and *pnChangeset to the size of the changeset in bytes before returning
11751** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11752** zero and return an SQLite error code.
11753**
11754** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11755** each representing a change to a single row of an attached table. An INSERT
11756** change contains the values of each field of a new database row. A DELETE
11757** contains the original values of each field of a deleted database row. An
11758** UPDATE change contains the original values of each field of an updated
11759** database row along with the updated values for each updated non-primary-key
11760** column. It is not possible for an UPDATE change to represent a change that
11761** modifies the values of primary key columns. If such a change is made, it
11762** is represented in a changeset as a DELETE followed by an INSERT.
11763**
11764** Changes are not recorded for rows that have NULL values stored in one or
11765** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11766** no corresponding change is present in the changesets returned by this
11767** function. If an existing row with one or more NULL values stored in
11768** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11769** only an INSERT is appears in the changeset. Similarly, if an existing row
11770** with non-NULL PRIMARY KEY values is updated so that one or more of its
11771** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11772** DELETE change only.
11773**
11774** The contents of a changeset may be traversed using an iterator created
11775** using the [sqlite3changeset_start()] API. A changeset may be applied to
11776** a database with a compatible schema using the [sqlite3changeset_apply()]
11777** API.
11778**
11779** Within a changeset generated by this function, all changes related to a
11780** single table are grouped together. In other words, when iterating through
11781** a changeset or when applying a changeset to a database, all changes related
11782** to a single table are processed before moving on to the next table. Tables
11783** are sorted in the same order in which they were attached (or auto-attached)
11784** to the sqlite3_session object. The order in which the changes related to
11785** a single table are stored is undefined.
11786**
11787** Following a successful call to this function, it is the responsibility of
11788** the caller to eventually free the buffer that *ppChangeset points to using
11789** [sqlite3_free()].
11790**
11791** <h3>Changeset Generation</h3>
11792**
11793** Once a table has been attached to a session object, the session object
11794** records the primary key values of all new rows inserted into the table.
11795** It also records the original primary key and other column values of any
11796** deleted or updated rows. For each unique primary key value, data is only
11797** recorded once - the first time a row with said primary key is inserted,
11798** updated or deleted in the lifetime of the session.
11799**
11800** There is one exception to the previous paragraph: when a row is inserted,
11801** updated or deleted, if one or more of its primary key columns contain a
11802** NULL value, no record of the change is made.
11803**
11804** The session object therefore accumulates two types of records - those
11805** that consist of primary key values only (created when the user inserts
11806** a new record) and those that consist of the primary key values and the
11807** original values of other table columns (created when the users deletes
11808** or updates a record).
11809**
11810** When this function is called, the requested changeset is created using
11811** both the accumulated records and the current contents of the database
11812** file. Specifically:
11813**
11814** <ul>
11815** <li> For each record generated by an insert, the database is queried
11816** for a row with a matching primary key. If one is found, an INSERT
11817** change is added to the changeset. If no such row is found, no change
11818** is added to the changeset.
11819**
11820** <li> For each record generated by an update or delete, the database is
11821** queried for a row with a matching primary key. If such a row is
11822** found and one or more of the non-primary key fields have been
11823** modified from their original values, an UPDATE change is added to
11824** the changeset. Or, if no such row is found in the table, a DELETE
11825** change is added to the changeset. If there is a row with a matching
11826** primary key in the database, but all fields contain their original
11827** values, no change is added to the changeset.
11828** </ul>
11829**
11830** This means, amongst other things, that if a row is inserted and then later
11831** deleted while a session object is active, neither the insert nor the delete
11832** will be present in the changeset. Or if a row is deleted and then later a
11833** row with the same primary key values inserted while a session object is
11834** active, the resulting changeset will contain an UPDATE change instead of
11835** a DELETE and an INSERT.
11836**
11837** When a session object is disabled (see the [sqlite3session_enable()] API),
11838** it does not accumulate records when rows are inserted, updated or deleted.
11839** This may appear to have some counter-intuitive effects if a single row
11840** is written to more than once during a session. For example, if a row
11841** is inserted while a session object is enabled, then later deleted while
11842** the same session object is disabled, no INSERT record will appear in the
11843** changeset, even though the delete took place while the session was disabled.
11844** Or, if one field of a row is updated while a session is enabled, and
11845** then another field of the same row is updated while the session is disabled,
11846** the resulting changeset will contain an UPDATE change that updates both
11847** fields.
11848*/
11849SQLITE_API int sqlite3session_changeset(
11850 sqlite3_session *pSession, /* Session object */
11851 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11852 void **ppChangeset /* OUT: Buffer containing changeset */
11853);
11854
11855/*
11856** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11857** METHOD: sqlite3_session
11858**
11859** By default, this function always returns 0. For it to return
11860** a useful result, the sqlite3_session object must have been configured
11861** to enable this API using sqlite3session_object_config() with the
11862** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11863**
11864** When enabled, this function returns an upper limit, in bytes, for the size
11865** of the changeset that might be produced if sqlite3session_changeset() were
11866** called. The final changeset size might be equal to or smaller than the
11867** size in bytes returned by this function.
11868*/
11869SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11870
11871/*
11872** CAPI3REF: Load The Difference Between Tables Into A Session
11873** METHOD: sqlite3_session
11874**
11875** If it is not already attached to the session object passed as the first
11876** argument, this function attaches table zTbl in the same manner as the
11877** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11878** does not have a primary key, this function is a no-op (but does not return
11879** an error).
11880**
11881** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11882** attached to the same database handle as the session object that contains
11883** a table compatible with the table attached to the session by this function.
11884** A table is considered compatible if it:
11885**
11886** <ul>
11887** <li> Has the same name,
11888** <li> Has the same set of columns declared in the same order, and
11889** <li> Has the same PRIMARY KEY definition.
11890** </ul>
11891**
11892** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11893** are compatible but do not have any PRIMARY KEY columns, it is not an error
11894** but no changes are added to the session object. As with other session
11895** APIs, tables without PRIMARY KEYs are simply ignored.
11896**
11897** This function adds a set of changes to the session object that could be
11898** used to update the table in database zFrom (call this the "from-table")
11899** so that its content is the same as the table attached to the session
11900** object (call this the "to-table"). Specifically:
11901**
11902** <ul>
11903** <li> For each row (primary key) that exists in the to-table but not in
11904** the from-table, an INSERT record is added to the session object.
11905**
11906** <li> For each row (primary key) that exists in the to-table but not in
11907** the from-table, a DELETE record is added to the session object.
11908**
11909** <li> For each row (primary key) that exists in both tables, but features
11910** different non-PK values in each, an UPDATE record is added to the
11911** session.
11912** </ul>
11913**
11914** To clarify, if this function is called and then a changeset constructed
11915** using [sqlite3session_changeset()], then after applying that changeset to
11916** database zFrom the contents of the two compatible tables would be
11917** identical.
11918**
11919** Unless the call to this function is a no-op as described above, it is an
11920** error if database zFrom does not exist or does not contain the required
11921** compatible table.
11922**
11923** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11924** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11925** may be set to point to a buffer containing an English language error
11926** message. It is the responsibility of the caller to free this buffer using
11927** sqlite3_free().
11928*/
11929SQLITE_API int sqlite3session_diff(
11930 sqlite3_session *pSession,
11931 const char *zFromDb,
11932 const char *zTbl,
11933 char **pzErrMsg
11934);
11935
11936
11937/*
11938** CAPI3REF: Generate A Patchset From A Session Object
11939** METHOD: sqlite3_session
11940**
11941** The differences between a patchset and a changeset are that:
11942**
11943** <ul>
11944** <li> DELETE records consist of the primary key fields only. The
11945** original values of other fields are omitted.
11946** <li> The original values of any modified fields are omitted from
11947** UPDATE records.
11948** </ul>
11949**
11950** A patchset blob may be used with up to date versions of all
11951** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11952** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11953** attempting to use a patchset blob with old versions of the
11954** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11955**
11956** Because the non-primary key "old.*" fields are omitted, no
11957** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11958** is passed to the sqlite3changeset_apply() API. Other conflict types work
11959** in the same way as for changesets.
11960**
11961** Changes within a patchset are ordered in the same way as for changesets
11962** generated by the sqlite3session_changeset() function (i.e. all changes for
11963** a single table are grouped together, tables appear in the order in which
11964** they were attached to the session object).
11965*/
11966SQLITE_API int sqlite3session_patchset(
11967 sqlite3_session *pSession, /* Session object */
11968 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11969 void **ppPatchset /* OUT: Buffer containing patchset */
11970);
11971
11972/*
11973** CAPI3REF: Test if a changeset has recorded any changes.
11974**
11975** Return non-zero if no changes to attached tables have been recorded by
11976** the session object passed as the first argument. Otherwise, if one or
11977** more changes have been recorded, return zero.
11978**
11979** Even if this function returns zero, it is possible that calling
11980** [sqlite3session_changeset()] on the session handle may still return a
11981** changeset that contains no changes. This can happen when a row in
11982** an attached table is modified and then later on the original values
11983** are restored. However, if this function returns non-zero, then it is
11984** guaranteed that a call to sqlite3session_changeset() will return a
11985** changeset containing zero changes.
11986*/
11987SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11988
11989/*
11990** CAPI3REF: Query for the amount of heap memory used by a session object.
11991**
11992** This API returns the total amount of heap memory in bytes currently
11993** used by the session object passed as the only argument.
11994*/
11995SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11996
11997/*
11998** CAPI3REF: Create An Iterator To Traverse A Changeset
11999** CONSTRUCTOR: sqlite3_changeset_iter
12000**
12001** Create an iterator used to iterate through the contents of a changeset.
12002** If successful, *pp is set to point to the iterator handle and SQLITE_OK
12003** is returned. Otherwise, if an error occurs, *pp is set to zero and an
12004** SQLite error code is returned.
12005**
12006** The following functions can be used to advance and query a changeset
12007** iterator created by this function:
12008**
12009** <ul>
12010** <li> [sqlite3changeset_next()]
12011** <li> [sqlite3changeset_op()]
12012** <li> [sqlite3changeset_new()]
12013** <li> [sqlite3changeset_old()]
12014** </ul>
12015**
12016** It is the responsibility of the caller to eventually destroy the iterator
12017** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
12018** changeset (pChangeset) must remain valid until after the iterator is
12019** destroyed.
12020**
12021** Assuming the changeset blob was created by one of the
12022** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
12023** [sqlite3changeset_invert()] functions, all changes within the changeset
12024** that apply to a single table are grouped together. This means that when
12025** an application iterates through a changeset using an iterator created by
12026** this function, all changes that relate to a single table are visited
12027** consecutively. There is no chance that the iterator will visit a change
12028** the applies to table X, then one for table Y, and then later on visit
12029** another change for table X.
12030**
12031** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
12032** may be modified by passing a combination of
12033** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
12034**
12035** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
12036** and therefore subject to change.
