2** This file is an amalgamation of many separate C source files from SQLite
3** version  By combining all the individual C code files into this
4** single large file, the entire code can be compiled as a single translation
5** unit.  This allows many compilers to do optimizations that would not be
6** possible if the files were compiled separately.  Performance improvements
7** of 5% or more are commonly seen when SQLite is compiled as a single
8** translation unit.
10** This file is all you need to compile SQLite.  To use SQLite in other
11** programs, you need this file and the "sqlite3.h" header file that defines
12** the programming interface to the SQLite library.  (If you do not have
13** the "sqlite3.h" header file at hand, you will find a copy embedded within
14** the text of this file.  Search for "Begin file sqlite3.h" to find the start
15** of the embedded sqlite3.h header file.) Additional code files may be needed
16** if you want a wrapper to interface SQLite with your choice of programming
17** language. The code for the "sqlite3" command-line shell is also in a
18** separate file. This file contains only code for the core SQLite library.
20#define SQLITE_CORE 1
23# define SQLITE_PRIVATE static
25#ifndef SQLITE_API
26# define SQLITE_API
28/************** Begin file sqliteInt.h ***************************************/
30** 2001 September 15
32** The author disclaims copyright to this source code.  In place of
33** a legal notice, here is a blessing:
35**    May you do good and not evil.
36**    May you find forgiveness for yourself and forgive others.
37**    May you share freely, never taking more than you give.
40** Internal interface definitions for SQLite.
43#ifndef _SQLITEINT_H_
44#define _SQLITEINT_H_
47** These #defines should enable >2GB file support on POSIX if the
48** underlying operating system supports it.  If the OS lacks
49** large file support, or if the OS is windows, these should be no-ops.
51** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
52** system #includes.  Hence, this block of code must be the very first
53** code in all source files.
55** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
56** on the compiler command line.  This is necessary if you are compiling
57** on a recent machine (ex: Red Hat 7.2) but you want your code to work
58** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
59** without this option, LFS is enable.  But LFS does not exist in the kernel
60** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
61** portability you should omit LFS.
63** The previous paragraph was written in 2005.  (This paragraph is written
64** on 2008-11-28.) These days, all Linux kernels support large files, so
65** you should probably leave LFS enabled.  But some embedded platforms might
66** lack LFS in which case the SQLITE_DISABLE_LFS macro might still be useful.
68** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
71# define _LARGE_FILE       1
72# ifndef _FILE_OFFSET_BITS
73#   define _FILE_OFFSET_BITS 64
74# endif
75# define _LARGEFILE_SOURCE 1
79** For MinGW, check to see if we can include the header file containing its
80** version information, among other things.  Normally, this internal MinGW
81** header file would [only] be included automatically by other MinGW header
82** files; however, the contained version information is now required by this
83** header file to work around binary compatibility issues (see below) and
84** this is the only known way to reliably obtain it.  This entire #if block
85** would be completely unnecessary if there was any other way of detecting
86** MinGW via their preprocessor (e.g. if they customized their GCC to define
87** some MinGW-specific macros).  When compiling for MinGW, either the
88** _HAVE_MINGW_H or _HAVE__MINGW_H (note the extra underscore) macro must be
89** defined; otherwise, detection of conditions specific to MinGW will be
90** disabled.
92#if defined(_HAVE_MINGW_H)
93# include "mingw.h"
94#elif defined(_HAVE__MINGW_H)
95# include "_mingw.h"
99** For MinGW version 4.x (and higher), check to see if the _USE_32BIT_TIME_T
100** define is required to maintain binary compatibility with the MSVC runtime
101** library in use (e.g. for Windows XP).
103#if !defined(_USE_32BIT_TIME_T) && !defined(_USE_64BIT_TIME_T) && \
104    defined(_WIN32) && !defined(_WIN64) && \
105    defined(__MINGW_MAJOR_VERSION) && __MINGW_MAJOR_VERSION >= 4 && \
106    defined(__MSVCRT__)
107# define _USE_32BIT_TIME_T
110/* The public SQLite interface.  The _FILE_OFFSET_BITS macro must appear
111** first in QNX.  Also, the _USE_32BIT_TIME_T macro must appear first for
112** MinGW.
114/************** Include sqlite3.h in the middle of sqliteInt.h ***************/
115/************** Begin file sqlite3.h *****************************************/
117** 2001 September 15
119** The author disclaims copyright to this source code.  In place of
120** a legal notice, here is a blessing:
122**    May you do good and not evil.
123**    May you find forgiveness for yourself and forgive others.
124**    May you share freely, never taking more than you give.
127** This header file defines the interface that the SQLite library
128** presents to client programs.  If a C-function, structure, datatype,
129** or constant definition does not appear in this file, then it is
130** not a published API of SQLite, is subject to change without
131** notice, and should not be referenced by programs that use SQLite.
133** Some of the definitions that are in this file are marked as
134** "experimental".  Experimental interfaces are normally new
135** features recently added to SQLite.  We do not anticipate changes
136** to experimental interfaces but reserve the right to make minor changes
137** if experience from use "in the wild" suggest such changes are prudent.
139** The official C-language API documentation for SQLite is derived
140** from comments in this file.  This file is the authoritative source
141** on how SQLite interfaces are suppose to operate.
143** The name of this file under configuration management is "sqlite.h.in".
144** The makefile makes some minor changes to this file (such as inserting
145** the version number) and changes its name to "sqlite3.h" as
146** part of the build process.
148#ifndef _SQLITE3_H_
149#define _SQLITE3_H_
150#include <stdarg.h>     /* Needed for the definition of va_list */
153** Make sure we can call this stuff from C++.
155#if 0
156extern "C" {
161** Add the ability to override 'extern'
163#ifndef SQLITE_EXTERN
164# define SQLITE_EXTERN extern
167#ifndef SQLITE_API
168# define SQLITE_API
173** These no-op macros are used in front of interfaces to mark those
174** interfaces as either deprecated or experimental.  New applications
175** should not use deprecated interfaces - they are support for backwards
176** compatibility only.  Application writers should be aware that
177** experimental interfaces are subject to change in point releases.
179** These macros used to resolve to various kinds of compiler magic that
180** would generate warning messages when they were used.  But that
181** compiler magic ended up generating such a flurry of bug reports
182** that we have taken it all out and gone back to using simple
183** noop macros.
189** Ensure these symbols were not defined by some previous header file.
199** CAPI3REF: Compile-Time Library Version Numbers
201** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
202** evaluates to a string literal that is the SQLite version in the
203** format "X.Y.Z" where X is the major version number (always 3 for
204** SQLite3) and Y is the minor version number and Z is the release number.)^
205** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
206** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
207** numbers used in [SQLITE_VERSION].)^
208** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
209** be larger than the release from which it is derived.  Either Y will
210** be held constant and Z will be incremented or else Y will be incremented
211** and Z will be reset to zero.
213** Since version 3.6.18, SQLite source code has been stored in the
214** <a href="http://www.fossil-scm.org/">Fossil configuration management
215** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
216** a string which identifies a particular check-in of SQLite
217** within its configuration management system.  ^The SQLITE_SOURCE_ID
218** string contains the date and time of the check-in (UTC) and an SHA1
219** hash of the entire source tree.
221** See also: [sqlite3_libversion()],
222** [sqlite3_libversion_number()], [sqlite3_sourceid()],
223** [sqlite_version()] and [sqlite_source_id()].
225#define SQLITE_VERSION        ""
226#define SQLITE_VERSION_NUMBER 3008004
227#define SQLITE_SOURCE_ID      "2014-04-03 16:53:12 a611fa96c4a848614efe899130359c9f6fb889c3"
230** CAPI3REF: Run-Time Library Version Numbers
231** KEYWORDS: sqlite3_version, sqlite3_sourceid
233** These interfaces provide the same information as the [SQLITE_VERSION],
234** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
235** but are associated with the library instead of the header file.  ^(Cautious
236** programmers might include assert() statements in their application to
237** verify that values returned by these interfaces match the macros in
238** the header, and thus insure that the application is
239** compiled with matching library and header files.
241** <blockquote><pre>
242** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
243** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
244** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
245** </pre></blockquote>)^
247** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
248** macro.  ^The sqlite3_libversion() function returns a pointer to the
249** to the sqlite3_version[] string constant.  The sqlite3_libversion()
250** function is provided for use in DLLs since DLL users usually do not have
251** direct access to string constants within the DLL.  ^The
252** sqlite3_libversion_number() function returns an integer equal to
253** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function returns
254** a pointer to a string constant whose value is the same as the
255** [SQLITE_SOURCE_ID] C preprocessor macro.
257** See also: [sqlite_version()] and [sqlite_source_id()].
259SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
260SQLITE_API const char *sqlite3_libversion(void);
261SQLITE_API const char *sqlite3_sourceid(void);
262SQLITE_API int sqlite3_libversion_number(void);
265** CAPI3REF: Run-Time Library Compilation Options Diagnostics
267** ^The sqlite3_compileoption_used() function returns 0 or 1
268** indicating whether the specified option was defined at
269** compile time.  ^The SQLITE_ prefix may be omitted from the
270** option name passed to sqlite3_compileoption_used().
272** ^The sqlite3_compileoption_get() function allows iterating
273** over the list of options that were defined at compile time by
274** returning the N-th compile time option string.  ^If N is out of range,
275** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
276** prefix is omitted from any strings returned by
277** sqlite3_compileoption_get().
279** ^Support for the diagnostic functions sqlite3_compileoption_used()
280** and sqlite3_compileoption_get() may be omitted by specifying the
281** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
283** See also: SQL functions [sqlite_compileoption_used()] and
284** [sqlite_compileoption_get()] and the [compile_options pragma].
287SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
288SQLITE_API const char *sqlite3_compileoption_get(int N);
292** CAPI3REF: Test To See If The Library Is Threadsafe
294** ^The sqlite3_threadsafe() function returns zero if and only if
295** SQLite was compiled with mutexing code omitted due to the
296** [SQLITE_THREADSAFE] compile-time option being set to 0.
298** SQLite can be compiled with or without mutexes.  When
299** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
300** are enabled and SQLite is threadsafe.  When the
301** [SQLITE_THREADSAFE] macro is 0,
302** the mutexes are omitted.  Without the mutexes, it is not safe
303** to use SQLite concurrently from more than one thread.
305** Enabling mutexes incurs a measurable performance penalty.
306** So if speed is of utmost importance, it makes sense to disable
307** the mutexes.  But for maximum safety, mutexes should be enabled.
308** ^The default behavior is for mutexes to be enabled.
310** This interface can be used by an application to make sure that the
311** version of SQLite that it is linking against was compiled with
312** the desired setting of the [SQLITE_THREADSAFE] macro.
314** This interface only reports on the compile-time mutex setting
315** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
316** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
317** can be fully or partially disabled using a call to [sqlite3_config()]
319** or [SQLITE_CONFIG_MUTEX].  ^(The return value of the
320** sqlite3_threadsafe() function shows only the compile-time setting of
321** thread safety, not any run-time changes to that setting made by
322** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
323** is unchanged by calls to sqlite3_config().)^
325** See the [threading mode] documentation for additional information.
327SQLITE_API int sqlite3_threadsafe(void);
330** CAPI3REF: Database Connection Handle
331** KEYWORDS: {database connection} {database connections}
333** Each open SQLite database is represented by a pointer to an instance of
334** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
335** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
336** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
337** and [sqlite3_close_v2()] are its destructors.  There are many other
338** interfaces (such as
339** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
340** [sqlite3_busy_timeout()] to name but three) that are methods on an
341** sqlite3 object.
343typedef struct sqlite3 sqlite3;
346** CAPI3REF: 64-Bit Integer Types
347** KEYWORDS: sqlite_int64 sqlite_uint64
349** Because there is no cross-platform way to specify 64-bit integer types
350** SQLite includes typedefs for 64-bit signed and unsigned integers.
352** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
353** The sqlite_int64 and sqlite_uint64 types are supported for backwards
354** compatibility only.
356** ^The sqlite3_int64 and sqlite_int64 types can store integer values
357** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
358** sqlite3_uint64 and sqlite_uint64 types can store integer values
359** between 0 and +18446744073709551615 inclusive.
361#ifdef SQLITE_INT64_TYPE
362  typedef SQLITE_INT64_TYPE sqlite_int64;
363  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
364#elif defined(_MSC_VER) || defined(__BORLANDC__)
365  typedef __int64 sqlite_int64;
366  typedef unsigned __int64 sqlite_uint64;
368  typedef long long int sqlite_int64;
369  typedef unsigned long long int sqlite_uint64;
371typedef sqlite_int64 sqlite3_int64;
372typedef sqlite_uint64 sqlite3_uint64;
375** If compiling for a processor that lacks floating point support,
376** substitute integer for floating-point.
379# define double sqlite3_int64
383** CAPI3REF: Closing A Database Connection
385** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
386** for the [sqlite3] object.
387** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
388** the [sqlite3] object is successfully destroyed and all associated
389** resources are deallocated.
391** ^If the database connection is associated with unfinalized prepared
392** statements or unfinished sqlite3_backup objects then sqlite3_close()
393** will leave the database connection open and return [SQLITE_BUSY].
394** ^If sqlite3_close_v2() is called with unfinalized prepared statements
395** and unfinished sqlite3_backups, then the database connection becomes
396** an unusable "zombie" which will automatically be deallocated when the
397** last prepared statement is finalized or the last sqlite3_backup is
398** finished.  The sqlite3_close_v2() interface is intended for use with
399** host languages that are garbage collected, and where the order in which
400** destructors are called is arbitrary.
402** Applications should [sqlite3_finalize | finalize] all [prepared statements],
403** [sqlite3_blob_close | close] all [BLOB handles], and
404** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
405** with the [sqlite3] object prior to attempting to close the object.  ^If
406** sqlite3_close_v2() is called on a [database connection] that still has
407** outstanding [prepared statements], [BLOB handles], and/or
408** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
409** of resources is deferred until all [prepared statements], [BLOB handles],
410** and [sqlite3_backup] objects are also destroyed.
412** ^If an [sqlite3] object is destroyed while a transaction is open,
413** the transaction is automatically rolled back.
415** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
416** must be either a NULL
417** pointer or an [sqlite3] object pointer obtained
418** from [sqlite3_open()], [sqlite3_open16()], or
419** [sqlite3_open_v2()], and not previously closed.
420** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
421** argument is a harmless no-op.
423SQLITE_API int sqlite3_close(sqlite3*);
424SQLITE_API int sqlite3_close_v2(sqlite3*);
427** The type for a callback function.
428** This is legacy and deprecated.  It is included for historical
429** compatibility and is not documented.
431typedef int (*sqlite3_callback)(void*,int,char**, char**);
434** CAPI3REF: One-Step Query Execution Interface
436** The sqlite3_exec() interface is a convenience wrapper around
437** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
438** that allows an application to run multiple statements of SQL
439** without having to use a lot of C code.
441** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
442** semicolon-separate SQL statements passed into its 2nd argument,
443** in the context of the [database connection] passed in as its 1st
444** argument.  ^If the callback function of the 3rd argument to
445** sqlite3_exec() is not NULL, then it is invoked for each result row
446** coming out of the evaluated SQL statements.  ^The 4th argument to
447** sqlite3_exec() is relayed through to the 1st argument of each
448** callback invocation.  ^If the callback pointer to sqlite3_exec()
449** is NULL, then no callback is ever invoked and result rows are
450** ignored.
452** ^If an error occurs while evaluating the SQL statements passed into
453** sqlite3_exec(), then execution of the current statement stops and
454** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
455** is not NULL then any error message is written into memory obtained
456** from [sqlite3_malloc()] and passed back through the 5th parameter.
457** To avoid memory leaks, the application should invoke [sqlite3_free()]
458** on error message strings returned through the 5th parameter of
459** of sqlite3_exec() after the error message string is no longer needed.
460** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
461** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
462** NULL before returning.
464** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
465** routine returns SQLITE_ABORT without invoking the callback again and
466** without running any subsequent SQL statements.
468** ^The 2nd argument to the sqlite3_exec() callback function is the
469** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
470** callback is an array of pointers to strings obtained as if from
471** [sqlite3_column_text()], one for each column.  ^If an element of a
472** result row is NULL then the corresponding string pointer for the
473** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
474** sqlite3_exec() callback is an array of pointers to strings where each
475** entry represents the name of corresponding result column as obtained
476** from [sqlite3_column_name()].
478** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
479** to an empty string, or a pointer that contains only whitespace and/or
480** SQL comments, then no SQL statements are evaluated and the database
481** is not changed.
483** Restrictions:
485** <ul>
486** <li> The application must insure that the 1st parameter to sqlite3_exec()
487**      is a valid and open [database connection].
488** <li> The application must not close the [database connection] specified by
489**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
490** <li> The application must not modify the SQL statement text passed into
491**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
492** </ul>
494SQLITE_API int sqlite3_exec(
495  sqlite3*,                                  /* An open database */
496  const char *sql,                           /* SQL to be evaluated */
497  int (*callback)(void*,int,char**,char**),  /* Callback function */
498  void *,                                    /* 1st argument to callback */
499  char **errmsg                              /* Error msg written here */
503** CAPI3REF: Result Codes
504** KEYWORDS: SQLITE_OK {error code} {error codes}
505** KEYWORDS: {result code} {result codes}
507** Many SQLite functions return an integer result code from the set shown
508** here in order to indicate success or failure.
510** New error codes may be added in future versions of SQLite.
512** See also: [SQLITE_IOERR_READ | extended result codes],
513** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
515#define SQLITE_OK           0   /* Successful result */
516/* beginning-of-error-codes */
517#define SQLITE_ERROR        1   /* SQL error or missing database */
518#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
519#define SQLITE_PERM         3   /* Access permission denied */
520#define SQLITE_ABORT        4   /* Callback routine requested an abort */
521#define SQLITE_BUSY         5   /* The database file is locked */
522#define SQLITE_LOCKED       6   /* A table in the database is locked */
523#define SQLITE_NOMEM        7   /* A malloc() failed */
524#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
525#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
526#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
527#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
528#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
529#define SQLITE_FULL        13   /* Insertion failed because database is full */
530#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
531#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
532#define SQLITE_EMPTY       16   /* Database is empty */
533#define SQLITE_SCHEMA      17   /* The database schema changed */
534#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
535#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
536#define SQLITE_MISMATCH    20   /* Data type mismatch */
537#define SQLITE_MISUSE      21   /* Library used incorrectly */
538#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
539#define SQLITE_AUTH        23   /* Authorization denied */
540#define SQLITE_FORMAT      24   /* Auxiliary database format error */
541#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
542#define SQLITE_NOTADB      26   /* File opened that is not a database file */
543#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
544#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
545#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
546#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
547/* end-of-error-codes */
550** CAPI3REF: Extended Result Codes
551** KEYWORDS: {extended error code} {extended error codes}
552** KEYWORDS: {extended result code} {extended result codes}
554** In its default configuration, SQLite API routines return one of 26 integer
555** [SQLITE_OK | result codes].  However, experience has shown that many of
556** these result codes are too coarse-grained.  They do not provide as
557** much information about problems as programmers might like.  In an effort to
558** address this, newer versions of SQLite (version 3.3.8 and later) include
559** support for additional result codes that provide more detailed information
560** about errors. The extended result codes are enabled or disabled
561** on a per database connection basis using the
562** [sqlite3_extended_result_codes()] API.
564** Some of the available extended result codes are listed here.
565** One may expect the number of extended result codes will increase
566** over time.  Software that uses extended result codes should expect
567** to see new result codes in future releases of SQLite.
569** The SQLITE_OK result code will never be extended.  It will always
570** be exactly zero.
572#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
573#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
574#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
575#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
576#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
577#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
578#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
579#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
580#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
581#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
582#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
583#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
584#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
586#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
587#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
588#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
589#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
590#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
591#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
592#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
593#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
594#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
595#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
596#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
597#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
599#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
600#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
602#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
605#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
610#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
626** CAPI3REF: Flags For File Open Operations
628** These bit values are intended for use in the
629** 3rd parameter to the [sqlite3_open_v2()] interface and
630** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
632#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
633#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
634#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
635#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
636#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
637#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
638#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
639#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
640#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
641#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
642#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
643#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
644#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
645#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
646#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
647#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
648#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
649#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
650#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
651#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
653/* Reserved:                         0x00F00000 */
656** CAPI3REF: Device Characteristics
658** The xDeviceCharacteristics method of the [sqlite3_io_methods]
659** object returns an integer which is a vector of these
660** bit values expressing I/O characteristics of the mass storage
661** device that holds the file that the [sqlite3_io_methods]
662** refers to.
664** The SQLITE_IOCAP_ATOMIC property means that all writes of
665** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
666** mean that writes of blocks that are nnn bytes in size and
667** are aligned to an address which is an integer multiple of
668** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
669** that when data is appended to a file, the data is appended
670** first then the size of the file is extended, never the other
671** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
672** information is written to disk in the same order as calls
673** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
674** after reboot following a crash or power loss, the only bytes in a
675** file that were written at the application level might have changed
676** and that adjacent bytes, even bytes within the same sector are
677** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
678** flag indicate that a file cannot be deleted when open.
680#define SQLITE_IOCAP_ATOMIC                 0x00000001
681#define SQLITE_IOCAP_ATOMIC512              0x00000002
682#define SQLITE_IOCAP_ATOMIC1K               0x00000004
683#define SQLITE_IOCAP_ATOMIC2K               0x00000008
684#define SQLITE_IOCAP_ATOMIC4K               0x00000010
685#define SQLITE_IOCAP_ATOMIC8K               0x00000020
686#define SQLITE_IOCAP_ATOMIC16K              0x00000040
687#define SQLITE_IOCAP_ATOMIC32K              0x00000080
688#define SQLITE_IOCAP_ATOMIC64K              0x00000100
689#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
690#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
695** CAPI3REF: File Locking Levels
697** SQLite uses one of these integer values as the second
698** argument to calls it makes to the xLock() and xUnlock() methods
699** of an [sqlite3_io_methods] object.
701#define SQLITE_LOCK_NONE          0
702#define SQLITE_LOCK_SHARED        1
703#define SQLITE_LOCK_RESERVED      2
704#define SQLITE_LOCK_PENDING       3
705#define SQLITE_LOCK_EXCLUSIVE     4
708** CAPI3REF: Synchronization Type Flags
710** When SQLite invokes the xSync() method of an
711** [sqlite3_io_methods] object it uses a combination of
712** these integer values as the second argument.
714** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
715** sync operation only needs to flush data to mass storage.  Inode
716** information need not be flushed. If the lower four bits of the flag
717** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
718** If the lower four bits equal SQLITE_SYNC_FULL, that means
719** to use Mac OS X style fullsync instead of fsync().
721** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
722** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
723** settings.  The [synchronous pragma] determines when calls to the
724** xSync VFS method occur and applies uniformly across all platforms.
725** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
726** energetic or rigorous or forceful the sync operations are and
727** only make a difference on Mac OSX for the default SQLite code.
728** (Third-party VFS implementations might also make the distinction
729** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
730** operating systems natively supported by SQLite, only Mac OSX
731** cares about the difference.)
733#define SQLITE_SYNC_NORMAL        0x00002
734#define SQLITE_SYNC_FULL          0x00003
735#define SQLITE_SYNC_DATAONLY      0x00010
738** CAPI3REF: OS Interface Open File Handle
740** An [sqlite3_file] object represents an open file in the
741** [sqlite3_vfs | OS interface layer].  Individual OS interface
742** implementations will
743** want to subclass this object by appending additional fields
744** for their own use.  The pMethods entry is a pointer to an
745** [sqlite3_io_methods] object that defines methods for performing
746** I/O operations on the open file.
748typedef struct sqlite3_file sqlite3_file;
749struct sqlite3_file {
750  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
754** CAPI3REF: OS Interface File Virtual Methods Object
756** Every file opened by the [sqlite3_vfs.xOpen] method populates an
757** [sqlite3_file] object (or, more commonly, a subclass of the
758** [sqlite3_file] object) with a pointer to an instance of this object.
759** This object defines the methods used to perform various operations
760** against the open file represented by the [sqlite3_file] object.
762** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
763** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
764** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
765** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
766** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
767** to NULL.
769** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
770** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
771** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
772** flag may be ORed in to indicate that only the data of the file
773** and not its inode needs to be synced.
775** The integer values to xLock() and xUnlock() are one of
776** <ul>
777** <li> [SQLITE_LOCK_NONE],
778** <li> [SQLITE_LOCK_SHARED],
780** <li> [SQLITE_LOCK_PENDING], or
782** </ul>
783** xLock() increases the lock. xUnlock() decreases the lock.
784** The xCheckReservedLock() method checks whether any database connection,
785** either in this process or in some other process, is holding a RESERVED,
786** PENDING, or EXCLUSIVE lock on the file.  It returns true
787** if such a lock exists and false otherwise.
789** The xFileControl() method is a generic interface that allows custom
790** VFS implementations to directly control an open file using the
791** [sqlite3_file_control()] interface.  The second "op" argument is an
792** integer opcode.  The third argument is a generic pointer intended to
793** point to a structure that may contain arguments or space in which to
794** write return values.  Potential uses for xFileControl() might be
795** functions to enable blocking locks with timeouts, to change the
796** locking strategy (for example to use dot-file locks), to inquire
797** about the status of a lock, or to break stale locks.  The SQLite
798** core reserves all opcodes less than 100 for its own use.
799** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
800** Applications that define a custom xFileControl method should use opcodes
801** greater than 100 to avoid conflicts.  VFS implementations should
802** return [SQLITE_NOTFOUND] for file control opcodes that they do not
803** recognize.
805** The xSectorSize() method returns the sector size of the
806** device that underlies the file.  The sector size is the
807** minimum write that can be performed without disturbing
808** other bytes in the file.  The xDeviceCharacteristics()
809** method returns a bit vector describing behaviors of the
810** underlying device:
812** <ul>
814** <li> [SQLITE_IOCAP_ATOMIC512]
824** </ul>
826** The SQLITE_IOCAP_ATOMIC property means that all writes of
827** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
828** mean that writes of blocks that are nnn bytes in size and
829** are aligned to an address which is an integer multiple of
830** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
831** that when data is appended to a file, the data is appended
832** first then the size of the file is extended, never the other
833** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
834** information is written to disk in the same order as calls
835** to xWrite().
837** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
838** in the unread portions of the buffer with zeros.  A VFS that
839** fails to zero-fill short reads might seem to work.  However,
840** failure to zero-fill short reads will eventually lead to
841** database corruption.
843typedef struct sqlite3_io_methods sqlite3_io_methods;
844struct sqlite3_io_methods {
845  int iVersion;
846  int (*xClose)(sqlite3_file*);
847  int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
848  int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
849  int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
850  int (*xSync)(sqlite3_file*, int flags);
851  int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
852  int (*xLock)(sqlite3_file*, int);
853  int (*xUnlock)(sqlite3_file*, int);
854  int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
855  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
856  int (*xSectorSize)(sqlite3_file*);
857  int (*xDeviceCharacteristics)(sqlite3_file*);
858  /* Methods above are valid for version 1 */
859  int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
860  int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
861  void (*xShmBarrier)(sqlite3_file*);
862  int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
863  /* Methods above are valid for version 2 */
864  int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
865  int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
866  /* Methods above are valid for version 3 */
867  /* Additional methods may be added in future releases */
871** CAPI3REF: Standard File Control Opcodes
873** These integer constants are opcodes for the xFileControl method
874** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
875** interface.
877** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
878** opcode causes the xFileControl method to write the current state of
879** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
881** into an integer that the pArg argument points to. This capability
882** is used during testing and only needs to be supported when SQLITE_TEST
883** is defined.
884** <ul>
886** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
887** layer a hint of how large the database file will grow to be during the
888** current transaction.  This hint is not guaranteed to be accurate but it
889** is often close.  The underlying VFS might choose to preallocate database
890** file space based on this hint in order to help writes to the database
891** file run faster.
894** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
895** extends and truncates the database file in chunks of a size specified
896** by the user. The fourth argument to [sqlite3_file_control()] should
897** point to an integer (type int) containing the new chunk-size to use
898** for the nominated database. Allocating database file space in large
899** chunks (say 1MB at a time), may reduce file-system fragmentation and
900** improve performance on some systems.
903** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
904** to the [sqlite3_file] object associated with a particular database
905** connection.  See the [sqlite3_file_control()] documentation for
906** additional information.
909** No longer in use.
911** <li>[[SQLITE_FCNTL_SYNC]]
912** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
913** sent to the VFS immediately before the xSync method is invoked on a
914** database file descriptor. Or, if the xSync method is not invoked
915** because the user has configured SQLite with
916** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
917** of the xSync method. In most cases, the pointer argument passed with
918** this file-control is NULL. However, if the database file is being synced
919** as part of a multi-database commit, the argument points to a nul-terminated
920** string containing the transactions master-journal file name. VFSes that
921** do not need this signal should silently ignore this opcode. Applications
922** should not call [sqlite3_file_control()] with this opcode as doing so may
923** disrupt the operation of the specialized VFSes that do require it.
926** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
927** and sent to the VFS after a transaction has been committed immediately
928** but before the database is unlocked. VFSes that do not need this signal
929** should silently ignore this opcode. Applications should not call
930** [sqlite3_file_control()] with this opcode as doing so may disrupt the
931** operation of the specialized VFSes that do require it.
934** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
935** retry counts and intervals for certain disk I/O operations for the
936** windows [VFS] in order to provide robustness in the presence of
937** anti-virus programs.  By default, the windows VFS will retry file read,
938** file write, and file delete operations up to 10 times, with a delay
939** of 25 milliseconds before the first retry and with the delay increasing
940** by an additional 25 milliseconds with each subsequent retry.  This
941** opcode allows these two values (10 retries and 25 milliseconds of delay)
942** to be adjusted.  The values are changed for all database connections
943** within the same process.  The argument is a pointer to an array of two
944** integers where the first integer i the new retry count and the second
945** integer is the delay.  If either integer is negative, then the setting
946** is not changed but instead the prior value of that setting is written
947** into the array entry, allowing the current retry settings to be
948** interrogated.  The zDbName parameter is ignored.
951** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
952** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
953** write ahead log and shared memory files used for transaction control
954** are automatically deleted when the latest connection to the database
955** closes.  Setting persistent WAL mode causes those files to persist after
956** close.  Persisting the files is useful when other processes that do not
957** have write permission on the directory containing the database file want
958** to read the database file, as the WAL and shared memory files must exist
959** in order for the database to be readable.  The fourth parameter to
960** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
961** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
962** WAL mode.  If the integer is -1, then it is overwritten with the current
963** WAL persistence setting.
966** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
967** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
968** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
969** xDeviceCharacteristics methods. The fourth parameter to
970** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
971** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
972** mode.  If the integer is -1, then it is overwritten with the current
973** zero-damage mode setting.
976** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
977** a write transaction to indicate that, unless it is rolled back for some
978** reason, the entire database file will be overwritten by the current
979** transaction. This is used by VACUUM operations.
982** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
983** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
984** final bottom-level VFS are written into memory obtained from
985** [sqlite3_malloc()] and the result is stored in the char* variable
986** that the fourth parameter of [sqlite3_file_control()] points to.
987** The caller is responsible for freeing the memory when done.  As with
988** all file-control actions, there is no guarantee that this will actually
989** do anything.  Callers should initialize the char* variable to a NULL
990** pointer in case this file-control is not implemented.  This file-control
991** is intended for diagnostic use only.
994** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
995** file control is sent to the open [sqlite3_file] object corresponding
996** to the database file to which the pragma statement refers. ^The argument
997** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
998** pointers to strings (char**) in which the second element of the array
999** is the name of the pragma and the third element is the argument to the
1000** pragma or NULL if the pragma has no argument.  ^The handler for an
1001** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1002** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1003** or the equivalent and that string will become the result of the pragma or
1004** the error message if the pragma fails. ^If the
1005** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1006** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
1007** file control returns [SQLITE_OK], then the parser assumes that the
1008** VFS has handled the PRAGMA itself and the parser generates a no-op
1009** prepared statement.  ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1010** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1011** that the VFS encountered an error while handling the [PRAGMA] and the
1012** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
1013** file control occurs at the beginning of pragma statement analysis and so
1014** it is able to override built-in [PRAGMA] statements.
1018** file-control may be invoked by SQLite on the database file handle
1019** shortly after it is opened in order to provide a custom VFS with access
1020** to the connections busy-handler callback. The argument is of type (void **)
1021** - an array of two (void *) values. The first (void *) actually points
1022** to a function of type (int (*)(void *)). In order to invoke the connections
1023** busy-handler, this function should be invoked with the second (void *) in
1024** the array as the only argument. If it returns non-zero, then the operation
1025** should be retried. If it returns zero, the custom VFS should abandon the
1026** current operation.
1029** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1030** to have SQLite generate a
1031** temporary filename using the same algorithm that is followed to generate
1032** temporary filenames for TEMP tables and other internal uses.  The
1033** argument should be a char** which will be filled with the filename
1034** written into memory obtained from [sqlite3_malloc()].  The caller should
1035** invoke [sqlite3_free()] on the result to avoid a memory leak.
1038** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1039** maximum number of bytes that will be used for memory-mapped I/O.
1040** The argument is a pointer to a value of type sqlite3_int64 that
1041** is an advisory maximum number of bytes in the file to memory map.  The
1042** pointer is overwritten with the old value.  The limit is not changed if
1043** the value originally pointed to is negative, and so the current limit
1044** can be queried by passing in a pointer to a negative number.  This
1045** file-control is used internally to implement [PRAGMA mmap_size].
1047** <li>[[SQLITE_FCNTL_TRACE]]
1048** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1049** to the VFS about what the higher layers of the SQLite stack are doing.
1050** This file control is used by some VFS activity tracing [shims].
1051** The argument is a zero-terminated string.  Higher layers in the
1052** SQLite stack may generate instances of this file control if
1053** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1056** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1057** pointer to an integer and it writes a boolean into that integer depending
1058** on whether or not the file has been renamed, moved, or deleted since it
1059** was first opened.
1061** </ul>
1063#define SQLITE_FCNTL_LOCKSTATE               1
1064#define SQLITE_GET_LOCKPROXYFILE             2
1065#define SQLITE_SET_LOCKPROXYFILE             3
1066#define SQLITE_LAST_ERRNO                    4
1067#define SQLITE_FCNTL_SIZE_HINT               5
1068#define SQLITE_FCNTL_CHUNK_SIZE              6
1069#define SQLITE_FCNTL_FILE_POINTER            7
1070#define SQLITE_FCNTL_SYNC_OMITTED            8
1071#define SQLITE_FCNTL_WIN32_AV_RETRY          9
1072#define SQLITE_FCNTL_PERSIST_WAL            10
1073#define SQLITE_FCNTL_OVERWRITE              11
1074#define SQLITE_FCNTL_VFSNAME                12
1076#define SQLITE_FCNTL_PRAGMA                 14
1077#define SQLITE_FCNTL_BUSYHANDLER            15
1078#define SQLITE_FCNTL_TEMPFILENAME           16
1079#define SQLITE_FCNTL_MMAP_SIZE              18
1080#define SQLITE_FCNTL_TRACE                  19
1081#define SQLITE_FCNTL_HAS_MOVED              20
1082#define SQLITE_FCNTL_SYNC                   21
1083#define SQLITE_FCNTL_COMMIT_PHASETWO        22
1086** CAPI3REF: Mutex Handle
1088** The mutex module within SQLite defines [sqlite3_mutex] to be an
1089** abstract type for a mutex object.  The SQLite core never looks
1090** at the internal representation of an [sqlite3_mutex].  It only
1091** deals with pointers to the [sqlite3_mutex] object.
1093** Mutexes are created using [sqlite3_mutex_alloc()].
1095typedef struct sqlite3_mutex sqlite3_mutex;
1098** CAPI3REF: OS Interface Object
1100** An instance of the sqlite3_vfs object defines the interface between
1101** the SQLite core and the underlying operating system.  The "vfs"
1102** in the name of the object stands for "virtual file system".  See
1103** the [VFS | VFS documentation] for further information.
1105** The value of the iVersion field is initially 1 but may be larger in
1106** future versions of SQLite.  Additional fields may be appended to this
1107** object when the iVersion value is increased.  Note that the structure
1108** of the sqlite3_vfs object changes in the transaction between
1109** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
1110** modified.
1112** The szOsFile field is the size of the subclassed [sqlite3_file]
1113** structure used by this VFS.  mxPathname is the maximum length of
1114** a pathname in this VFS.
1116** Registered sqlite3_vfs objects are kept on a linked list formed by
1117** the pNext pointer.  The [sqlite3_vfs_register()]
1118** and [sqlite3_vfs_unregister()] interfaces manage this list
1119** in a thread-safe way.  The [sqlite3_vfs_find()] interface
1120** searches the list.  Neither the application code nor the VFS
1121** implementation should use the pNext pointer.
1123** The pNext field is the only field in the sqlite3_vfs
1124** structure that SQLite will ever modify.  SQLite will only access
1125** or modify this field while holding a particular static mutex.
1126** The application should never modify anything within the sqlite3_vfs
1127** object once the object has been registered.
1129** The zName field holds the name of the VFS module.  The name must
1130** be unique across all VFS modules.
1132** [[sqlite3_vfs.xOpen]]
1133** ^SQLite guarantees that the zFilename parameter to xOpen
1134** is either a NULL pointer or string obtained
1135** from xFullPathname() with an optional suffix added.
1136** ^If a suffix is added to the zFilename parameter, it will
1137** consist of a single "-" character followed by no more than
1138** 11 alphanumeric and/or "-" characters.
1139** ^SQLite further guarantees that
1140** the string will be valid and unchanged until xClose() is
1141** called. Because of the previous sentence,
1142** the [sqlite3_file] can safely store a pointer to the
1143** filename if it needs to remember the filename for some reason.
1144** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1145** must invent its own temporary name for the file.  ^Whenever the
1146** xFilename parameter is NULL it will also be the case that the
1147** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1149** The flags argument to xOpen() includes all bits set in
1150** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
1151** or [sqlite3_open16()] is used, then flags includes at least
1153** If xOpen() opens a file read-only then it sets *pOutFlags to
1154** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
1156** ^(SQLite will also add one of the following flags to the xOpen()
1157** call, depending on the object being opened:
1159** <ul>
1160** <li>  [SQLITE_OPEN_MAIN_DB]
1162** <li>  [SQLITE_OPEN_TEMP_DB]
1167** <li>  [SQLITE_OPEN_WAL]
1168** </ul>)^
1170** The file I/O implementation can use the object type flags to
1171** change the way it deals with files.  For example, an application
1172** that does not care about crash recovery or rollback might make
1173** the open of a journal file a no-op.  Writes to this journal would
1174** also be no-ops, and any attempt to read the journal would return
1175** SQLITE_IOERR.  Or the implementation might recognize that a database
1176** file will be doing page-aligned sector reads and writes in a random
1177** order and set up its I/O subsystem accordingly.
1179** SQLite might also add one of the following flags to the xOpen method:
1181** <ul>
1184** </ul>
1186** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1187** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
1188** will be set for TEMP databases and their journals, transient
1189** databases, and subjournals.
1191** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1192** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1193** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1194** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1195** SQLITE_OPEN_CREATE, is used to indicate that file should always
1196** be created, and that it is an error if it already exists.
1197** It is <i>not</i> used to indicate the file should be opened
1198** for exclusive access.
1200** ^At least szOsFile bytes of memory are allocated by SQLite
1201** to hold the  [sqlite3_file] structure passed as the third
1202** argument to xOpen.  The xOpen method does not have to
1203** allocate the structure; it should just fill it in.  Note that
1204** the xOpen method must set the sqlite3_file.pMethods to either
1205** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
1206** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
1207** element will be valid after xOpen returns regardless of the success
1208** or failure of the xOpen call.
1210** [[sqlite3_vfs.xAccess]]
1211** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1212** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1213** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1214** to test whether a file is at least readable.   The file can be a
1215** directory.
1217** ^SQLite will always allocate at least mxPathname+1 bytes for the
1218** output buffer xFullPathname.  The exact size of the output buffer
1219** is also passed as a parameter to both  methods. If the output buffer
1220** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1221** handled as a fatal error by SQLite, vfs implementations should endeavor
1222** to prevent this by setting mxPathname to a sufficiently large value.
1224** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1225** interfaces are not strictly a part of the filesystem, but they are
1226** included in the VFS structure for completeness.
1227** The xRandomness() function attempts to return nBytes bytes
1228** of good-quality randomness into zOut.  The return value is
1229** the actual number of bytes of randomness obtained.
1230** The xSleep() method causes the calling thread to sleep for at
1231** least the number of microseconds given.  ^The xCurrentTime()
1232** method returns a Julian Day Number for the current date and time as
1233** a floating point value.
1234** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1235** Day Number multiplied by 86400000 (the number of milliseconds in
1236** a 24-hour day).
1237** ^SQLite will use the xCurrentTimeInt64() method to get the current
1238** date and time if that method is available (if iVersion is 2 or
1239** greater and the function pointer is not NULL) and will fall back
1240** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1242** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1243** are not used by the SQLite core.  These optional interfaces are provided
1244** by some VFSes to facilitate testing of the VFS code. By overriding
1245** system calls with functions under its control, a test program can
1246** simulate faults and error conditions that would otherwise be difficult
1247** or impossible to induce.  The set of system calls that can be overridden
1248** varies from one VFS to another, and from one version of the same VFS to the
1249** next.  Applications that use these interfaces must be prepared for any
1250** or all of these interfaces to be NULL or for their behavior to change
1251** from one release to the next.  Applications must not attempt to access
1252** any of these methods if the iVersion of the VFS is less than 3.
1254typedef struct sqlite3_vfs sqlite3_vfs;
1255typedef void (*sqlite3_syscall_ptr)(void);
1256struct sqlite3_vfs {
1257  int iVersion;            /* Structure version number (currently 3) */
1258  int szOsFile;            /* Size of subclassed sqlite3_file */
1259  int mxPathname;          /* Maximum file pathname length */
1260  sqlite3_vfs *pNext;      /* Next registered VFS */
1261  const char *zName;       /* Name of this virtual file system */
1262  void *pAppData;          /* Pointer to application-specific data */
1263  int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1264               int flags, int *pOutFlags);
1265  int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1266  int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1267  int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1268  void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1269  void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1270  void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1271  void (*xDlClose)(sqlite3_vfs*, void*);
1272  int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1273  int (*xSleep)(sqlite3_vfs*, int microseconds);
1274  int (*xCurrentTime)(sqlite3_vfs*, double*);
1275  int (*xGetLastError)(sqlite3_vfs*, int, char *);
1276  /*
1277  ** The methods above are in version 1 of the sqlite_vfs object
1278  ** definition.  Those that follow are added in version 2 or later
1279  */
1280  int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1281  /*
1282  ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1283  ** Those below are for version 3 and greater.
1284  */
1285  int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1286  sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1287  const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1288  /*
1289  ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1290  ** New fields may be appended in figure versions.  The iVersion
1291  ** value will increment whenever this happens.
1292  */
1296** CAPI3REF: Flags for the xAccess VFS method
1298** These integer constants can be used as the third parameter to
1299** the xAccess method of an [sqlite3_vfs] object.  They determine
1300** what kind of permissions the xAccess method is looking for.
1301** With SQLITE_ACCESS_EXISTS, the xAccess method
1302** simply checks whether the file exists.
1303** With SQLITE_ACCESS_READWRITE, the xAccess method
1304** checks whether the named directory is both readable and writable
1305** (in other words, if files can be added, removed, and renamed within
1306** the directory).
1307** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1308** [temp_store_directory pragma], though this could change in a future
1309** release of SQLite.
1310** With SQLITE_ACCESS_READ, the xAccess method
1311** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
1312** currently unused, though it might be used in a future release of
1313** SQLite.
1315#define SQLITE_ACCESS_EXISTS    0
1316#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
1317#define SQLITE_ACCESS_READ      2   /* Unused */
1320** CAPI3REF: Flags for the xShmLock VFS method
1322** These integer constants define the various locking operations
1323** allowed by the xShmLock method of [sqlite3_io_methods].  The
1324** following are the only legal combinations of flags to the
1325** xShmLock method:
1327** <ul>
1332** </ul>
1334** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1335** was given no the corresponding lock.
1337** The xShmLock method can transition between unlocked and SHARED or
1338** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
1339** and EXCLUSIVE.
1341#define SQLITE_SHM_UNLOCK       1
1342#define SQLITE_SHM_LOCK         2
1343#define SQLITE_SHM_SHARED       4
1344#define SQLITE_SHM_EXCLUSIVE    8
1347** CAPI3REF: Maximum xShmLock index
1349** The xShmLock method on [sqlite3_io_methods] may use values
1350** between 0 and this upper bound as its "offset" argument.
1351** The SQLite core will never attempt to acquire or release a
1352** lock outside of this range
1354#define SQLITE_SHM_NLOCK        8
1358** CAPI3REF: Initialize The SQLite Library
1360** ^The sqlite3_initialize() routine initializes the
1361** SQLite library.  ^The sqlite3_shutdown() routine
1362** deallocates any resources that were allocated by sqlite3_initialize().
1363** These routines are designed to aid in process initialization and
1364** shutdown on embedded systems.  Workstation applications using
1365** SQLite normally do not need to invoke either of these routines.
1367** A call to sqlite3_initialize() is an "effective" call if it is
1368** the first time sqlite3_initialize() is invoked during the lifetime of
1369** the process, or if it is the first time sqlite3_initialize() is invoked
1370** following a call to sqlite3_shutdown().  ^(Only an effective call
1371** of sqlite3_initialize() does any initialization.  All other calls
1372** are harmless no-ops.)^
1374** A call to sqlite3_shutdown() is an "effective" call if it is the first
1375** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
1376** an effective call to sqlite3_shutdown() does any deinitialization.
1377** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1379** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1380** is not.  The sqlite3_shutdown() interface must only be called from a
1381** single thread.  All open [database connections] must be closed and all
1382** other SQLite resources must be deallocated prior to invoking
1383** sqlite3_shutdown().
1385** Among other things, ^sqlite3_initialize() will invoke
1386** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
1387** will invoke sqlite3_os_end().
1389** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1390** ^If for some reason, sqlite3_initialize() is unable to initialize
1391** the library (perhaps it is unable to allocate a needed resource such
1392** as a mutex) it returns an [error code] other than [SQLITE_OK].
1394** ^The sqlite3_initialize() routine is called internally by many other
1395** SQLite interfaces so that an application usually does not need to
1396** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
1397** calls sqlite3_initialize() so the SQLite library will be automatically
1398** initialized when [sqlite3_open()] is called if it has not be initialized
1399** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1400** compile-time option, then the automatic calls to sqlite3_initialize()
1401** are omitted and the application must call sqlite3_initialize() directly
1402** prior to using any other SQLite interface.  For maximum portability,
1403** it is recommended that applications always invoke sqlite3_initialize()
1404** directly prior to using any other SQLite interface.  Future releases
1405** of SQLite may require this.  In other words, the behavior exhibited
1406** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1407** default behavior in some future release of SQLite.
1409** The sqlite3_os_init() routine does operating-system specific
1410** initialization of the SQLite library.  The sqlite3_os_end()
1411** routine undoes the effect of sqlite3_os_init().  Typical tasks
1412** performed by these routines include allocation or deallocation
1413** of static resources, initialization of global variables,
1414** setting up a default [sqlite3_vfs] module, or setting up
1415** a default configuration using [sqlite3_config()].
1417** The application should never invoke either sqlite3_os_init()
1418** or sqlite3_os_end() directly.  The application should only invoke
1419** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
1420** interface is called automatically by sqlite3_initialize() and
1421** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
1422** implementations for sqlite3_os_init() and sqlite3_os_end()
1423** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1424** When [custom builds | built for other platforms]
1425** (using the [SQLITE_OS_OTHER=1] compile-time
1426** option) the application must supply a suitable implementation for
1427** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
1428** implementation of sqlite3_os_init() or sqlite3_os_end()
1429** must return [SQLITE_OK] on success and some other [error code] upon
1430** failure.
1432SQLITE_API int sqlite3_initialize(void);
1433SQLITE_API int sqlite3_shutdown(void);
1434SQLITE_API int sqlite3_os_init(void);
1435SQLITE_API int sqlite3_os_end(void);
1438** CAPI3REF: Configuring The SQLite Library
1440** The sqlite3_config() interface is used to make global configuration
1441** changes to SQLite in order to tune SQLite to the specific needs of
1442** the application.  The default configuration is recommended for most
1443** applications and so this routine is usually not necessary.  It is
1444** provided to support rare applications with unusual needs.
1446** The sqlite3_config() interface is not threadsafe.  The application
1447** must insure that no other SQLite interfaces are invoked by other
1448** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
1449** may only be invoked prior to library initialization using
1450** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1451** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1452** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1453** Note, however, that ^sqlite3_config() can be called as part of the
1454** implementation of an application-defined [sqlite3_os_init()].
1456** The first argument to sqlite3_config() is an integer
1457** [configuration option] that determines
1458** what property of SQLite is to be configured.  Subsequent arguments
1459** vary depending on the [configuration option]
1460** in the first argument.
1462** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1463** ^If the option is unknown or SQLite is unable to set the option
1464** then this routine returns a non-zero [error code].
1466SQLITE_API int sqlite3_config(int, ...);
1469** CAPI3REF: Configure database connections
1471** The sqlite3_db_config() interface is used to make configuration
1472** changes to a [database connection].  The interface is similar to
1473** [sqlite3_config()] except that the changes apply to a single
1474** [database connection] (specified in the first argument).
1476** The second argument to sqlite3_db_config(D,V,...)  is the
1477** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1478** that indicates what aspect of the [database connection] is being configured.
1479** Subsequent arguments vary depending on the configuration verb.
1481** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1482** the call is considered successful.
1484SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1487** CAPI3REF: Memory Allocation Routines
1489** An instance of this object defines the interface between SQLite
1490** and low-level memory allocation routines.
1492** This object is used in only one place in the SQLite interface.
1493** A pointer to an instance of this object is the argument to
1494** [sqlite3_config()] when the configuration option is
1496** By creating an instance of this object
1497** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1498** during configuration, an application can specify an alternative
1499** memory allocation subsystem for SQLite to use for all of its
1500** dynamic memory needs.
1502** Note that SQLite comes with several [built-in memory allocators]
1503** that are perfectly adequate for the overwhelming majority of applications
1504** and that this object is only useful to a tiny minority of applications
1505** with specialized memory allocation requirements.  This object is
1506** also used during testing of SQLite in order to specify an alternative
1507** memory allocator that simulates memory out-of-memory conditions in
1508** order to verify that SQLite recovers gracefully from such
1509** conditions.
1511** The xMalloc, xRealloc, and xFree methods must work like the
1512** malloc(), realloc() and free() functions from the standard C library.
1513** ^SQLite guarantees that the second argument to
1514** xRealloc is always a value returned by a prior call to xRoundup.
1516** xSize should return the allocated size of a memory allocation
1517** previously obtained from xMalloc or xRealloc.  The allocated size
1518** is always at least as big as the requested size but may be larger.
1520** The xRoundup method returns what would be the allocated size of
1521** a memory allocation given a particular requested size.  Most memory
1522** allocators round up memory allocations at least to the next multiple
1523** of 8.  Some allocators round up to a larger multiple or to a power of 2.
1524** Every memory allocation request coming in through [sqlite3_malloc()]
1525** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
1526** that causes the corresponding memory allocation to fail.
1528** The xInit method initializes the memory allocator.  For example,
1529** it might allocate any require mutexes or initialize internal data
1530** structures.  The xShutdown method is invoked (indirectly) by
1531** [sqlite3_shutdown()] and should deallocate any resources acquired
1532** by xInit.  The pAppData pointer is used as the only parameter to
1533** xInit and xShutdown.
1535** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1536** the xInit method, so the xInit method need not be threadsafe.  The
1537** xShutdown method is only called from [sqlite3_shutdown()] so it does
1538** not need to be threadsafe either.  For all other methods, SQLite
1539** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1540** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1541** it is by default) and so the methods are automatically serialized.
1542** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1543** methods must be threadsafe or else make their own arrangements for
1544** serialization.
1546** SQLite will never invoke xInit() more than once without an intervening
1547** call to xShutdown().
1549typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1550struct sqlite3_mem_methods {
1551  void *(*xMalloc)(int);         /* Memory allocation function */
1552  void (*xFree)(void*);          /* Free a prior allocation */
1553  void *(*xRealloc)(void*,int);  /* Resize an allocation */
1554  int (*xSize)(void*);           /* Return the size of an allocation */
1555  int (*xRoundup)(int);          /* Round up request size to allocation size */
1556  int (*xInit)(void*);           /* Initialize the memory allocator */
1557  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
1558  void *pAppData;                /* Argument to xInit() and xShutdown() */
1562** CAPI3REF: Configuration Options
1563** KEYWORDS: {configuration option}
1565** These constants are the available integer configuration options that
1566** can be passed as the first argument to the [sqlite3_config()] interface.
1568** New configuration options may be added in future releases of SQLite.
1569** Existing configuration options might be discontinued.  Applications
1570** should check the return code from [sqlite3_config()] to make sure that
1571** the call worked.  The [sqlite3_config()] interface will return a
1572** non-zero [error code] if a discontinued or unsupported configuration option
1573** is invoked.
1575** <dl>
1577** <dd>There are no arguments to this option.  ^This option sets the
1578** [threading mode] to Single-thread.  In other words, it disables
1579** all mutexing and puts SQLite into a mode where it can only be used
1580** by a single thread.   ^If SQLite is compiled with
1581** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1582** it is not possible to change the [threading mode] from its default
1583** value of Single-thread and so [sqlite3_config()] will return
1585** configuration option.</dd>
1588** <dd>There are no arguments to this option.  ^This option sets the
1589** [threading mode] to Multi-thread.  In other words, it disables
1590** mutexing on [database connection] and [prepared statement] objects.
1591** The application is responsible for serializing access to
1592** [database connections] and [prepared statements].  But other mutexes
1593** are enabled so that SQLite will be safe to use in a multi-threaded
1594** environment as long as no two threads attempt to use the same
1595** [database connection] at the same time.  ^If SQLite is compiled with
1596** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1597** it is not possible to set the Multi-thread [threading mode] and
1598** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1599** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1602** <dd>There are no arguments to this option.  ^This option sets the
1603** [threading mode] to Serialized. In other words, this option enables
1604** all mutexes including the recursive
1605** mutexes on [database connection] and [prepared statement] objects.
1606** In this mode (which is the default when SQLite is compiled with
1607** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1608** to [database connections] and [prepared statements] so that the
1609** application is free to use the same [database connection] or the
1610** same [prepared statement] in different threads at the same time.
1611** ^If SQLite is compiled with
1612** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1613** it is not possible to set the Serialized [threading mode] and
1614** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1615** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1618** <dd> ^(This option takes a single argument which is a pointer to an
1619** instance of the [sqlite3_mem_methods] structure.  The argument specifies
1620** alternative low-level memory allocation routines to be used in place of
1621** the memory allocation routines built into SQLite.)^ ^SQLite makes
1622** its own private copy of the content of the [sqlite3_mem_methods] structure
1623** before the [sqlite3_config()] call returns.</dd>
1626** <dd> ^(This option takes a single argument which is a pointer to an
1627** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
1628** structure is filled with the currently defined memory allocation routines.)^
1629** This option can be used to overload the default memory allocation
1630** routines with a wrapper that simulations memory allocation failure or
1631** tracks memory usage, for example. </dd>
1634** <dd> ^This option takes single argument of type int, interpreted as a
1635** boolean, which enables or disables the collection of memory allocation
1636** statistics. ^(When memory allocation statistics are disabled, the
1637** following SQLite interfaces become non-operational:
1638**   <ul>
1639**   <li> [sqlite3_memory_used()]
1640**   <li> [sqlite3_memory_highwater()]
1641**   <li> [sqlite3_soft_heap_limit64()]
1642**   <li> [sqlite3_status()]
1643**   </ul>)^
1644** ^Memory allocation statistics are enabled by default unless SQLite is
1645** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1646** allocation statistics are disabled by default.
1647** </dd>
1650** <dd> ^This option specifies a static memory buffer that SQLite can use for
1651** scratch memory.  There are three arguments:  A pointer an 8-byte
1652** aligned memory buffer from which the scratch allocations will be
1653** drawn, the size of each scratch allocation (sz),
1654** and the maximum number of scratch allocations (N).  The sz
1655** argument must be a multiple of 16.
1656** The first argument must be a pointer to an 8-byte aligned buffer
1657** of at least sz*N bytes of memory.
1658** ^SQLite will use no more than two scratch buffers per thread.  So
1659** N should be set to twice the expected maximum number of threads.
1660** ^SQLite will never require a scratch buffer that is more than 6
1661** times the database page size. ^If SQLite needs needs additional
1662** scratch memory beyond what is provided by this configuration option, then
1663** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1666** <dd> ^This option specifies a static memory buffer that SQLite can use for
1667** the database page cache with the default page cache implementation.
1668** This configuration should not be used if an application-define page
1669** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
1670** There are three arguments to this option: A pointer to 8-byte aligned
1671** memory, the size of each page buffer (sz), and the number of pages (N).
1672** The sz argument should be the size of the largest database page
1673** (a power of two between 512 and 32768) plus a little extra for each
1674** page header.  ^The page header size is 20 to 40 bytes depending on
1675** the host architecture.  ^It is harmless, apart from the wasted memory,
1676** to make sz a little too large.  The first
1677** argument should point to an allocation of at least sz*N bytes of memory.
1678** ^SQLite will use the memory provided by the first argument to satisfy its
1679** memory needs for the first N pages that it adds to cache.  ^If additional
1680** page cache memory is needed beyond what is provided by this option, then
1681** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1682** The pointer in the first argument must
1683** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1684** will be undefined.</dd>
1687** <dd> ^This option specifies a static memory buffer that SQLite will use
1688** for all of its dynamic memory allocation needs beyond those provided
1690** There are three arguments: An 8-byte aligned pointer to the memory,
1691** the number of bytes in the memory buffer, and the minimum allocation size.
1692** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1693** to using its default memory allocator (the system malloc() implementation),
1694** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
1695** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1696** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1697** allocator is engaged to handle all of SQLites memory allocation needs.
1698** The first pointer (the memory pointer) must be aligned to an 8-byte
1699** boundary or subsequent behavior of SQLite will be undefined.
1700** The minimum allocation size is capped at 2**12. Reasonable values
1701** for the minimum allocation size are 2**5 through 2**8.</dd>
1704** <dd> ^(This option takes a single argument which is a pointer to an
1705** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
1706** alternative low-level mutex routines to be used in place
1707** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
1708** content of the [sqlite3_mutex_methods] structure before the call to
1709** [sqlite3_config()] returns. ^If SQLite is compiled with
1710** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1711** the entire mutexing subsystem is omitted from the build and hence calls to
1712** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1713** return [SQLITE_ERROR].</dd>
1716** <dd> ^(This option takes a single argument which is a pointer to an
1717** instance of the [sqlite3_mutex_methods] structure.  The
1718** [sqlite3_mutex_methods]
1719** structure is filled with the currently defined mutex routines.)^
1720** This option can be used to overload the default mutex allocation
1721** routines with a wrapper used to track mutex usage for performance
1722** profiling or testing, for example.   ^If SQLite is compiled with
1723** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1724** the entire mutexing subsystem is omitted from the build and hence calls to
1725** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1726** return [SQLITE_ERROR].</dd>
1729** <dd> ^(This option takes two arguments that determine the default
1730** memory allocation for the lookaside memory allocator on each
1731** [database connection].  The first argument is the
1732** size of each lookaside buffer slot and the second is the number of
1733** slots allocated to each database connection.)^  ^(This option sets the
1734** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1735** verb to [sqlite3_db_config()] can be used to change the lookaside
1736** configuration on individual connections.)^ </dd>
1739** <dd> ^(This option takes a single argument which is a pointer to
1740** an [sqlite3_pcache_methods2] object.  This object specifies the interface
1741** to a custom page cache implementation.)^  ^SQLite makes a copy of the
1742** object and uses it for page cache memory allocations.</dd>
1745** <dd> ^(This option takes a single argument which is a pointer to an
1746** [sqlite3_pcache_methods2] object.  SQLite copies of the current
1747** page cache implementation into that object.)^ </dd>
1750** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1751** global [error log].
1752** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1753** function with a call signature of void(*)(void*,int,const char*),
1754** and a pointer to void. ^If the function pointer is not NULL, it is
1755** invoked by [sqlite3_log()] to process each logging event.  ^If the
1756** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1757** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1758** passed through as the first parameter to the application-defined logger
1759** function whenever that function is invoked.  ^The second parameter to
1760** the logger function is a copy of the first parameter to the corresponding
1761** [sqlite3_log()] call and is intended to be a [result code] or an
1762** [extended result code].  ^The third parameter passed to the logger is
1763** log message after formatting via [sqlite3_snprintf()].
1764** The SQLite logging interface is not reentrant; the logger function
1765** supplied by the application must not invoke any SQLite interface.
1766** In a multi-threaded application, the application-defined logger
1767** function must be threadsafe. </dd>
1770** <dd>^(This option takes a single argument of type int. If non-zero, then
1771** URI handling is globally enabled. If the parameter is zero, then URI handling
1772** is globally disabled.)^ ^If URI handling is globally enabled, all filenames
1773** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
1774** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1775** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1776** connection is opened. ^If it is globally disabled, filenames are
1777** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1778** database connection is opened. ^(By default, URI handling is globally
1779** disabled. The default value may be changed by compiling with the
1780** [SQLITE_USE_URI] symbol defined.)^
1783** <dd>^This option takes a single integer argument which is interpreted as
1784** a boolean in order to enable or disable the use of covering indices for
1785** full table scans in the query optimizer.  ^The default setting is determined
1786** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1787** if that compile-time option is omitted.
1788** The ability to disable the use of covering indices for full table scans
1789** is because some incorrectly coded legacy applications might malfunction
1790** when the optimization is enabled.  Providing the ability to
1791** disable the optimization allows the older, buggy application code to work
1792** without change even with newer versions of SQLite.
1796** <dd> These options are obsolete and should not be used by new code.
1797** They are retained for backwards compatibility but are now no-ops.
1798** </dd>
1802** <dd>This option is only available if sqlite is compiled with the
1803** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1804** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1805** The second should be of type (void*). The callback is invoked by the library
1806** in three separate circumstances, identified by the value passed as the
1807** fourth parameter. If the fourth parameter is 0, then the database connection
1808** passed as the second argument has just been opened. The third argument
1809** points to a buffer containing the name of the main database file. If the
1810** fourth parameter is 1, then the SQL statement that the third parameter
1811** points to has just been executed. Or, if the fourth parameter is 2, then
1812** the connection being passed as the second parameter is being closed. The
1813** third parameter is passed NULL In this case.  An example of using this
1814** configuration option can be seen in the "test_sqllog.c" source file in
1815** the canonical SQLite source tree.</dd>
1819** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1820** that are the default mmap size limit (the default setting for
1821** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1822** ^The default setting can be overridden by each database connection using
1823** either the [PRAGMA mmap_size] command, or by using the
1824** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
1825** cannot be changed at run-time.  Nor may the maximum allowed mmap size
1826** exceed the compile-time maximum mmap size set by the
1827** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1828** ^If either argument to this option is negative, then that argument is
1829** changed to its compile-time default.