12037*/
12038SQLITE_API int sqlite3changeset_start(
12039 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
12040 int nChangeset, /* Size of changeset blob in bytes */
12041 void *pChangeset /* Pointer to blob containing changeset */
12042);
12043SQLITE_API int sqlite3changeset_start_v2(
12044 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
12045 int nChangeset, /* Size of changeset blob in bytes */
12046 void *pChangeset, /* Pointer to blob containing changeset */
12047 int flags /* SESSION_CHANGESETSTART_* flags */
12048);
12049
12050/*
12051** CAPI3REF: Flags for sqlite3changeset_start_v2
12052**
12053** The following flags may passed via the 4th parameter to
12054** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
12055**
12056** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
12057** Invert the changeset while iterating through it. This is equivalent to
12058** inverting a changeset using sqlite3changeset_invert() before applying it.
12059** It is an error to specify this flag with a patchset.
12060*/
12061#define SQLITE_CHANGESETSTART_INVERT 0x0002
12062
12063
12064/*
12065** CAPI3REF: Advance A Changeset Iterator
12066** METHOD: sqlite3_changeset_iter
12067**
12068** This function may only be used with iterators created by the function
12069** [sqlite3changeset_start()]. If it is called on an iterator passed to
12070** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
12071** is returned and the call has no effect.
12072**
12073** Immediately after an iterator is created by sqlite3changeset_start(), it
12074** does not point to any change in the changeset. Assuming the changeset
12075** is not empty, the first call to this function advances the iterator to
12076** point to the first change in the changeset. Each subsequent call advances
12077** the iterator to point to the next change in the changeset (if any). If
12078** no error occurs and the iterator points to a valid change after a call
12079** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
12080** Otherwise, if all changes in the changeset have already been visited,
12081** SQLITE_DONE is returned.
12082**
12083** If an error occurs, an SQLite error code is returned. Possible error
12084** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
12085** SQLITE_NOMEM.
12086*/
12087SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
12088
12089/*
12090** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
12091** METHOD: sqlite3_changeset_iter
12092**
12093** The pIter argument passed to this function may either be an iterator
12094** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12095** created by [sqlite3changeset_start()]. In the latter case, the most recent
12096** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
12097** is not the case, this function returns [SQLITE_MISUSE].
12098**
12099** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
12100** outputs are set through these pointers:
12101**
12102** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
12103** depending on the type of change that the iterator currently points to;
12104**
12105** *pnCol is set to the number of columns in the table affected by the change; and
12106**
12107** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
12108** the name of the table affected by the current change. The buffer remains
12109** valid until either sqlite3changeset_next() is called on the iterator
12110** or until the conflict-handler function returns.
12111**
12112** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
12113** is an indirect change, or false (0) otherwise. See the documentation for
12114** [sqlite3session_indirect()] for a description of direct and indirect
12115** changes.
12116**
12117** If no error occurs, SQLITE_OK is returned. If an error does occur, an
12118** SQLite error code is returned. The values of the output variables may not
12119** be trusted in this case.
12120*/
12121SQLITE_API int sqlite3changeset_op(
12122 sqlite3_changeset_iter *pIter, /* Iterator object */
12123 const char **pzTab, /* OUT: Pointer to table name */
12124 int *pnCol, /* OUT: Number of columns in table */
12125 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
12126 int *pbIndirect /* OUT: True for an 'indirect' change */
12127);
12128
12129/*
12130** CAPI3REF: Obtain The Primary Key Definition Of A Table
12131** METHOD: sqlite3_changeset_iter
12132**
12133** For each modified table, a changeset includes the following:
12134**
12135** <ul>
12136** <li> The number of columns in the table, and
12137** <li> Which of those columns make up the tables PRIMARY KEY.
12138** </ul>
12139**
12140** This function is used to find which columns comprise the PRIMARY KEY of
12141** the table modified by the change that iterator pIter currently points to.
12142** If successful, *pabPK is set to point to an array of nCol entries, where
12143** nCol is the number of columns in the table. Elements of *pabPK are set to
12144** 0x01 if the corresponding column is part of the tables primary key, or
12145** 0x00 if it is not.
12146**
12147** If argument pnCol is not NULL, then *pnCol is set to the number of columns
12148** in the table.
12149**
12150** If this function is called when the iterator does not point to a valid
12151** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
12152** SQLITE_OK is returned and the output variables populated as described
12153** above.
12154*/
12155SQLITE_API int sqlite3changeset_pk(
12156 sqlite3_changeset_iter *pIter, /* Iterator object */
12157 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
12158 int *pnCol /* OUT: Number of entries in output array */
12159);
12160
12161/*
12162** CAPI3REF: Obtain old.* Values From A Changeset Iterator
12163** METHOD: sqlite3_changeset_iter
12164**
12165** The pIter argument passed to this function may either be an iterator
12166** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12167** created by [sqlite3changeset_start()]. In the latter case, the most recent
12168** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12169** Furthermore, it may only be called if the type of change that the iterator
12170** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
12171** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12172**
12173** Argument iVal must be greater than or equal to 0, and less than the number
12174** of columns in the table affected by the current change. Otherwise,
12175** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12176**
12177** If successful, this function sets *ppValue to point to a protected
12178** sqlite3_value object containing the iVal'th value from the vector of
12179** original row values stored as part of the UPDATE or DELETE change and
12180** returns SQLITE_OK. The name of the function comes from the fact that this
12181** is similar to the "old.*" columns available to update or delete triggers.
12182**
12183** If some other error occurs (e.g. an OOM condition), an SQLite error code
12184** is returned and *ppValue is set to NULL.
12185*/
12186SQLITE_API int sqlite3changeset_old(
12187 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12188 int iVal, /* Column number */
12189 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
12190);
12191
12192/*
12193** CAPI3REF: Obtain new.* Values From A Changeset Iterator
12194** METHOD: sqlite3_changeset_iter
12195**
12196** The pIter argument passed to this function may either be an iterator
12197** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12198** created by [sqlite3changeset_start()]. In the latter case, the most recent
12199** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12200** Furthermore, it may only be called if the type of change that the iterator
12201** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
12202** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12203**
12204** Argument iVal must be greater than or equal to 0, and less than the number
12205** of columns in the table affected by the current change. Otherwise,
12206** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12207**
12208** If successful, this function sets *ppValue to point to a protected
12209** sqlite3_value object containing the iVal'th value from the vector of
12210** new row values stored as part of the UPDATE or INSERT change and
12211** returns SQLITE_OK. If the change is an UPDATE and does not include
12212** a new value for the requested column, *ppValue is set to NULL and
12213** SQLITE_OK returned. The name of the function comes from the fact that
12214** this is similar to the "new.*" columns available to update or delete
12215** triggers.
12216**
12217** If some other error occurs (e.g. an OOM condition), an SQLite error code
12218** is returned and *ppValue is set to NULL.
12219*/
12220SQLITE_API int sqlite3changeset_new(
12221 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12222 int iVal, /* Column number */
12223 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
12224);
12225
12226/*
12227** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
12228** METHOD: sqlite3_changeset_iter
12229**
12230** This function should only be used with iterator objects passed to a
12231** conflict-handler callback by [sqlite3changeset_apply()] with either
12232** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
12233** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
12234** is set to NULL.
12235**
12236** Argument iVal must be greater than or equal to 0, and less than the number
12237** of columns in the table affected by the current change. Otherwise,
12238** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12239**
12240** If successful, this function sets *ppValue to point to a protected
12241** sqlite3_value object containing the iVal'th value from the
12242** "conflicting row" associated with the current conflict-handler callback
12243** and returns SQLITE_OK.
12244**
12245** If some other error occurs (e.g. an OOM condition), an SQLite error code
12246** is returned and *ppValue is set to NULL.
12247*/
12248SQLITE_API int sqlite3changeset_conflict(
12249 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12250 int iVal, /* Column number */
12251 sqlite3_value **ppValue /* OUT: Value from conflicting row */
12252);
12253
12254/*
12255** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
12256** METHOD: sqlite3_changeset_iter
12257**
12258** This function may only be called with an iterator passed to an
12259** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
12260** it sets the output variable to the total number of known foreign key
12261** violations in the destination database and returns SQLITE_OK.
12262**
12263** In all other cases this function returns SQLITE_MISUSE.
12264*/
12265SQLITE_API int sqlite3changeset_fk_conflicts(
12266 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12267 int *pnOut /* OUT: Number of FK violations */
12268);
12269
12270
12271/*
12272** CAPI3REF: Finalize A Changeset Iterator
12273** METHOD: sqlite3_changeset_iter
12274**
12275** This function is used to finalize an iterator allocated with
12276** [sqlite3changeset_start()].
12277**
12278** This function should only be called on iterators created using the
12279** [sqlite3changeset_start()] function. If an application calls this
12280** function with an iterator passed to a conflict-handler by
12281** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
12282** call has no effect.
12283**
12284** If an error was encountered within a call to an sqlite3changeset_xxx()
12285** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
12286** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
12287** to that error is returned by this function. Otherwise, SQLITE_OK is
12288** returned. This is to allow the following pattern (pseudo-code):
12289**
12290** <pre>
12291** sqlite3changeset_start();
12292** while( SQLITE_ROW==sqlite3changeset_next() ){
12293** // Do something with change.
12294** }
12295** rc = sqlite3changeset_finalize();
12296** if( rc!=SQLITE_OK ){
12297** // An error has occurred
12298** }
12299** </pre>
12300*/
12301SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
12302
12303/*
12304** CAPI3REF: Invert A Changeset
12305**
12306** This function is used to "invert" a changeset object. Applying an inverted
12307** changeset to a database reverses the effects of applying the uninverted
12308** changeset. Specifically:
12309**
12310** <ul>
12311** <li> Each DELETE change is changed to an INSERT, and
12312** <li> Each INSERT change is changed to a DELETE, and
12313** <li> For each UPDATE change, the old.* and new.* values are exchanged.
12314** </ul>
12315**
12316** This function does not change the order in which changes appear within
12317** the changeset. It merely reverses the sense of each individual change.
12318**
12319** If successful, a pointer to a buffer containing the inverted changeset
12320** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
12321** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
12322** zeroed and an SQLite error code returned.
12323**
12324** It is the responsibility of the caller to eventually call sqlite3_free()
12325** on the *ppOut pointer to free the buffer allocation following a successful
12326** call to this function.
12327**
12328** WARNING/TODO: This function currently assumes that the input is a valid
12329** changeset. If it is not, the results are undefined.
12330*/
12331SQLITE_API int sqlite3changeset_invert(
12332 int nIn, const void *pIn, /* Input changeset */
12333 int *pnOut, void **ppOut /* OUT: Inverse of input */
12334);
12335
12336/*
12337** CAPI3REF: Concatenate Two Changeset Objects
12338**
12339** This function is used to concatenate two changesets, A and B, into a
12340** single changeset. The result is a changeset equivalent to applying
12341** changeset A followed by changeset B.
12342**
12343** This function combines the two input changesets using an
12344** sqlite3_changegroup object. Calling it produces similar results as the
12345** following code fragment:
12346**
12347** <pre>
12348** sqlite3_changegroup *pGrp;
12349** rc = sqlite3_changegroup_new(&pGrp);
12350** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
12351** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
12352** if( rc==SQLITE_OK ){
12353** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
12354** }else{
12355** *ppOut = 0;
12356** *pnOut = 0;
12357** }
12358** </pre>
12359**
12360** Refer to the sqlite3_changegroup documentation below for details.
12361*/
12362SQLITE_API int sqlite3changeset_concat(
12363 int nA, /* Number of bytes in buffer pA */
12364 void *pA, /* Pointer to buffer containing changeset A */
12365 int nB, /* Number of bytes in buffer pB */
12366 void *pB, /* Pointer to buffer containing changeset B */
12367 int *pnOut, /* OUT: Number of bytes in output changeset */
12368 void **ppOut /* OUT: Buffer containing output changeset */
12369);
12370
12371/*
12372** CAPI3REF: Changegroup Handle
12373**
12374** A changegroup is an object used to combine two or more
12375** [changesets] or [patchsets]
12376*/
12377typedef struct sqlite3_changegroup sqlite3_changegroup;
12378
12379/*
12380** CAPI3REF: Create A New Changegroup Object
12381** CONSTRUCTOR: sqlite3_changegroup
12382**
12383** An sqlite3_changegroup object is used to combine two or more changesets
12384** (or patchsets) into a single changeset (or patchset). A single changegroup
12385** object may combine changesets or patchsets, but not both. The output is
12386** always in the same format as the input.
12387**
12388** If successful, this function returns SQLITE_OK and populates (*pp) with
12389** a pointer to a new sqlite3_changegroup object before returning. The caller
12390** should eventually free the returned object using a call to
12391** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
12392** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
12393**
12394** The usual usage pattern for an sqlite3_changegroup object is as follows:
12395**
12396** <ul>
12397** <li> It is created using a call to sqlite3changegroup_new().
12398**
12399** <li> Zero or more changesets (or patchsets) are added to the object
12400** by calling sqlite3changegroup_add().
12401**
12402** <li> The result of combining all input changesets together is obtained
12403** by the application via a call to sqlite3changegroup_output().
12404**
12405** <li> The object is deleted using a call to sqlite3changegroup_delete().
12406** </ul>
12407**
12408** Any number of calls to add() and output() may be made between the calls to
12409** new() and delete(), and in any order.
12410**
12411** As well as the regular sqlite3changegroup_add() and
12412** sqlite3changegroup_output() functions, also available are the streaming
12413** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
12414*/
12415SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
12416
12417/*
12418** CAPI3REF: Add a Schema to a Changegroup
12419** METHOD: sqlite3_changegroup_schema
12420**
12421** This method may be used to optionally enforce the rule that the changesets
12422** added to the changegroup handle must match the schema of database zDb
12423** ("main", "temp", or the name of an attached database). If
12424** sqlite3changegroup_add() is called to add a changeset that is not compatible
12425** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
12426** object is left in an undefined state.
12427**
12428** A changeset schema is considered compatible with the database schema in
12429** the same way as for sqlite3changeset_apply(). Specifically, for each
12430** table in the changeset, there exists a database table with:
12431**
12432** <ul>
12433** <li> The name identified by the changeset, and
12434** <li> at least as many columns as recorded in the changeset, and
12435** <li> the primary key columns in the same position as recorded in
12436** the changeset.
12437** </ul>
12438**
12439** The output of the changegroup object always has the same schema as the
12440** database nominated using this function. In cases where changesets passed
12441** to sqlite3changegroup_add() have fewer columns than the corresponding table
12442** in the database schema, these are filled in using the default column
12443** values from the database schema. This makes it possible to combined
12444** changesets that have different numbers of columns for a single table
12445** within a changegroup, provided that they are otherwise compatible.
12446*/
12447SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
12448
12449/*
12450** CAPI3REF: Add A Changeset To A Changegroup
12451** METHOD: sqlite3_changegroup
12452**
12453** Add all changes within the changeset (or patchset) in buffer pData (size
12454** nData bytes) to the changegroup.
12455**
12456** If the buffer contains a patchset, then all prior calls to this function
12457** on the same changegroup object must also have specified patchsets. Or, if
12458** the buffer contains a changeset, so must have the earlier calls to this
12459** function. Otherwise, SQLITE_ERROR is returned and no changes are added
12460** to the changegroup.
12461**
12462** Rows within the changeset and changegroup are identified by the values in
12463** their PRIMARY KEY columns. A change in the changeset is considered to
12464** apply to the same row as a change already present in the changegroup if
12465** the two rows have the same primary key.
12466**
12467** Changes to rows that do not already appear in the changegroup are
12468** simply copied into it. Or, if both the new changeset and the changegroup
12469** contain changes that apply to a single row, the final contents of the
12470** changegroup depends on the type of each change, as follows:
12471**
12472** <table border=1 style="margin-left:8ex;margin-right:8ex">
12473** <tr><th style="white-space:pre">Existing Change </th>
12474** <th style="white-space:pre">New Change </th>
12475** <th>Output Change
12476** <tr><td>INSERT <td>INSERT <td>
12477** The new change is ignored. This case does not occur if the new
12478** changeset was recorded immediately after the changesets already
12479** added to the changegroup.
12480** <tr><td>INSERT <td>UPDATE <td>
12481** The INSERT change remains in the changegroup. The values in the
12482** INSERT change are modified as if the row was inserted by the
12483** existing change and then updated according to the new change.
12484** <tr><td>INSERT <td>DELETE <td>
12485** The existing INSERT is removed from the changegroup. The DELETE is
12486** not added.
12487** <tr><td>UPDATE <td>INSERT <td>
12488** The new change is ignored. This case does not occur if the new
12489** changeset was recorded immediately after the changesets already
12490** added to the changegroup.
12491** <tr><td>UPDATE <td>UPDATE <td>
12492** The existing UPDATE remains within the changegroup. It is amended
12493** so that the accompanying values are as if the row was updated once
12494** by the existing change and then again by the new change.
12495** <tr><td>UPDATE <td>DELETE <td>
12496** The existing UPDATE is replaced by the new DELETE within the
12497** changegroup.
12498** <tr><td>DELETE <td>INSERT <td>
12499** If one or more of the column values in the row inserted by the
12500** new change differ from those in the row deleted by the existing
12501** change, the existing DELETE is replaced by an UPDATE within the
12502** changegroup. Otherwise, if the inserted row is exactly the same
12503** as the deleted row, the existing DELETE is simply discarded.
12504** <tr><td>DELETE <td>UPDATE <td>
12505** The new change is ignored. This case does not occur if the new
12506** changeset was recorded immediately after the changesets already
12507** added to the changegroup.
12508** <tr><td>DELETE <td>DELETE <td>
12509** The new change is ignored. This case does not occur if the new
12510** changeset was recorded immediately after the changesets already
12511** added to the changegroup.
12512** </table>
12513**
12514** If the new changeset contains changes to a table that is already present
12515** in the changegroup, then the number of columns and the position of the
12516** primary key columns for the table must be consistent. If this is not the
12517** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12518** object has been configured with a database schema using the
12519** sqlite3changegroup_schema() API, then it is possible to combine changesets
12520** with different numbers of columns for a single table, provided that
12521** they are otherwise compatible.
12522**
12523** If the input changeset appears to be corrupt and the corruption is
12524** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12525** occurs during processing, this function returns SQLITE_NOMEM.
12526**
12527** In all cases, if an error occurs the state of the final contents of the
12528** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12529*/
12530SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12531
12532/*
12533** CAPI3REF: Add A Single Change To A Changegroup
12534** METHOD: sqlite3_changegroup
12535**
12536** This function adds the single change currently indicated by the iterator
12537** passed as the second argument to the changegroup object. The rules for
12538** adding the change are just as described for [sqlite3changegroup_add()].
12539**
12540** If the change is successfully added to the changegroup, SQLITE_OK is
12541** returned. Otherwise, an SQLite error code is returned.
12542**
12543** The iterator must point to a valid entry when this function is called.
12544** If it does not, SQLITE_ERROR is returned and no change is added to the
12545** changegroup. Additionally, the iterator must not have been opened with
12546** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12547** returned.
12548*/
12549SQLITE_API int sqlite3changegroup_add_change(
12550 sqlite3_changegroup*,
12551 sqlite3_changeset_iter*
12552);
12553
12554
12555
12556/*
12557** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12558** METHOD: sqlite3_changegroup
12559**
12560** Obtain a buffer containing a changeset (or patchset) representing the
12561** current contents of the changegroup. If the inputs to the changegroup
12562** were themselves changesets, the output is a changeset. Or, if the
12563** inputs were patchsets, the output is also a patchset.
12564**
12565** As with the output of the sqlite3session_changeset() and
12566** sqlite3session_patchset() functions, all changes related to a single
12567** table are grouped together in the output of this function. Tables appear
12568** in the same order as for the very first changeset added to the changegroup.
12569** If the second or subsequent changesets added to the changegroup contain
12570** changes for tables that do not appear in the first changeset, they are
12571** appended onto the end of the output changeset, again in the order in
12572** which they are first encountered.
12573**
12574** If an error occurs, an SQLite error code is returned and the output
12575** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12576** is returned and the output variables are set to the size of and a
12577** pointer to the output buffer, respectively. In this case it is the
12578** responsibility of the caller to eventually free the buffer using a
12579** call to sqlite3_free().
12580*/
12581SQLITE_API int sqlite3changegroup_output(
12582 sqlite3_changegroup*,
12583 int *pnData, /* OUT: Size of output buffer in bytes */
12584 void **ppData /* OUT: Pointer to output buffer */
12585);
12586
12587/*
12588** CAPI3REF: Delete A Changegroup Object
12589** DESTRUCTOR: sqlite3_changegroup
12590*/
12591SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12592
12593/*
12594** CAPI3REF: Apply A Changeset To A Database
12595**
12596** Apply a changeset or patchset to a database. These functions attempt to
12597** update the "main" database attached to handle db with the changes found in
12598** the changeset passed via the second and third arguments.
12599**
12600** All changes made by these functions are enclosed in a savepoint transaction.
12601** If any other error (aside from a constraint failure when attempting to
12602** write to the target database) occurs, then the savepoint transaction is
12603** rolled back, restoring the target database to its original state, and an
12604** SQLite error code returned. Additionally, starting with version 3.51.0,
12605** an error code and error message that may be accessed using the
12606** [sqlite3_errcode()] and [sqlite3_errmsg()] APIs are left in the database
12607** handle.
12608**
12609** The fourth argument (xFilter) passed to these functions is the "filter
12610** callback". This may be passed NULL, in which case all changes in the
12611** changeset are applied to the database. For sqlite3changeset_apply() and
12612** sqlite3_changeset_apply_v2(), if it is not NULL, then it is invoked once
12613** for each table affected by at least one change in the changeset. In this
12614** case the table name is passed as the second argument, and a copy of
12615** the context pointer passed as the sixth argument to apply() or apply_v2()
12616** as the first. If the "filter callback" returns zero, then no attempt is
12617** made to apply any changes to the table. Otherwise, if the return value is
12618** non-zero, all changes related to the table are attempted.
12619**
12620** For sqlite3_changeset_apply_v3(), the xFilter callback is invoked once
12621** per change. The second argument in this case is an sqlite3_changeset_iter
12622** that may be queried using the usual APIs for the details of the current
12623** change. If the "filter callback" returns zero in this case, then no attempt
12624** is made to apply the current change. If it returns non-zero, the change
12625** is applied.
12626**
12627** For each table that is not excluded by the filter callback, this function
12628** tests that the target database contains a compatible table. A table is
12629** considered compatible if all of the following are true:
12630**
12631** <ul>
12632** <li> The table has the same name as the name recorded in the
12633** changeset, and
12634** <li> The table has at least as many columns as recorded in the
12635** changeset, and
12636** <li> The table has primary key columns in the same position as
12637** recorded in the changeset.