1833** <dd>^This option is only available if SQLite is compiled for Windows
1834** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
1835** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1836** that specifies the maximum size of the created heap.
1837** </dl>
1839#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
1840#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
1841#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
1842#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
1843#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
1844#define SQLITE_CONFIG_SCRATCH       6  /* void*, int sz, int N */
1845#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
1846#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
1847#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
1848#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
1849#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
1850/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1851#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
1852#define SQLITE_CONFIG_PCACHE       14  /* no-op */
1853#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
1854#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
1855#define SQLITE_CONFIG_URI          17  /* int */
1856#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
1857#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
1858#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
1859#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
1860#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
1861#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
1864** CAPI3REF: Database Connection Configuration Options
1866** These constants are the available integer configuration options that
1867** can be passed as the second argument to the [sqlite3_db_config()] interface.
1869** New configuration options may be added in future releases of SQLite.
1870** Existing configuration options might be discontinued.  Applications
1871** should check the return code from [sqlite3_db_config()] to make sure that
1872** the call worked.  ^The [sqlite3_db_config()] interface will return a
1873** non-zero [error code] if a discontinued or unsupported configuration option
1874** is invoked.
1876** <dl>
1878** <dd> ^This option takes three additional arguments that determine the
1879** [lookaside memory allocator] configuration for the [database connection].
1880** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1881** pointer to a memory buffer to use for lookaside memory.
1882** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1883** may be NULL in which case SQLite will allocate the
1884** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1885** size of each lookaside buffer slot.  ^The third argument is the number of
1886** slots.  The size of the buffer in the first argument must be greater than
1887** or equal to the product of the second and third arguments.  The buffer
1888** must be aligned to an 8-byte boundary.  ^If the second argument to
1889** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1890** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
1891** configuration for a database connection can only be changed when that
1892** connection is not currently using lookaside memory, or in other words
1893** when the "current value" returned by
1894** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1895** Any attempt to change the lookaside memory configuration when lookaside
1896** memory is in use leaves the configuration unchanged and returns
1897** [SQLITE_BUSY].)^</dd>
1900** <dd> ^This option is used to enable or disable the enforcement of
1901** [foreign key constraints].  There should be two additional arguments.
1902** The first argument is an integer which is 0 to disable FK enforcement,
1903** positive to enable FK enforcement or negative to leave FK enforcement
1904** unchanged.  The second parameter is a pointer to an integer into which
1905** is written 0 or 1 to indicate whether FK enforcement is off or on
1906** following this call.  The second parameter may be a NULL pointer, in
1907** which case the FK enforcement setting is not reported back. </dd>
1910** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1911** There should be two additional arguments.
1912** The first argument is an integer which is 0 to disable triggers,
1913** positive to enable triggers or negative to leave the setting unchanged.
1914** The second parameter is a pointer to an integer into which
1915** is written 0 or 1 to indicate whether triggers are disabled or enabled
1916** following this call.  The second parameter may be a NULL pointer, in
1917** which case the trigger setting is not reported back. </dd>
1919** </dl>
1921#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
1922#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
1923#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
1927** CAPI3REF: Enable Or Disable Extended Result Codes
1929** ^The sqlite3_extended_result_codes() routine enables or disables the
1930** [extended result codes] feature of SQLite. ^The extended result
1931** codes are disabled by default for historical compatibility.
1933SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
1936** CAPI3REF: Last Insert Rowid
1938** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
1939** has a unique 64-bit signed
1940** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1941** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1942** names are not also used by explicitly declared columns. ^If
1943** the table has a column of type [INTEGER PRIMARY KEY] then that column
1944** is another alias for the rowid.
1946** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
1947** most recent successful [INSERT] into a rowid table or [virtual table]
1948** on database connection D.
1949** ^Inserts into [WITHOUT ROWID] tables are not recorded.
1950** ^If no successful [INSERT]s into rowid tables
1951** have ever occurred on the database connection D,
1952** then sqlite3_last_insert_rowid(D) returns zero.
1954** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
1955** method, then this routine will return the [rowid] of the inserted
1956** row as long as the trigger or virtual table method is running.
1957** But once the trigger or virtual table method ends, the value returned
1958** by this routine reverts to what it was before the trigger or virtual
1959** table method began.)^
1961** ^An [INSERT] that fails due to a constraint violation is not a
1962** successful [INSERT] and does not change the value returned by this
1964** and INSERT OR ABORT make no changes to the return value of this
1965** routine when their insertion fails.  ^(When INSERT OR REPLACE
1966** encounters a constraint violation, it does not fail.  The
1967** INSERT continues to completion after deleting rows that caused
1968** the constraint problem so INSERT OR REPLACE will always change
1969** the return value of this interface.)^
1971** ^For the purposes of this routine, an [INSERT] is considered to
1972** be successful even if it is subsequently rolled back.
1974** This function is accessible to SQL statements via the
1975** [last_insert_rowid() SQL function].
1977** If a separate thread performs a new [INSERT] on the same
1978** database connection while the [sqlite3_last_insert_rowid()]
1979** function is running and thus changes the last insert [rowid],
1980** then the value returned by [sqlite3_last_insert_rowid()] is
1981** unpredictable and might not equal either the old or the new
1982** last insert [rowid].
1984SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
1987** CAPI3REF: Count The Number Of Rows Modified
1989** ^This function returns the number of database rows that were changed
1990** or inserted or deleted by the most recently completed SQL statement
1991** on the [database connection] specified by the first parameter.
1992** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
1993** or [DELETE] statement are counted.  Auxiliary changes caused by
1994** triggers or [foreign key actions] are not counted.)^ Use the
1995** [sqlite3_total_changes()] function to find the total number of changes
1996** including changes caused by triggers and foreign key actions.
1998** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
1999** are not counted.  Only real table changes are counted.
2001** ^(A "row change" is a change to a single row of a single table
2002** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
2003** are changed as side effects of [REPLACE] constraint resolution,
2004** rollback, ABORT processing, [DROP TABLE], or by any other
2005** mechanisms do not count as direct row changes.)^
2007** A "trigger context" is a scope of execution that begins and
2008** ends with the script of a [CREATE TRIGGER | trigger].
2009** Most SQL statements are
2010** evaluated outside of any trigger.  This is the "top level"
2011** trigger context.  If a trigger fires from the top level, a
2012** new trigger context is entered for the duration of that one
2013** trigger.  Subtriggers create subcontexts for their duration.
2015** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
2016** not create a new trigger context.
2018** ^This function returns the number of direct row changes in the
2019** most recent INSERT, UPDATE, or DELETE statement within the same
2020** trigger context.
2022** ^Thus, when called from the top level, this function returns the
2023** number of changes in the most recent INSERT, UPDATE, or DELETE
2024** that also occurred at the top level.  ^(Within the body of a trigger,
2025** the sqlite3_changes() interface can be called to find the number of
2026** changes in the most recently completed INSERT, UPDATE, or DELETE
2027** statement within the body of the same trigger.
2028** However, the number returned does not include changes
2029** caused by subtriggers since those have their own context.)^
2031** See also the [sqlite3_total_changes()] interface, the
2032** [count_changes pragma], and the [changes() SQL function].
2034** If a separate thread makes changes on the same database connection
2035** while [sqlite3_changes()] is running then the value returned
2036** is unpredictable and not meaningful.
2038SQLITE_API int sqlite3_changes(sqlite3*);
2041** CAPI3REF: Total Number Of Rows Modified
2043** ^This function returns the number of row changes caused by [INSERT],
2044** [UPDATE] or [DELETE] statements since the [database connection] was opened.
2045** ^(The count returned by sqlite3_total_changes() includes all changes
2046** from all [CREATE TRIGGER | trigger] contexts and changes made by
2047** [foreign key actions]. However,
2048** the count does not include changes used to implement [REPLACE] constraints,
2049** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
2050** count does not include rows of views that fire an [INSTEAD OF trigger],
2051** though if the INSTEAD OF trigger makes changes of its own, those changes
2052** are counted.)^
2053** ^The sqlite3_total_changes() function counts the changes as soon as
2054** the statement that makes them is completed (when the statement handle
2055** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
2057** See also the [sqlite3_changes()] interface, the
2058** [count_changes pragma], and the [total_changes() SQL function].
2060** If a separate thread makes changes on the same database connection
2061** while [sqlite3_total_changes()] is running then the value
2062** returned is unpredictable and not meaningful.
2064SQLITE_API int sqlite3_total_changes(sqlite3*);
2067** CAPI3REF: Interrupt A Long-Running Query
2069** ^This function causes any pending database operation to abort and
2070** return at its earliest opportunity. This routine is typically
2071** called in response to a user action such as pressing "Cancel"
2072** or Ctrl-C where the user wants a long query operation to halt
2073** immediately.
2075** ^It is safe to call this routine from a thread different from the
2076** thread that is currently running the database operation.  But it
2077** is not safe to call this routine with a [database connection] that
2078** is closed or might close before sqlite3_interrupt() returns.
2080** ^If an SQL operation is very nearly finished at the time when
2081** sqlite3_interrupt() is called, then it might not have an opportunity
2082** to be interrupted and might continue to completion.
2084** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2085** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2086** that is inside an explicit transaction, then the entire transaction
2087** will be rolled back automatically.
2089** ^The sqlite3_interrupt(D) call is in effect until all currently running
2090** SQL statements on [database connection] D complete.  ^Any new SQL statements
2091** that are started after the sqlite3_interrupt() call and before the
2092** running statements reaches zero are interrupted as if they had been
2093** running prior to the sqlite3_interrupt() call.  ^New SQL statements
2094** that are started after the running statement count reaches zero are
2095** not effected by the sqlite3_interrupt().
2096** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2097** SQL statements is a no-op and has no effect on SQL statements
2098** that are started after the sqlite3_interrupt() call returns.
2100** If the database connection closes while [sqlite3_interrupt()]
2101** is running then bad things will likely happen.
2103SQLITE_API void sqlite3_interrupt(sqlite3*);
2106** CAPI3REF: Determine If An SQL Statement Is Complete
2108** These routines are useful during command-line input to determine if the
2109** currently entered text seems to form a complete SQL statement or
2110** if additional input is needed before sending the text into
2111** SQLite for parsing.  ^These routines return 1 if the input string
2112** appears to be a complete SQL statement.  ^A statement is judged to be
2113** complete if it ends with a semicolon token and is not a prefix of a
2114** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
2115** string literals or quoted identifier names or comments are not
2116** independent tokens (they are part of the token in which they are
2117** embedded) and thus do not count as a statement terminator.  ^Whitespace
2118** and comments that follow the final semicolon are ignored.
2120** ^These routines return 0 if the statement is incomplete.  ^If a
2121** memory allocation fails, then SQLITE_NOMEM is returned.
2123** ^These routines do not parse the SQL statements thus
2124** will not detect syntactically incorrect SQL.
2126** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2127** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2128** automatically by sqlite3_complete16().  If that initialization fails,
2129** then the return value from sqlite3_complete16() will be non-zero
2130** regardless of whether or not the input SQL is complete.)^
2132** The input to [sqlite3_complete()] must be a zero-terminated
2133** UTF-8 string.
2135** The input to [sqlite3_complete16()] must be a zero-terminated
2136** UTF-16 string in native byte order.
2138SQLITE_API int sqlite3_complete(const char *sql);
2139SQLITE_API int sqlite3_complete16(const void *sql);
2142** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2144** ^This routine sets a callback function that might be invoked whenever
2145** an attempt is made to open a database table that another thread
2146** or process has locked.
2148** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
2149** is returned immediately upon encountering the lock.  ^If the busy callback
2150** is not NULL, then the callback might be invoked with two arguments.
2152** ^The first argument to the busy handler is a copy of the void* pointer which
2153** is the third argument to sqlite3_busy_handler().  ^The second argument to
2154** the busy handler callback is the number of times that the busy handler has
2155** been invoked for this locking event.  ^If the
2156** busy callback returns 0, then no additional attempts are made to
2157** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
2158** ^If the callback returns non-zero, then another attempt
2159** is made to open the database for reading and the cycle repeats.
2161** The presence of a busy handler does not guarantee that it will be invoked
2162** when there is lock contention. ^If SQLite determines that invoking the busy
2163** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2164** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
2165** Consider a scenario where one process is holding a read lock that
2166** it is trying to promote to a reserved lock and
2167** a second process is holding a reserved lock that it is trying
2168** to promote to an exclusive lock.  The first process cannot proceed
2169** because it is blocked by the second and the second process cannot
2170** proceed because it is blocked by the first.  If both processes
2171** invoke the busy handlers, neither will make any progress.  Therefore,
2172** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2173** will induce the first process to release its read lock and allow
2174** the second process to proceed.
2176** ^The default busy callback is NULL.
2178** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
2179** when SQLite is in the middle of a large transaction where all the
2180** changes will not fit into the in-memory cache.  SQLite will
2181** already hold a RESERVED lock on the database file, but it needs
2182** to promote this lock to EXCLUSIVE so that it can spill cache
2183** pages into the database file without harm to concurrent
2184** readers.  ^If it is unable to promote the lock, then the in-memory
2185** cache will be left in an inconsistent state and so the error
2186** code is promoted from the relatively benign [SQLITE_BUSY] to
2187** the more severe [SQLITE_IOERR_BLOCKED].  ^This error code promotion
2188** forces an automatic rollback of the changes.  See the
2189** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
2190** CorruptionFollowingBusyError</a> wiki page for a discussion of why
2191** this is important.
2193** ^(There can only be a single busy handler defined for each
2194** [database connection].  Setting a new busy handler clears any
2195** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
2196** will also set or clear the busy handler.
2198** The busy callback should not take any actions which modify the
2199** database connection that invoked the busy handler.  Any such actions
2200** result in undefined behavior.
2202** A busy handler must not close the database connection
2203** or [prepared statement] that invoked the busy handler.
2205SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
2208** CAPI3REF: Set A Busy Timeout
2210** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2211** for a specified amount of time when a table is locked.  ^The handler
2212** will sleep multiple times until at least "ms" milliseconds of sleeping
2213** have accumulated.  ^After at least "ms" milliseconds of sleeping,
2214** the handler returns 0 which causes [sqlite3_step()] to return
2217** ^Calling this routine with an argument less than or equal to zero
2218** turns off all busy handlers.
2220** ^(There can only be a single busy handler for a particular
2221** [database connection] any any given moment.  If another busy handler
2222** was defined  (using [sqlite3_busy_handler()]) prior to calling
2223** this routine, that other busy handler is cleared.)^
2225SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2228** CAPI3REF: Convenience Routines For Running Queries
2230** This is a legacy interface that is preserved for backwards compatibility.
2231** Use of this interface is not recommended.
2233** Definition: A <b>result table</b> is memory data structure created by the
2234** [sqlite3_get_table()] interface.  A result table records the
2235** complete query results from one or more queries.
2237** The table conceptually has a number of rows and columns.  But
2238** these numbers are not part of the result table itself.  These
2239** numbers are obtained separately.  Let N be the number of rows
2240** and M be the number of columns.
2242** A result table is an array of pointers to zero-terminated UTF-8 strings.
2243** There are (N+1)*M elements in the array.  The first M pointers point
2244** to zero-terminated strings that  contain the names of the columns.
2245** The remaining entries all point to query results.  NULL values result
2246** in NULL pointers.  All other values are in their UTF-8 zero-terminated
2247** string representation as returned by [sqlite3_column_text()].
2249** A result table might consist of one or more memory allocations.
2250** It is not safe to pass a result table directly to [sqlite3_free()].
2251** A result table should be deallocated using [sqlite3_free_table()].
2253** ^(As an example of the result table format, suppose a query result
2254** is as follows:
2256** <blockquote><pre>
2257**        Name        | Age
2258**        -----------------------
2259**        Alice       | 43
2260**        Bob         | 28
2261**        Cindy       | 21
2262** </pre></blockquote>
2264** There are two column (M==2) and three rows (N==3).  Thus the
2265** result table has 8 entries.  Suppose the result table is stored
2266** in an array names azResult.  Then azResult holds this content:
2268** <blockquote><pre>
2269**        azResult&#91;0] = "Name";
2270**        azResult&#91;1] = "Age";
2271**        azResult&#91;2] = "Alice";
2272**        azResult&#91;3] = "43";
2273**        azResult&#91;4] = "Bob";
2274**        azResult&#91;5] = "28";
2275**        azResult&#91;6] = "Cindy";
2276**        azResult&#91;7] = "21";
2277** </pre></blockquote>)^
2279** ^The sqlite3_get_table() function evaluates one or more
2280** semicolon-separated SQL statements in the zero-terminated UTF-8
2281** string of its 2nd parameter and returns a result table to the
2282** pointer given in its 3rd parameter.
2284** After the application has finished with the result from sqlite3_get_table(),
2285** it must pass the result table pointer to sqlite3_free_table() in order to
2286** release the memory that was malloced.  Because of the way the
2287** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2288** function must not try to call [sqlite3_free()] directly.  Only
2289** [sqlite3_free_table()] is able to release the memory properly and safely.
2291** The sqlite3_get_table() interface is implemented as a wrapper around
2292** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
2293** to any internal data structures of SQLite.  It uses only the public
2294** interface defined here.  As a consequence, errors that occur in the
2295** wrapper layer outside of the internal [sqlite3_exec()] call are not
2296** reflected in subsequent calls to [sqlite3_errcode()] or
2297** [sqlite3_errmsg()].
2299SQLITE_API int sqlite3_get_table(
2300  sqlite3 *db,          /* An open database */
2301  const char *zSql,     /* SQL to be evaluated */
2302  char ***pazResult,    /* Results of the query */
2303  int *pnRow,           /* Number of result rows written here */
2304  int *pnColumn,        /* Number of result columns written here */
2305  char **pzErrmsg       /* Error msg written here */
2307SQLITE_API void sqlite3_free_table(char **result);
2310** CAPI3REF: Formatted String Printing Functions
2312** These routines are work-alikes of the "printf()" family of functions
2313** from the standard C library.
2315** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2316** results into memory obtained from [sqlite3_malloc()].
2317** The strings returned by these two routines should be
2318** released by [sqlite3_free()].  ^Both routines return a
2319** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2320** memory to hold the resulting string.
2322** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2323** the standard C library.  The result is written into the
2324** buffer supplied as the second parameter whose size is given by
2325** the first parameter. Note that the order of the
2326** first two parameters is reversed from snprintf().)^  This is an
2327** historical accident that cannot be fixed without breaking
2328** backwards compatibility.  ^(Note also that sqlite3_snprintf()
2329** returns a pointer to its buffer instead of the number of
2330** characters actually written into the buffer.)^  We admit that
2331** the number of characters written would be a more useful return
2332** value but we cannot change the implementation of sqlite3_snprintf()
2333** now without breaking compatibility.
2335** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2336** guarantees that the buffer is always zero-terminated.  ^The first
2337** parameter "n" is the total size of the buffer, including space for
2338** the zero terminator.  So the longest string that can be completely
2339** written will be n-1 characters.
2341** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2343** These routines all implement some additional formatting
2344** options that are useful for constructing SQL statements.
2345** All of the usual printf() formatting options apply.  In addition, there
2346** is are "%q", "%Q", and "%z" options.
2348** ^(The %q option works like %s in that it substitutes a nul-terminated
2349** string from the argument list.  But %q also doubles every '\'' character.
2350** %q is designed for use inside a string literal.)^  By doubling each '\''
2351** character it escapes that character and allows it to be inserted into
2352** the string.
2354** For example, assume the string variable zText contains text as follows:
2356** <blockquote><pre>
2357**  char *zText = "It's a happy day!";
2358** </pre></blockquote>
2360** One can use this text in an SQL statement as follows:
2362** <blockquote><pre>
2363**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2364**  sqlite3_exec(db, zSQL, 0, 0, 0);
2365**  sqlite3_free(zSQL);
2366** </pre></blockquote>
2368** Because the %q format string is used, the '\'' character in zText
2369** is escaped and the SQL generated is as follows:
2371** <blockquote><pre>
2372**  INSERT INTO table1 VALUES('It''s a happy day!')
2373** </pre></blockquote>
2375** This is correct.  Had we used %s instead of %q, the generated SQL
2376** would have looked like this:
2378** <blockquote><pre>
2379**  INSERT INTO table1 VALUES('It's a happy day!');
2380** </pre></blockquote>
2382** This second example is an SQL syntax error.  As a general rule you should
2383** always use %q instead of %s when inserting text into a string literal.
2385** ^(The %Q option works like %q except it also adds single quotes around
2386** the outside of the total string.  Additionally, if the parameter in the
2387** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2388** single quotes).)^  So, for example, one could say:
2390** <blockquote><pre>
2391**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2392**  sqlite3_exec(db, zSQL, 0, 0, 0);
2393**  sqlite3_free(zSQL);
2394** </pre></blockquote>
2396** The code above will render a correct SQL statement in the zSQL
2397** variable even if the zText variable is a NULL pointer.
2399** ^(The "%z" formatting option works like "%s" but with the
2400** addition that after the string has been read and copied into
2401** the result, [sqlite3_free()] is called on the input string.)^
2403SQLITE_API char *sqlite3_mprintf(const char*,...);
2404SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2405SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2406SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2409** CAPI3REF: Memory Allocation Subsystem
2411** The SQLite core uses these three routines for all of its own
2412** internal memory allocation needs. "Core" in the previous sentence
2413** does not include operating-system specific VFS implementation.  The
2414** Windows VFS uses native malloc() and free() for some operations.
2416** ^The sqlite3_malloc() routine returns a pointer to a block
2417** of memory at least N bytes in length, where N is the parameter.
2418** ^If sqlite3_malloc() is unable to obtain sufficient free
2419** memory, it returns a NULL pointer.  ^If the parameter N to
2420** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2421** a NULL pointer.
2423** ^Calling sqlite3_free() with a pointer previously returned
2424** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2425** that it might be reused.  ^The sqlite3_free() routine is
2426** a no-op if is called with a NULL pointer.  Passing a NULL pointer
2427** to sqlite3_free() is harmless.  After being freed, memory
2428** should neither be read nor written.  Even reading previously freed
2429** memory might result in a segmentation fault or other severe error.
2430** Memory corruption, a segmentation fault, or other severe error
2431** might result if sqlite3_free() is called with a non-NULL pointer that
2432** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2434** ^(The sqlite3_realloc() interface attempts to resize a
2435** prior memory allocation to be at least N bytes, where N is the
2436** second parameter.  The memory allocation to be resized is the first
2437** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2438** is a NULL pointer then its behavior is identical to calling
2439** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2440** ^If the second parameter to sqlite3_realloc() is zero or
2441** negative then the behavior is exactly the same as calling
2442** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2443** ^sqlite3_realloc() returns a pointer to a memory allocation
2444** of at least N bytes in size or NULL if sufficient memory is unavailable.
2445** ^If M is the size of the prior allocation, then min(N,M) bytes
2446** of the prior allocation are copied into the beginning of buffer returned
2447** by sqlite3_realloc() and the prior allocation is freed.
2448** ^If sqlite3_realloc() returns NULL, then the prior allocation
2449** is not freed.
2451** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2452** is always aligned to at least an 8 byte boundary, or to a
2453** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2454** option is used.
2456** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2457** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2458** implementation of these routines to be omitted.  That capability
2459** is no longer provided.  Only built-in memory allocators can be used.
2461** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2462** the system malloc() and free() directly when converting
2463** filenames between the UTF-8 encoding used by SQLite
2464** and whatever filename encoding is used by the particular Windows
2465** installation.  Memory allocation errors were detected, but
2466** they were reported back as [SQLITE_CANTOPEN] or
2467** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2469** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2470** must be either NULL or else pointers obtained from a prior
2471** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2472** not yet been released.
2474** The application must not read or write any part of
2475** a block of memory after it has been released using
2476** [sqlite3_free()] or [sqlite3_realloc()].
2478SQLITE_API void *sqlite3_malloc(int);
2479SQLITE_API void *sqlite3_realloc(void*, int);
2480SQLITE_API void sqlite3_free(void*);
2483** CAPI3REF: Memory Allocator Statistics
2485** SQLite provides these two interfaces for reporting on the status
2486** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2487** routines, which form the built-in memory allocation subsystem.
2489** ^The [sqlite3_memory_used()] routine returns the number of bytes
2490** of memory currently outstanding (malloced but not freed).
2491** ^The [sqlite3_memory_highwater()] routine returns the maximum
2492** value of [sqlite3_memory_used()] since the high-water mark
2493** was last reset.  ^The values returned by [sqlite3_memory_used()] and
2494** [sqlite3_memory_highwater()] include any overhead
2495** added by SQLite in its implementation of [sqlite3_malloc()],
2496** but not overhead added by the any underlying system library
2497** routines that [sqlite3_malloc()] may call.
2499** ^The memory high-water mark is reset to the current value of
2500** [sqlite3_memory_used()] if and only if the parameter to
2501** [sqlite3_memory_highwater()] is true.  ^The value returned
2502** by [sqlite3_memory_highwater(1)] is the high-water mark
2503** prior to the reset.
2505SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2506SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2509** CAPI3REF: Pseudo-Random Number Generator
2511** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2512** select random [ROWID | ROWIDs] when inserting new records into a table that
2513** already uses the largest possible [ROWID].  The PRNG is also used for
2514** the build-in random() and randomblob() SQL functions.  This interface allows
2515** applications to access the same PRNG for other purposes.
2517** ^A call to this routine stores N bytes of randomness into buffer P.
2518** ^If N is less than one, then P can be a NULL pointer.
2520** ^If this routine has not been previously called or if the previous
2521** call had N less than one, then the PRNG is seeded using randomness
2522** obtained from the xRandomness method of the default [sqlite3_vfs] object.
2523** ^If the previous call to this routine had an N of 1 or more then
2524** the pseudo-randomness is generated
2525** internally and without recourse to the [sqlite3_vfs] xRandomness
2526** method.
2528SQLITE_API void sqlite3_randomness(int N, void *P);
2531** CAPI3REF: Compile-Time Authorization Callbacks
2533** ^This routine registers an authorizer callback with a particular
2534** [database connection], supplied in the first argument.
2535** ^The authorizer callback is invoked as SQL statements are being compiled
2536** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2537** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
2538** points during the compilation process, as logic is being created
2539** to perform various actions, the authorizer callback is invoked to
2540** see if those actions are allowed.  ^The authorizer callback should
2541** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2542** specific action but allow the SQL statement to continue to be
2543** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2544** rejected with an error.  ^If the authorizer callback returns
2545** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2546** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2547** the authorizer will fail with an error message.
2549** When the callback returns [SQLITE_OK], that means the operation
2550** requested is ok.  ^When the callback returns [SQLITE_DENY], the
2551** [sqlite3_prepare_v2()] or equivalent call that triggered the
2552** authorizer will fail with an error message explaining that
2553** access is denied.
2555** ^The first parameter to the authorizer callback is a copy of the third
2556** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2557** to the callback is an integer [SQLITE_COPY | action code] that specifies
2558** the particular action to be authorized. ^The third through sixth parameters
2559** to the callback are zero-terminated strings that contain additional
2560** details about the action to be authorized.
2562** ^If the action code is [SQLITE_READ]
2563** and the callback returns [SQLITE_IGNORE] then the
2564** [prepared statement] statement is constructed to substitute
2565** a NULL value in place of the table column that would have
2566** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
2567** return can be used to deny an untrusted user access to individual
2568** columns of a table.
2569** ^If the action code is [SQLITE_DELETE] and the callback returns
2570** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2571** [truncate optimization] is disabled and all rows are deleted individually.
2573** An authorizer is used when [sqlite3_prepare | preparing]
2574** SQL statements from an untrusted source, to ensure that the SQL statements
2575** do not try to access data they are not allowed to see, or that they do not
2576** try to execute malicious statements that damage the database.  For
2577** example, an application may allow a user to enter arbitrary
2578** SQL queries for evaluation by a database.  But the application does
2579** not want the user to be able to make arbitrary changes to the
2580** database.  An authorizer could then be put in place while the
2581** user-entered SQL is being [sqlite3_prepare | prepared] that
2582** disallows everything except [SELECT] statements.
2584** Applications that need to process SQL from untrusted sources
2585** might also consider lowering resource limits using [sqlite3_limit()]
2586** and limiting database size using the [max_page_count] [PRAGMA]
2587** in addition to using an authorizer.
2589** ^(Only a single authorizer can be in place on a database connection
2590** at a time.  Each call to sqlite3_set_authorizer overrides the
2591** previous call.)^  ^Disable the authorizer by installing a NULL callback.
2592** The authorizer is disabled by default.
2594** The authorizer callback must not do anything that will modify
2595** the database connection that invoked the authorizer callback.
2596** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2597** database connections for the meaning of "modify" in this paragraph.
2599** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2600** statement might be re-prepared during [sqlite3_step()] due to a
2601** schema change.  Hence, the application should ensure that the
2602** correct authorizer callback remains in place during the [sqlite3_step()].
2604** ^Note that the authorizer callback is invoked only during
2605** [sqlite3_prepare()] or its variants.  Authorization is not
2606** performed during statement evaluation in [sqlite3_step()], unless
2607** as stated in the previous paragraph, sqlite3_step() invokes
2608** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2610SQLITE_API int sqlite3_set_authorizer(
2611  sqlite3*,
2612  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2613  void *pUserData
2617** CAPI3REF: Authorizer Return Codes
2619** The [sqlite3_set_authorizer | authorizer callback function] must
2620** return either [SQLITE_OK] or one of these two constants in order
2621** to signal SQLite whether or not the action is permitted.  See the
2622** [sqlite3_set_authorizer | authorizer documentation] for additional
2623** information.
2625** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
2626** from the [sqlite3_vtab_on_conflict()] interface.
2628#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
2629#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
2632** CAPI3REF: Authorizer Action Codes
2634** The [sqlite3_set_authorizer()] interface registers a callback function
2635** that is invoked to authorize certain SQL statement actions.  The
2636** second parameter to the callback is an integer code that specifies
2637** what action is being authorized.  These are the integer action codes that
2638** the authorizer callback may be passed.
2640** These action code values signify what kind of operation is to be
2641** authorized.  The 3rd and 4th parameters to the authorization
2642** callback function will be parameters or NULL depending on which of these
2643** codes is used as the second parameter.  ^(The 5th parameter to the
2644** authorizer callback is the name of the database ("main", "temp",
2645** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
2646** is the name of the inner-most trigger or view that is responsible for
2647** the access attempt or NULL if this access attempt is directly from
2648** top-level SQL code.
2650/******************************************* 3rd ************ 4th ***********/
2651#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
2652#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
2653#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
2654#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
2655#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
2656#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
2657#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
2658#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
2659#define SQLITE_DELETE                9   /* Table Name      NULL            */
2660#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
2661#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
2662#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
2663#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
2664#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
2665#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
2666#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
2667#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
2668#define SQLITE_INSERT               18   /* Table Name      NULL            */
2669#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
2670#define SQLITE_READ                 20   /* Table Name      Column Name     */
2671#define SQLITE_SELECT               21   /* NULL            NULL            */
2672#define SQLITE_TRANSACTION          22   /* Operation       NULL            */
2673#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
2674#define SQLITE_ATTACH               24   /* Filename        NULL            */
2675#define SQLITE_DETACH               25   /* Database Name   NULL            */
2676#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
2677#define SQLITE_REINDEX              27   /* Index Name      NULL            */
2678#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
2679#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
2680#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
2681#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
2682#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
2683#define SQLITE_COPY                  0   /* No longer used */
2684#define SQLITE_RECURSIVE            33   /* NULL            NULL            */
2687** CAPI3REF: Tracing And Profiling Functions
2689** These routines register callback functions that can be used for
2690** tracing and profiling the execution of SQL statements.
2692** ^The callback function registered by sqlite3_trace() is invoked at
2693** various times when an SQL statement is being run by [sqlite3_step()].
2694** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2695** SQL statement text as the statement first begins executing.
2696** ^(Additional sqlite3_trace() callbacks might occur
2697** as each triggered subprogram is entered.  The callbacks for triggers
2698** contain a UTF-8 SQL comment that identifies the trigger.)^
2700** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2701** the length of [bound parameter] expansion in the output of sqlite3_trace().
2703** ^The callback function registered by sqlite3_profile() is invoked
2704** as each SQL statement finishes.  ^The profile callback contains
2705** the original statement text and an estimate of wall-clock time
2706** of how long that statement took to run.  ^The profile callback
2707** time is in units of nanoseconds, however the current implementation
2708** is only capable of millisecond resolution so the six least significant
2709** digits in the time are meaningless.  Future versions of SQLite
2710** might provide greater resolution on the profiler callback.  The
2711** sqlite3_profile() function is considered experimental and is
2712** subject to change in future versions of SQLite.
2714SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2715SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
2716   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2719** CAPI3REF: Query Progress Callbacks
2721** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2722** function X to be invoked periodically during long running calls to
2723** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2724** database connection D.  An example use for this
2725** interface is to keep a GUI updated during a large query.
2727** ^The parameter P is passed through as the only parameter to the
2728** callback function X.  ^The parameter N is the approximate number of
2729** [virtual machine instructions] that are evaluated between successive
2730** invocations of the callback X.  ^If N is less than one then the progress
2731** handler is disabled.
2733** ^Only a single progress handler may be defined at one time per
2734** [database connection]; setting a new progress handler cancels the
2735** old one.  ^Setting parameter X to NULL disables the progress handler.
2736** ^The progress handler is also disabled by setting N to a value less
2737** than 1.
2739** ^If the progress callback returns non-zero, the operation is
2740** interrupted.  This feature can be used to implement a
2741** "Cancel" button on a GUI progress dialog box.
2743** The progress handler callback must not do anything that will modify
2744** the database connection that invoked the progress handler.
2745** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2746** database connections for the meaning of "modify" in this paragraph.
2749SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2752** CAPI3REF: Opening A New Database Connection
2754** ^These routines open an SQLite database file as specified by the
2755** filename argument. ^The filename argument is interpreted as UTF-8 for
2756** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2757** order for sqlite3_open16(). ^(A [database connection] handle is usually
2758** returned in *ppDb, even if an error occurs.  The only exception is that
2759** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2760** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2761** object.)^ ^(If the database is opened (and/or created) successfully, then
2762** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
2763** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2764** an English language description of the error following a failure of any
2765** of the sqlite3_open() routines.
2767** ^The default encoding for the database will be UTF-8 if
2768** sqlite3_open() or sqlite3_open_v2() is called and
2769** UTF-16 in the native byte order if sqlite3_open16() is used.
2771** Whether or not an error occurs when it is opened, resources
2772** associated with the [database connection] handle should be released by
2773** passing it to [sqlite3_close()] when it is no longer required.
2775** The sqlite3_open_v2() interface works like sqlite3_open()
2776** except that it accepts two additional parameters for additional control
2777** over the new database connection.  ^(The flags parameter to
2778** sqlite3_open_v2() can take one of
2779** the following three values, optionally combined with the
2783** <dl>
2784** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2785** <dd>The database is opened in read-only mode.  If the database does not
2786** already exist, an error is returned.</dd>)^
2788** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2789** <dd>The database is opened for reading and writing if possible, or reading
2790** only if the file is write protected by the operating system.  In either
2791** case the database must already exist, otherwise an error is returned.</dd>)^
2794** <dd>The database is opened for reading and writing, and is created if
2795** it does not already exist. This is the behavior that is always used for
2796** sqlite3_open() and sqlite3_open16().</dd>)^
2797** </dl>
2799** If the 3rd parameter to sqlite3_open_v2() is not one of the
2800** combinations shown above optionally combined with other
2802** then the behavior is undefined.
2804** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2805** opens in the multi-thread [threading mode] as long as the single-thread
2806** mode has not been set at compile-time or start-time.  ^If the
2807** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2808** in the serialized [threading mode] unless single-thread was
2809** previously selected at compile-time or start-time.
2810** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2811** eligible to use [shared cache mode], regardless of whether or not shared
2812** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
2813** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2814** participate in [shared cache mode] even if it is enabled.
2816** ^The fourth parameter to sqlite3_open_v2() is the name of the
2817** [sqlite3_vfs] object that defines the operating system interface that
2818** the new database connection should use.  ^If the fourth parameter is
2819** a NULL pointer then the default [sqlite3_vfs] object is used.
2821** ^If the filename is ":memory:", then a private, temporary in-memory database
2822** is created for the connection.  ^This in-memory database will vanish when
2823** the database connection is closed.  Future versions of SQLite might
2824** make use of additional special filenames that begin with the ":" character.
2825** It is recommended that when a database filename actually does begin with
2826** a ":" character you should prefix the filename with a pathname such as
2827** "./" to avoid ambiguity.
2829** ^If the filename is an empty string, then a private, temporary
2830** on-disk database will be created.  ^This private database will be
2831** automatically deleted as soon as the database connection is closed.
2833** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2835** ^If [URI filename] interpretation is enabled, and the filename argument
2836** begins with "file:", then the filename is interpreted as a URI. ^URI
2837** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2838** set in the fourth argument to sqlite3_open_v2(), or if it has
2839** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2840** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2841** As of SQLite version 3.7.7, URI filename interpretation is turned off
2842** by default, but future releases of SQLite might enable URI filename
2843** interpretation by default.  See "[URI filenames]" for additional
2844** information.
2846** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2847** authority, then it must be either an empty string or the string
2848** "localhost". ^If the authority is not an empty string or "localhost", an
2849** error is returned to the caller. ^The fragment component of a URI, if
2850** present, is ignored.
2852** ^SQLite uses the path component of the URI as the name of the disk file
2853** which contains the database. ^If the path begins with a '/' character,
2854** then it is interpreted as an absolute path. ^If the path does not begin
2855** with a '/' (meaning that the authority section is omitted from the URI)
2856** then the path is interpreted as a relative path.
2857** ^On windows, the first component of an absolute path
2858** is a drive specification (e.g. "C:").
2860** [[core URI query parameters]]
2861** The query component of a URI may contain parameters that are interpreted
2862** either by SQLite itself, or by a [VFS | custom VFS implementation].
2863** SQLite interprets the following three query parameters:
2865** <ul>
2866**   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
2867**     a VFS object that provides the operating system interface that should
2868**     be used to access the database file on disk. ^If this option is set to
2869**     an empty string the default VFS object is used. ^Specifying an unknown
2870**     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
2871**     present, then the VFS specified by the option takes precedence over
2872**     the value passed as the fourth parameter to sqlite3_open_v2().
2874**   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
2875**     "rwc", or "memory". Attempting to set it to any other value is
2876**     an error)^.
2877**     ^If "ro" is specified, then the database is opened for read-only
2878**     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
2879**     third argument to sqlite3_open_v2(). ^If the mode option is set to
2880**     "rw", then the database is opened for read-write (but not create)
2881**     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
2882**     been set. ^Value "rwc" is equivalent to setting both
2883**     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
2884**     set to "memory" then a pure [in-memory database] that never reads
2885**     or writes from disk is used. ^It is an error to specify a value for
2886**     the mode parameter that is less restrictive than that specified by
2887**     the flags passed in the third parameter to sqlite3_open_v2().
2889**   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
2890**     "private". ^Setting it to "shared" is equivalent to setting the
2891**     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
2892**     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
2893**     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
2894**     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
2895**     a URI filename, its value overrides any behavior requested by setting
2897** </ul>
2899** ^Specifying an unknown parameter in the query component of a URI is not an
2900** error.  Future versions of SQLite might understand additional query
2901** parameters.  See "[query parameters with special meaning to SQLite]" for
2902** additional information.
2904** [[URI filename examples]] <h3>URI filename examples</h3>
2906** <table border="1" align=center cellpadding=5>
2907** <tr><th> URI filenames <th> Results
2908** <tr><td> file:data.db <td>
2909**          Open the file "data.db" in the current directory.
2910** <tr><td> file:/home/fred/data.db<br>
2911**          file:///home/fred/data.db <br>
2912**          file://localhost/home/fred/data.db <br> <td>
2913**          Open the database file "/home/fred/data.db".
2914** <tr><td> file://darkstar/home/fred/data.db <td>
2915**          An error. "darkstar" is not a recognized authority.
2916** <tr><td style="white-space:nowrap">
2917**          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
2918**     <td> Windows only: Open the file "data.db" on fred's desktop on drive
2919**          C:. Note that the %20 escaping in this example is not strictly
2920**          necessary - space characters can be used literally
2921**          in URI filenames.
2922** <tr><td> file:data.db?mode=ro&cache=private <td>
2923**          Open file "data.db" in the current directory for read-only access.
2924**          Regardless of whether or not shared-cache mode is enabled by
2925**          default, use a private cache.
2926** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
2927**          Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
2928** <tr><td> file:data.db?mode=readonly <td>
2929**          An error. "readonly" is not a valid option for the "mode" parameter.
2930** </table>
2932** ^URI hexadecimal escape sequences (%HH) are supported within the path and
2933** query components of a URI. A hexadecimal escape sequence consists of a
2934** percent sign - "%" - followed by exactly two hexadecimal digits
2935** specifying an octet value. ^Before the path or query components of a
2936** URI filename are interpreted, they are encoded using UTF-8 and all
2937** hexadecimal escape sequences replaced by a single byte containing the
2938** corresponding octet. If this process generates an invalid UTF-8 encoding,
2939** the results are undefined.
2941** <b>Note to Windows users:</b>  The encoding used for the filename argument
2942** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2943** codepage is currently defined.  Filenames containing international
2944** characters must be converted to UTF-8 prior to passing them into
2945** sqlite3_open() or sqlite3_open_v2().
2947** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
2948** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
2949** features that require the use of temporary files may fail.
2951** See also: [sqlite3_temp_directory]
2953SQLITE_API int sqlite3_open(
2954  const char *filename,   /* Database filename (UTF-8) */
2955  sqlite3 **ppDb          /* OUT: SQLite db handle */
2957SQLITE_API int sqlite3_open16(
2958  const void *filename,   /* Database filename (UTF-16) */
2959  sqlite3 **ppDb          /* OUT: SQLite db handle */
2961SQLITE_API int sqlite3_open_v2(
2962  const char *filename,   /* Database filename (UTF-8) */
2963  sqlite3 **ppDb,         /* OUT: SQLite db handle */
2964  int flags,              /* Flags */
2965  const char *zVfs        /* Name of VFS module to use */
2969** CAPI3REF: Obtain Values For URI Parameters
2971** These are utility routines, useful to VFS implementations, that check
2972** to see if a database file was a URI that contained a specific query
2973** parameter, and if so obtains the value of that query parameter.
2975** If F is the database filename pointer passed into the xOpen() method of
2976** a VFS implementation when the flags parameter to xOpen() has one or
2977** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
2978** P is the name of the query parameter, then
2979** sqlite3_uri_parameter(F,P) returns the value of the P
2980** parameter if it exists or a NULL pointer if P does not appear as a
2981** query parameter on F.  If P is a query parameter of F
2982** has no explicit value, then sqlite3_uri_parameter(F,P) returns
2983** a pointer to an empty string.
2985** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
2986** parameter and returns true (1) or false (0) according to the value
2987** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
2988** value of query parameter P is one of "yes", "true", or "on" in any
2989** case or if the value begins with a non-zero number.  The
2990** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
2991** query parameter P is one of "no", "false", or "off" in any case or
2992** if the value begins with a numeric zero.  If P is not a query
2993** parameter on F or if the value of P is does not match any of the
2994** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
2996** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
2997** 64-bit signed integer and returns that integer, or D if P does not
2998** exist.  If the value of P is something other than an integer, then
2999** zero is returned.
3001** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3002** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
3003** is not a database file pathname pointer that SQLite passed into the xOpen
3004** VFS method, then the behavior of this routine is undefined and probably
3005** undesirable.
3007SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3008SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3009SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3013** CAPI3REF: Error Codes And Messages
3015** ^The sqlite3_errcode() interface returns the numeric [result code] or
3016** [extended result code] for the most recent failed sqlite3_* API call
3017** associated with a [database connection]. If a prior API call failed
3018** but the most recent API call succeeded, the return value from
3019** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
3020** interface is the same except that it always returns the
3021** [extended result code] even when extended result codes are
3022** disabled.
3024** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3025** text that describes the error, as either UTF-8 or UTF-16 respectively.
3026** ^(Memory to hold the error message string is managed internally.
3027** The application does not need to worry about freeing the result.
3028** However, the error string might be overwritten or deallocated by
3029** subsequent calls to other SQLite interface functions.)^
3031** ^The sqlite3_errstr() interface returns the English-language text
3032** that describes the [result code], as UTF-8.
3033** ^(Memory to hold the error message string is managed internally
3034** and must not be freed by the application)^.
3036** When the serialized [threading mode] is in use, it might be the
3037** case that a second error occurs on a separate thread in between
3038** the time of the first error and the call to these interfaces.
3039** When that happens, the second error will be reported since these
3040** interfaces always report the most recent result.  To avoid
3041** this, each thread can obtain exclusive use of the [database connection] D
3042** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3043** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3044** all calls to the interfaces listed here are completed.
3046** If an interface fails with SQLITE_MISUSE, that means the interface
3047** was invoked incorrectly by the application.  In that case, the
3048** error code and message may or may not be set.
3050SQLITE_API int sqlite3_errcode(sqlite3 *db);
3051SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3052SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3053SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3054SQLITE_API const char *sqlite3_errstr(int);
3057** CAPI3REF: SQL Statement Object
3058** KEYWORDS: {prepared statement} {prepared statements}
3060** An instance of this object represents a single SQL statement.
3061** This object is variously known as a "prepared statement" or a
3062** "compiled SQL statement" or simply as a "statement".
3064** The life of a statement object goes something like this:
3066** <ol>
3067** <li> Create the object using [sqlite3_prepare_v2()] or a related
3068**      function.
3069** <li> Bind values to [host parameters] using the sqlite3_bind_*()
3070**      interfaces.
3071** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3072** <li> Reset the statement using [sqlite3_reset()] then go back
3073**      to step 2.  Do this zero or more times.
3074** <li> Destroy the object using [sqlite3_finalize()].
3075** </ol>
3077** Refer to documentation on individual methods above for additional
3078** information.
3080typedef struct sqlite3_stmt sqlite3_stmt;
3083** CAPI3REF: Run-time Limits
3085** ^(This interface allows the size of various constructs to be limited
3086** on a connection by connection basis.  The first parameter is the
3087** [database connection] whose limit is to be set or queried.  The
3088** second parameter is one of the [limit categories] that define a
3089** class of constructs to be size limited.  The third parameter is the
3090** new limit for that construct.)^
3092** ^If the new limit is a negative number, the limit is unchanged.
3093** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3094** [limits | hard upper bound]
3095** set at compile-time by a C preprocessor macro called
3096** [limits | SQLITE_MAX_<i>NAME</i>].
3097** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3098** ^Attempts to increase a limit above its hard upper bound are
3099** silently truncated to the hard upper bound.
3101** ^Regardless of whether or not the limit was changed, the
3102** [sqlite3_limit()] interface returns the prior value of the limit.
3103** ^Hence, to find the current value of a limit without changing it,
3104** simply invoke this interface with the third parameter set to -1.
3106** Run-time limits are intended for use in applications that manage
3107** both their own internal database and also databases that are controlled
3108** by untrusted external sources.  An example application might be a
3109** web browser that has its own databases for storing history and
3110** separate databases controlled by JavaScript applications downloaded
3111** off the Internet.  The internal databases can be given the
3112** large, default limits.  Databases managed by external sources can
3113** be given much smaller limits designed to prevent a denial of service
3114** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
3115** interface to further control untrusted SQL.  The size of the database
3116** created by an untrusted script can be contained using the
3117** [max_page_count] [PRAGMA].
3119** New run-time limit categories may be added in future releases.
3121SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3124** CAPI3REF: Run-Time Limit Categories
3125** KEYWORDS: {limit category} {*limit categories}
3127** These constants define various performance limits
3128** that can be lowered at run-time using [sqlite3_limit()].
3129** The synopsis of the meanings of the various limits is shown below.
3130** Additional information is available at [limits | Limits in SQLite].
3132** <dl>
3134** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3137** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3140** <dd>The maximum number of columns in a table definition or in the
3141** result set of a [SELECT] or the maximum number of columns in an index
3142** or in an ORDER BY or GROUP BY clause.</dd>)^
3145** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3148** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3151** <dd>The maximum number of instructions in a virtual machine program
3152** used to implement an SQL statement.  This limit is not currently
3153** enforced, though that might be added in some future release of
3154** SQLite.</dd>)^
3157** <dd>The maximum number of arguments on a function.</dd>)^
3160** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3164** <dd>The maximum length of the pattern argument to the [LIKE] or
3165** [GLOB] operators.</dd>)^
3169** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3172** <dd>The maximum depth of recursion for triggers.</dd>)^
3173** </dl>
3175#define SQLITE_LIMIT_LENGTH                    0
3176#define SQLITE_LIMIT_SQL_LENGTH                1
3177#define SQLITE_LIMIT_COLUMN                    2
3178#define SQLITE_LIMIT_EXPR_DEPTH                3
3179#define SQLITE_LIMIT_COMPOUND_SELECT           4
3180#define SQLITE_LIMIT_VDBE_OP                   5
3181#define SQLITE_LIMIT_FUNCTION_ARG              6
3182#define SQLITE_LIMIT_ATTACHED                  7
3184#define SQLITE_LIMIT_VARIABLE_NUMBER           9
3185#define SQLITE_LIMIT_TRIGGER_DEPTH            10
3188** CAPI3REF: Compiling An SQL Statement
3189** KEYWORDS: {SQL statement compiler}
3191** To execute an SQL query, it must first be compiled into a byte-code
3192** program using one of these routines.
3194** The first argument, "db", is a [database connection] obtained from a
3195** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3196** [sqlite3_open16()].  The database connection must not have been closed.
3198** The second argument, "zSql", is the statement to be compiled, encoded
3199** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
3200** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3201** use UTF-16.
3203** ^If the nByte argument is less than zero, then zSql is read up to the
3204** first zero terminator. ^If nByte is non-negative, then it is the maximum
3205** number of  bytes read from zSql.  ^When nByte is non-negative, the
3206** zSql string ends at either the first '\000' or '\u0000' character or
3207** the nByte-th byte, whichever comes first. If the caller knows
3208** that the supplied string is nul-terminated, then there is a small
3209** performance advantage to be gained by passing an nByte parameter that
3210** is equal to the number of bytes in the input string <i>including</i>
3211** the nul-terminator bytes as this saves SQLite from having to
3212** make a copy of the input string.
3214** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3215** past the end of the first SQL statement in zSql.  These routines only
3216** compile the first statement in zSql, so *pzTail is left pointing to
3217** what remains uncompiled.
3219** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3220** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
3221** to NULL.  ^If the input text contains no SQL (if the input is an empty
3222** string or a comment) then *ppStmt is set to NULL.
3223** The calling procedure is responsible for deleting the compiled
3224** SQL statement using [sqlite3_finalize()] after it has finished with it.
3225** ppStmt may not be NULL.
3227** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3228** otherwise an [error code] is returned.
3230** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3231** recommended for all new programs. The two older interfaces are retained
3232** for backwards compatibility, but their use is discouraged.
3233** ^In the "v2" interfaces, the prepared statement
3234** that is returned (the [sqlite3_stmt] object) contains a copy of the
3235** original SQL text. This causes the [sqlite3_step()] interface to
3236** behave differently in three ways:
3238** <ol>
3239** <li>
3240** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3241** always used to do, [sqlite3_step()] will automatically recompile the SQL
3242** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3243** retries will occur before sqlite3_step() gives up and returns an error.
3244** </li>
3246** <li>
3247** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3248** [error codes] or [extended error codes].  ^The legacy behavior was that
3249** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3250** and the application would have to make a second call to [sqlite3_reset()]
3251** in order to find the underlying cause of the problem. With the "v2" prepare
3252** interfaces, the underlying reason for the error is returned immediately.
3253** </li>
3255** <li>
3256** ^If the specific value bound to [parameter | host parameter] in the
3257** WHERE clause might influence the choice of query plan for a statement,
3258** then the statement will be automatically recompiled, as if there had been
3259** a schema change, on the first  [sqlite3_step()] call following any change
3260** to the [sqlite3_bind_text | bindings] of that [parameter].
3261** ^The specific value of WHERE-clause [parameter] might influence the
3262** choice of query plan if the parameter is the left-hand side of a [LIKE]
3263** or [GLOB] operator or if the parameter is compared to an indexed column
3264** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3265** </li>
3266** </ol>
3268SQLITE_API int sqlite3_prepare(
3269  sqlite3 *db,            /* Database handle */
3270  const char *zSql,       /* SQL statement, UTF-8 encoded */
3271  int nByte,              /* Maximum length of zSql in bytes. */
3272  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3273  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3275SQLITE_API int sqlite3_prepare_v2(
3276  sqlite3 *db,            /* Database handle */
3277  const char *zSql,       /* SQL statement, UTF-8 encoded */
3278  int nByte,              /* Maximum length of zSql in bytes. */
3279  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3280  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
3282SQLITE_API int sqlite3_prepare16(
3283  sqlite3 *db,            /* Database handle */
3284  const void *zSql,       /* SQL statement, UTF-16 encoded */
3285  int nByte,              /* Maximum length of zSql in bytes. */
3286  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3287  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3289SQLITE_API int sqlite3_prepare16_v2(
3290  sqlite3 *db,            /* Database handle */
3291  const void *zSql,       /* SQL statement, UTF-16 encoded */
3292  int nByte,              /* Maximum length of zSql in bytes. */
3293  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
3294  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
3298** CAPI3REF: Retrieving Statement SQL
3300** ^This interface can be used to retrieve a saved copy of the original
3301** SQL text used to create a [prepared statement] if that statement was
3302** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3304SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3307** CAPI3REF: Determine If An SQL Statement Writes The Database
3309** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3310** and only if the [prepared statement] X makes no direct changes to
3311** the content of the database file.
3313** Note that [application-defined SQL functions] or
3314** [virtual tables] might change the database indirectly as a side effect.
3315** ^(For example, if an application defines a function "eval()" that
3316** calls [sqlite3_exec()], then the following SQL statement would
3317** change the database file through side-effects:
3319** <blockquote><pre>
3320**    SELECT eval('DELETE FROM t1') FROM t2;
3321** </pre></blockquote>
3323** But because the [SELECT] statement does not change the database file
3324** directly, sqlite3_stmt_readonly() would still return true.)^
3326** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3327** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3328** since the statements themselves do not actually modify the database but
3329** rather they control the timing of when other statements modify the
3330** database.  ^The [ATTACH] and [DETACH] statements also cause
3331** sqlite3_stmt_readonly() to return true since, while those statements
3332** change the configuration of a database connection, they do not make
3333** changes to the content of the database files on disk.
3335SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3338** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3340** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3341** [prepared statement] S has been stepped at least once using
3342** [sqlite3_step(S)] but has not run to completion and/or has not
3343** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
3344** interface returns false if S is a NULL pointer.  If S is not a
3345** NULL pointer and is not a pointer to a valid [prepared statement]
3346** object, then the behavior is undefined and probably undesirable.
3348** This interface can be used in combination [sqlite3_next_stmt()]
3349** to locate all prepared statements associated with a database
3350** connection that are in need of being reset.  This can be used,
3351** for example, in diagnostic routines to search for prepared
3352** statements that are holding a transaction open.
3354SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3357** CAPI3REF: Dynamically Typed Value Object
3358** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3360** SQLite uses the sqlite3_value object to represent all values
3361** that can be stored in a database table. SQLite uses dynamic typing
3362** for the values it stores.  ^Values stored in sqlite3_value objects
3363** can be integers, floating point values, strings, BLOBs, or NULL.
3365** An sqlite3_value object may be either "protected" or "unprotected".
3366** Some interfaces require a protected sqlite3_value.  Other interfaces
3367** will accept either a protected or an unprotected sqlite3_value.
3368** Every interface that accepts sqlite3_value arguments specifies
3369** whether or not it requires a protected sqlite3_value.
3371** The terms "protected" and "unprotected" refer to whether or not
3372** a mutex is held.  An internal mutex is held for a protected
3373** sqlite3_value object but no mutex is held for an unprotected
3374** sqlite3_value object.  If SQLite is compiled to be single-threaded
3375** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3376** or if SQLite is run in one of reduced mutex modes
3378** then there is no distinction between protected and unprotected
3379** sqlite3_value objects and they can be used interchangeably.  However,
3380** for maximum code portability it is recommended that applications
3381** still make the distinction between protected and unprotected
3382** sqlite3_value objects even when not strictly required.
3384** ^The sqlite3_value objects that are passed as parameters into the
3385** implementation of [application-defined SQL functions] are protected.
3386** ^The sqlite3_value object returned by
3387** [sqlite3_column_value()] is unprotected.
3388** Unprotected sqlite3_value objects may only be used with
3389** [sqlite3_result_value()] and [sqlite3_bind_value()].
3390** The [sqlite3_value_blob | sqlite3_value_type()] family of
3391** interfaces require protected sqlite3_value objects.
3393typedef struct Mem sqlite3_value;
3396** CAPI3REF: SQL Function Context Object
3398** The context in which an SQL function executes is stored in an
3399** sqlite3_context object.  ^A pointer to an sqlite3_context object
3400** is always first parameter to [application-defined SQL functions].
3401** The application-defined SQL function implementation will pass this
3402** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3403** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3404** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3405** and/or [sqlite3_set_auxdata()].
3407typedef struct sqlite3_context sqlite3_context;
3410** CAPI3REF: Binding Values To Prepared Statements
3411** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3412** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3414** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3415** literals may be replaced by a [parameter] that matches one of following
3416** templates:
3418** <ul>
3419** <li>  ?
3420** <li>  ?NNN
3421** <li>  :VVV
3422** <li>  @VVV
3423** <li>  $VVV
3424** </ul>
3426** In the templates above, NNN represents an integer literal,
3427** and VVV represents an alphanumeric identifier.)^  ^The values of these
3428** parameters (also called "host parameter names" or "SQL parameters")
3429** can be set using the sqlite3_bind_*() routines defined here.
3431** ^The first argument to the sqlite3_bind_*() routines is always
3432** a pointer to the [sqlite3_stmt] object returned from
3433** [sqlite3_prepare_v2()] or its variants.
3435** ^The second argument is the index of the SQL parameter to be set.
3436** ^The leftmost SQL parameter has an index of 1.  ^When the same named
3437** SQL parameter is used more than once, second and subsequent
3438** occurrences have the same index as the first occurrence.
3439** ^The index for named parameters can be looked up using the
3440** [sqlite3_bind_parameter_index()] API if desired.  ^The index
3441** for "?NNN" parameters is the value of NNN.
3442** ^The NNN value must be between 1 and the [sqlite3_limit()]
3443** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3445** ^The third argument is the value to bind to the parameter.
3446** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3447** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3448** is ignored and the end result is the same as sqlite3_bind_null().
3450** ^(In those routines that have a fourth argument, its value is the
3451** number of bytes in the parameter.  To be clear: the value is the
3452** number of <u>bytes</u> in the value, not the number of characters.)^
3453** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3454** is negative, then the length of the string is
3455** the number of bytes up to the first zero terminator.
3456** If the fourth parameter to sqlite3_bind_blob() is negative, then
3457** the behavior is undefined.
3458** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3459** or sqlite3_bind_text16() then that parameter must be the byte offset
3460** where the NUL terminator would occur assuming the string were NUL
3461** terminated.  If any NUL characters occur at byte offsets less than
3462** the value of the fourth parameter then the resulting string value will
3463** contain embedded NULs.  The result of expressions involving strings
3464** with embedded NULs is undefined.
3466** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3467** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
3468** string after SQLite has finished with it.  ^The destructor is called
3469** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
3470** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
3471** ^If the fifth argument is
3472** the special value [SQLITE_STATIC], then SQLite assumes that the
3473** information is in static, unmanaged space and does not need to be freed.
3474** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3475** SQLite makes its own private copy of the data immediately, before
3476** the sqlite3_bind_*() routine returns.
3478** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3479** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
3480** (just an integer to hold its size) while it is being processed.
3481** Zeroblobs are intended to serve as placeholders for BLOBs whose
3482** content is later written using
3483** [sqlite3_blob_open | incremental BLOB I/O] routines.
3484** ^A negative value for the zeroblob results in a zero-length BLOB.
3486** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3487** for the [prepared statement] or with a prepared statement for which
3488** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3489** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
3490** routine is passed a [prepared statement] that has been finalized, the
3491** result is undefined and probably harmful.
3493** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3494** ^Unbound parameters are interpreted as NULL.
3496** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3497** [error code] if anything goes wrong.
3498** ^[SQLITE_RANGE] is returned if the parameter
3499** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
3501** See also: [sqlite3_bind_parameter_count()],
3502** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3504SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3505SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3506SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3507SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3508SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3509SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3510SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3511SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3512SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3515** CAPI3REF: Number Of SQL Parameters
3517** ^This routine can be used to find the number of [SQL parameters]
3518** in a [prepared statement].  SQL parameters are tokens of the
3519** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3520** placeholders for values that are [sqlite3_bind_blob | bound]
3521** to the parameters at a later time.
3523** ^(This routine actually returns the index of the largest (rightmost)
3524** parameter. For all forms except ?NNN, this will correspond to the
3525** number of unique parameters.  If parameters of the ?NNN form are used,
3526** there may be gaps in the list.)^
3528** See also: [sqlite3_bind_blob|sqlite3_bind()],
3529** [sqlite3_bind_parameter_name()], and
3530** [sqlite3_bind_parameter_index()].
3532SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3535** CAPI3REF: Name Of A Host Parameter
3537** ^The sqlite3_bind_parameter_name(P,N) interface returns
3538** the name of the N-th [SQL parameter] in the [prepared statement] P.
3539** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3540** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3541** respectively.
3542** In other words, the initial ":" or "$" or "@" or "?"
3543** is included as part of the name.)^
3544** ^Parameters of the form "?" without a following integer have no name
3545** and are referred to as "nameless" or "anonymous parameters".
3547** ^The first host parameter has an index of 1, not 0.
3549** ^If the value N is out of range or if the N-th parameter is
3550** nameless, then NULL is returned.  ^The returned string is
3551** always in UTF-8 encoding even if the named parameter was
3552** originally specified as UTF-16 in [sqlite3_prepare16()] or
3553** [sqlite3_prepare16_v2()].
3555** See also: [sqlite3_bind_blob|sqlite3_bind()],
3556** [sqlite3_bind_parameter_count()], and
3557** [sqlite3_bind_parameter_index()].
3559SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3562** CAPI3REF: Index Of A Parameter With A Given Name
3564** ^Return the index of an SQL parameter given its name.  ^The
3565** index value returned is suitable for use as the second
3566** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
3567** is returned if no matching parameter is found.  ^The parameter
3568** name must be given in UTF-8 even if the original statement
3569** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3571** See also: [sqlite3_bind_blob|sqlite3_bind()],
3572** [sqlite3_bind_parameter_count()], and
3573** [sqlite3_bind_parameter_index()].