12638** </ul>
12639**
12640** If there is no compatible table, it is not an error, but none of the
12641** changes associated with the table are applied. A warning message is issued
12642** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12643** one such warning is issued for each table in the changeset.
12644**
12645** For each change for which there is a compatible table, an attempt is made
12646** to modify the table contents according to each UPDATE, INSERT or DELETE
12647** change that is not excluded by a filter callback. If a change cannot be
12648** applied cleanly, the conflict handler function passed as the fifth argument
12649** to sqlite3changeset_apply() may be invoked. A description of exactly when
12650** the conflict handler is invoked for each type of change is below.
12651**
12652** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12653** of passing anything other than a valid function pointer as the xConflict
12654** argument are undefined.
12655**
12656** Each time the conflict handler function is invoked, it must return one
12657** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12658** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12659** if the second argument passed to the conflict handler is either
12660** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12661** returns an illegal value, any changes already made are rolled back and
12662** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12663** actions are taken by sqlite3changeset_apply() depending on the value
12664** returned by each invocation of the conflict-handler function. Refer to
12665** the documentation for the three
12666** [SQLITE_CHANGESET_OMIT|available return values] for details.
12667**
12668** <dl>
12669** <dt>DELETE Changes<dd>
12670** For each DELETE change, the function checks if the target database
12671** contains a row with the same primary key value (or values) as the
12672** original row values stored in the changeset. If it does, and the values
12673** stored in all non-primary key columns also match the values stored in
12674** the changeset the row is deleted from the target database.
12675**
12676** If a row with matching primary key values is found, but one or more of
12677** the non-primary key fields contains a value different from the original
12678** row value stored in the changeset, the conflict-handler function is
12679** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12680** database table has more columns than are recorded in the changeset,
12681** only the values of those non-primary key fields are compared against
12682** the current database contents - any trailing database table columns
12683** are ignored.
12684**
12685** If no row with matching primary key values is found in the database,
12686** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12687** passed as the second argument.
12688**
12689** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12690** (which can only happen if a foreign key constraint is violated), the
12691** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12692** passed as the second argument. This includes the case where the DELETE
12693** operation is attempted because an earlier call to the conflict handler
12694** function returned [SQLITE_CHANGESET_REPLACE].
12695**
12696** <dt>INSERT Changes<dd>
12697** For each INSERT change, an attempt is made to insert the new row into
12698** the database. If the changeset row contains fewer fields than the
12699** database table, the trailing fields are populated with their default
12700** values.
12701**
12702** If the attempt to insert the row fails because the database already
12703** contains a row with the same primary key values, the conflict handler
12704** function is invoked with the second argument set to
12705** [SQLITE_CHANGESET_CONFLICT].
12706**
12707** If the attempt to insert the row fails because of some other constraint
12708** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12709** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12710** This includes the case where the INSERT operation is re-attempted because
12711** an earlier call to the conflict handler function returned
12712** [SQLITE_CHANGESET_REPLACE].
12713**
12714** <dt>UPDATE Changes<dd>
12715** For each UPDATE change, the function checks if the target database
12716** contains a row with the same primary key value (or values) as the
12717** original row values stored in the changeset. If it does, and the values
12718** stored in all modified non-primary key columns also match the values
12719** stored in the changeset the row is updated within the target database.
12720**
12721** If a row with matching primary key values is found, but one or more of
12722** the modified non-primary key fields contains a value different from an
12723** original row value stored in the changeset, the conflict-handler function
12724** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12725** UPDATE changes only contain values for non-primary key fields that are
12726** to be modified, only those fields need to match the original values to
12727** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12728**
12729** If no row with matching primary key values is found in the database,
12730** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12731** passed as the second argument.
12732**
12733** If the UPDATE operation is attempted, but SQLite returns
12734** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12735** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12736** This includes the case where the UPDATE operation is attempted after
12737** an earlier call to the conflict handler function returned
12738** [SQLITE_CHANGESET_REPLACE].
12739** </dl>
12740**
12741** It is safe to execute SQL statements, including those that write to the
12742** table that the callback related to, from within the xConflict callback.
12743** This can be used to further customize the application's conflict
12744** resolution strategy.
12745**
12746** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12747** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12748** may set (*ppRebase) to point to a "rebase" that may be used with the
12749** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12750** is set to the size of the buffer in bytes. It is the responsibility of the
12751** caller to eventually free any such buffer using sqlite3_free(). The buffer
12752** is only allocated and populated if one or more conflicts were encountered
12753** while applying the patchset. See comments surrounding the sqlite3_rebaser
12754** APIs for further details.
12755**
12756** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12757** may be modified by passing a combination of
12758** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12759**
12760** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12761** and therefore subject to change.
12762*/
12763SQLITE_API int sqlite3changeset_apply(
12764 sqlite3 *db, /* Apply change to "main" db of this handle */
12765 int nChangeset, /* Size of changeset in bytes */
12766 void *pChangeset, /* Changeset blob */
12767 int(*xFilter)(
12768 void *pCtx, /* Copy of sixth arg to _apply() */
12769 const char *zTab /* Table name */
12770 ),
12771 int(*xConflict)(
12772 void *pCtx, /* Copy of sixth arg to _apply() */
12773 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12774 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12775 ),
12776 void *pCtx /* First argument passed to xConflict */
12777);
12778SQLITE_API int sqlite3changeset_apply_v2(
12779 sqlite3 *db, /* Apply change to "main" db of this handle */
12780 int nChangeset, /* Size of changeset in bytes */
12781 void *pChangeset, /* Changeset blob */
12782 int(*xFilter)(
12783 void *pCtx, /* Copy of sixth arg to _apply() */
12784 const char *zTab /* Table name */
12785 ),
12786 int(*xConflict)(
12787 void *pCtx, /* Copy of sixth arg to _apply() */
12788 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12789 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12790 ),
12791 void *pCtx, /* First argument passed to xConflict */
12792 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12793 int flags /* SESSION_CHANGESETAPPLY_* flags */
12794);
12795SQLITE_API int sqlite3changeset_apply_v3(
12796 sqlite3 *db, /* Apply change to "main" db of this handle */
12797 int nChangeset, /* Size of changeset in bytes */
12798 void *pChangeset, /* Changeset blob */
12799 int(*xFilter)(
12800 void *pCtx, /* Copy of sixth arg to _apply() */
12801 sqlite3_changeset_iter *p /* Handle describing change */
12802 ),
12803 int(*xConflict)(
12804 void *pCtx, /* Copy of sixth arg to _apply() */
12805 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12806 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12807 ),
12808 void *pCtx, /* First argument passed to xConflict */
12809 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12810 int flags /* SESSION_CHANGESETAPPLY_* flags */
12811);
12812
12813/*
12814** CAPI3REF: Flags for sqlite3changeset_apply_v2
12815**
12816** The following flags may passed via the 9th parameter to
12817** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12818**
12819** <dl>
12820** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12821** Usually, the sessions module encloses all operations performed by
12822** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12823** SAVEPOINT is committed if the changeset or patchset is successfully
12824** applied, or rolled back if an error occurs. Specifying this flag
12825** causes the sessions module to omit this savepoint. In this case, if the
12826** caller has an open transaction or savepoint when apply_v2() is called,
12827** it may revert the partially applied changeset by rolling it back.
12828**
12829** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12830** Invert the changeset before applying it. This is equivalent to inverting
12831** a changeset using sqlite3changeset_invert() before applying it. It is
12832** an error to specify this flag with a patchset.
12833**
12834** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12835** Do not invoke the conflict handler callback for any changes that
12836** would not actually modify the database even if they were applied.
12837** Specifically, this means that the conflict handler is not invoked
12838** for:
12839** <ul>
12840** <li>a delete change if the row being deleted cannot be found,
12841** <li>an update change if the modified fields are already set to
12842** their new values in the conflicting row, or
12843** <li>an insert change if all fields of the conflicting row match
12844** the row being inserted.
12845** </ul>
12846**
12847** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12848** If this flag it set, then all foreign key constraints in the target
12849** database behave as if they were declared with "ON UPDATE NO ACTION ON
12850** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12851** or SET DEFAULT.
12852*/
12853#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12854#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12855#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12856#define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12857
12858/*
12859** CAPI3REF: Constants Passed To The Conflict Handler
12860**
12861** Values that may be passed as the second argument to a conflict-handler.
12862**
12863** <dl>
12864** <dt>SQLITE_CHANGESET_DATA<dd>
12865** The conflict handler is invoked with CHANGESET_DATA as the second argument
12866** when processing a DELETE or UPDATE change if a row with the required
12867** PRIMARY KEY fields is present in the database, but one or more other
12868** (non primary-key) fields modified by the update do not contain the
12869** expected "before" values.
12870**
12871** The conflicting row, in this case, is the database row with the matching
12872** primary key.
12873**
12874** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12875** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12876** argument when processing a DELETE or UPDATE change if a row with the
12877** required PRIMARY KEY fields is not present in the database.
12878**
12879** There is no conflicting row in this case. The results of invoking the
12880** sqlite3changeset_conflict() API are undefined.
12881**
12882** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12883** CHANGESET_CONFLICT is passed as the second argument to the conflict
12884** handler while processing an INSERT change if the operation would result
12885** in duplicate primary key values.
12886**
12887** The conflicting row in this case is the database row with the matching
12888** primary key.
12889**
12890** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12891** If foreign key handling is enabled, and applying a changeset leaves the
12892** database in a state containing foreign key violations, the conflict
12893** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12894** exactly once before the changeset is committed. If the conflict handler
12895** returns CHANGESET_OMIT, the changes, including those that caused the
12896** foreign key constraint violation, are committed. Or, if it returns
12897** CHANGESET_ABORT, the changeset is rolled back.
12898**
12899** No current or conflicting row information is provided. The only function
12900** it is possible to call on the supplied sqlite3_changeset_iter handle
12901** is sqlite3changeset_fk_conflicts().
12902**
12903** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12904** If any other constraint violation occurs while applying a change (i.e.
12905** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12906** invoked with CHANGESET_CONSTRAINT as the second argument.
12907**
12908** There is no conflicting row in this case. The results of invoking the
12909** sqlite3changeset_conflict() API are undefined.
12910**
12911** </dl>
12912*/
12913#define SQLITE_CHANGESET_DATA 1
12914#define SQLITE_CHANGESET_NOTFOUND 2
12915#define SQLITE_CHANGESET_CONFLICT 3
12916#define SQLITE_CHANGESET_CONSTRAINT 4
12917#define SQLITE_CHANGESET_FOREIGN_KEY 5
12918
12919/*
12920** CAPI3REF: Constants Returned By The Conflict Handler
12921**
12922** A conflict handler callback must return one of the following three values.
12923**
12924** <dl>
12925** <dt>SQLITE_CHANGESET_OMIT<dd>
12926** If a conflict handler returns this value no special action is taken. The
12927** change that caused the conflict is not applied. The session module
12928** continues to the next change in the changeset.
12929**
12930** <dt>SQLITE_CHANGESET_REPLACE<dd>
12931** This value may only be returned if the second argument to the conflict
12932** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12933** is not the case, any changes applied so far are rolled back and the
12934** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12935**
12936** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12937** handler, then the conflicting row is either updated or deleted, depending
12938** on the type of change.
12939**
12940** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12941** handler, then the conflicting row is removed from the database and a
12942** second attempt to apply the change is made. If this second attempt fails,
12943** the original row is restored to the database before continuing.
12944**
12945** <dt>SQLITE_CHANGESET_ABORT<dd>
12946** If this value is returned, any changes applied so far are rolled back
12947** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12948** </dl>
12949*/
12950#define SQLITE_CHANGESET_OMIT 0
12951#define SQLITE_CHANGESET_REPLACE 1
12952#define SQLITE_CHANGESET_ABORT 2
12953
12954/*
12955** CAPI3REF: Rebasing changesets
12956** EXPERIMENTAL
12957**
12958** Suppose there is a site hosting a database in state S0. And that
12959** modifications are made that move that database to state S1 and a
12960** changeset recorded (the "local" changeset). Then, a changeset based
12961** on S0 is received from another site (the "remote" changeset) and
12962** applied to the database. The database is then in state
12963** (S1+"remote"), where the exact state depends on any conflict
12964** resolution decisions (OMIT or REPLACE) made while applying "remote".
12965** Rebasing a changeset is to update it to take those conflict
12966** resolution decisions into account, so that the same conflicts
12967** do not have to be resolved elsewhere in the network.
12968**
12969** For example, if both the local and remote changesets contain an
12970** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12971**
12972** local: INSERT INTO t1 VALUES(1, 'v1');
12973** remote: INSERT INTO t1 VALUES(1, 'v2');
12974**
12975** and the conflict resolution is REPLACE, then the INSERT change is
12976** removed from the local changeset (it was overridden). Or, if the
12977** conflict resolution was "OMIT", then the local changeset is modified
12978** to instead contain:
12979**
12980** UPDATE t1 SET b = 'v2' WHERE a=1;
12981**
12982** Changes within the local changeset are rebased as follows:
12983**
12984** <dl>
12985** <dt>Local INSERT<dd>
12986** This may only conflict with a remote INSERT. If the conflict
12987** resolution was OMIT, then add an UPDATE change to the rebased
12988** changeset. Or, if the conflict resolution was REPLACE, add
12989** nothing to the rebased changeset.
12990**
12991** <dt>Local DELETE<dd>
12992** This may conflict with a remote UPDATE or DELETE. In both cases the
12993** only possible resolution is OMIT. If the remote operation was a
12994** DELETE, then add no change to the rebased changeset. If the remote
12995** operation was an UPDATE, then the old.* fields of change are updated
12996** to reflect the new.* values in the UPDATE.
12997**
12998** <dt>Local UPDATE<dd>
12999** This may conflict with a remote UPDATE or DELETE. If it conflicts
13000** with a DELETE, and the conflict resolution was OMIT, then the update
13001** is changed into an INSERT. Any undefined values in the new.* record
13002** from the update change are filled in using the old.* values from
13003** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
13004** the UPDATE change is simply omitted from the rebased changeset.
13005**
13006** If conflict is with a remote UPDATE and the resolution is OMIT, then
13007** the old.* values are rebased using the new.* values in the remote
13008** change. Or, if the resolution is REPLACE, then the change is copied
13009** into the rebased changeset with updates to columns also updated by
13010** the conflicting remote UPDATE removed. If this means no columns would
13011** be updated, the change is omitted.
13012** </dl>
13013**
13014** A local change may be rebased against multiple remote changes
13015** simultaneously. If a single key is modified by multiple remote
13016** changesets, they are combined as follows before the local changeset
13017** is rebased:
13018**
13019** <ul>
13020** <li> If there has been one or more REPLACE resolutions on a
13021** key, it is rebased according to a REPLACE.
13022**
13023** <li> If there have been no REPLACE resolutions on a key, then
13024** the local changeset is rebased according to the most recent
13025** of the OMIT resolutions.
13026** </ul>
13027**
13028** Note that conflict resolutions from multiple remote changesets are
13029** combined on a per-field basis, not per-row. This means that in the
13030** case of multiple remote UPDATE operations, some fields of a single
13031** local change may be rebased for REPLACE while others are rebased for
13032** OMIT.
13033**
13034** In order to rebase a local changeset, the remote changeset must first
13035** be applied to the local database using sqlite3changeset_apply_v2() and
13036** the buffer of rebase information captured. Then:
13037**
13038** <ol>
13039** <li> An sqlite3_rebaser object is created by calling
13040** sqlite3rebaser_create().
13041** <li> The new object is configured with the rebase buffer obtained from
13042** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
13043** If the local changeset is to be rebased against multiple remote
13044** changesets, then sqlite3rebaser_configure() should be called
13045** multiple times, in the same order that the multiple
13046** sqlite3changeset_apply_v2() calls were made.
13047** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
13048** <li> The sqlite3_rebaser object is deleted by calling
13049** sqlite3rebaser_delete().
13050** </ol>
13051*/
13052typedef struct sqlite3_rebaser sqlite3_rebaser;
13053
13054/*
13055** CAPI3REF: Create a changeset rebaser object.
13056** EXPERIMENTAL
13057**
13058** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
13059** point to the new object and return SQLITE_OK. Otherwise, if an error
13060** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
13061** to NULL.
13062*/
13063SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
13064
13065/*
13066** CAPI3REF: Configure a changeset rebaser object.
13067** EXPERIMENTAL
13068**
13069** Configure the changeset rebaser object to rebase changesets according
13070** to the conflict resolutions described by buffer pRebase (size nRebase
13071** bytes), which must have been obtained from a previous call to
13072** sqlite3changeset_apply_v2().
13073*/
13074SQLITE_API int sqlite3rebaser_configure(
13075 sqlite3_rebaser*,
13076 int nRebase, const void *pRebase
13077);
13078
13079/*
13080** CAPI3REF: Rebase a changeset
13081** EXPERIMENTAL
13082**
13083** Argument pIn must point to a buffer containing a changeset nIn bytes
13084** in size. This function allocates and populates a buffer with a copy
13085** of the changeset rebased according to the configuration of the
13086** rebaser object passed as the first argument. If successful, (*ppOut)
13087** is set to point to the new buffer containing the rebased changeset and
13088** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
13089** responsibility of the caller to eventually free the new buffer using
13090** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
13091** are set to zero and an SQLite error code returned.
13092*/
13093SQLITE_API int sqlite3rebaser_rebase(
13094 sqlite3_rebaser*,
13095 int nIn, const void *pIn,
13096 int *pnOut, void **ppOut
13097);
13098
13099/*
13100** CAPI3REF: Delete a changeset rebaser object.
13101** EXPERIMENTAL
13102**
13103** Delete the changeset rebaser object and all associated resources. There
13104** should be one call to this function for each successful invocation
13105** of sqlite3rebaser_create().
13106*/
13107SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
13108
13109/*
13110** CAPI3REF: Streaming Versions of API functions.
13111**
13112** The six streaming API xxx_strm() functions serve similar purposes to the
13113** corresponding non-streaming API functions:
13114**
13115** <table border=1 style="margin-left:8ex;margin-right:8ex">
13116** <tr><th>Streaming function<th>Non-streaming equivalent</th>
13117** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
13118** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
13119** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
13120** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
13121** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
13122** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
13123** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
13124** </table>
13125**
13126** Non-streaming functions that accept changesets (or patchsets) as input
13127** require that the entire changeset be stored in a single buffer in memory.
13128** Similarly, those that return a changeset or patchset do so by returning
13129** a pointer to a single large buffer allocated using sqlite3_malloc().
13130** Normally this is convenient. However, if an application running in a
13131** low-memory environment is required to handle very large changesets, the
13132** large contiguous memory allocations required can become onerous.
13133**
13134** In order to avoid this problem, instead of a single large buffer, input
13135** is passed to a streaming API functions by way of a callback function that
13136** the sessions module invokes to incrementally request input data as it is
13137** required. In all cases, a pair of API function parameters such as
13138**
13139** <pre>
13140** &nbsp; int nChangeset,
13141** &nbsp; void *pChangeset,
13142** </pre>
13143**
13144** Is replaced by:
13145**
13146** <pre>
13147** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
13148** &nbsp; void *pIn,
13149** </pre>
13150**
13151** Each time the xInput callback is invoked by the sessions module, the first
13152** argument passed is a copy of the supplied pIn context pointer. The second
13153** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
13154** error occurs the xInput method should copy up to (*pnData) bytes of data
13155** into the buffer and set (*pnData) to the actual number of bytes copied
13156** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
13157** should be set to zero to indicate this. Or, if an error occurs, an SQLite
13158** error code should be returned. In all cases, if an xInput callback returns
13159** an error, all processing is abandoned and the streaming API function
13160** returns a copy of the error code to the caller.
13161**
13162** In the case of sqlite3changeset_start_strm(), the xInput callback may be
13163** invoked by the sessions module at any point during the lifetime of the
13164** iterator. If such an xInput callback returns an error, the iterator enters
13165** an error state, whereby all subsequent calls to iterator functions
13166** immediately fail with the same error code as returned by xInput.
13167**
13168** Similarly, streaming API functions that return changesets (or patchsets)
13169** return them in chunks by way of a callback function instead of via a
13170** pointer to a single large buffer. In this case, a pair of parameters such
13171** as:
13172**
13173** <pre>
13174** &nbsp; int *pnChangeset,
13175** &nbsp; void **ppChangeset,
13176** </pre>
13177**
13178** Is replaced by:
13179**
13180** <pre>
13181** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
13182** &nbsp; void *pOut
13183** </pre>
13184**
13185** The xOutput callback is invoked zero or more times to return data to
13186** the application. The first parameter passed to each call is a copy of the
13187** pOut pointer supplied by the application. The second parameter, pData,
13188** points to a buffer nData bytes in size containing the chunk of output
13189** data being returned. If the xOutput callback successfully processes the
13190** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
13191** it should return some other SQLite error code. In this case processing
13192** is immediately abandoned and the streaming API function returns a copy
13193** of the xOutput error code to the application.
13194**
13195** The sessions module never invokes an xOutput callback with the third
13196** parameter set to a value less than or equal to zero. Other than this,
13197** no guarantees are made as to the size of the chunks of data returned.