3575SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3578** CAPI3REF: Reset All Bindings On A Prepared Statement
3580** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3581** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3582** ^Use this routine to reset all host parameters to NULL.
3584SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3587** CAPI3REF: Number Of Columns In A Result Set
3589** ^Return the number of columns in the result set returned by the
3590** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3591** statement that does not return data (for example an [UPDATE]).
3593** See also: [sqlite3_data_count()]
3595SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3598** CAPI3REF: Column Names In A Result Set
3600** ^These routines return the name assigned to a particular column
3601** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
3602** interface returns a pointer to a zero-terminated UTF-8 string
3603** and sqlite3_column_name16() returns a pointer to a zero-terminated
3604** UTF-16 string.  ^The first parameter is the [prepared statement]
3605** that implements the [SELECT] statement. ^The second parameter is the
3606** column number.  ^The leftmost column is number 0.
3608** ^The returned string pointer is valid until either the [prepared statement]
3609** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3610** reprepared by the first call to [sqlite3_step()] for a particular run
3611** or until the next call to
3612** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3614** ^If sqlite3_malloc() fails during the processing of either routine
3615** (for example during a conversion from UTF-8 to UTF-16) then a
3616** NULL pointer is returned.
3618** ^The name of a result column is the value of the "AS" clause for
3619** that column, if there is an AS clause.  If there is no AS clause
3620** then the name of the column is unspecified and may change from
3621** one release of SQLite to the next.
3623SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3624SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3627** CAPI3REF: Source Of Data In A Query Result
3629** ^These routines provide a means to determine the database, table, and
3630** table column that is the origin of a particular result column in
3631** [SELECT] statement.
3632** ^The name of the database or table or column can be returned as
3633** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
3634** the database name, the _table_ routines return the table name, and
3635** the origin_ routines return the column name.
3636** ^The returned string is valid until the [prepared statement] is destroyed
3637** using [sqlite3_finalize()] or until the statement is automatically
3638** reprepared by the first call to [sqlite3_step()] for a particular run
3639** or until the same information is requested
3640** again in a different encoding.
3642** ^The names returned are the original un-aliased names of the
3643** database, table, and column.
3645** ^The first argument to these interfaces is a [prepared statement].
3646** ^These functions return information about the Nth result column returned by
3647** the statement, where N is the second function argument.
3648** ^The left-most column is column 0 for these routines.
3650** ^If the Nth column returned by the statement is an expression or
3651** subquery and is not a column value, then all of these functions return
3652** NULL.  ^These routine might also return NULL if a memory allocation error
3653** occurs.  ^Otherwise, they return the name of the attached database, table,
3654** or column that query result column was extracted from.
3656** ^As with all other SQLite APIs, those whose names end with "16" return
3657** UTF-16 encoded strings and the other functions return UTF-8.
3659** ^These APIs are only available if the library was compiled with the
3660** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3662** If two or more threads call one or more of these routines against the same
3663** prepared statement and column at the same time then the results are
3664** undefined.
3666** If two or more threads call one or more
3667** [sqlite3_column_database_name | column metadata interfaces]
3668** for the same [prepared statement] and result column
3669** at the same time then the results are undefined.
3671SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3672SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3673SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3674SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3675SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3676SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
3679** CAPI3REF: Declared Datatype Of A Query Result
3681** ^(The first parameter is a [prepared statement].
3682** If this statement is a [SELECT] statement and the Nth column of the
3683** returned result set of that [SELECT] is a table column (not an
3684** expression or subquery) then the declared type of the table
3685** column is returned.)^  ^If the Nth column of the result set is an
3686** expression or subquery, then a NULL pointer is returned.
3687** ^The returned string is always UTF-8 encoded.
3689** ^(For example, given the database schema:
3693** and the following statement to be compiled:
3695** SELECT c1 + 1, c1 FROM t1;
3697** this routine would return the string "VARIANT" for the second result
3698** column (i==1), and a NULL pointer for the first result column (i==0).)^
3700** ^SQLite uses dynamic run-time typing.  ^So just because a column
3701** is declared to contain a particular type does not mean that the
3702** data stored in that column is of the declared type.  SQLite is
3703** strongly typed, but the typing is dynamic not static.  ^Type
3704** is associated with individual values, not with the containers
3705** used to hold those values.
3707SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
3708SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
3711** CAPI3REF: Evaluate An SQL Statement
3713** After a [prepared statement] has been prepared using either
3714** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3715** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3716** must be called one or more times to evaluate the statement.
3718** The details of the behavior of the sqlite3_step() interface depend
3719** on whether the statement was prepared using the newer "v2" interface
3720** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3721** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
3722** new "v2" interface is recommended for new applications but the legacy
3723** interface will continue to be supported.
3725** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3727** ^With the "v2" interface, any of the other [result codes] or
3728** [extended result codes] might be returned as well.
3730** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3731** database locks it needs to do its job.  ^If the statement is a [COMMIT]
3732** or occurs outside of an explicit transaction, then you can retry the
3733** statement.  If the statement is not a [COMMIT] and occurs within an
3734** explicit transaction then you should rollback the transaction before
3735** continuing.
3737** ^[SQLITE_DONE] means that the statement has finished executing
3738** successfully.  sqlite3_step() should not be called again on this virtual
3739** machine without first calling [sqlite3_reset()] to reset the virtual
3740** machine back to its initial state.
3742** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3743** is returned each time a new row of data is ready for processing by the
3744** caller. The values may be accessed using the [column access functions].
3745** sqlite3_step() is called again to retrieve the next row of data.
3747** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3748** violation) has occurred.  sqlite3_step() should not be called again on
3749** the VM. More information may be found by calling [sqlite3_errmsg()].
3750** ^With the legacy interface, a more specific error code (for example,
3752** can be obtained by calling [sqlite3_reset()] on the
3753** [prepared statement].  ^In the "v2" interface,
3754** the more specific error code is returned directly by sqlite3_step().
3756** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3757** Perhaps it was called on a [prepared statement] that has
3758** already been [sqlite3_finalize | finalized] or on one that had
3759** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
3760** be the case that the same database connection is being used by two or
3761** more threads at the same moment in time.
3763** For all versions of SQLite up to and including, a call to
3764** [sqlite3_reset()] was required after sqlite3_step() returned anything
3765** other than [SQLITE_ROW] before any subsequent invocation of
3766** sqlite3_step().  Failure to reset the prepared statement using
3767** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3768** sqlite3_step().  But after version, sqlite3_step() began
3769** calling [sqlite3_reset()] automatically in this circumstance rather
3770** than returning [SQLITE_MISUSE].  This is not considered a compatibility
3771** break because any application that ever receives an SQLITE_MISUSE error
3772** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
3773** can be used to restore the legacy behavior.
3775** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3776** API always returns a generic error code, [SQLITE_ERROR], following any
3777** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
3778** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3779** specific [error codes] that better describes the error.
3780** We admit that this is a goofy design.  The problem has been fixed
3781** with the "v2" interface.  If you prepare all of your SQL statements
3782** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3783** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3784** then the more specific [error codes] are returned directly
3785** by sqlite3_step().  The use of the "v2" interface is recommended.
3787SQLITE_API int sqlite3_step(sqlite3_stmt*);
3790** CAPI3REF: Number of columns in a result set
3792** ^The sqlite3_data_count(P) interface returns the number of columns in the
3793** current row of the result set of [prepared statement] P.
3794** ^If prepared statement P does not have results ready to return
3795** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3796** interfaces) then sqlite3_data_count(P) returns 0.
3797** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3798** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
3799** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
3800** will return non-zero if previous call to [sqlite3_step](P) returned
3801** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
3802** where it always returns zero since each step of that multi-step
3803** pragma returns 0 columns of data.
3805** See also: [sqlite3_column_count()]
3807SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
3810** CAPI3REF: Fundamental Datatypes
3813** ^(Every value in SQLite has one of five fundamental datatypes:
3815** <ul>
3816** <li> 64-bit signed integer
3817** <li> 64-bit IEEE floating point number
3818** <li> string
3819** <li> BLOB
3820** <li> NULL
3821** </ul>)^
3823** These constants are codes for each of those types.
3825** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3826** for a completely different meaning.  Software that links against both
3827** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3830#define SQLITE_INTEGER  1
3831#define SQLITE_FLOAT    2
3832#define SQLITE_BLOB     4
3833#define SQLITE_NULL     5
3834#ifdef SQLITE_TEXT
3835# undef SQLITE_TEXT
3837# define SQLITE_TEXT     3
3839#define SQLITE3_TEXT     3
3842** CAPI3REF: Result Values From A Query
3843** KEYWORDS: {column access functions}
3845** These routines form the "result set" interface.
3847** ^These routines return information about a single column of the current
3848** result row of a query.  ^In every case the first argument is a pointer
3849** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3850** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3851** and the second argument is the index of the column for which information
3852** should be returned. ^The leftmost column of the result set has the index 0.
3853** ^The number of columns in the result can be determined using
3854** [sqlite3_column_count()].
3856** If the SQL statement does not currently point to a valid row, or if the
3857** column index is out of range, the result is undefined.
3858** These routines may only be called when the most recent call to
3859** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3860** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3861** If any of these routines are called after [sqlite3_reset()] or
3862** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3863** something other than [SQLITE_ROW], the results are undefined.
3864** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3865** are called from a different thread while any of these routines
3866** are pending, then the results are undefined.
3868** ^The sqlite3_column_type() routine returns the
3869** [SQLITE_INTEGER | datatype code] for the initial data type
3870** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
3872** returned by sqlite3_column_type() is only meaningful if no type
3873** conversions have occurred as described below.  After a type conversion,
3874** the value returned by sqlite3_column_type() is undefined.  Future
3875** versions of SQLite may change the behavior of sqlite3_column_type()
3876** following a type conversion.
3878** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3879** routine returns the number of bytes in that BLOB or string.
3880** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3881** the string to UTF-8 and then returns the number of bytes.
3882** ^If the result is a numeric value then sqlite3_column_bytes() uses
3883** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3884** the number of bytes in that string.
3885** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3887** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3888** routine returns the number of bytes in that BLOB or string.
3889** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3890** the string to UTF-16 and then returns the number of bytes.
3891** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3892** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3893** the number of bytes in that string.
3894** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3896** ^The values returned by [sqlite3_column_bytes()] and
3897** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3898** of the string.  ^For clarity: the values returned by
3899** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3900** bytes in the string, not the number of characters.
3902** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3903** even empty strings, are always zero-terminated.  ^The return
3904** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3906** ^The object returned by [sqlite3_column_value()] is an
3907** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
3908** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3909** If the [unprotected sqlite3_value] object returned by
3910** [sqlite3_column_value()] is used in any other way, including calls
3911** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3912** or [sqlite3_value_bytes()], then the behavior is undefined.
3914** These routines attempt to convert the value where appropriate.  ^For
3915** example, if the internal representation is FLOAT and a text result
3916** is requested, [sqlite3_snprintf()] is used internally to perform the
3917** conversion automatically.  ^(The following table details the conversions
3918** that are applied:
3920** <blockquote>
3921** <table border="1">
3922** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
3924** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
3925** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
3926** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
3927** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
3928** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
3929** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
3930** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
3931** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
3932** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
3933** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
3934** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
3935** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
3936** <tr><td>  TEXT    <td>   BLOB    <td> No change
3937** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
3938** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
3939** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
3940** </table>
3941** </blockquote>)^
3943** The table above makes reference to standard C library functions atoi()
3944** and atof().  SQLite does not really use these functions.  It has its
3945** own equivalent internal routines.  The atoi() and atof() names are
3946** used in the table for brevity and because they are familiar to most
3947** C programmers.
3949** Note that when type conversions occur, pointers returned by prior
3950** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3951** sqlite3_column_text16() may be invalidated.
3952** Type conversions and pointer invalidations might occur
3953** in the following cases:
3955** <ul>
3956** <li> The initial content is a BLOB and sqlite3_column_text() or
3957**      sqlite3_column_text16() is called.  A zero-terminator might
3958**      need to be added to the string.</li>
3959** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3960**      sqlite3_column_text16() is called.  The content must be converted
3961**      to UTF-16.</li>
3962** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3963**      sqlite3_column_text() is called.  The content must be converted
3964**      to UTF-8.</li>
3965** </ul>
3967** ^Conversions between UTF-16be and UTF-16le are always done in place and do
3968** not invalidate a prior pointer, though of course the content of the buffer
3969** that the prior pointer references will have been modified.  Other kinds
3970** of conversion are done in place when it is possible, but sometimes they
3971** are not possible and in those cases prior pointers are invalidated.
3973** The safest and easiest to remember policy is to invoke these routines
3974** in one of the following ways:
3976** <ul>
3977**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3978**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3979**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3980** </ul>
3982** In other words, you should call sqlite3_column_text(),
3983** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3984** into the desired format, then invoke sqlite3_column_bytes() or
3985** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
3986** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3987** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3988** with calls to sqlite3_column_bytes().
3990** ^The pointers returned are valid until a type conversion occurs as
3991** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3992** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
3993** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
3994** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3995** [sqlite3_free()].
3997** ^(If a memory allocation error occurs during the evaluation of any
3998** of these routines, a default value is returned.  The default value
3999** is either the integer 0, the floating point number 0.0, or a NULL
4000** pointer.  Subsequent calls to [sqlite3_errcode()] will return
4001** [SQLITE_NOMEM].)^
4003SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4004SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4005SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4006SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4007SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4008SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4009SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4010SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4011SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4012SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4015** CAPI3REF: Destroy A Prepared Statement Object
4017** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4018** ^If the most recent evaluation of the statement encountered no errors
4019** or if the statement is never been evaluated, then sqlite3_finalize() returns
4020** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
4021** sqlite3_finalize(S) returns the appropriate [error code] or
4022** [extended error code].
4024** ^The sqlite3_finalize(S) routine can be called at any point during
4025** the life cycle of [prepared statement] S:
4026** before statement S is ever evaluated, after
4027** one or more calls to [sqlite3_reset()], or after any call
4028** to [sqlite3_step()] regardless of whether or not the statement has
4029** completed execution.
4031** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4033** The application must finalize every [prepared statement] in order to avoid
4034** resource leaks.  It is a grievous error for the application to try to use
4035** a prepared statement after it has been finalized.  Any use of a prepared
4036** statement after it has been finalized can result in undefined and
4037** undesirable behavior such as segfaults and heap corruption.
4039SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4042** CAPI3REF: Reset A Prepared Statement Object
4044** The sqlite3_reset() function is called to reset a [prepared statement]
4045** object back to its initial state, ready to be re-executed.
4046** ^Any SQL statement variables that had values bound to them using
4047** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4048** Use [sqlite3_clear_bindings()] to reset the bindings.
4050** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4051** back to the beginning of its program.
4053** ^If the most recent call to [sqlite3_step(S)] for the
4054** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4055** or if [sqlite3_step(S)] has never before been called on S,
4056** then [sqlite3_reset(S)] returns [SQLITE_OK].
4058** ^If the most recent call to [sqlite3_step(S)] for the
4059** [prepared statement] S indicated an error, then
4060** [sqlite3_reset(S)] returns an appropriate [error code].
4062** ^The [sqlite3_reset(S)] interface does not change the values
4063** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4065SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4068** CAPI3REF: Create Or Redefine SQL Functions
4069** KEYWORDS: {function creation routines}
4070** KEYWORDS: {application-defined SQL function}
4071** KEYWORDS: {application-defined SQL functions}
4073** ^These functions (collectively known as "function creation routines")
4074** are used to add SQL functions or aggregates or to redefine the behavior
4075** of existing SQL functions or aggregates.  The only differences between
4076** these routines are the text encoding expected for
4077** the second parameter (the name of the function being created)
4078** and the presence or absence of a destructor callback for
4079** the application data pointer.
4081** ^The first parameter is the [database connection] to which the SQL
4082** function is to be added.  ^If an application uses more than one database
4083** connection then application-defined SQL functions must be added
4084** to each database connection separately.
4086** ^The second parameter is the name of the SQL function to be created or
4087** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
4088** representation, exclusive of the zero-terminator.  ^Note that the name
4089** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4090** ^Any attempt to create a function with a longer name
4091** will result in [SQLITE_MISUSE] being returned.
4093** ^The third parameter (nArg)
4094** is the number of arguments that the SQL function or
4095** aggregate takes. ^If this parameter is -1, then the SQL function or
4096** aggregate may take any number of arguments between 0 and the limit
4097** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
4098** parameter is less than -1 or greater than 127 then the behavior is
4099** undefined.
4101** ^The fourth parameter, eTextRep, specifies what
4102** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4103** its parameters.  The application should set this parameter to
4104** [SQLITE_UTF16LE] if the function implementation invokes
4105** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4106** implementation invokes [sqlite3_value_text16be()] on an input, or
4107** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4108** otherwise.  ^The same SQL function may be registered multiple times using
4109** different preferred text encodings, with different implementations for
4110** each encoding.
4111** ^When multiple implementations of the same function are available, SQLite
4112** will pick the one that involves the least amount of data conversion.
4114** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4115** to signal that the function will always return the same result given
4116** the same inputs within a single SQL statement.  Most SQL functions are
4117** deterministic.  The built-in [random()] SQL function is an example of a
4118** function that is not deterministic.  The SQLite query planner is able to
4119** perform additional optimizations on deterministic functions, so use
4120** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4122** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
4123** function can gain access to this pointer using [sqlite3_user_data()].)^
4125** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4126** pointers to C-language functions that implement the SQL function or
4127** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4128** callback only; NULL pointers must be passed as the xStep and xFinal
4129** parameters. ^An aggregate SQL function requires an implementation of xStep
4130** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4131** SQL function or aggregate, pass NULL pointers for all three function
4132** callbacks.
4134** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4135** then it is destructor for the application data pointer.
4136** The destructor is invoked when the function is deleted, either by being
4137** overloaded or when the database connection closes.)^
4138** ^The destructor is also invoked if the call to
4139** sqlite3_create_function_v2() fails.
4140** ^When the destructor callback of the tenth parameter is invoked, it
4141** is passed a single argument which is a copy of the application data
4142** pointer which was the fifth parameter to sqlite3_create_function_v2().
4144** ^It is permitted to register multiple implementations of the same
4145** functions with the same name but with either differing numbers of
4146** arguments or differing preferred text encodings.  ^SQLite will use
4147** the implementation that most closely matches the way in which the
4148** SQL function is used.  ^A function implementation with a non-negative
4149** nArg parameter is a better match than a function implementation with
4150** a negative nArg.  ^A function where the preferred text encoding
4151** matches the database encoding is a better
4152** match than a function where the encoding is different.
4153** ^A function where the encoding difference is between UTF16le and UTF16be
4154** is a closer match than a function where the encoding difference is
4155** between UTF8 and UTF16.
4157** ^Built-in functions may be overloaded by new application-defined functions.
4159** ^An application-defined function is permitted to call other
4160** SQLite interfaces.  However, such calls must not
4161** close the database connection nor finalize or reset the prepared
4162** statement in which the function is running.
4164SQLITE_API int sqlite3_create_function(
4165  sqlite3 *db,
4166  const char *zFunctionName,
4167  int nArg,
4168  int eTextRep,
4169  void *pApp,
4170  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4171  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4172  void (*xFinal)(sqlite3_context*)
4174SQLITE_API int sqlite3_create_function16(
4175  sqlite3 *db,
4176  const void *zFunctionName,
4177  int nArg,
4178  int eTextRep,
4179  void *pApp,
4180  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4181  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4182  void (*xFinal)(sqlite3_context*)
4184SQLITE_API int sqlite3_create_function_v2(
4185  sqlite3 *db,
4186  const char *zFunctionName,
4187  int nArg,
4188  int eTextRep,
4189  void *pApp,
4190  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4191  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4192  void (*xFinal)(sqlite3_context*),
4193  void(*xDestroy)(void*)
4197** CAPI3REF: Text Encodings
4199** These constant define integer codes that represent the various
4200** text encodings supported by SQLite.
4202#define SQLITE_UTF8           1
4203#define SQLITE_UTF16LE        2
4204#define SQLITE_UTF16BE        3
4205#define SQLITE_UTF16          4    /* Use native byte order */
4206#define SQLITE_ANY            5    /* Deprecated */
4207#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
4210** CAPI3REF: Function Flags
4212** These constants may be ORed together with the
4213** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4214** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4215** [sqlite3_create_function_v2()].
4217#define SQLITE_DETERMINISTIC    0x800
4220** CAPI3REF: Deprecated Functions
4223** These functions are [deprecated].  In order to maintain
4224** backwards compatibility with older code, these functions continue
4225** to be supported.  However, new applications should avoid
4226** the use of these functions.  To help encourage people to avoid
4227** using these functions, we are not going to tell you what they do.
4230SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4231SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4232SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4233SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4234SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4235SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4236                      void*,sqlite3_int64);
4240** CAPI3REF: Obtaining SQL Function Parameter Values
4242** The C-language implementation of SQL functions and aggregates uses
4243** this set of interface routines to access the parameter values on
4244** the function or aggregate.
4246** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4247** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4248** define callbacks that implement the SQL functions and aggregates.
4249** The 3rd parameter to these callbacks is an array of pointers to
4250** [protected sqlite3_value] objects.  There is one [sqlite3_value] object for
4251** each parameter to the SQL function.  These routines are used to
4252** extract values from the [sqlite3_value] objects.
4254** These routines work only with [protected sqlite3_value] objects.
4255** Any attempt to use these routines on an [unprotected sqlite3_value]
4256** object results in undefined behavior.
4258** ^These routines work just like the corresponding [column access functions]
4259** except that  these routines take a single [protected sqlite3_value] object
4260** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4262** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4263** in the native byte-order of the host machine.  ^The
4264** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4265** extract UTF-16 strings as big-endian and little-endian respectively.
4267** ^(The sqlite3_value_numeric_type() interface attempts to apply
4268** numeric affinity to the value.  This means that an attempt is
4269** made to convert the value to an integer or floating point.  If
4270** such a conversion is possible without loss of information (in other
4271** words, if the value is a string that looks like a number)
4272** then the conversion is performed.  Otherwise no conversion occurs.
4273** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4275** Please pay particular attention to the fact that the pointer returned
4276** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4277** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4278** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4279** or [sqlite3_value_text16()].
4281** These routines must be called from the same thread as
4282** the SQL function that supplied the [sqlite3_value*] parameters.
4284SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4285SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4286SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4287SQLITE_API double sqlite3_value_double(sqlite3_value*);
4288SQLITE_API int sqlite3_value_int(sqlite3_value*);
4289SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4290SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4291SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4292SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4293SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4294SQLITE_API int sqlite3_value_type(sqlite3_value*);
4295SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4298** CAPI3REF: Obtain Aggregate Function Context
4300** Implementations of aggregate SQL functions use this
4301** routine to allocate memory for storing their state.
4303** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4304** for a particular aggregate function, SQLite
4305** allocates N of memory, zeroes out that memory, and returns a pointer
4306** to the new memory. ^On second and subsequent calls to
4307** sqlite3_aggregate_context() for the same aggregate function instance,
4308** the same buffer is returned.  Sqlite3_aggregate_context() is normally
4309** called once for each invocation of the xStep callback and then one
4310** last time when the xFinal callback is invoked.  ^(When no rows match
4311** an aggregate query, the xStep() callback of the aggregate function
4312** implementation is never called and xFinal() is called exactly once.
4313** In those cases, sqlite3_aggregate_context() might be called for the
4314** first time from within xFinal().)^
4316** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
4317** when first called if N is less than or equal to zero or if a memory
4318** allocate error occurs.
4320** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4321** determined by the N parameter on first successful call.  Changing the
4322** value of N in subsequent call to sqlite3_aggregate_context() within
4323** the same aggregate function instance will not resize the memory
4324** allocation.)^  Within the xFinal callback, it is customary to set
4325** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
4326** pointless memory allocations occur.
4328** ^SQLite automatically frees the memory allocated by
4329** sqlite3_aggregate_context() when the aggregate query concludes.
4331** The first parameter must be a copy of the
4332** [sqlite3_context | SQL function context] that is the first parameter
4333** to the xStep or xFinal callback routine that implements the aggregate
4334** function.
4336** This routine must be called from the same thread in which
4337** the aggregate SQL function is running.
4339SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4342** CAPI3REF: User Data For Functions
4344** ^The sqlite3_user_data() interface returns a copy of
4345** the pointer that was the pUserData parameter (the 5th parameter)
4346** of the [sqlite3_create_function()]
4347** and [sqlite3_create_function16()] routines that originally
4348** registered the application defined function.
4350** This routine must be called from the same thread in which
4351** the application-defined function is running.
4353SQLITE_API void *sqlite3_user_data(sqlite3_context*);
4356** CAPI3REF: Database Connection For Functions
4358** ^The sqlite3_context_db_handle() interface returns a copy of
4359** the pointer to the [database connection] (the 1st parameter)
4360** of the [sqlite3_create_function()]
4361** and [sqlite3_create_function16()] routines that originally
4362** registered the application defined function.
4364SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4367** CAPI3REF: Function Auxiliary Data
4369** These functions may be used by (non-aggregate) SQL functions to
4370** associate metadata with argument values. If the same value is passed to
4371** multiple invocations of the same SQL function during query execution, under
4372** some circumstances the associated metadata may be preserved.  An example
4373** of where this might be useful is in a regular-expression matching
4374** function. The compiled version of the regular expression can be stored as
4375** metadata associated with the pattern string.
4376** Then as long as the pattern string remains the same,
4377** the compiled regular expression can be reused on multiple
4378** invocations of the same function.
4380** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4381** associated by the sqlite3_set_auxdata() function with the Nth argument
4382** value to the application-defined function. ^If there is no metadata
4383** associated with the function argument, this sqlite3_get_auxdata() interface
4384** returns a NULL pointer.
4386** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4387** argument of the application-defined function.  ^Subsequent
4388** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4389** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4390** NULL if the metadata has been discarded.
4391** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4392** SQLite will invoke the destructor function X with parameter P exactly
4393** once, when the metadata is discarded.
4394** SQLite is free to discard the metadata at any time, including: <ul>
4395** <li> when the corresponding function parameter changes, or
4396** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4397**      SQL statement, or
4398** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
4399** <li> during the original sqlite3_set_auxdata() call when a memory
4400**      allocation error occurs. </ul>)^
4402** Note the last bullet in particular.  The destructor X in
4403** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4404** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
4405** should be called near the end of the function implementation and the
4406** function implementation should not make any use of P after
4407** sqlite3_set_auxdata() has been called.
4409** ^(In practice, metadata is preserved between function calls for
4410** function parameters that are compile-time constants, including literal
4411** values and [parameters] and expressions composed from the same.)^
4413** These routines must be called from the same thread in which
4414** the SQL function is running.
4416SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4417SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4421** CAPI3REF: Constants Defining Special Destructor Behavior
4423** These are special values for the destructor that is passed in as the
4424** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
4425** argument is SQLITE_STATIC, it means that the content pointer is constant
4426** and will never change.  It does not need to be destroyed.  ^The
4427** SQLITE_TRANSIENT value means that the content will likely change in
4428** the near future and that SQLite should make its own private copy of
4429** the content before returning.
4431** The typedef is necessary to work around problems in certain
4432** C++ compilers.
4434typedef void (*sqlite3_destructor_type)(void*);
4435#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
4436#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
4439** CAPI3REF: Setting The Result Of An SQL Function
4441** These routines are used by the xFunc or xFinal callbacks that
4442** implement SQL functions and aggregates.  See
4443** [sqlite3_create_function()] and [sqlite3_create_function16()]
4444** for additional information.
4446** These functions work very much like the [parameter binding] family of
4447** functions used to bind values to host parameters in prepared statements.
4448** Refer to the [SQL parameter] documentation for additional information.
4450** ^The sqlite3_result_blob() interface sets the result from
4451** an application-defined function to be the BLOB whose content is pointed
4452** to by the second parameter and which is N bytes long where N is the
4453** third parameter.
4455** ^The sqlite3_result_zeroblob() interfaces set the result of
4456** the application-defined function to be a BLOB containing all zero
4457** bytes and N bytes in size, where N is the value of the 2nd parameter.
4459** ^The sqlite3_result_double() interface sets the result from
4460** an application-defined function to be a floating point value specified
4461** by its 2nd argument.
4463** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4464** cause the implemented SQL function to throw an exception.
4465** ^SQLite uses the string pointed to by the
4466** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4467** as the text of an error message.  ^SQLite interprets the error
4468** message string from sqlite3_result_error() as UTF-8. ^SQLite
4469** interprets the string from sqlite3_result_error16() as UTF-16 in native
4470** byte order.  ^If the third parameter to sqlite3_result_error()
4471** or sqlite3_result_error16() is negative then SQLite takes as the error
4472** message all text up through the first zero character.
4473** ^If the third parameter to sqlite3_result_error() or
4474** sqlite3_result_error16() is non-negative then SQLite takes that many
4475** bytes (not characters) from the 2nd parameter as the error message.
4476** ^The sqlite3_result_error() and sqlite3_result_error16()
4477** routines make a private copy of the error message text before
4478** they return.  Hence, the calling function can deallocate or
4479** modify the text after they return without harm.
4480** ^The sqlite3_result_error_code() function changes the error code
4481** returned by SQLite as a result of an error in a function.  ^By default,
4482** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
4483** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4485** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4486** error indicating that a string or BLOB is too long to represent.
4488** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4489** error indicating that a memory allocation failed.
4491** ^The sqlite3_result_int() interface sets the return value
4492** of the application-defined function to be the 32-bit signed integer
4493** value given in the 2nd argument.
4494** ^The sqlite3_result_int64() interface sets the return value
4495** of the application-defined function to be the 64-bit signed integer
4496** value given in the 2nd argument.
4498** ^The sqlite3_result_null() interface sets the return value
4499** of the application-defined function to be NULL.
4501** ^The sqlite3_result_text(), sqlite3_result_text16(),
4502** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4503** set the return value of the application-defined function to be
4504** a text string which is represented as UTF-8, UTF-16 native byte order,
4505** UTF-16 little endian, or UTF-16 big endian, respectively.
4506** ^SQLite takes the text result from the application from
4507** the 2nd parameter of the sqlite3_result_text* interfaces.
4508** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4509** is negative, then SQLite takes result text from the 2nd parameter
4510** through the first zero character.
4511** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4512** is non-negative, then as many bytes (not characters) of the text
4513** pointed to by the 2nd parameter are taken as the application-defined
4514** function result.  If the 3rd parameter is non-negative, then it
4515** must be the byte offset into the string where the NUL terminator would
4516** appear if the string where NUL terminated.  If any NUL characters occur
4517** in the string at a byte offset that is less than the value of the 3rd
4518** parameter, then the resulting string will contain embedded NULs and the
4519** result of expressions operating on strings with embedded NULs is undefined.
4520** ^If the 4th parameter to the sqlite3_result_text* interfaces
4521** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4522** function as the destructor on the text or BLOB result when it has
4523** finished using that result.
4524** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4525** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4526** assumes that the text or BLOB result is in constant space and does not
4527** copy the content of the parameter nor call a destructor on the content
4528** when it has finished using that result.
4529** ^If the 4th parameter to the sqlite3_result_text* interfaces
4530** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4531** then SQLite makes a copy of the result into space obtained from
4532** from [sqlite3_malloc()] before it returns.
4534** ^The sqlite3_result_value() interface sets the result of
4535** the application-defined function to be a copy the
4536** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
4537** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4538** so that the [sqlite3_value] specified in the parameter may change or
4539** be deallocated after sqlite3_result_value() returns without harm.
4540** ^A [protected sqlite3_value] object may always be used where an
4541** [unprotected sqlite3_value] object is required, so either
4542** kind of [sqlite3_value] object can be used with this interface.