13198*/
13199SQLITE_API int sqlite3changeset_apply_strm(
13200 sqlite3 *db, /* Apply change to "main" db of this handle */
13201 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13202 void *pIn, /* First arg for xInput */
13203 int(*xFilter)(
13204 void *pCtx, /* Copy of sixth arg to _apply() */
13205 const char *zTab /* Table name */
13206 ),
13207 int(*xConflict)(
13208 void *pCtx, /* Copy of sixth arg to _apply() */
13209 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13210 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13211 ),
13212 void *pCtx /* First argument passed to xConflict */
13213);
13214SQLITE_API int sqlite3changeset_apply_v2_strm(
13215 sqlite3 *db, /* Apply change to "main" db of this handle */
13216 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13217 void *pIn, /* First arg for xInput */
13218 int(*xFilter)(
13219 void *pCtx, /* Copy of sixth arg to _apply() */
13220 const char *zTab /* Table name */
13221 ),
13222 int(*xConflict)(
13223 void *pCtx, /* Copy of sixth arg to _apply() */
13224 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13225 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13226 ),
13227 void *pCtx, /* First argument passed to xConflict */
13228 void **ppRebase, int *pnRebase,
13229 int flags
13230);
13231SQLITE_API int sqlite3changeset_apply_v3_strm(
13232 sqlite3 *db, /* Apply change to "main" db of this handle */
13233 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13234 void *pIn, /* First arg for xInput */
13235 int(*xFilter)(
13236 void *pCtx, /* Copy of sixth arg to _apply() */
13237 sqlite3_changeset_iter *p
13238 ),
13239 int(*xConflict)(
13240 void *pCtx, /* Copy of sixth arg to _apply() */
13241 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13242 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13243 ),
13244 void *pCtx, /* First argument passed to xConflict */
13245 void **ppRebase, int *pnRebase,
13246 int flags
13247);
13248SQLITE_API int sqlite3changeset_concat_strm(
13249 int (*xInputA)(void *pIn, void *pData, int *pnData),
13250 void *pInA,
13251 int (*xInputB)(void *pIn, void *pData, int *pnData),
13252 void *pInB,
13253 int (*xOutput)(void *pOut, const void *pData, int nData),
13254 void *pOut
13255);
13256SQLITE_API int sqlite3changeset_invert_strm(
13257 int (*xInput)(void *pIn, void *pData, int *pnData),
13258 void *pIn,
13259 int (*xOutput)(void *pOut, const void *pData, int nData),
13260 void *pOut
13261);
13262SQLITE_API int sqlite3changeset_start_strm(
13263 sqlite3_changeset_iter **pp,
13264 int (*xInput)(void *pIn, void *pData, int *pnData),
13265 void *pIn
13266);
13267SQLITE_API int sqlite3changeset_start_v2_strm(
13268 sqlite3_changeset_iter **pp,
13269 int (*xInput)(void *pIn, void *pData, int *pnData),
13270 void *pIn,
13271 int flags
13272);
13273SQLITE_API int sqlite3session_changeset_strm(
13274 sqlite3_session *pSession,
13275 int (*xOutput)(void *pOut, const void *pData, int nData),
13276 void *pOut
13277);
13278SQLITE_API int sqlite3session_patchset_strm(
13279 sqlite3_session *pSession,
13280 int (*xOutput)(void *pOut, const void *pData, int nData),
13281 void *pOut
13282);
13283SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
13284 int (*xInput)(void *pIn, void *pData, int *pnData),
13285 void *pIn
13286);
13287SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
13288 int (*xOutput)(void *pOut, const void *pData, int nData),
13289 void *pOut
13290);
13291SQLITE_API int sqlite3rebaser_rebase_strm(
13292 sqlite3_rebaser *pRebaser,
13293 int (*xInput)(void *pIn, void *pData, int *pnData),
13294 void *pIn,
13295 int (*xOutput)(void *pOut, const void *pData, int nData),
13296 void *pOut
13297);
13298
13299/*
13300** CAPI3REF: Configure global parameters
13301**
13302** The sqlite3session_config() interface is used to make global configuration
13303** changes to the sessions module in order to tune it to the specific needs
13304** of the application.
13305**
13306** The sqlite3session_config() interface is not threadsafe. If it is invoked
13307** while any other thread is inside any other sessions method then the
13308** results are undefined. Furthermore, if it is invoked after any sessions
13309** related objects have been created, the results are also undefined.
13310**
13311** The first argument to the sqlite3session_config() function must be one
13312** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
13313** interpretation of the (void*) value passed as the second parameter and
13314** the effect of calling this function depends on the value of the first
13315** parameter.
13316**
13317** <dl>
13318** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
13319** By default, the sessions module streaming interfaces attempt to input
13320** and output data in approximately 1 KiB chunks. This operand may be used
13321** to set and query the value of this configuration setting. The pointer
13322** passed as the second argument must point to a value of type (int).
13323** If this value is greater than 0, it is used as the new streaming data
13324** chunk size for both input and output. Before returning, the (int) value
13325** pointed to by pArg is set to the final value of the streaming interface
13326** chunk size.
13327** </dl>
13328**
13329** This function returns SQLITE_OK if successful, or an SQLite error code
13330** otherwise.
13331*/
13332SQLITE_API int sqlite3session_config(int op, void *pArg);
13333
13334/*
13335** CAPI3REF: Values for sqlite3session_config().
13336*/
13337#define SQLITE_SESSION_CONFIG_STRMSIZE 1
13338
13339/*
13340** Make sure we can call this stuff from C++.
13341*/
13342#ifdef __cplusplus
13343}
13344#endif
13345
13346#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
13347
13348/******** End of sqlite3session.h *********/
13349/******** Begin file fts5.h *********/
13350/*
13351** 2014 May 31
13352**
13353** The author disclaims copyright to this source code. In place of
13354** a legal notice, here is a blessing:
13355**
13356** May you do good and not evil.
13357** May you find forgiveness for yourself and forgive others.
13358** May you share freely, never taking more than you give.
13359**
13360******************************************************************************
13361**
13362** Interfaces to extend FTS5. Using the interfaces defined in this file,
13363** FTS5 may be extended with:
13364**
13365** * custom tokenizers, and
13366** * custom auxiliary functions.
13367*/
13368
13369
13370#ifndef _FTS5_H
13371#define _FTS5_H
13372
13373
13374#ifdef __cplusplus
13375extern "C" {
13376#endif
13377
13378/*************************************************************************
13379** CUSTOM AUXILIARY FUNCTIONS
13380**
13381** Virtual table implementations may overload SQL functions by implementing
13382** the sqlite3_module.xFindFunction() method.
13383*/
13384
13385typedef struct Fts5ExtensionApi Fts5ExtensionApi;
13386typedef struct Fts5Context Fts5Context;
13387typedef struct Fts5PhraseIter Fts5PhraseIter;
13388
13389typedef void (*fts5_extension_function)(
13390 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
13391 Fts5Context *pFts, /* First arg to pass to pApi functions */
13392 sqlite3_context *pCtx, /* Context for returning result/error */
13393 int nVal, /* Number of values in apVal[] array */
13394 sqlite3_value **apVal /* Array of trailing arguments */
13395);
13396
13397struct Fts5PhraseIter {
13398 const unsigned char *a;
13399 const unsigned char *b;
13400};
13401
13402/*
13403** EXTENSION API FUNCTIONS
13404**
13405** xUserData(pFts):
13406** Return a copy of the pUserData pointer passed to the xCreateFunction()
13407** API when the extension function was registered.
13408**
13409** xColumnTotalSize(pFts, iCol, pnToken):
13410** If parameter iCol is less than zero, set output variable *pnToken
13411** to the total number of tokens in the FTS5 table. Or, if iCol is
13412** non-negative but less than the number of columns in the table, return
13413** the total number of tokens in column iCol, considering all rows in
13414** the FTS5 table.
13415**
13416** If parameter iCol is greater than or equal to the number of columns
13417** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13418** an OOM condition or IO error), an appropriate SQLite error code is
13419** returned.
13420**
13421** xColumnCount(pFts):
13422** Return the number of columns in the table.
13423**
13424** xColumnSize(pFts, iCol, pnToken):
13425** If parameter iCol is less than zero, set output variable *pnToken
13426** to the total number of tokens in the current row. Or, if iCol is
13427** non-negative but less than the number of columns in the table, set
13428** *pnToken to the number of tokens in column iCol of the current row.
13429**
13430** If parameter iCol is greater than or equal to the number of columns
13431** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13432** an OOM condition or IO error), an appropriate SQLite error code is
13433** returned.
13434**
13435** This function may be quite inefficient if used with an FTS5 table
13436** created with the "columnsize=0" option.
13437**
13438** xColumnText:
13439** If parameter iCol is less than zero, or greater than or equal to the
13440** number of columns in the table, SQLITE_RANGE is returned.
13441**
13442** Otherwise, this function attempts to retrieve the text of column iCol of
13443** the current document. If successful, (*pz) is set to point to a buffer
13444** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
13445** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
13446** if an error occurs, an SQLite error code is returned and the final values
13447** of (*pz) and (*pn) are undefined.
13448**
13449** xPhraseCount:
13450** Returns the number of phrases in the current query expression.
13451**
13452** xPhraseSize:
13453** If parameter iCol is less than zero, or greater than or equal to the
13454** number of phrases in the current query, as returned by xPhraseCount,
13455** 0 is returned. Otherwise, this function returns the number of tokens in
13456** phrase iPhrase of the query. Phrases are numbered starting from zero.
13457**
13458** xInstCount:
13459** Set *pnInst to the total number of occurrences of all phrases within
13460** the query within the current row. Return SQLITE_OK if successful, or
13461** an error code (i.e. SQLITE_NOMEM) if an error occurs.
13462**
13463** This API can be quite slow if used with an FTS5 table created with the
13464** "detail=none" or "detail=column" option. If the FTS5 table is created
13465** with either "detail=none" or "detail=column" and "content=" option
13466** (i.e. if it is a contentless table), then this API always returns 0.
13467**
13468** xInst:
13469** Query for the details of phrase match iIdx within the current row.
13470** Phrase matches are numbered starting from zero, so the iIdx argument
13471** should be greater than or equal to zero and smaller than the value
13472** output by xInstCount(). If iIdx is less than zero or greater than
13473** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
13474**
13475** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
13476** to the column in which it occurs and *piOff the token offset of the
13477** first token of the phrase. SQLITE_OK is returned if successful, or an
13478** error code (i.e. SQLITE_NOMEM) if an error occurs.
13479**
13480** This API can be quite slow if used with an FTS5 table created with the
13481** "detail=none" or "detail=column" option.
13482**
13483** xRowid:
13484** Returns the rowid of the current row.
13485**
13486** xTokenize:
13487** Tokenize text using the tokenizer belonging to the FTS5 table.
13488**
13489** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
13490** This API function is used to query the FTS table for phrase iPhrase
13491** of the current query. Specifically, a query equivalent to:
13492**
13493** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
13494**
13495** with $p set to a phrase equivalent to the phrase iPhrase of the
13496** current query is executed. Any column filter that applies to
13497** phrase iPhrase of the current query is included in $p. For each
13498** row visited, the callback function passed as the fourth argument
13499** is invoked. The context and API objects passed to the callback
13500** function may be used to access the properties of each matched row.
13501** Invoking Api.xUserData() returns a copy of the pointer passed as
13502** the third argument to pUserData.
13503**
13504** If parameter iPhrase is less than zero, or greater than or equal to
13505** the number of phrases in the query, as returned by xPhraseCount(),
13506** this function returns SQLITE_RANGE.
13507**
13508** If the callback function returns any value other than SQLITE_OK, the
13509** query is abandoned and the xQueryPhrase function returns immediately.
13510** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
13511** Otherwise, the error code is propagated upwards.
13512**
13513** If the query runs to completion without incident, SQLITE_OK is returned.
13514** Or, if some error occurs before the query completes or is aborted by
13515** the callback, an SQLite error code is returned.
13516**
13517**
13518** xSetAuxdata(pFts5, pAux, xDelete)
13519**
13520** Save the pointer passed as the second argument as the extension function's
13521** "auxiliary data". The pointer may then be retrieved by the current or any
13522** future invocation of the same fts5 extension function made as part of
13523** the same MATCH query using the xGetAuxdata() API.