4544** If these routines are called from within the different thread
4545** than the one containing the application-defined function that received
4546** the [sqlite3_context] pointer, the results are undefined.
4548SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4549SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4550SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4551SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4552SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4553SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4554SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4555SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4556SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4557SQLITE_API void sqlite3_result_null(sqlite3_context*);
4558SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4559SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4560SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4561SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4562SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4563SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4566** CAPI3REF: Define New Collating Sequences
4568** ^These functions add, remove, or modify a [collation] associated
4569** with the [database connection] specified as the first argument.
4571** ^The name of the collation is a UTF-8 string
4572** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4573** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4574** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4575** considered to be the same name.
4577** ^(The third argument (eTextRep) must be one of the constants:
4578** <ul>
4579** <li> [SQLITE_UTF8],
4580** <li> [SQLITE_UTF16LE],
4581** <li> [SQLITE_UTF16BE],
4582** <li> [SQLITE_UTF16], or
4583** <li> [SQLITE_UTF16_ALIGNED].
4584** </ul>)^
4585** ^The eTextRep argument determines the encoding of strings passed
4586** to the collating function callback, xCallback.
4587** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4588** force strings to be UTF16 with native byte order.
4589** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4590** on an even byte address.
4592** ^The fourth argument, pArg, is an application data pointer that is passed
4593** through as the first argument to the collating function callback.
4595** ^The fifth argument, xCallback, is a pointer to the collating function.
4596** ^Multiple collating functions can be registered using the same name but
4597** with different eTextRep parameters and SQLite will use whichever
4598** function requires the least amount of data transformation.
4599** ^If the xCallback argument is NULL then the collating function is
4600** deleted.  ^When all collating functions having the same name are deleted,
4601** that collation is no longer usable.
4603** ^The collating function callback is invoked with a copy of the pArg
4604** application data pointer and with two strings in the encoding specified
4605** by the eTextRep argument.  The collating function must return an
4606** integer that is negative, zero, or positive
4607** if the first string is less than, equal to, or greater than the second,
4608** respectively.  A collating function must always return the same answer
4609** given the same inputs.  If two or more collating functions are registered
4610** to the same collation name (using different eTextRep values) then all
4611** must give an equivalent answer when invoked with equivalent strings.
4612** The collating function must obey the following properties for all
4613** strings A, B, and C:
4615** <ol>
4616** <li> If A==B then B==A.
4617** <li> If A==B and B==C then A==C.
4618** <li> If A&lt;B THEN B&gt;A.
4619** <li> If A&lt;B and B&lt;C then A&lt;C.
4620** </ol>
4622** If a collating function fails any of the above constraints and that
4623** collating function is  registered and used, then the behavior of SQLite
4624** is undefined.
4626** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4627** with the addition that the xDestroy callback is invoked on pArg when
4628** the collating function is deleted.
4629** ^Collating functions are deleted when they are overridden by later
4630** calls to the collation creation functions or when the
4631** [database connection] is closed using [sqlite3_close()].
4633** ^The xDestroy callback is <u>not</u> called if the
4634** sqlite3_create_collation_v2() function fails.  Applications that invoke
4635** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4636** check the return code and dispose of the application data pointer
4637** themselves rather than expecting SQLite to deal with it for them.
4638** This is different from every other SQLite interface.  The inconsistency
4639** is unfortunate but cannot be changed without breaking backwards
4640** compatibility.
4642** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4644SQLITE_API int sqlite3_create_collation(
4645  sqlite3*,
4646  const char *zName,
4647  int eTextRep,
4648  void *pArg,
4649  int(*xCompare)(void*,int,const void*,int,const void*)
4651SQLITE_API int sqlite3_create_collation_v2(
4652  sqlite3*,
4653  const char *zName,
4654  int eTextRep,
4655  void *pArg,
4656  int(*xCompare)(void*,int,const void*,int,const void*),
4657  void(*xDestroy)(void*)
4659SQLITE_API int sqlite3_create_collation16(
4660  sqlite3*,
4661  const void *zName,
4662  int eTextRep,
4663  void *pArg,
4664  int(*xCompare)(void*,int,const void*,int,const void*)
4668** CAPI3REF: Collation Needed Callbacks
4670** ^To avoid having to register all collation sequences before a database
4671** can be used, a single callback function may be registered with the
4672** [database connection] to be invoked whenever an undefined collation
4673** sequence is required.
4675** ^If the function is registered using the sqlite3_collation_needed() API,
4676** then it is passed the names of undefined collation sequences as strings
4677** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4678** the names are passed as UTF-16 in machine native byte order.
4679** ^A call to either function replaces the existing collation-needed callback.
4681** ^(When the callback is invoked, the first argument passed is a copy
4682** of the second argument to sqlite3_collation_needed() or
4683** sqlite3_collation_needed16().  The second argument is the database
4684** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4685** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4686** sequence function required.  The fourth parameter is the name of the
4687** required collation sequence.)^
4689** The callback function should register the desired collation using
4690** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4691** [sqlite3_create_collation_v2()].
4693SQLITE_API int sqlite3_collation_needed(
4694  sqlite3*,
4695  void*,
4696  void(*)(void*,sqlite3*,int eTextRep,const char*)
4698SQLITE_API int sqlite3_collation_needed16(
4699  sqlite3*,
4700  void*,
4701  void(*)(void*,sqlite3*,int eTextRep,const void*)
4706** Specify the key for an encrypted database.  This routine should be
4707** called right after sqlite3_open().
4709** The code to implement this API is not available in the public release
4710** of SQLite.
4712SQLITE_API int sqlite3_key(
4713  sqlite3 *db,                   /* Database to be rekeyed */
4714  const void *pKey, int nKey     /* The key */
4716SQLITE_API int sqlite3_key_v2(
4717  sqlite3 *db,                   /* Database to be rekeyed */
4718  const char *zDbName,           /* Name of the database */
4719  const void *pKey, int nKey     /* The key */
4723** Change the key on an open database.  If the current database is not
4724** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
4725** database is decrypted.
4727** The code to implement this API is not available in the public release
4728** of SQLite.
4730SQLITE_API int sqlite3_rekey(
4731  sqlite3 *db,                   /* Database to be rekeyed */
4732  const void *pKey, int nKey     /* The new key */
4734SQLITE_API int sqlite3_rekey_v2(
4735  sqlite3 *db,                   /* Database to be rekeyed */
4736  const char *zDbName,           /* Name of the database */
4737  const void *pKey, int nKey     /* The new key */
4741** Specify the activation key for a SEE database.  Unless
4742** activated, none of the SEE routines will work.
4744SQLITE_API void sqlite3_activate_see(
4745  const char *zPassPhrase        /* Activation phrase */
4751** Specify the activation key for a CEROD database.  Unless
4752** activated, none of the CEROD routines will work.
4754SQLITE_API void sqlite3_activate_cerod(
4755  const char *zPassPhrase        /* Activation phrase */
4760** CAPI3REF: Suspend Execution For A Short Time
4762** The sqlite3_sleep() function causes the current thread to suspend execution
4763** for at least a number of milliseconds specified in its parameter.
4765** If the operating system does not support sleep requests with
4766** millisecond time resolution, then the time will be rounded up to
4767** the nearest second. The number of milliseconds of sleep actually
4768** requested from the operating system is returned.
4770** ^SQLite implements this interface by calling the xSleep()
4771** method of the default [sqlite3_vfs] object.  If the xSleep() method
4772** of the default VFS is not implemented correctly, or not implemented at
4773** all, then the behavior of sqlite3_sleep() may deviate from the description
4774** in the previous paragraphs.
4776SQLITE_API int sqlite3_sleep(int);
4779** CAPI3REF: Name Of The Folder Holding Temporary Files
4781** ^(If this global variable is made to point to a string which is
4782** the name of a folder (a.k.a. directory), then all temporary files
4783** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4784** will be placed in that directory.)^  ^If this variable
4785** is a NULL pointer, then SQLite performs a search for an appropriate
4786** temporary file directory.
4788** It is not safe to read or modify this variable in more than one
4789** thread at a time.  It is not safe to read or modify this variable
4790** if a [database connection] is being used at the same time in a separate
4791** thread.
4792** It is intended that this variable be set once
4793** as part of process initialization and before any SQLite interface
4794** routines have been called and that this variable remain unchanged
4795** thereafter.
4797** ^The [temp_store_directory pragma] may modify this variable and cause
4798** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
4799** the [temp_store_directory pragma] always assumes that any string
4800** that this variable points to is held in memory obtained from
4801** [sqlite3_malloc] and the pragma may attempt to free that memory
4802** using [sqlite3_free].
4803** Hence, if this variable is modified directly, either it should be
4804** made NULL or made to point to memory obtained from [sqlite3_malloc]
4805** or else the use of the [temp_store_directory pragma] should be avoided.
4807** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
4808** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
4809** features that require the use of temporary files may fail.  Here is an
4810** example of how to do this using C++ with the Windows Runtime:
4812** <blockquote><pre>
4813** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
4814** &nbsp;     TemporaryFolder->Path->Data();
4815** char zPathBuf&#91;MAX_PATH + 1&#93;;
4816** memset(zPathBuf, 0, sizeof(zPathBuf));
4817** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
4818** &nbsp;     NULL, NULL);
4819** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
4820** </pre></blockquote>
4822SQLITE_API char *sqlite3_temp_directory;
4825** CAPI3REF: Name Of The Folder Holding Database Files
4827** ^(If this global variable is made to point to a string which is
4828** the name of a folder (a.k.a. directory), then all database files
4829** specified with a relative pathname and created or accessed by
4830** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
4831** to be relative to that directory.)^ ^If this variable is a NULL
4832** pointer, then SQLite assumes that all database files specified
4833** with a relative pathname are relative to the current directory
4834** for the process.  Only the windows VFS makes use of this global
4835** variable; it is ignored by the unix VFS.
4837** Changing the value of this variable while a database connection is
4838** open can result in a corrupt database.
4840** It is not safe to read or modify this variable in more than one
4841** thread at a time.  It is not safe to read or modify this variable
4842** if a [database connection] is being used at the same time in a separate
4843** thread.
4844** It is intended that this variable be set once
4845** as part of process initialization and before any SQLite interface
4846** routines have been called and that this variable remain unchanged
4847** thereafter.
4849** ^The [data_store_directory pragma] may modify this variable and cause
4850** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
4851** the [data_store_directory pragma] always assumes that any string
4852** that this variable points to is held in memory obtained from
4853** [sqlite3_malloc] and the pragma may attempt to free that memory
4854** using [sqlite3_free].
4855** Hence, if this variable is modified directly, either it should be
4856** made NULL or made to point to memory obtained from [sqlite3_malloc]
4857** or else the use of the [data_store_directory pragma] should be avoided.
4859SQLITE_API char *sqlite3_data_directory;
4862** CAPI3REF: Test For Auto-Commit Mode
4863** KEYWORDS: {autocommit mode}
4865** ^The sqlite3_get_autocommit() interface returns non-zero or
4866** zero if the given database connection is or is not in autocommit mode,
4867** respectively.  ^Autocommit mode is on by default.
4868** ^Autocommit mode is disabled by a [BEGIN] statement.
4869** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4871** If certain kinds of errors occur on a statement within a multi-statement
4872** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4874** transaction might be rolled back automatically.  The only way to
4875** find out whether SQLite automatically rolled back the transaction after
4876** an error is to use this function.
4878** If another thread changes the autocommit status of the database
4879** connection while this routine is running, then the return value
4880** is undefined.
4882SQLITE_API int sqlite3_get_autocommit(sqlite3*);
4885** CAPI3REF: Find The Database Handle Of A Prepared Statement
4887** ^The sqlite3_db_handle interface returns the [database connection] handle
4888** to which a [prepared statement] belongs.  ^The [database connection]
4889** returned by sqlite3_db_handle is the same [database connection]
4890** that was the first argument
4891** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4892** create the statement in the first place.
4894SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
4897** CAPI3REF: Return The Filename For A Database Connection
4899** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
4900** associated with database N of connection D.  ^The main database file
4901** has the name "main".  If there is no attached database N on the database
4902** connection D, or if database N is a temporary or in-memory database, then
4903** a NULL pointer is returned.
4905** ^The filename returned by this function is the output of the
4906** xFullPathname method of the [VFS].  ^In other words, the filename
4907** will be an absolute pathname, even if the filename used
4908** to open the database originally was a URI or relative pathname.
4910SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
4913** CAPI3REF: Determine if a database is read-only
4915** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
4916** of connection D is read-only, 0 if it is read/write, or -1 if N is not
4917** the name of a database on connection D.
4919SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
4922** CAPI3REF: Find the next prepared statement
4924** ^This interface returns a pointer to the next [prepared statement] after
4925** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
4926** then this interface returns a pointer to the first prepared statement
4927** associated with the database connection pDb.  ^If no prepared statement
4928** satisfies the conditions of this routine, it returns NULL.
4930** The [database connection] pointer D in a call to
4931** [sqlite3_next_stmt(D,S)] must refer to an open database
4932** connection and in particular must not be a NULL pointer.
4934SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
4937** CAPI3REF: Commit And Rollback Notification Callbacks
4939** ^The sqlite3_commit_hook() interface registers a callback
4940** function to be invoked whenever a transaction is [COMMIT | committed].
4941** ^Any callback set by a previous call to sqlite3_commit_hook()
4942** for the same database connection is overridden.
4943** ^The sqlite3_rollback_hook() interface registers a callback
4944** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4945** ^Any callback set by a previous call to sqlite3_rollback_hook()
4946** for the same database connection is overridden.
4947** ^The pArg argument is passed through to the callback.
4948** ^If the callback on a commit hook function returns non-zero,
4949** then the commit is converted into a rollback.
4951** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4952** return the P argument from the previous call of the same function
4953** on the same [database connection] D, or NULL for
4954** the first call for each function on D.
4956** The commit and rollback hook callbacks are not reentrant.
4957** The callback implementation must not do anything that will modify
4958** the database connection that invoked the callback.  Any actions
4959** to modify the database connection must be deferred until after the
4960** completion of the [sqlite3_step()] call that triggered the commit
4961** or rollback hook in the first place.
4962** Note that running any other SQL statements, including SELECT statements,
4963** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
4964** the database connections for the meaning of "modify" in this paragraph.
4966** ^Registering a NULL function disables the callback.
4968** ^When the commit hook callback routine returns zero, the [COMMIT]
4969** operation is allowed to continue normally.  ^If the commit hook
4970** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4971** ^The rollback hook is invoked on a rollback that results from a commit
4972** hook returning non-zero, just as it would be with any other rollback.
4974** ^For the purposes of this API, a transaction is said to have been
4975** rolled back if an explicit "ROLLBACK" statement is executed, or
4976** an error or constraint causes an implicit rollback to occur.
4977** ^The rollback callback is not invoked if a transaction is
4978** automatically rolled back because the database connection is closed.
4980** See also the [sqlite3_update_hook()] interface.
4982SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4983SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4986** CAPI3REF: Data Change Notification Callbacks
4988** ^The sqlite3_update_hook() interface registers a callback function
4989** with the [database connection] identified by the first argument
4990** to be invoked whenever a row is updated, inserted or deleted in
4991** a rowid table.
4992** ^Any callback set by a previous call to this function
4993** for the same database connection is overridden.
4995** ^The second argument is a pointer to the function to invoke when a
4996** row is updated, inserted or deleted in a rowid table.
4997** ^The first argument to the callback is a copy of the third argument
4998** to sqlite3_update_hook().
4999** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5000** or [SQLITE_UPDATE], depending on the operation that caused the callback
5001** to be invoked.
5002** ^The third and fourth arguments to the callback contain pointers to the
5003** database and table name containing the affected row.
5004** ^The final callback parameter is the [rowid] of the row.
5005** ^In the case of an update, this is the [rowid] after the update takes place.
5007** ^(The update hook is not invoked when internal system tables are
5008** modified (i.e. sqlite_master and sqlite_sequence).)^
5009** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5011** ^In the current implementation, the update hook
5012** is not invoked when duplication rows are deleted because of an
5013** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
5014** invoked when rows are deleted using the [truncate optimization].
5015** The exceptions defined in this paragraph might change in a future
5016** release of SQLite.
5018** The update hook implementation must not do anything that will modify
5019** the database connection that invoked the update hook.  Any actions
5020** to modify the database connection must be deferred until after the
5021** completion of the [sqlite3_step()] call that triggered the update hook.
5022** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5023** database connections for the meaning of "modify" in this paragraph.
5025** ^The sqlite3_update_hook(D,C,P) function
5026** returns the P argument from the previous call
5027** on the same [database connection] D, or NULL for
5028** the first call on D.
5030** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
5031** interfaces.
5033SQLITE_API void *sqlite3_update_hook(
5034  sqlite3*,
5035  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5036  void*
5040** CAPI3REF: Enable Or Disable Shared Pager Cache
5042** ^(This routine enables or disables the sharing of the database cache
5043** and schema data structures between [database connection | connections]
5044** to the same database. Sharing is enabled if the argument is true
5045** and disabled if the argument is false.)^
5047** ^Cache sharing is enabled and disabled for an entire process.
5048** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
5049** sharing was enabled or disabled for each thread separately.
5051** ^(The cache sharing mode set by this interface effects all subsequent
5052** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5053** Existing database connections continue use the sharing mode
5054** that was in effect at the time they were opened.)^
5056** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5057** successfully.  An [error code] is returned otherwise.)^
5059** ^Shared cache is disabled by default. But this might change in
5060** future releases of SQLite.  Applications that care about shared
5061** cache setting should set it explicitly.
5063** This interface is threadsafe on processors where writing a
5064** 32-bit integer is atomic.
5066** See Also:  [SQLite Shared-Cache Mode]
5068SQLITE_API int sqlite3_enable_shared_cache(int);
5071** CAPI3REF: Attempt To Free Heap Memory
5073** ^The sqlite3_release_memory() interface attempts to free N bytes
5074** of heap memory by deallocating non-essential memory allocations
5075** held by the database library.   Memory used to cache database
5076** pages to improve performance is an example of non-essential memory.
5077** ^sqlite3_release_memory() returns the number of bytes actually freed,
5078** which might be more or less than the amount requested.
5079** ^The sqlite3_release_memory() routine is a no-op returning zero
5080** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5082** See also: [sqlite3_db_release_memory()]
5084SQLITE_API int sqlite3_release_memory(int);
5087** CAPI3REF: Free Memory Used By A Database Connection
5089** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5090** memory as possible from database connection D. Unlike the
5091** [sqlite3_release_memory()] interface, this interface is in effect even
5092** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5093** omitted.
5095** See also: [sqlite3_release_memory()]
5097SQLITE_API int sqlite3_db_release_memory(sqlite3*);
5100** CAPI3REF: Impose A Limit On Heap Size
5102** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5103** soft limit on the amount of heap memory that may be allocated by SQLite.
5104** ^SQLite strives to keep heap memory utilization below the soft heap
5105** limit by reducing the number of pages held in the page cache
5106** as heap memory usages approaches the limit.
5107** ^The soft heap limit is "soft" because even though SQLite strives to stay
5108** below the limit, it will exceed the limit rather than generate
5109** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
5110** is advisory only.
5112** ^The return value from sqlite3_soft_heap_limit64() is the size of
5113** the soft heap limit prior to the call, or negative in the case of an
5114** error.  ^If the argument N is negative
5115** then no change is made to the soft heap limit.  Hence, the current
5116** size of the soft heap limit can be determined by invoking
5117** sqlite3_soft_heap_limit64() with a negative argument.
5119** ^If the argument N is zero then the soft heap limit is disabled.
5121** ^(The soft heap limit is not enforced in the current implementation
5122** if one or more of following conditions are true:
5124** <ul>
5125** <li> The soft heap limit is set to zero.
5126** <li> Memory accounting is disabled using a combination of the
5127**      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5128**      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5129** <li> An alternative page cache implementation is specified using
5130**      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5131** <li> The page cache allocates from its own memory pool supplied
5132**      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5133**      from the heap.
5134** </ul>)^
5136** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
5137** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5138** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5139** the soft heap limit is enforced on every memory allocation.  Without
5140** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5141** when memory is allocated by the page cache.  Testing suggests that because
5142** the page cache is the predominate memory user in SQLite, most
5143** applications will achieve adequate soft heap limit enforcement without
5146** The circumstances under which SQLite will enforce the soft heap limit may
5147** changes in future releases of SQLite.
5149SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5152** CAPI3REF: Deprecated Soft Heap Limit Interface
5155** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5156** interface.  This routine is provided for historical compatibility
5157** only.  All new applications should use the
5158** [sqlite3_soft_heap_limit64()] interface rather than this one.
5160SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5164** CAPI3REF: Extract Metadata About A Column Of A Table
5166** ^This routine returns metadata about a specific column of a specific
5167** database table accessible using the [database connection] handle
5168** passed as the first function argument.
5170** ^The column is identified by the second, third and fourth parameters to
5171** this function. ^The second parameter is either the name of the database
5172** (i.e. "main", "temp", or an attached database) containing the specified
5173** table or NULL. ^If it is NULL, then all attached databases are searched
5174** for the table using the same algorithm used by the database engine to
5175** resolve unqualified table references.
5177** ^The third and fourth parameters to this function are the table and column
5178** name of the desired column, respectively. Neither of these parameters
5179** may be NULL.
5181** ^Metadata is returned by writing to the memory locations passed as the 5th
5182** and subsequent parameters to this function. ^Any of these arguments may be
5183** NULL, in which case the corresponding element of metadata is omitted.
5185** ^(<blockquote>
5186** <table border="1">
5187** <tr><th> Parameter <th> Output<br>Type <th>  Description
5189** <tr><td> 5th <td> const char* <td> Data type
5190** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5191** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
5192** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
5193** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
5194** </table>
5195** </blockquote>)^
5197** ^The memory pointed to by the character pointers returned for the
5198** declaration type and collation sequence is valid only until the next
5199** call to any SQLite API function.
5201** ^If the specified table is actually a view, an [error code] is returned.
5203** ^If the specified column is "rowid", "oid" or "_rowid_" and an
5204** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5205** parameters are set for the explicitly declared column. ^(If there is no
5206** explicitly declared [INTEGER PRIMARY KEY] column, then the output
5207** parameters are set as follows:
5209** <pre>
5210**     data type: "INTEGER"
5211**     collation sequence: "BINARY"
5212**     not null: 0
5213**     primary key: 1
5214**     auto increment: 0
5215** </pre>)^
5217** ^(This function may load one or more schemas from database files. If an
5218** error occurs during this process, or if the requested table or column
5219** cannot be found, an [error code] is returned and an error message left
5220** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
5222** ^This API is only available if the library was compiled with the
5223** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
5225SQLITE_API int sqlite3_table_column_metadata(
5226  sqlite3 *db,                /* Connection handle */
5227  const char *zDbName,        /* Database name or NULL */
5228  const char *zTableName,     /* Table name */
5229  const char *zColumnName,    /* Column name */
5230  char const **pzDataType,    /* OUTPUT: Declared data type */
5231  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
5232  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
5233  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
5234  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
5238** CAPI3REF: Load An Extension
5240** ^This interface loads an SQLite extension library from the named file.
5242** ^The sqlite3_load_extension() interface attempts to load an
5243** [SQLite extension] library contained in the file zFile.  If
5244** the file cannot be loaded directly, attempts are made to load
5245** with various operating-system specific extensions added.
5246** So for example, if "samplelib" cannot be loaded, then names like
5247** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5248** be tried also.
5250** ^The entry point is zProc.
5251** ^(zProc may be 0, in which case SQLite will try to come up with an
5252** entry point name on its own.  It first tries "sqlite3_extension_init".
5253** If that does not work, it constructs a name "sqlite3_X_init" where the
5254** X is consists of the lower-case equivalent of all ASCII alphabetic
5255** characters in the filename from the last "/" to the first following
5256** "." and omitting any initial "lib".)^
5257** ^The sqlite3_load_extension() interface returns
5258** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5259** ^If an error occurs and pzErrMsg is not 0, then the
5260** [sqlite3_load_extension()] interface shall attempt to
5261** fill *pzErrMsg with error message text stored in memory
5262** obtained from [sqlite3_malloc()]. The calling function
5263** should free this memory by calling [sqlite3_free()].
5265** ^Extension loading must be enabled using
5266** [sqlite3_enable_load_extension()] prior to calling this API,
5267** otherwise an error will be returned.
5269** See also the [load_extension() SQL function].
5271SQLITE_API int sqlite3_load_extension(
5272  sqlite3 *db,          /* Load the extension into this database connection */
5273  const char *zFile,    /* Name of the shared library containing extension */
5274  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
5275  char **pzErrMsg       /* Put error message here if not 0 */
5279** CAPI3REF: Enable Or Disable Extension Loading
5281** ^So as not to open security holes in older applications that are
5282** unprepared to deal with [extension loading], and as a means of disabling
5283** [extension loading] while evaluating user-entered SQL, the following API
5284** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5286** ^Extension loading is off by default.
5287** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5288** to turn extension loading on and call it with onoff==0 to turn
5289** it back off again.
5291SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5294** CAPI3REF: Automatically Load Statically Linked Extensions
5296** ^This interface causes the xEntryPoint() function to be invoked for
5297** each new [database connection] that is created.  The idea here is that
5298** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5299** that is to be automatically loaded into all new database connections.
5301** ^(Even though the function prototype shows that xEntryPoint() takes
5302** no arguments and returns void, SQLite invokes xEntryPoint() with three
5303** arguments and expects and integer result as if the signature of the
5304** entry point where as follows:
5306** <blockquote><pre>
5307** &nbsp;  int xEntryPoint(
5308** &nbsp;    sqlite3 *db,
5309** &nbsp;    const char **pzErrMsg,
5310** &nbsp;    const struct sqlite3_api_routines *pThunk
5311** &nbsp;  );
5312** </pre></blockquote>)^
5314** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5315** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5316** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
5317** is NULL before calling the xEntryPoint().  ^SQLite will invoke
5318** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
5319** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5320** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5322** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5323** on the list of automatic extensions is a harmless no-op. ^No entry point
5324** will be called more than once for each database connection that is opened.
5326** See also: [sqlite3_reset_auto_extension()]
5327** and [sqlite3_cancel_auto_extension()]
5329SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
5332** CAPI3REF: Cancel Automatic Extension Loading
5334** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
5335** initialization routine X that was registered using a prior call to
5336** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
5337** routine returns 1 if initialization routine X was successfully
5338** unregistered and it returns 0 if X was not on the list of initialization
5339** routines.
5341SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
5344** CAPI3REF: Reset Automatic Extension Loading
5346** ^This interface disables all automatic extensions previously
5347** registered using [sqlite3_auto_extension()].
5349SQLITE_API void sqlite3_reset_auto_extension(void);
5352** The interface to the virtual-table mechanism is currently considered
5353** to be experimental.  The interface might change in incompatible ways.
5354** If this is a problem for you, do not use the interface at this time.
5356** When the virtual-table mechanism stabilizes, we will declare the
5357** interface fixed, support it indefinitely, and remove this comment.
5361** Structures used by the virtual table interface
5363typedef struct sqlite3_vtab sqlite3_vtab;
5364typedef struct sqlite3_index_info sqlite3_index_info;
5365typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5366typedef struct sqlite3_module sqlite3_module;
5369** CAPI3REF: Virtual Table Object
5370** KEYWORDS: sqlite3_module {virtual table module}
5372** This structure, sometimes called a "virtual table module",
5373** defines the implementation of a [virtual tables].
5374** This structure consists mostly of methods for the module.
5376** ^A virtual table module is created by filling in a persistent
5377** instance of this structure and passing a pointer to that instance
5378** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5379** ^The registration remains valid until it is replaced by a different
5380** module or until the [database connection] closes.  The content
5381** of this structure must not change while it is registered with
5382** any database connection.
5384struct sqlite3_module {
5385  int iVersion;
5386  int (*xCreate)(sqlite3*, void *pAux,
5387               int argc, const char *const*argv,
5388               sqlite3_vtab **ppVTab, char**);
5389  int (*xConnect)(sqlite3*, void *pAux,
5390               int argc, const char *const*argv,
5391               sqlite3_vtab **ppVTab, char**);
5392  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5393  int (*xDisconnect)(sqlite3_vtab *pVTab);
5394  int (*xDestroy)(sqlite3_vtab *pVTab);
5395  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5396  int (*xClose)(sqlite3_vtab_cursor*);
5397  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5398                int argc, sqlite3_value **argv);
5399  int (*xNext)(sqlite3_vtab_cursor*);
5400  int (*xEof)(sqlite3_vtab_cursor*);
5401  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5402  int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5403  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5404  int (*xBegin)(sqlite3_vtab *pVTab);
5405  int (*xSync)(sqlite3_vtab *pVTab);
5406  int (*xCommit)(sqlite3_vtab *pVTab);
5407  int (*xRollback)(sqlite3_vtab *pVTab);
5408  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5409                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5410                       void **ppArg);
5411  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5412  /* The methods above are in version 1 of the sqlite_module object. Those
5413  ** below are for version 2 and greater. */
5414  int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5415  int (*xRelease)(sqlite3_vtab *pVTab, int);
5416  int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5420** CAPI3REF: Virtual Table Indexing Information
5421** KEYWORDS: sqlite3_index_info
5423** The sqlite3_index_info structure and its substructures is used as part
5424** of the [virtual table] interface to
5425** pass information into and receive the reply from the [xBestIndex]
5426** method of a [virtual table module].  The fields under **Inputs** are the
5427** inputs to xBestIndex and are read-only.  xBestIndex inserts its
5428** results into the **Outputs** fields.
5430** ^(The aConstraint[] array records WHERE clause constraints of the form:
5432** <blockquote>column OP expr</blockquote>
5434** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
5435** stored in aConstraint[].op using one of the
5437** ^(The index of the column is stored in
5438** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
5439** expr on the right-hand side can be evaluated (and thus the constraint
5440** is usable) and false if it cannot.)^
5442** ^The optimizer automatically inverts terms of the form "expr OP column"
5443** and makes other simplifications to the WHERE clause in an attempt to
5444** get as many WHERE clause terms into the form shown above as possible.
5445** ^The aConstraint[] array only reports WHERE clause terms that are
5446** relevant to the particular virtual table being queried.
5448** ^Information about the ORDER BY clause is stored in aOrderBy[].
5449** ^Each term of aOrderBy records a column of the ORDER BY clause.
5451** The [xBestIndex] method must fill aConstraintUsage[] with information
5452** about what parameters to pass to xFilter.  ^If argvIndex>0 then
5453** the right-hand side of the corresponding aConstraint[] is evaluated
5454** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
5455** is true, then the constraint is assumed to be fully handled by the
5456** virtual table and is not checked again by SQLite.)^
5458** ^The idxNum and idxPtr values are recorded and passed into the
5459** [xFilter] method.
5460** ^[sqlite3_free()] is used to free idxPtr if and only if
5461** needToFreeIdxPtr is true.
5463** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5464** the correct order to satisfy the ORDER BY clause so that no separate
5465** sorting step is required.
5467** ^The estimatedCost value is an estimate of the cost of a particular
5468** strategy. A cost of N indicates that the cost of the strategy is similar
5469** to a linear scan of an SQLite table with N rows. A cost of log(N)
5470** indicates that the expense of the operation is similar to that of a
5471** binary search on a unique indexed field of an SQLite table with N rows.
5473** ^The estimatedRows value is an estimate of the number of rows that
5474** will be returned by the strategy.
5476** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
5477** structure for SQLite version 3.8.2. If a virtual table extension is
5478** used with an SQLite version earlier than 3.8.2, the results of attempting
5479** to read or write the estimatedRows field are undefined (but are likely
5480** to included crashing the application). The estimatedRows field should
5481** therefore only be used if [sqlite3_libversion_number()] returns a
5482** value greater than or equal to 3008002.
5484struct sqlite3_index_info {
5485  /* Inputs */
5486  int nConstraint;           /* Number of entries in aConstraint */
5487  struct sqlite3_index_constraint {
5488     int iColumn;              /* Column on left-hand side of constraint */
5489     unsigned char op;         /* Constraint operator */
5490     unsigned char usable;     /* True if this constraint is usable */
5491     int iTermOffset;          /* Used internally - xBestIndex should ignore */
5492  } *aConstraint;            /* Table of WHERE clause constraints */
5493  int nOrderBy;              /* Number of terms in the ORDER BY clause */
5494  struct sqlite3_index_orderby {
5495     int iColumn;              /* Column number */
5496     unsigned char desc;       /* True for DESC.  False for ASC. */
5497  } *aOrderBy;               /* The ORDER BY clause */
5498  /* Outputs */
5499  struct sqlite3_index_constraint_usage {
5500    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
5501    unsigned char omit;      /* Do not code a test for this constraint */
5502  } *aConstraintUsage;
5503  int idxNum;                /* Number used to identify the index */
5504  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
5505  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
5506  int orderByConsumed;       /* True if output is already ordered */
5507  double estimatedCost;           /* Estimated cost of using this index */
5508  /* Fields below are only available in SQLite 3.8.2 and later */
5509  sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
5513** CAPI3REF: Virtual Table Constraint Operator Codes
5515** These macros defined the allowed values for the
5516** [sqlite3_index_info].aConstraint[].op field.  Each value represents
5517** an operator that is part of a constraint term in the wHERE clause of
5518** a query that uses a [virtual table].
5528** CAPI3REF: Register A Virtual Table Implementation
5530** ^These routines are used to register a new [virtual table module] name.
5531** ^Module names must be registered before
5532** creating a new [virtual table] using the module and before using a
5533** preexisting [virtual table] for the module.
5535** ^The module name is registered on the [database connection] specified
5536** by the first parameter.  ^The name of the module is given by the
5537** second parameter.  ^The third parameter is a pointer to
5538** the implementation of the [virtual table module].   ^The fourth
5539** parameter is an arbitrary client data pointer that is passed through
5540** into the [xCreate] and [xConnect] methods of the virtual table module
5541** when a new virtual table is be being created or reinitialized.
5543** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5544** is a pointer to a destructor for the pClientData.  ^SQLite will
5545** invoke the destructor function (if it is not NULL) when SQLite
5546** no longer needs the pClientData pointer.  ^The destructor will also
5547** be invoked if the call to sqlite3_create_module_v2() fails.
5548** ^The sqlite3_create_module()
5549** interface is equivalent to sqlite3_create_module_v2() with a NULL
5550** destructor.
5552SQLITE_API int sqlite3_create_module(
5553  sqlite3 *db,               /* SQLite connection to register module with */
5554  const char *zName,         /* Name of the module */
5555  const sqlite3_module *p,   /* Methods for the module */
5556  void *pClientData          /* Client data for xCreate/xConnect */
5558SQLITE_API int sqlite3_create_module_v2(
5559  sqlite3 *db,               /* SQLite connection to register module with */
5560  const char *zName,         /* Name of the module */
5561  const sqlite3_module *p,   /* Methods for the module */
5562  void *pClientData,         /* Client data for xCreate/xConnect */
5563  void(*xDestroy)(void*)     /* Module destructor function */
5567** CAPI3REF: Virtual Table Instance Object
5568** KEYWORDS: sqlite3_vtab
5570** Every [virtual table module] implementation uses a subclass
5571** of this object to describe a particular instance
5572** of the [virtual table].  Each subclass will
5573** be tailored to the specific needs of the module implementation.
5574** The purpose of this superclass is to define certain fields that are
5575** common to all module implementations.
5577** ^Virtual tables methods can set an error message by assigning a
5578** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
5579** take care that any prior string is freed by a call to [sqlite3_free()]
5580** prior to assigning a new string to zErrMsg.  ^After the error message
5581** is delivered up to the client application, the string will be automatically
5582** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5584struct sqlite3_vtab {
5585  const sqlite3_module *pModule;  /* The module for this virtual table */
5586  int nRef;                       /* NO LONGER USED */
5587  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
5588  /* Virtual table implementations will typically add additional fields */
5592** CAPI3REF: Virtual Table Cursor Object
5593** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5595** Every [virtual table module] implementation uses a subclass of the
5596** following structure to describe cursors that point into the
5597** [virtual table] and are used
5598** to loop through the virtual table.  Cursors are created using the
5599** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5600** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
5601** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5602** of the module.  Each module implementation will define
5603** the content of a cursor structure to suit its own needs.
5605** This superclass exists in order to define fields of the cursor that
5606** are common to all implementations.
5608struct sqlite3_vtab_cursor {
5609  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
5610  /* Virtual table implementations will typically add additional fields */
5614** CAPI3REF: Declare The Schema Of A Virtual Table
5616** ^The [xCreate] and [xConnect] methods of a
5617** [virtual table module] call this interface
5618** to declare the format (the names and datatypes of the columns) of
5619** the virtual tables they implement.
5621SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5624** CAPI3REF: Overload A Function For A Virtual Table
5626** ^(Virtual tables can provide alternative implementations of functions
5627** using the [xFindFunction] method of the [virtual table module].
5628** But global versions of those functions
5629** must exist in order to be overloaded.)^
5631** ^(This API makes sure a global version of a function with a particular
5632** name and number of parameters exists.  If no such function exists
5633** before this API is called, a new function is created.)^  ^The implementation
5634** of the new function always causes an exception to be thrown.  So
5635** the new function is not good for anything by itself.  Its only
5636** purpose is to be a placeholder function that can be overloaded
5637** by a [virtual table].
5639SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5642** The interface to the virtual-table mechanism defined above (back up
5643** to a comment remarkably similar to this one) is currently considered
5644** to be experimental.  The interface might change in incompatible ways.
5645** If this is a problem for you, do not use the interface at this time.
5647** When the virtual-table mechanism stabilizes, we will declare the
5648** interface fixed, support it indefinitely, and remove this comment.
5652** CAPI3REF: A Handle To An Open BLOB
5653** KEYWORDS: {BLOB handle} {BLOB handles}
5655** An instance of this object represents an open BLOB on which
5656** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5657** ^Objects of this type are created by [sqlite3_blob_open()]
5658** and destroyed by [sqlite3_blob_close()].
5659** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5660** can be used to read or write small subsections of the BLOB.
5661** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5663typedef struct sqlite3_blob sqlite3_blob;
5666** CAPI3REF: Open A BLOB For Incremental I/O
5668** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5669** in row iRow, column zColumn, table zTable in database zDb;
5670** in other words, the same BLOB that would be selected by:
5672** <pre>
5673**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5674** </pre>)^
5676** ^If the flags parameter is non-zero, then the BLOB is opened for read
5677** and write access. ^If it is zero, the BLOB is opened for read access.
5678** ^It is not possible to open a column that is part of an index or primary
5679** key for writing. ^If [foreign key constraints] are enabled, it is
5680** not possible to open a column that is part of a [child key] for writing.
5682** ^Note that the database name is not the filename that contains
5683** the database but rather the symbolic name of the database that
5684** appears after the AS keyword when the database is connected using [ATTACH].
5685** ^For the main database file, the database name is "main".
5686** ^For TEMP tables, the database name is "temp".
5688** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5689** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5690** to be a null pointer.)^
5691** ^This function sets the [database connection] error code and message
5692** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5693** functions. ^Note that the *ppBlob variable is always initialized in a
5694** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5695** regardless of the success or failure of this routine.
5697** ^(If the row that a BLOB handle points to is modified by an
5698** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5699** then the BLOB handle is marked as "expired".
5700** This is true if any column of the row is changed, even a column
5701** other than the one the BLOB handle is open on.)^
5702** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5703** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5704** ^(Changes written into a BLOB prior to the BLOB expiring are not
5705** rolled back by the expiration of the BLOB.  Such changes will eventually
5706** commit if the transaction continues to completion.)^
5708** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5709** the opened blob.  ^The size of a blob may not be changed by this
5710** interface.  Use the [UPDATE] SQL command to change the size of a
5711** blob.
5713** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID]
5714** table.  Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables.
5716** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5717** and the built-in [zeroblob] SQL function can be used, if desired,
5718** to create an empty, zero-filled blob in which to read or write using
5719** this interface.
5721** To avoid a resource leak, every open [BLOB handle] should eventually
5722** be released by a call to [sqlite3_blob_close()].
5724SQLITE_API int sqlite3_blob_open(
5725  sqlite3*,
5726  const char *zDb,
5727  const char *zTable,
5728  const char *zColumn,
5729  sqlite3_int64 iRow,
5730  int flags,
5731  sqlite3_blob **ppBlob
5735** CAPI3REF: Move a BLOB Handle to a New Row
5737** ^This function is used to move an existing blob handle so that it points
5738** to a different row of the same database table. ^The new row is identified
5739** by the rowid value passed as the second argument. Only the row can be
5740** changed. ^The database, table and column on which the blob handle is open
5741** remain the same. Moving an existing blob handle to a new row can be
5742** faster than closing the existing handle and opening a new one.
5744** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
5745** it must exist and there must be either a blob or text value stored in
5746** the nominated column.)^ ^If the new row is not present in the table, or if
5747** it does not contain a blob or text value, or if another error occurs, an
5748** SQLite error code is returned and the blob handle is considered aborted.
5749** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
5750** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
5751** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
5752** always returns zero.
5754** ^This function sets the database handle error code and message.
5756SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
5759** CAPI3REF: Close A BLOB Handle
5761** ^Closes an open [BLOB handle].
5763** ^Closing a BLOB shall cause the current transaction to commit
5764** if there are no other BLOBs, no pending prepared statements, and the
5765** database connection is in [autocommit mode].
5766** ^If any writes were made to the BLOB, they might be held in cache
5767** until the close operation if they will fit.
5769** ^(Closing the BLOB often forces the changes
5770** out to disk and so if any I/O errors occur, they will likely occur
5771** at the time when the BLOB is closed.  Any errors that occur during
5772** closing are reported as a non-zero return value.)^
5774** ^(The BLOB is closed unconditionally.  Even if this routine returns
5775** an error code, the BLOB is still closed.)^
5777** ^Calling this routine with a null pointer (such as would be returned
5778** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5780SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
5783** CAPI3REF: Return The Size Of An Open BLOB
5785** ^Returns the size in bytes of the BLOB accessible via the
5786** successfully opened [BLOB handle] in its only argument.  ^The
5787** incremental blob I/O routines can only read or overwriting existing
5788** blob content; they cannot change the size of a blob.
5790** This routine only works on a [BLOB handle] which has been created
5791** by a prior successful call to [sqlite3_blob_open()] and which has not
5792** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5793** to this routine results in undefined and probably undesirable behavior.
5795SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
5798** CAPI3REF: Read Data From A BLOB Incrementally
5800** ^(This function is used to read data from an open [BLOB handle] into a
5801** caller-supplied buffer. N bytes of data are copied into buffer Z
5802** from the open BLOB, starting at offset iOffset.)^
5804** ^If offset iOffset is less than N bytes from the end of the BLOB,
5805** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
5806** less than zero, [SQLITE_ERROR] is returned and no data is read.
5807** ^The size of the blob (and hence the maximum value of N+iOffset)
5808** can be determined using the [sqlite3_blob_bytes()] interface.
5810** ^An attempt to read from an expired [BLOB handle] fails with an
5811** error code of [SQLITE_ABORT].
5813** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5814** Otherwise, an [error code] or an [extended error code] is returned.)^
5816** This routine only works on a [BLOB handle] which has been created
5817** by a prior successful call to [sqlite3_blob_open()] and which has not
5818** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5819** to this routine results in undefined and probably undesirable behavior.
5821** See also: [sqlite3_blob_write()].
5823SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5826** CAPI3REF: Write Data Into A BLOB Incrementally
5828** ^This function is used to write data into an open [BLOB handle] from a
5829** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5830** into the open BLOB, starting at offset iOffset.
5832** ^If the [BLOB handle] passed as the first argument was not opened for
5833** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5834** this function returns [SQLITE_READONLY].
5836** ^This function may only modify the contents of the BLOB; it is
5837** not possible to increase the size of a BLOB using this API.
5838** ^If offset iOffset is less than N bytes from the end of the BLOB,
5839** [SQLITE_ERROR] is returned and no data is written.  ^If N is
5840** less than zero [SQLITE_ERROR] is returned and no data is written.
5841** The size of the BLOB (and hence the maximum value of N+iOffset)
5842** can be determined using the [sqlite3_blob_bytes()] interface.
5844** ^An attempt to write to an expired [BLOB handle] fails with an
5845** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
5846** before the [BLOB handle] expired are not rolled back by the
5847** expiration of the handle, though of course those changes might
5848** have been overwritten by the statement that expired the BLOB handle
5849** or by other independent statements.
5851** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5852** Otherwise, an  [error code] or an [extended error code] is returned.)^
5854** This routine only works on a [BLOB handle] which has been created
5855** by a prior successful call to [sqlite3_blob_open()] and which has not
5856** been closed by [sqlite3_blob_close()].  Passing any other pointer in
5857** to this routine results in undefined and probably undesirable behavior.
5859** See also: [sqlite3_blob_read()].
5861SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5864** CAPI3REF: Virtual File System Objects
5866** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5867** that SQLite uses to interact
5868** with the underlying operating system.  Most SQLite builds come with a
5869** single default VFS that is appropriate for the host computer.
5870** New VFSes can be registered and existing VFSes can be unregistered.
5871** The following interfaces are provided.
5873** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5874** ^Names are case sensitive.
5875** ^Names are zero-terminated UTF-8 strings.
5876** ^If there is no match, a NULL pointer is returned.
5877** ^If zVfsName is NULL then the default VFS is returned.
5879** ^New VFSes are registered with sqlite3_vfs_register().
5880** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5881** ^The same VFS can be registered multiple times without injury.
5882** ^To make an existing VFS into the default VFS, register it again
5883** with the makeDflt flag set.  If two different VFSes with the
5884** same name are registered, the behavior is undefined.  If a
5885** VFS is registered with a name that is NULL or an empty string,
5886** then the behavior is undefined.
5888** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5889** ^(If the default VFS is unregistered, another VFS is chosen as
5890** the default.  The choice for the new VFS is arbitrary.)^
5892SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5893SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5894SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
5897** CAPI3REF: Mutexes
5899** The SQLite core uses these routines for thread
5900** synchronization. Though they are intended for internal
5901** use by SQLite, code that links against SQLite is
5902** permitted to use any of these routines.
5904** The SQLite source code contains multiple implementations
5905** of these mutex routines.  An appropriate implementation
5906** is selected automatically at compile-time.  ^(The following
5907** implementations are available in the SQLite core:
5909** <ul>
5911** <li>   SQLITE_MUTEX_W32
5912** <li>   SQLITE_MUTEX_NOOP
5913** </ul>)^
5915** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5916** that does no real locking and is appropriate for use in
5917** a single-threaded application.  ^The SQLITE_MUTEX_PTHREADS and
5918** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
5919** and Windows.
5921** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5922** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5923** implementation is included with the library. In this case the
5924** application must supply a custom mutex implementation using the
5925** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5926** before calling sqlite3_initialize() or any other public sqlite3_
5927** function that calls sqlite3_initialize().)^
5929** ^The sqlite3_mutex_alloc() routine allocates a new
5930** mutex and returns a pointer to it. ^If it returns NULL
5931** that means that a mutex could not be allocated.  ^SQLite
5932** will unwind its stack and return an error.  ^(The argument
5933** to sqlite3_mutex_alloc() is one of these integer constants:
5935** <ul>
5936** <li>  SQLITE_MUTEX_FAST
5944** </ul>)^
5946** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5947** cause sqlite3_mutex_alloc() to create
5948** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5949** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5950** The mutex implementation does not need to make a distinction
5951** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5952** not want to.  ^SQLite will only request a recursive mutex in
5953** cases where it really needs one.  ^If a faster non-recursive mutex
5954** implementation is available on the host platform, the mutex subsystem
5955** might return such a mutex in response to SQLITE_MUTEX_FAST.
5957** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5959** a pointer to a static preexisting mutex.  ^Six static mutexes are
5960** used by the current version of SQLite.  Future versions of SQLite
5961** may add additional static mutexes.  Static mutexes are for internal
5962** use by SQLite only.  Applications that use SQLite mutexes should
5963** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5966** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5967** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5968** returns a different mutex on every call.  ^But for the static
5969** mutex types, the same mutex is returned on every call that has
5970** the same type number.
5972** ^The sqlite3_mutex_free() routine deallocates a previously
5973** allocated dynamic mutex.  ^SQLite is careful to deallocate every
5974** dynamic mutex that it allocates.  The dynamic mutexes must not be in
5975** use when they are deallocated.  Attempting to deallocate a static
5976** mutex results in undefined behavior.  ^SQLite never deallocates
5977** a static mutex.
5979** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5980** to enter a mutex.  ^If another thread is already within the mutex,
5981** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5982** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5983** upon successful entry.  ^(Mutexes created using
5984** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5985** In such cases the,
5986** mutex must be exited an equal number of times before another thread
5987** can enter.)^  ^(If the same thread tries to enter any other
5988** kind of mutex more than once, the behavior is undefined.
5989** SQLite will never exhibit
5990** such behavior in its own use of mutexes.)^
5992** ^(Some systems (for example, Windows 95) do not support the operation
5993** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
5994** will always return SQLITE_BUSY.  The SQLite core only ever uses
5995** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5997** ^The sqlite3_mutex_leave() routine exits a mutex that was
5998** previously entered by the same thread.   ^(The behavior
5999** is undefined if the mutex is not currently entered by the
6000** calling thread or is not currently allocated.  SQLite will
6001** never do either.)^
6003** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6004** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6005** behave as no-ops.
6007** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
6009SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
6010SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
6011SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
6012SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
6013SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
6016** CAPI3REF: Mutex Methods Object
6018** An instance of this structure defines the low-level routines
6019** used to allocate and use mutexes.
6021** Usually, the default mutex implementations provided by SQLite are
6022** sufficient, however the user has the option of substituting a custom
6023** implementation for specialized deployments or systems for which SQLite
6024** does not provide a suitable implementation. In this case, the user
6025** creates and populates an instance of this structure to pass
6026** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
6027** Additionally, an instance of this structure can be used as an
6028** output variable when querying the system for the current mutex
6029** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
6031** ^The xMutexInit method defined by this structure is invoked as
6032** part of system initialization by the sqlite3_initialize() function.
6033** ^The xMutexInit routine is called by SQLite exactly once for each
6034** effective call to [sqlite3_initialize()].
6036** ^The xMutexEnd method defined by this structure is invoked as
6037** part of system shutdown by the sqlite3_shutdown() function. The
6038** implementation of this method is expected to release all outstanding
6039** resources obtained by the mutex methods implementation, especially
6040** those obtained by the xMutexInit method.  ^The xMutexEnd()
6041** interface is invoked exactly once for each call to [sqlite3_shutdown()].
6043** ^(The remaining seven methods defined by this structure (xMutexAlloc,
6044** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6045** xMutexNotheld) implement the following interfaces (respectively):
6047** <ul>
6048**   <li>  [sqlite3_mutex_alloc()] </li>
6049**   <li>  [sqlite3_mutex_free()] </li>
6050**   <li>  [sqlite3_mutex_enter()] </li>
6051**   <li>  [sqlite3_mutex_try()] </li>
6052**   <li>  [sqlite3_mutex_leave()] </li>
6053**   <li>  [sqlite3_mutex_held()] </li>
6054**   <li>  [sqlite3_mutex_notheld()] </li>
6055** </ul>)^
6057** The only difference is that the public sqlite3_XXX functions enumerated
6058** above silently ignore any invocations that pass a NULL pointer instead
6059** of a valid mutex handle. The implementations of the methods defined
6060** by this structure are not required to handle this case, the results
6061** of passing a NULL pointer instead of a valid mutex handle are undefined
6062** (i.e. it is acceptable to provide an implementation that segfaults if
6063** it is passed a NULL pointer).
6065** The xMutexInit() method must be threadsafe.  ^It must be harmless to
6066** invoke xMutexInit() multiple times within the same process and without
6067** intervening calls to xMutexEnd().  Second and subsequent calls to
6068** xMutexInit() must be no-ops.
6070** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
6071** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
6072** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
6073** memory allocation for a fast or recursive mutex.
6075** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
6076** called, but only if the prior call to xMutexInit returned SQLITE_OK.
6077** If xMutexInit fails in any way, it is expected to clean up after itself
6078** prior to returning.
6080typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6081struct sqlite3_mutex_methods {
6082  int (*xMutexInit)(void);
6083  int (*xMutexEnd)(void);
6084  sqlite3_mutex *(*xMutexAlloc)(int);
6085  void (*xMutexFree)(sqlite3_mutex *);
6086  void (*xMutexEnter)(sqlite3_mutex *);
6087  int (*xMutexTry)(sqlite3_mutex *);
6088  void (*xMutexLeave)(sqlite3_mutex *);
6089  int (*xMutexHeld)(sqlite3_mutex *);
6090  int (*xMutexNotheld)(sqlite3_mutex *);
6094** CAPI3REF: Mutex Verification Routines
6096** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6097** are intended for use inside assert() statements.  ^The SQLite core
6098** never uses these routines except inside an assert() and applications
6099** are advised to follow the lead of the core.  ^The SQLite core only
6100** provides implementations for these routines when it is compiled
6101** with the SQLITE_DEBUG flag.  ^External mutex implementations
6102** are only required to provide these routines if SQLITE_DEBUG is
6103** defined and if NDEBUG is not defined.
6105** ^These routines should return true if the mutex in their argument
6106** is held or not held, respectively, by the calling thread.
6108** ^The implementation is not required to provide versions of these
6109** routines that actually work. If the implementation does not provide working
6110** versions of these routines, it should at least provide stubs that always
6111** return true so that one does not get spurious assertion failures.
6113** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
6114** the routine should return 1.   This seems counter-intuitive since
6115** clearly the mutex cannot be held if it does not exist.  But
6116** the reason the mutex does not exist is because the build is not
6117** using mutexes.  And we do not want the assert() containing the
6118** call to sqlite3_mutex_held() to fail, so a non-zero return is
6119** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
6120** interface should also return 1 when given a NULL pointer.
6122#ifndef NDEBUG
6123SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
6124SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
6128** CAPI3REF: Mutex Types
6130** The [sqlite3_mutex_alloc()] interface takes a single argument
6131** which is one of these integer constants.
6133** The set of static mutexes may change from one SQLite release to the
6134** next.  Applications that override the built-in mutex logic must be
6135** prepared to accommodate additional static mutexes.
6137#define SQLITE_MUTEX_FAST             0
6138#define SQLITE_MUTEX_RECURSIVE        1
6140#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
6141#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
6142#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
6143#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
6144#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
6145#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
6146#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
6149** CAPI3REF: Retrieve the mutex for a database connection
6151** ^This interface returns a pointer the [sqlite3_mutex] object that
6152** serializes access to the [database connection] given in the argument
6153** when the [threading mode] is Serialized.
6154** ^If the [threading mode] is Single-thread or Multi-thread then this
6155** routine returns a NULL pointer.
6157SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
6160** CAPI3REF: Low-Level Control Of Database Files
6162** ^The [sqlite3_file_control()] interface makes a direct call to the
6163** xFileControl method for the [sqlite3_io_methods] object associated
6164** with a particular database identified by the second argument. ^The
6165** name of the database is "main" for the main database or "temp" for the
6166** TEMP database, or the name that appears after the AS keyword for
6167** databases that are added using the [ATTACH] SQL command.
6168** ^A NULL pointer can be used in place of "main" to refer to the
6169** main database file.
6170** ^The third and fourth parameters to this routine
6171** are passed directly through to the second and third parameters of
6172** the xFileControl method.  ^The return value of the xFileControl
6173** method becomes the return value of this routine.
6175** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6176** a pointer to the underlying [sqlite3_file] object to be written into
6177** the space pointed to by the 4th parameter.  ^The SQLITE_FCNTL_FILE_POINTER
6178** case is a short-circuit path which does not actually invoke the
6179** underlying sqlite3_io_methods.xFileControl method.
6181** ^If the second parameter (zDbName) does not match the name of any
6182** open database file, then SQLITE_ERROR is returned.  ^This error
6183** code is not remembered and will not be recalled by [sqlite3_errcode()]
6184** or [sqlite3_errmsg()].  The underlying xFileControl method might
6185** also return SQLITE_ERROR.  There is no way to distinguish between
6186** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6187** xFileControl method.
6191SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6194** CAPI3REF: Testing Interface
6196** ^The sqlite3_test_control() interface is used to read out internal
6197** state of SQLite and to inject faults into SQLite for testing
6198** purposes.  ^The first parameter is an operation code that determines
6199** the number, meaning, and operation of all subsequent parameters.
6201** This interface is not for use by applications.  It exists solely
6202** for verifying the correct operation of the SQLite library.  Depending
6203** on how the SQLite library is compiled, this interface might not exist.
6205** The details of the operation codes, their meanings, the parameters
6206** they take, and what they do are all subject to change without notice.
6207** Unlike most of the SQLite API, this function is not guaranteed to
6208** operate consistently from one release to the next.
6210SQLITE_API int sqlite3_test_control(int op, ...);
6213** CAPI3REF: Testing Interface Operation Codes
6215** These constants are the valid operation code parameters used
6216** as the first argument to [sqlite3_test_control()].
6218** These parameters and their meanings are subject to change
6219** without notice.  These values are for testing purposes only.
6220** Applications should not use any of these parameters or the
6221** [sqlite3_test_control()] interface.
6223#define SQLITE_TESTCTRL_FIRST                    5
6224#define SQLITE_TESTCTRL_PRNG_SAVE                5
6225#define SQLITE_TESTCTRL_PRNG_RESTORE             6
6226#define SQLITE_TESTCTRL_PRNG_RESET               7
6227#define SQLITE_TESTCTRL_BITVEC_TEST              8
6228#define SQLITE_TESTCTRL_FAULT_INSTALL            9
6230#define SQLITE_TESTCTRL_PENDING_BYTE            11
6231#define SQLITE_TESTCTRL_ASSERT                  12
6232#define SQLITE_TESTCTRL_ALWAYS                  13
6233#define SQLITE_TESTCTRL_RESERVE                 14
6234#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
6235#define SQLITE_TESTCTRL_ISKEYWORD               16
6236#define SQLITE_TESTCTRL_SCRATCHMALLOC           17
6238#define SQLITE_TESTCTRL_EXPLAIN_STMT            19
6239#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
6240#define SQLITE_TESTCTRL_VDBE_COVERAGE           21
6241#define SQLITE_TESTCTRL_LAST                    21
6244** CAPI3REF: SQLite Runtime Status
6246** ^This interface is used to retrieve runtime status information
6247** about the performance of SQLite, and optionally to reset various
6248** highwater marks.  ^The first argument is an integer code for
6249** the specific parameter to measure.  ^(Recognized integer codes
6250** are of the form [status parameters | SQLITE_STATUS_...].)^
6251** ^The current value of the parameter is returned into *pCurrent.
6252** ^The highest recorded value is returned in *pHighwater.  ^If the
6253** resetFlag is true, then the highest record value is reset after
6254** *pHighwater is written.  ^(Some parameters do not record the highest
6255** value.  For those parameters
6256** nothing is written into *pHighwater and the resetFlag is ignored.)^
6257** ^(Other parameters record only the highwater mark and not the current
6258** value.  For these latter parameters nothing is written into *pCurrent.)^
6260** ^The sqlite3_status() routine returns SQLITE_OK on success and a
6261** non-zero [error code] on failure.
6263** This routine is threadsafe but is not atomic.  This routine can be
6264** called while other threads are running the same or different SQLite
6265** interfaces.  However the values returned in *pCurrent and
6266** *pHighwater reflect the status of SQLite at different points in time
6267** and it is possible that another thread might change the parameter
6268** in between the times when *pCurrent and *pHighwater are written.
6270** See also: [sqlite3_db_status()]
6272SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6276** CAPI3REF: Status Parameters
6277** KEYWORDS: {status parameters}
6279** These integer constants designate various run-time status parameters
6280** that can be returned by [sqlite3_status()].
6282** <dl>
6284** <dd>This parameter is the current amount of memory checked out
6285** using [sqlite3_malloc()], either directly or indirectly.  The
6286** figure includes calls made to [sqlite3_malloc()] by the application
6287** and internal memory usage by the SQLite library.  Scratch memory
6288** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6289** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6290** this parameter.  The amount returned is the sum of the allocation
6291** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6294** <dd>This parameter records the largest memory allocation request
6295** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6296** internal equivalents).  Only the value returned in the
6297** *pHighwater parameter to [sqlite3_status()] is of interest.
6298** The value written into the *pCurrent parameter is undefined.</dd>)^
6301** <dd>This parameter records the number of separate memory allocations
6302** currently checked out.</dd>)^
6305** <dd>This parameter returns the number of pages used out of the
6306** [pagecache memory allocator] that was configured using
6308** value returned is in pages, not in bytes.</dd>)^
6312** <dd>This parameter returns the number of bytes of page cache
6313** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6314** buffer and where forced to overflow to [sqlite3_malloc()].  The
6315** returned value includes allocations that overflowed because they
6316** where too large (they were larger than the "sz" parameter to
6317** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6318** no space was left in the page cache.</dd>)^
6321** <dd>This parameter records the largest memory allocation request
6322** handed to [pagecache memory allocator].  Only the value returned in the
6323** *pHighwater parameter to [sqlite3_status()] is of interest.
6324** The value written into the *pCurrent parameter is undefined.</dd>)^
6327** <dd>This parameter returns the number of allocations used out of the
6328** [scratch memory allocator] configured using
6329** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
6330** in bytes.  Since a single thread may only have one scratch allocation
6331** outstanding at time, this parameter also reports the number of threads
6332** using scratch memory at the same time.</dd>)^
6335** <dd>This parameter returns the number of bytes of scratch memory
6336** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6337** buffer and where forced to overflow to [sqlite3_malloc()].  The values
6338** returned include overflows because the requested allocation was too
6339** larger (that is, because the requested allocation was larger than the
6340** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6341** slots were available.
6342** </dd>)^
6345** <dd>This parameter records the largest memory allocation request
6346** handed to [scratch memory allocator].  Only the value returned in the
6347** *pHighwater parameter to [sqlite3_status()] is of interest.
6348** The value written into the *pCurrent parameter is undefined.</dd>)^
6351** <dd>This parameter records the deepest parser stack.  It is only
6352** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6353** </dl>
6355** New status parameters may be added from time to time.
6357#define SQLITE_STATUS_MEMORY_USED          0
6360#define SQLITE_STATUS_SCRATCH_USED         3
6362#define SQLITE_STATUS_MALLOC_SIZE          5
6363#define SQLITE_STATUS_PARSER_STACK         6
6365#define SQLITE_STATUS_SCRATCH_SIZE         8
6366#define SQLITE_STATUS_MALLOC_COUNT         9
6369** CAPI3REF: Database Connection Status
6371** ^This interface is used to retrieve runtime status information
6372** about a single [database connection].  ^The first argument is the
6373** database connection object to be interrogated.  ^The second argument
6374** is an integer constant, taken from the set of
6375** [SQLITE_DBSTATUS options], that
6376** determines the parameter to interrogate.  The set of
6377** [SQLITE_DBSTATUS options] is likely
6378** to grow in future releases of SQLite.