13524**
13525** Each extension function is allocated a single auxiliary data slot for
13526** each FTS query (MATCH expression). If the extension function is invoked
13527** more than once for a single FTS query, then all invocations share a
13528** single auxiliary data context.
13529**
13530** If there is already an auxiliary data pointer when this function is
13531** invoked, then it is replaced by the new pointer. If an xDelete callback
13532** was specified along with the original pointer, it is invoked at this
13533** point.
13534**
13535** The xDelete callback, if one is specified, is also invoked on the
13536** auxiliary data pointer after the FTS5 query has finished.
13537**
13538** If an error (e.g. an OOM condition) occurs within this function,
13539** the auxiliary data is set to NULL and an error code returned. If the
13540** xDelete parameter was not NULL, it is invoked on the auxiliary data
13541** pointer before returning.
13542**
13543**
13544** xGetAuxdata(pFts5, bClear)
13545**
13546** Returns the current auxiliary data pointer for the fts5 extension
13547** function. See the xSetAuxdata() method for details.
13548**
13549** If the bClear argument is non-zero, then the auxiliary data is cleared
13550** (set to NULL) before this function returns. In this case the xDelete,
13551** if any, is not invoked.
13552**
13553**
13554** xRowCount(pFts5, pnRow)
13555**
13556** This function is used to retrieve the total number of rows in the table.
13557** In other words, the same value that would be returned by:
13558**
13559** SELECT count(*) FROM ftstable;
13560**
13561** xPhraseFirst()
13562** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13563** method, to iterate through all instances of a single query phrase within
13564** the current row. This is the same information as is accessible via the
13565** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13566** to use, this API may be faster under some circumstances. To iterate
13567** through instances of phrase iPhrase, use the following code:
13568**
13569** Fts5PhraseIter iter;
13570** int iCol, iOff;
13571** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13572** iCol>=0;
13573** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13574** ){
13575** // An instance of phrase iPhrase at offset iOff of column iCol
13576** }
13577**
13578** The Fts5PhraseIter structure is defined above. Applications should not
13579** modify this structure directly - it should only be used as shown above
13580** with the xPhraseFirst() and xPhraseNext() API methods (and by
13581** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13582**
13583** This API can be quite slow if used with an FTS5 table created with the
13584** "detail=none" or "detail=column" option. If the FTS5 table is created
13585** with either "detail=none" or "detail=column" and "content=" option
13586** (i.e. if it is a contentless table), then this API always iterates
13587** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13588**
13589** In all cases, matches are visited in (column ASC, offset ASC) order.
13590** i.e. all those in column 0, sorted by offset, followed by those in
13591** column 1, etc.
13592**
13593** xPhraseNext()
13594** See xPhraseFirst above.
13595**
13596** xPhraseFirstColumn()
13597** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13598** and xPhraseNext() APIs described above. The difference is that instead
13599** of iterating through all instances of a phrase in the current row, these
13600** APIs are used to iterate through the set of columns in the current row
13601** that contain one or more instances of a specified phrase. For example:
13602**
13603** Fts5PhraseIter iter;
13604** int iCol;
13605** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13606** iCol>=0;
13607** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13608** ){
13609** // Column iCol contains at least one instance of phrase iPhrase
13610** }
13611**
13612** This API can be quite slow if used with an FTS5 table created with the
13613** "detail=none" option. If the FTS5 table is created with either
13614** "detail=none" "content=" option (i.e. if it is a contentless table),
13615** then this API always iterates through an empty set (all calls to
13616** xPhraseFirstColumn() set iCol to -1).
13617**
13618** The information accessed using this API and its companion
13619** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13620** (or xInst/xInstCount). The chief advantage of this API is that it is
13621** significantly more efficient than those alternatives when used with
13622** "detail=column" tables.
13623**
13624** xPhraseNextColumn()
13625** See xPhraseFirstColumn above.
13626**
13627** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13628** This is used to access token iToken of phrase iPhrase of the current
13629** query. Before returning, output parameter *ppToken is set to point
13630** to a buffer containing the requested token, and *pnToken to the
13631** size of this buffer in bytes.
13632**
13633** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13634** or equal to the number of phrases in the query as reported by
13635** xPhraseCount(), or if iToken is equal to or greater than the number of
13636** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13637 are both zeroed.
13638**
13639** The output text is not a copy of the query text that specified the
13640** token. It is the output of the tokenizer module. For tokendata=1
13641** tables, this includes any embedded 0x00 and trailing data.
13642**
13643** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13644** This is used to access token iToken of phrase hit iIdx within the
13645** current row. If iIdx is less than zero or greater than or equal to the
13646** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13647** output variable (*ppToken) is set to point to a buffer containing the
13648** matching document token, and (*pnToken) to the size of that buffer in
13649** bytes.
13650**
13651** The output text is not a copy of the document text that was tokenized.
13652** It is the output of the tokenizer module. For tokendata=1 tables, this
13653** includes any embedded 0x00 and trailing data.
13654**
13655** This API may be slow in some cases if the token identified by parameters
13656** iIdx and iToken matched a prefix token in the query. In most cases, the
13657** first call to this API for each prefix token in the query is forced
13658** to scan the portion of the full-text index that matches the prefix
13659** token to collect the extra data required by this API. If the prefix
13660** token matches a large number of token instances in the document set,
13661** this may be a performance problem.
13662**
13663** If the user knows in advance that a query may use this API for a
13664** prefix token, FTS5 may be configured to collect all required data as part
13665** of the initial querying of the full-text index, avoiding the second scan
13666** entirely. This also causes prefix queries that do not use this API to
13667** run more slowly and use more memory. FTS5 may be configured in this way
13668** either on a per-table basis using the [FTS5 insttoken | 'insttoken']
13669** option, or on a per-query basis using the
13670** [fts5_insttoken | fts5_insttoken()] user function.
13671**
13672** This API can be quite slow if used with an FTS5 table created with the
13673** "detail=none" or "detail=column" option.
13674**
13675** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
13676** If parameter iCol is less than zero, or greater than or equal to the
13677** number of columns in the table, SQLITE_RANGE is returned.
13678**
13679** Otherwise, this function attempts to retrieve the locale associated
13680** with column iCol of the current row. Usually, there is no associated
13681** locale, and output parameters (*pzLocale) and (*pnLocale) are set
13682** to NULL and 0, respectively. However, if the fts5_locale() function
13683** was used to associate a locale with the value when it was inserted
13684** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
13685** buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
13686** is set to the size in bytes of the buffer, not including the
13687** nul-terminator.
13688**
13689** If successful, SQLITE_OK is returned. Or, if an error occurs, an
13690** SQLite error code is returned. The final value of the output parameters
13691** is undefined in this case.
13692**
13693** xTokenize_v2:
13694** Tokenize text using the tokenizer belonging to the FTS5 table. This
13695** API is the same as the xTokenize() API, except that it allows a tokenizer
13696** locale to be specified.
13697*/
13698struct Fts5ExtensionApi {
13699 int iVersion; /* Currently always set to 4 */
13700
13701 void *(*xUserData)(Fts5Context*);
13702
13703 int (*xColumnCount)(Fts5Context*);
13704 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13705 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13706
13707 int (*xTokenize)(Fts5Context*,
13708 const char *pText, int nText, /* Text to tokenize */
13709 void *pCtx, /* Context passed to xToken() */
13710 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13711 );
13712
13713 int (*xPhraseCount)(Fts5Context*);
13714 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13715
13716 int (*xInstCount)(Fts5Context*, int *pnInst);
13717 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13718
13719 sqlite3_int64 (*xRowid)(Fts5Context*);
13720 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13721 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13722
13723 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13724 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13725 );
13726 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13727 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13728
13729 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13730 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13731
13732 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13733 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13734
13735 /* Below this point are iVersion>=3 only */
13736 int (*xQueryToken)(Fts5Context*,
13737 int iPhrase, int iToken,
13738 const char **ppToken, int *pnToken
13739 );
13740 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13741
13742 /* Below this point are iVersion>=4 only */
13743 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
13744 int (*xTokenize_v2)(Fts5Context*,
13745 const char *pText, int nText, /* Text to tokenize */
13746 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */
13747 void *pCtx, /* Context passed to xToken() */
13748 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13749 );
13750};
13751
13752/*
13753** CUSTOM AUXILIARY FUNCTIONS
13754*************************************************************************/
13755
13756/*************************************************************************
13757** CUSTOM TOKENIZERS
13758**
13759** Applications may also register custom tokenizer types. A tokenizer
13760** is registered by providing fts5 with a populated instance of the
13761** following structure. All structure methods must be defined, setting
13762** any member of the fts5_tokenizer struct to NULL leads to undefined
13763** behaviour. The structure methods are expected to function as follows:
13764**
13765** xCreate:
13766** This function is used to allocate and initialize a tokenizer instance.
13767** A tokenizer instance is required to actually tokenize text.
13768**
13769** The first argument passed to this function is a copy of the (void*)
13770** pointer provided by the application when the fts5_tokenizer_v2 object
13771** was registered with FTS5 (the third argument to xCreateTokenizer()).
13772** The second and third arguments are an array of nul-terminated strings
13773** containing the tokenizer arguments, if any, specified following the
13774** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13775** to create the FTS5 table.
13776**
13777** The final argument is an output variable. If successful, (*ppOut)
13778** should be set to point to the new tokenizer handle and SQLITE_OK
13779** returned. If an error occurs, some value other than SQLITE_OK should
13780** be returned. In this case, fts5 assumes that the final value of *ppOut
13781** is undefined.
13782**
13783** xDelete:
13784** This function is invoked to delete a tokenizer handle previously
13785** allocated using xCreate(). Fts5 guarantees that this function will
13786** be invoked exactly once for each successful call to xCreate().
13787**
13788** xTokenize:
13789** This function is expected to tokenize the nText byte string indicated
13790** by argument pText. pText may or may not be nul-terminated. The first
13791** argument passed to this function is a pointer to an Fts5Tokenizer object
13792** returned by an earlier call to xCreate().
13793**
13794** The third argument indicates the reason that FTS5 is requesting
13795** tokenization of the supplied text. This is always one of the following
13796** four values:
13797**
13798** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13799** or removed from the FTS table. The tokenizer is being invoked to
13800** determine the set of tokens to add to (or delete from) the
13801** FTS index.
13802**
13803** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13804** against the FTS index. The tokenizer is being called to tokenize
13805** a bareword or quoted string specified as part of the query.
13806**
13807** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13808** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13809** followed by a "*" character, indicating that the last token
13810** returned by the tokenizer will be treated as a token prefix.
13811**
13812** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13813** satisfy an fts5_api.xTokenize() request made by an auxiliary
13814** function. Or an fts5_api.xColumnSize() request made by the same
13815** on a columnsize=0 database.
13816** </ul>
13817**
13818** The sixth and seventh arguments passed to xTokenize() - pLocale and
13819** nLocale - are a pointer to a buffer containing the locale to use for
13820** tokenization (e.g. "en_US") and its size in bytes, respectively. The
13821** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
13822** which case nLocale is always 0) to indicate that the tokenizer should
13823** use its default locale.
13824**
13825** For each token in the input string, the supplied callback xToken() must
13826** be invoked. The first argument to it should be a copy of the pointer
13827** passed as the second argument to xTokenize(). The third and fourth
13828** arguments are a pointer to a buffer containing the token text, and the
13829** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13830** of the first byte of and first byte immediately following the text from
13831** which the token is derived within the input.
13832**
13833** The second argument passed to the xToken() callback ("tflags") should
13834** normally be set to 0. The exception is if the tokenizer supports
13835** synonyms. In this case see the discussion below for details.
13836**
13837** FTS5 assumes the xToken() callback is invoked for each token in the
13838** order that they occur within the input text.
13839**
13840** If an xToken() callback returns any value other than SQLITE_OK, then
13841** the tokenization should be abandoned and the xTokenize() method should
13842** immediately return a copy of the xToken() return value. Or, if the
13843** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13844** if an error occurs with the xTokenize() implementation itself, it
13845** may abandon the tokenization and return any error code other than
13846** SQLITE_OK or SQLITE_DONE.
13847**
13848** If the tokenizer is registered using an fts5_tokenizer_v2 object,
13849** then the xTokenize() method has two additional arguments - pLocale
13850** and nLocale. These specify the locale that the tokenizer should use
13851** for the current request. If pLocale and nLocale are both 0, then the
13852** tokenizer should use its default locale. Otherwise, pLocale points to
13853** an nLocale byte buffer containing the name of the locale to use as utf-8
13854** text. pLocale is not nul-terminated.
13855**
13856** FTS5_TOKENIZER
13857**
13858** There is also an fts5_tokenizer object. This is an older, deprecated,
13859** version of fts5_tokenizer_v2. It is similar except that:
13860**
13861** <ul>
13862** <li> There is no "iVersion" field, and
13863** <li> The xTokenize() method does not take a locale argument.
13864** </ul>
13865**
13866** Legacy fts5_tokenizer tokenizers must be registered using the
13867** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
13868**
13869** Tokenizer implementations registered using either API may be retrieved
13870** using both xFindTokenizer() and xFindTokenizer_v2().
13871**
13872** SYNONYM SUPPORT
13873**
13874** Custom tokenizers may also support synonyms. Consider a case in which a
13875** user wishes to query for a phrase such as "first place". Using the
13876** built-in tokenizers, the FTS5 query 'first + place' will match instances
13877** of "first place" within the document set, but not alternative forms
13878** such as "1st place". In some applications, it would be better to match
13879** all instances of "first place" or "1st place" regardless of which form
13880** the user specified in the MATCH query text.
13881**
13882** There are several ways to approach this in FTS5:
13883**
13884** <ol><li> By mapping all synonyms to a single token. In this case, using
13885** the above example, this means that the tokenizer returns the
13886** same token for inputs "first" and "1st". Say that token is in
13887** fact "first", so that when the user inserts the document "I won
13888** 1st place" entries are added to the index for tokens "i", "won",
13889** "first" and "place". If the user then queries for '1st + place',
13890** the tokenizer substitutes "first" for "1st" and the query works
13891** as expected.
13892**
13893** <li> By querying the index for all synonyms of each query term
13894** separately. In this case, when tokenizing query text, the
13895** tokenizer may provide multiple synonyms for a single term
13896** within the document. FTS5 then queries the index for each
13897** synonym individually. For example, faced with the query:
13898**
13899** <codeblock>
13900** ... MATCH 'first place'</codeblock>
13901**
13902** the tokenizer offers both "1st" and "first" as synonyms for the
13903** first token in the MATCH query and FTS5 effectively runs a query
13904** similar to:
13905**
13906** <codeblock>
13907** ... MATCH '(first OR 1st) place'</codeblock>
13908**
13909** except that, for the purposes of auxiliary functions, the query
13910** still appears to contain just two phrases - "(first OR 1st)"
13911** being treated as a single phrase.
13912**
13913** <li> By adding multiple synonyms for a single term to the FTS index.
13914** Using this method, when tokenizing document text, the tokenizer
13915** provides multiple synonyms for each token. So that when a
13916** document such as "I won first place" is tokenized, entries are
13917** added to the FTS index for "i", "won", "first", "1st" and
13918** "place".
13919**
13920** This way, even if the tokenizer does not provide synonyms
13921** when tokenizing query text (it should not - to do so would be
13922** inefficient), it doesn't matter if the user queries for
13923** 'first + place' or '1st + place', as there are entries in the
13924** FTS index corresponding to both forms of the first token.
13925** </ol>
13926**
13927** Whether it is parsing document or query text, any call to xToken that
13928** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13929** is considered to supply a synonym for the previous token. For example,
13930** when parsing the document "I won first place", a tokenizer that supports
13931** synonyms would call xToken() 5 times, as follows:
13932**
13933** <codeblock>
13934** xToken(pCtx, 0, "i", 1, 0, 1);
13935** xToken(pCtx, 0, "won", 3, 2, 5);
13936** xToken(pCtx, 0, "first", 5, 6, 11);
13937** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13938** xToken(pCtx, 0, "place", 5, 12, 17);
13939**</codeblock>
13940**
13941** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13942** xToken() is called. Multiple synonyms may be specified for a single token
13943** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13944** There is no limit to the number of synonyms that may be provided for a
13945** single token.
13946**
13947** In many cases, method (1) above is the best approach. It does not add
13948** extra data to the FTS index or require FTS5 to query for multiple terms,
13949** so it is efficient in terms of disk space and query speed. However, it
13950** does not support prefix queries very well. If, as suggested above, the
13951** token "first" is substituted for "1st" by the tokenizer, then the query:
13952**
13953** <codeblock>
13954** ... MATCH '1s*'</codeblock>
13955**
13956** will not match documents that contain the token "1st" (as the tokenizer
13957** will probably not map "1s" to any prefix of "first").
13958**
13959** For full prefix support, method (3) may be preferred. In this case,
13960** because the index contains entries for both "first" and "1st", prefix
13961** queries such as 'fi*' or '1s*' will match correctly. However, because
13962** extra entries are added to the FTS index, this method uses more space
13963** within the database.
13964**
13965** Method (2) offers a midpoint between (1) and (3). Using this method,
13966** a query such as '1s*' will match documents that contain the literal
13967** token "1st", but not "first" (assuming the tokenizer is not able to
13968** provide synonyms for prefixes). However, a non-prefix query like '1st'
13969** will match against "1st" and "first". This method does not require
13970** extra disk space, as no extra entries are added to the FTS index.
13971** On the other hand, it may require more CPU cycles to run MATCH queries,
13972** as separate queries of the FTS index are required for each synonym.
13973**
13974** When using methods (2) or (3), it is important that the tokenizer only
13975** provide synonyms when tokenizing document text (method (3)) or query
13976** text (method (2)), not both. Doing so will not cause any errors, but is
13977** inefficient.
13978*/
13979typedef struct Fts5Tokenizer Fts5Tokenizer;
13980typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
13981struct fts5_tokenizer_v2 {
13982 int iVersion; /* Currently always 2 */
13983
13984 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13985 void (*xDelete)(Fts5Tokenizer*);
13986 int (*xTokenize)(Fts5Tokenizer*,
13987 void *pCtx,
13988 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13989 const char *pText, int nText,
13990 const char *pLocale, int nLocale,
13991 int (*xToken)(
13992 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13993 int tflags, /* Mask of FTS5_TOKEN_* flags */
13994 const char *pToken, /* Pointer to buffer containing token */
13995 int nToken, /* Size of token in bytes */
13996 int iStart, /* Byte offset of token within input text */
13997 int iEnd /* Byte offset of end of token within input text */
13998 )
13999 );
14000};
14001
14002/*
14003** New code should use the fts5_tokenizer_v2 type to define tokenizer
14004** implementations. The following type is included for legacy applications
14005** that still use it.
14006*/
14007typedef struct fts5_tokenizer fts5_tokenizer;
14008struct fts5_tokenizer {
14009 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
14010 void (*xDelete)(Fts5Tokenizer*);
14011 int (*xTokenize)(Fts5Tokenizer*,
14012 void *pCtx,
14013 int flags, /* Mask of FTS5_TOKENIZE_* flags */
14014 const char *pText, int nText,
14015 int (*xToken)(
14016 void *pCtx, /* Copy of 2nd argument to xTokenize() */
14017 int tflags, /* Mask of FTS5_TOKEN_* flags */
14018 const char *pToken, /* Pointer to buffer containing token */
14019 int nToken, /* Size of token in bytes */
14020 int iStart, /* Byte offset of token within input text */
14021 int iEnd /* Byte offset of end of token within input text */
14022 )
14023 );
14024};
14025
14026
14027/* Flags that may be passed as the third argument to xTokenize() */
14028#define FTS5_TOKENIZE_QUERY 0x0001
14029#define FTS5_TOKENIZE_PREFIX 0x0002
14030#define FTS5_TOKENIZE_DOCUMENT 0x0004
14031#define FTS5_TOKENIZE_AUX 0x0008
14032
14033/* Flags that may be passed by the tokenizer implementation back to FTS5
14034** as the third argument to the supplied xToken callback. */
14035#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
14036
14037/*
14038** END OF CUSTOM TOKENIZERS
14039*************************************************************************/
14040
14041/*************************************************************************
14042** FTS5 EXTENSION REGISTRATION API
14043*/
14044typedef struct fts5_api fts5_api;
14045struct fts5_api {
14046 int iVersion; /* Currently always set to 3 */
14047
14048 /* Create a new tokenizer */
14049 int (*xCreateTokenizer)(
14050 fts5_api *pApi,
14051 const char *zName,
14052 void *pUserData,
14053 fts5_tokenizer *pTokenizer,
14054 void (*xDestroy)(void*)
14055 );
14056
14057 /* Find an existing tokenizer */
14058 int (*xFindTokenizer)(
14059 fts5_api *pApi,
14060 const char *zName,
14061 void **ppUserData,
14062 fts5_tokenizer *pTokenizer
14063 );
14064
14065 /* Create a new auxiliary function */
14066 int (*xCreateFunction)(
14067 fts5_api *pApi,
14068 const char *zName,
14069 void *pUserData,
14070 fts5_extension_function xFunction,
14071 void (*xDestroy)(void*)
14072 );
14073
14074 /* APIs below this point are only available if iVersion>=3 */
14075
14076 /* Create a new tokenizer */
14077 int (*xCreateTokenizer_v2)(
14078 fts5_api *pApi,
14079 const char *zName,
14080 void *pUserData,
14081 fts5_tokenizer_v2 *pTokenizer,
14082 void (*xDestroy)(void*)
14083 );
14084
14085 /* Find an existing tokenizer */
14086 int (*xFindTokenizer_v2)(
14087 fts5_api *pApi,
14088 const char *zName,
14089 void **ppUserData,
14090 fts5_tokenizer_v2 **ppTokenizer
14091 );
14092};
14093
14094/*
14095** END OF REGISTRATION API
14096*************************************************************************/
14097
14098#ifdef __cplusplus
14099} /* end of the 'extern "C"' block */
14100#endif
14101
14102#endif /* _FTS5_H */
14103
14104/******** End of fts5.h *********/
14105#endif /* SQLITE3_H */
14106