6380** ^The current value of the requested parameter is written into *pCur
6381** and the highest instantaneous value is written into *pHiwtr.  ^If
6382** the resetFlg is true, then the highest instantaneous value is
6383** reset back down to the current value.
6385** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6386** non-zero [error code] on failure.
6388** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6390SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6393** CAPI3REF: Status Parameters for database connections
6396** These constants are the available integer "verbs" that can be passed as
6397** the second argument to the [sqlite3_db_status()] interface.
6399** New verbs may be added in future releases of SQLite. Existing verbs
6400** might be discontinued. Applications should check the return code from
6401** [sqlite3_db_status()] to make sure that the call worked.
6402** The [sqlite3_db_status()] interface will return a non-zero error code
6403** if a discontinued or unsupported verb is invoked.
6405** <dl>
6407** <dd>This parameter returns the number of lookaside memory slots currently
6408** checked out.</dd>)^
6411** <dd>This parameter returns the number malloc attempts that were
6412** satisfied using lookaside memory. Only the high-water value is meaningful;
6413** the current value is always zero.)^
6417** <dd>This parameter returns the number malloc attempts that might have
6418** been satisfied using lookaside memory but failed due to the amount of
6419** memory requested being larger than the lookaside slot size.
6420** Only the high-water value is meaningful;
6421** the current value is always zero.)^
6425** <dd>This parameter returns the number malloc attempts that might have
6426** been satisfied using lookaside memory but failed due to all lookaside
6427** memory already being in use.
6428** Only the high-water value is meaningful;
6429** the current value is always zero.)^
6432** <dd>This parameter returns the approximate number of of bytes of heap
6433** memory used by all pager caches associated with the database connection.)^
6434** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6437** <dd>This parameter returns the approximate number of of bytes of heap
6438** memory used to store the schema for all databases associated
6439** with the connection - main, temp, and any [ATTACH]-ed databases.)^
6440** ^The full amount of memory used by the schemas is reported, even if the
6441** schema memory is shared with other database connections due to
6442** [shared cache mode] being enabled.
6443** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6446** <dd>This parameter returns the approximate number of of bytes of heap
6447** and lookaside memory used by all prepared statements associated with
6448** the database connection.)^
6449** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
6450** </dd>
6453** <dd>This parameter returns the number of pager cache hits that have
6454** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
6455** is always 0.
6456** </dd>
6459** <dd>This parameter returns the number of pager cache misses that have
6460** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
6461** is always 0.
6462** </dd>
6465** <dd>This parameter returns the number of dirty cache entries that have
6466** been written to disk. Specifically, the number of pages written to the
6467** wal file in wal mode databases, or the number of pages written to the
6468** database file in rollback mode databases. Any pages written as part of
6469** transaction rollback or database recovery operations are not included.
6470** If an IO or other error occurs while writing a page to disk, the effect
6471** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
6472** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
6473** </dd>
6476** <dd>This parameter returns zero for the current value if and only if
6477** all foreign key constraints (deferred or immediate) have been
6478** resolved.)^  ^The highwater mark is always 0.
6479** </dd>
6480** </dl>
6483#define SQLITE_DBSTATUS_CACHE_USED           1
6484#define SQLITE_DBSTATUS_SCHEMA_USED          2
6485#define SQLITE_DBSTATUS_STMT_USED            3
6489#define SQLITE_DBSTATUS_CACHE_HIT            7
6490#define SQLITE_DBSTATUS_CACHE_MISS           8
6491#define SQLITE_DBSTATUS_CACHE_WRITE          9
6492#define SQLITE_DBSTATUS_DEFERRED_FKS        10
6493#define SQLITE_DBSTATUS_MAX                 10   /* Largest defined DBSTATUS */
6497** CAPI3REF: Prepared Statement Status
6499** ^(Each prepared statement maintains various
6500** [SQLITE_STMTSTATUS counters] that measure the number
6501** of times it has performed specific operations.)^  These counters can
6502** be used to monitor the performance characteristics of the prepared
6503** statements.  For example, if the number of table steps greatly exceeds
6504** the number of table searches or result rows, that would tend to indicate
6505** that the prepared statement is using a full table scan rather than
6506** an index.
6508** ^(This interface is used to retrieve and reset counter values from
6509** a [prepared statement].  The first argument is the prepared statement
6510** object to be interrogated.  The second argument
6511** is an integer code for a specific [SQLITE_STMTSTATUS counter]
6512** to be interrogated.)^
6513** ^The current value of the requested counter is returned.
6514** ^If the resetFlg is true, then the counter is reset to zero after this
6515** interface call returns.
6517** See also: [sqlite3_status()] and [sqlite3_db_status()].
6519SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
6522** CAPI3REF: Status Parameters for prepared statements
6525** These preprocessor macros define integer codes that name counter
6526** values associated with the [sqlite3_stmt_status()] interface.
6527** The meanings of the various counters are as follows:
6529** <dl>
6531** <dd>^This is the number of times that SQLite has stepped forward in
6532** a table as part of a full table scan.  Large numbers for this counter
6533** may indicate opportunities for performance improvement through
6534** careful use of indices.</dd>
6537** <dd>^This is the number of sort operations that have occurred.
6538** A non-zero value in this counter may indicate an opportunity to
6539** improvement performance through careful use of indices.</dd>
6542** <dd>^This is the number of rows inserted into transient indices that
6543** were created automatically in order to help joins run faster.
6544** A non-zero value in this counter may indicate an opportunity to
6545** improvement performance by adding permanent indices that do not
6546** need to be reinitialized each time the statement is run.</dd>
6549** <dd>^This is the number of virtual machine operations executed
6550** by the prepared statement if that number is less than or equal
6551** to 2147483647.  The number of virtual machine operations can be
6552** used as a proxy for the total work done by the prepared statement.
6553** If the number of virtual machine operations exceeds 2147483647
6554** then the value returned by this statement status code is undefined.
6555** </dd>
6556** </dl>
6559#define SQLITE_STMTSTATUS_SORT              2
6561#define SQLITE_STMTSTATUS_VM_STEP           4
6564** CAPI3REF: Custom Page Cache Object
6566** The sqlite3_pcache type is opaque.  It is implemented by
6567** the pluggable module.  The SQLite core has no knowledge of
6568** its size or internal structure and never deals with the
6569** sqlite3_pcache object except by holding and passing pointers
6570** to the object.
6572** See [sqlite3_pcache_methods2] for additional information.
6574typedef struct sqlite3_pcache sqlite3_pcache;
6577** CAPI3REF: Custom Page Cache Object
6579** The sqlite3_pcache_page object represents a single page in the
6580** page cache.  The page cache will allocate instances of this
6581** object.  Various methods of the page cache use pointers to instances
6582** of this object as parameters or as their return value.
6584** See [sqlite3_pcache_methods2] for additional information.
6586typedef struct sqlite3_pcache_page sqlite3_pcache_page;
6587struct sqlite3_pcache_page {
6588  void *pBuf;        /* The content of the page */
6589  void *pExtra;      /* Extra information associated with the page */
6593** CAPI3REF: Application Defined Page Cache.
6594** KEYWORDS: {page cache}
6596** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
6597** register an alternative page cache implementation by passing in an
6598** instance of the sqlite3_pcache_methods2 structure.)^
6599** In many applications, most of the heap memory allocated by
6600** SQLite is used for the page cache.
6601** By implementing a
6602** custom page cache using this API, an application can better control
6603** the amount of memory consumed by SQLite, the way in which
6604** that memory is allocated and released, and the policies used to
6605** determine exactly which parts of a database file are cached and for
6606** how long.
6608** The alternative page cache mechanism is an
6609** extreme measure that is only needed by the most demanding applications.
6610** The built-in page cache is recommended for most uses.
6612** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
6613** internal buffer by SQLite within the call to [sqlite3_config].  Hence
6614** the application may discard the parameter after the call to
6615** [sqlite3_config()] returns.)^
6617** [[the xInit() page cache method]]
6618** ^(The xInit() method is called once for each effective
6619** call to [sqlite3_initialize()])^
6620** (usually only once during the lifetime of the process). ^(The xInit()
6621** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
6622** The intent of the xInit() method is to set up global data structures
6623** required by the custom page cache implementation.
6624** ^(If the xInit() method is NULL, then the
6625** built-in default page cache is used instead of the application defined
6626** page cache.)^
6628** [[the xShutdown() page cache method]]
6629** ^The xShutdown() method is called by [sqlite3_shutdown()].
6630** It can be used to clean up
6631** any outstanding resources before process shutdown, if required.
6632** ^The xShutdown() method may be NULL.
6634** ^SQLite automatically serializes calls to the xInit method,
6635** so the xInit method need not be threadsafe.  ^The
6636** xShutdown method is only called from [sqlite3_shutdown()] so it does
6637** not need to be threadsafe either.  All other methods must be threadsafe
6638** in multithreaded applications.
6640** ^SQLite will never invoke xInit() more than once without an intervening
6641** call to xShutdown().
6643** [[the xCreate() page cache methods]]
6644** ^SQLite invokes the xCreate() method to construct a new cache instance.
6645** SQLite will typically create one cache instance for each open database file,
6646** though this is not guaranteed. ^The
6647** first parameter, szPage, is the size in bytes of the pages that must
6648** be allocated by the cache.  ^szPage will always a power of two.  ^The
6649** second parameter szExtra is a number of bytes of extra storage
6650** associated with each page cache entry.  ^The szExtra parameter will
6651** a number less than 250.  SQLite will use the
6652** extra szExtra bytes on each page to store metadata about the underlying
6653** database page on disk.  The value passed into szExtra depends
6654** on the SQLite version, the target platform, and how SQLite was compiled.
6655** ^The third argument to xCreate(), bPurgeable, is true if the cache being
6656** created will be used to cache database pages of a file stored on disk, or
6657** false if it is used for an in-memory database. The cache implementation
6658** does not have to do anything special based with the value of bPurgeable;
6659** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
6660** never invoke xUnpin() except to deliberately delete a page.
6661** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6662** false will always have the "discard" flag set to true.
6663** ^Hence, a cache created with bPurgeable false will
6664** never contain any unpinned pages.
6666** [[the xCachesize() page cache method]]
6667** ^(The xCachesize() method may be called at any time by SQLite to set the
6668** suggested maximum cache-size (number of pages stored by) the cache
6669** instance passed as the first argument. This is the value configured using
6670** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
6671** parameter, the implementation is not required to do anything with this
6672** value; it is advisory only.
6674** [[the xPagecount() page cache methods]]
6675** The xPagecount() method must return the number of pages currently
6676** stored in the cache, both pinned and unpinned.
6678** [[the xFetch() page cache methods]]
6679** The xFetch() method locates a page in the cache and returns a pointer to
6680** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
6681** The pBuf element of the returned sqlite3_pcache_page object will be a
6682** pointer to a buffer of szPage bytes used to store the content of a
6683** single database page.  The pExtra element of sqlite3_pcache_page will be
6684** a pointer to the szExtra bytes of extra storage that SQLite has requested
6685** for each entry in the page cache.
6687** The page to be fetched is determined by the key. ^The minimum key value
6688** is 1.  After it has been retrieved using xFetch, the page is considered
6689** to be "pinned".
6691** If the requested page is already in the page cache, then the page cache
6692** implementation must return a pointer to the page buffer with its content
6693** intact.  If the requested page is not already in the cache, then the
6694** cache implementation should use the value of the createFlag
6695** parameter to help it determined what action to take:
6697** <table border=1 width=85% align=center>
6698** <tr><th> createFlag <th> Behavior when page is not already in cache
6699** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
6700** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
6701**                 Otherwise return NULL.
6702** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
6703**                 NULL if allocating a new page is effectively impossible.
6704** </table>
6706** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
6707** will only use a createFlag of 2 after a prior call with a createFlag of 1
6708** failed.)^  In between the to xFetch() calls, SQLite may
6709** attempt to unpin one or more cache pages by spilling the content of
6710** pinned pages to disk and synching the operating system disk cache.
6712** [[the xUnpin() page cache method]]
6713** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
6714** as its second argument.  If the third parameter, discard, is non-zero,
6715** then the page must be evicted from the cache.
6716** ^If the discard parameter is
6717** zero, then the page may be discarded or retained at the discretion of
6718** page cache implementation. ^The page cache implementation
6719** may choose to evict unpinned pages at any time.
6721** The cache must not perform any reference counting. A single
6722** call to xUnpin() unpins the page regardless of the number of prior calls
6723** to xFetch().
6725** [[the xRekey() page cache methods]]
6726** The xRekey() method is used to change the key value associated with the
6727** page passed as the second argument. If the cache
6728** previously contains an entry associated with newKey, it must be
6729** discarded. ^Any prior cache entry associated with newKey is guaranteed not
6730** to be pinned.
6732** When SQLite calls the xTruncate() method, the cache must discard all
6733** existing cache entries with page numbers (keys) greater than or equal
6734** to the value of the iLimit parameter passed to xTruncate(). If any
6735** of these pages are pinned, they are implicitly unpinned, meaning that
6736** they can be safely discarded.
6738** [[the xDestroy() page cache method]]
6739** ^The xDestroy() method is used to delete a cache allocated by xCreate().
6740** All resources associated with the specified cache should be freed. ^After
6741** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
6742** handle invalid, and will not use it with any other sqlite3_pcache_methods2
6743** functions.
6745** [[the xShrink() page cache method]]
6746** ^SQLite invokes the xShrink() method when it wants the page cache to
6747** free up as much of heap memory as possible.  The page cache implementation
6748** is not obligated to free any memory, but well-behaved implementations should
6749** do their best.
6751typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
6752struct sqlite3_pcache_methods2 {
6753  int iVersion;
6754  void *pArg;
6755  int (*xInit)(void*);
6756  void (*xShutdown)(void*);
6757  sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
6758  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6759  int (*xPagecount)(sqlite3_pcache*);
6760  sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6761  void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
6762  void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
6763      unsigned oldKey, unsigned newKey);
6764  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6765  void (*xDestroy)(sqlite3_pcache*);
6766  void (*xShrink)(sqlite3_pcache*);
6770** This is the obsolete pcache_methods object that has now been replaced
6771** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
6772** retained in the header file for backwards compatibility only.
6774typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
6775struct sqlite3_pcache_methods {
6776  void *pArg;
6777  int (*xInit)(void*);
6778  void (*xShutdown)(void*);
6779  sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
6780  void (*xCachesize)(sqlite3_pcache*, int nCachesize);
6781  int (*xPagecount)(sqlite3_pcache*);
6782  void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
6783  void (*xUnpin)(sqlite3_pcache*, void*, int discard);
6784  void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
6785  void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
6786  void (*xDestroy)(sqlite3_pcache*);
6791** CAPI3REF: Online Backup Object
6793** The sqlite3_backup object records state information about an ongoing
6794** online backup operation.  ^The sqlite3_backup object is created by
6795** a call to [sqlite3_backup_init()] and is destroyed by a call to
6796** [sqlite3_backup_finish()].
6798** See Also: [Using the SQLite Online Backup API]
6800typedef struct sqlite3_backup sqlite3_backup;
6803** CAPI3REF: Online Backup API.
6805** The backup API copies the content of one database into another.
6806** It is useful either for creating backups of databases or
6807** for copying in-memory databases to or from persistent files.
6809** See Also: [Using the SQLite Online Backup API]
6811** ^SQLite holds a write transaction open on the destination database file
6812** for the duration of the backup operation.
6813** ^The source database is read-locked only while it is being read;
6814** it is not locked continuously for the entire backup operation.
6815** ^Thus, the backup may be performed on a live source database without
6816** preventing other database connections from
6817** reading or writing to the source database while the backup is underway.
6819** ^(To perform a backup operation:
6820**   <ol>
6821**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
6822**         backup,
6823**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
6824**         the data between the two databases, and finally
6825**     <li><b>sqlite3_backup_finish()</b> is called to release all resources
6826**         associated with the backup operation.
6827**   </ol>)^
6828** There should be exactly one call to sqlite3_backup_finish() for each
6829** successful call to sqlite3_backup_init().
6831** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
6833** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
6834** [database connection] associated with the destination database
6835** and the database name, respectively.
6836** ^The database name is "main" for the main database, "temp" for the
6837** temporary database, or the name specified after the AS keyword in
6838** an [ATTACH] statement for an attached database.
6839** ^The S and M arguments passed to
6840** sqlite3_backup_init(D,N,S,M) identify the [database connection]
6841** and database name of the source database, respectively.
6842** ^The source and destination [database connections] (parameters S and D)
6843** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
6844** an error.
6846** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
6847** returned and an error code and error message are stored in the
6848** destination [database connection] D.
6849** ^The error code and message for the failed call to sqlite3_backup_init()
6850** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
6851** [sqlite3_errmsg16()] functions.
6852** ^A successful call to sqlite3_backup_init() returns a pointer to an
6853** [sqlite3_backup] object.
6854** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
6855** sqlite3_backup_finish() functions to perform the specified backup
6856** operation.
6858** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
6860** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
6861** the source and destination databases specified by [sqlite3_backup] object B.
6862** ^If N is negative, all remaining source pages are copied.
6863** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
6864** are still more pages to be copied, then the function returns [SQLITE_OK].
6865** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
6866** from source to destination, then it returns [SQLITE_DONE].
6867** ^If an error occurs while running sqlite3_backup_step(B,N),
6868** then an [error code] is returned. ^As well as [SQLITE_OK] and
6869** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
6871** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
6873** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
6874** <ol>
6875** <li> the destination database was opened read-only, or
6876** <li> the destination database is using write-ahead-log journaling
6877** and the destination and source page sizes differ, or
6878** <li> the destination database is an in-memory database and the
6879** destination and source page sizes differ.
6880** </ol>)^
6882** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
6883** the [sqlite3_busy_handler | busy-handler function]
6884** is invoked (if one is specified). ^If the
6885** busy-handler returns non-zero before the lock is available, then
6886** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
6887** sqlite3_backup_step() can be retried later. ^If the source
6888** [database connection]
6889** is being used to write to the source database when sqlite3_backup_step()
6890** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
6891** case the call to sqlite3_backup_step() can be retried later on. ^(If
6893** [SQLITE_READONLY] is returned, then
6894** there is no point in retrying the call to sqlite3_backup_step(). These
6895** errors are considered fatal.)^  The application must accept
6896** that the backup operation has failed and pass the backup operation handle
6897** to the sqlite3_backup_finish() to release associated resources.
6899** ^The first call to sqlite3_backup_step() obtains an exclusive lock
6900** on the destination file. ^The exclusive lock is not released until either
6901** sqlite3_backup_finish() is called or the backup operation is complete
6902** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
6903** sqlite3_backup_step() obtains a [shared lock] on the source database that
6904** lasts for the duration of the sqlite3_backup_step() call.
6905** ^Because the source database is not locked between calls to
6906** sqlite3_backup_step(), the source database may be modified mid-way
6907** through the backup process.  ^If the source database is modified by an
6908** external process or via a database connection other than the one being
6909** used by the backup operation, then the backup will be automatically
6910** restarted by the next call to sqlite3_backup_step(). ^If the source
6911** database is modified by the using the same database connection as is used
6912** by the backup operation, then the backup database is automatically
6913** updated at the same time.
6915** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
6917** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
6918** application wishes to abandon the backup operation, the application
6919** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
6920** ^The sqlite3_backup_finish() interfaces releases all
6921** resources associated with the [sqlite3_backup] object.
6922** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
6923** active write-transaction on the destination database is rolled back.
6924** The [sqlite3_backup] object is invalid
6925** and may not be used following a call to sqlite3_backup_finish().
6927** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
6928** sqlite3_backup_step() errors occurred, regardless or whether or not
6929** sqlite3_backup_step() completed.
6930** ^If an out-of-memory condition or IO error occurred during any prior
6931** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
6932** sqlite3_backup_finish() returns the corresponding [error code].
6934** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
6935** is not a permanent error and does not affect the return value of
6936** sqlite3_backup_finish().
6938** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
6939** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
6941** ^Each call to sqlite3_backup_step() sets two values inside
6942** the [sqlite3_backup] object: the number of pages still to be backed
6943** up and the total number of pages in the source database file.
6944** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
6945** retrieve these two values, respectively.
6947** ^The values returned by these functions are only updated by
6948** sqlite3_backup_step(). ^If the source database is modified during a backup
6949** operation, then the values are not updated to account for any extra
6950** pages that need to be updated or the size of the source database file
6951** changing.
6953** <b>Concurrent Usage of Database Handles</b>
6955** ^The source [database connection] may be used by the application for other
6956** purposes while a backup operation is underway or being initialized.
6957** ^If SQLite is compiled and configured to support threadsafe database
6958** connections, then the source database connection may be used concurrently
6959** from within other threads.
6961** However, the application must guarantee that the destination
6962** [database connection] is not passed to any other API (by any thread) after
6963** sqlite3_backup_init() is called and before the corresponding call to
6964** sqlite3_backup_finish().  SQLite does not currently check to see
6965** if the application incorrectly accesses the destination [database connection]
6966** and so no error code is reported, but the operations may malfunction
6967** nevertheless.  Use of the destination database connection while a
6968** backup is in progress might also also cause a mutex deadlock.
6970** If running in [shared cache mode], the application must
6971** guarantee that the shared cache used by the destination database
6972** is not accessed while the backup is running. In practice this means
6973** that the application must guarantee that the disk file being
6974** backed up to is not accessed by any connection within the process,
6975** not just the specific connection that was passed to sqlite3_backup_init().
6977** The [sqlite3_backup] object itself is partially threadsafe. Multiple
6978** threads may safely make multiple concurrent calls to sqlite3_backup_step().
6979** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
6980** APIs are not strictly speaking threadsafe. If they are invoked at the
6981** same time as another thread is invoking sqlite3_backup_step() it is
6982** possible that they return invalid values.
6984SQLITE_API sqlite3_backup *sqlite3_backup_init(
6985  sqlite3 *pDest,                        /* Destination database handle */
6986  const char *zDestName,                 /* Destination database name */
6987  sqlite3 *pSource,                      /* Source database handle */
6988  const char *zSourceName                /* Source database name */
6990SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
6991SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
6992SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
6993SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
6996** CAPI3REF: Unlock Notification
6998** ^When running in shared-cache mode, a database operation may fail with
6999** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
7000** individual tables within the shared-cache cannot be obtained. See
7001** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
7002** ^This API may be used to register a callback that SQLite will invoke
7003** when the connection currently holding the required lock relinquishes it.
7004** ^This API is only available if the library was compiled with the
7005** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
7007** See Also: [Using the SQLite Unlock Notification Feature].
7009** ^Shared-cache locks are released when a database connection concludes
7010** its current transaction, either by committing it or rolling it back.
7012** ^When a connection (known as the blocked connection) fails to obtain a
7013** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
7014** identity of the database connection (the blocking connection) that
7015** has locked the required resource is stored internally. ^After an
7016** application receives an SQLITE_LOCKED error, it may call the
7017** sqlite3_unlock_notify() method with the blocked connection handle as
7018** the first argument to register for a callback that will be invoked
7019** when the blocking connections current transaction is concluded. ^The
7020** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
7021** call that concludes the blocking connections transaction.
7023** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
7024** there is a chance that the blocking connection will have already
7025** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
7026** If this happens, then the specified callback is invoked immediately,
7027** from within the call to sqlite3_unlock_notify().)^
7029** ^If the blocked connection is attempting to obtain a write-lock on a
7030** shared-cache table, and more than one other connection currently holds
7031** a read-lock on the same table, then SQLite arbitrarily selects one of
7032** the other connections to use as the blocking connection.
7034** ^(There may be at most one unlock-notify callback registered by a
7035** blocked connection. If sqlite3_unlock_notify() is called when the
7036** blocked connection already has a registered unlock-notify callback,
7037** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
7038** called with a NULL pointer as its second argument, then any existing
7039** unlock-notify callback is canceled. ^The blocked connections
7040** unlock-notify callback may also be canceled by closing the blocked
7041** connection using [sqlite3_close()].
7043** The unlock-notify callback is not reentrant. If an application invokes
7044** any sqlite3_xxx API functions from within an unlock-notify callback, a
7045** crash or deadlock may be the result.
7047** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
7048** returns SQLITE_OK.
7050** <b>Callback Invocation Details</b>
7052** When an unlock-notify callback is registered, the application provides a
7053** single void* pointer that is passed to the callback when it is invoked.
7054** However, the signature of the callback function allows SQLite to pass
7055** it an array of void* context pointers. The first argument passed to
7056** an unlock-notify callback is a pointer to an array of void* pointers,
7057** and the second is the number of entries in the array.
7059** When a blocking connections transaction is concluded, there may be
7060** more than one blocked connection that has registered for an unlock-notify
7061** callback. ^If two or more such blocked connections have specified the
7062** same callback function, then instead of invoking the callback function
7063** multiple times, it is invoked once with the set of void* context pointers
7064** specified by the blocked connections bundled together into an array.
7065** This gives the application an opportunity to prioritize any actions
7066** related to the set of unblocked database connections.
7068** <b>Deadlock Detection</b>
7070** Assuming that after registering for an unlock-notify callback a
7071** database waits for the callback to be issued before taking any further
7072** action (a reasonable assumption), then using this API may cause the
7073** application to deadlock. For example, if connection X is waiting for
7074** connection Y's transaction to be concluded, and similarly connection
7075** Y is waiting on connection X's transaction, then neither connection
7076** will proceed and the system may remain deadlocked indefinitely.
7078** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
7079** detection. ^If a given call to sqlite3_unlock_notify() would put the
7080** system in a deadlocked state, then SQLITE_LOCKED is returned and no
7081** unlock-notify callback is registered. The system is said to be in
7082** a deadlocked state if connection A has registered for an unlock-notify
7083** callback on the conclusion of connection B's transaction, and connection
7084** B has itself registered for an unlock-notify callback when connection
7085** A's transaction is concluded. ^Indirect deadlock is also detected, so
7086** the system is also considered to be deadlocked if connection B has
7087** registered for an unlock-notify callback on the conclusion of connection
7088** C's transaction, where connection C is waiting on connection A. ^Any
7089** number of levels of indirection are allowed.
7091** <b>The "DROP TABLE" Exception</b>
7093** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
7094** always appropriate to call sqlite3_unlock_notify(). There is however,
7095** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
7096** SQLite checks if there are any currently executing SELECT statements
7097** that belong to the same connection. If there are, SQLITE_LOCKED is
7098** returned. In this case there is no "blocking connection", so invoking
7099** sqlite3_unlock_notify() results in the unlock-notify callback being
7100** invoked immediately. If the application then re-attempts the "DROP TABLE"
7101** or "DROP INDEX" query, an infinite loop might be the result.
7103** One way around this problem is to check the extended error code returned
7104** by an sqlite3_step() call. ^(If there is a blocking connection, then the
7105** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
7106** the special "DROP TABLE/INDEX" case, the extended error code is just
7109SQLITE_API int sqlite3_unlock_notify(
7110  sqlite3 *pBlocked,                          /* Waiting connection */
7111  void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
7112  void *pNotifyArg                            /* Argument to pass to xNotify */
7117** CAPI3REF: String Comparison
7119** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7120** and extensions to compare the contents of two buffers containing UTF-8
7121** strings in a case-independent fashion, using the same definition of "case
7122** independence" that SQLite uses internally when comparing identifiers.
7124SQLITE_API int sqlite3_stricmp(const char *, const char *);
7125SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
7128** CAPI3REF: String Globbing
7130** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches
7131** the glob pattern P, and it returns non-zero if string X does not match
7132** the glob pattern P.  ^The definition of glob pattern matching used in
7133** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
7134** SQL dialect used by SQLite.  ^The sqlite3_strglob(P,X) function is case
7135** sensitive.
7137** Note that this routine returns zero on a match and non-zero if the strings
7138** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7140SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
7143** CAPI3REF: Error Logging Interface
7145** ^The [sqlite3_log()] interface writes a message into the [error log]
7146** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7147** ^If logging is enabled, the zFormat string and subsequent arguments are
7148** used with [sqlite3_snprintf()] to generate the final output string.
7150** The sqlite3_log() interface is intended for use by extensions such as
7151** virtual tables, collating functions, and SQL functions.  While there is
7152** nothing to prevent an application from calling sqlite3_log(), doing so
7153** is considered bad form.
7155** The zFormat string must not be NULL.
7157** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7158** will not use dynamically allocated memory.  The log message is stored in
7159** a fixed-length buffer on the stack.  If the log message is longer than
7160** a few hundred characters, it will be truncated to the length of the
7161** buffer.
7163SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
7166** CAPI3REF: Write-Ahead Log Commit Hook
7168** ^The [sqlite3_wal_hook()] function is used to register a callback that
7169** will be invoked each time a database connection commits data to a
7170** [write-ahead log] (i.e. whenever a transaction is committed in
7171** [journal_mode | journal_mode=WAL mode]).
7173** ^The callback is invoked by SQLite after the commit has taken place and
7174** the associated write-lock on the database released, so the implementation
7175** may read, write or [checkpoint] the database as required.
7177** ^The first parameter passed to the callback function when it is invoked
7178** is a copy of the third parameter passed to sqlite3_wal_hook() when
7179** registering the callback. ^The second is a copy of the database handle.
7180** ^The third parameter is the name of the database that was written to -
7181** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7182** is the number of pages currently in the write-ahead log file,
7183** including those that were just committed.
7185** The callback function should normally return [SQLITE_OK].  ^If an error
7186** code is returned, that error will propagate back up through the
7187** SQLite code base to cause the statement that provoked the callback
7188** to report an error, though the commit will have still occurred. If the
7189** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7190** that does not correspond to any valid SQLite error code, the results
7191** are undefined.
7193** A single database handle may have at most a single write-ahead log callback
7194** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7195** previously registered write-ahead log callback. ^Note that the
7196** [sqlite3_wal_autocheckpoint()] interface and the
7197** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7198** those overwrite any prior [sqlite3_wal_hook()] settings.
7200SQLITE_API void *sqlite3_wal_hook(
7201  sqlite3*,
7202  int(*)(void *,sqlite3*,const char*,int),
7203  void*
7207** CAPI3REF: Configure an auto-checkpoint
7209** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7210** [sqlite3_wal_hook()] that causes any database on [database connection] D
7211** to automatically [checkpoint]
7212** after committing a transaction if there are N or
7213** more frames in the [write-ahead log] file.  ^Passing zero or
7214** a negative value as the nFrame parameter disables automatic
7215** checkpoints entirely.
7217** ^The callback registered by this function replaces any existing callback
7218** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
7219** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7220** configured by this function.
7222** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7223** from SQL.
7225** ^Every new [database connection] defaults to having the auto-checkpoint
7226** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7227** pages.  The use of this interface
7228** is only necessary if the default setting is found to be suboptimal
7229** for a particular application.
7231SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7234** CAPI3REF: Checkpoint a database
7236** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
7237** on [database connection] D to be [checkpointed].  ^If X is NULL or an
7238** empty string, then a checkpoint is run on all databases of
7239** connection D.  ^If the database connection D is not in
7240** [WAL | write-ahead log mode] then this interface is a harmless no-op.
7242** ^The [wal_checkpoint pragma] can be used to invoke this interface
7243** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
7244** [wal_autocheckpoint pragma] can be used to cause this interface to be
7245** run whenever the WAL reaches a certain size threshold.
7247** See also: [sqlite3_wal_checkpoint_v2()]
7249SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7252** CAPI3REF: Checkpoint a database
7254** Run a checkpoint operation on WAL database zDb attached to database
7255** handle db. The specific operation is determined by the value of the
7256** eMode parameter:
7258** <dl>
7260**   Checkpoint as many frames as possible without waiting for any database
7261**   readers or writers to finish. Sync the db file if all frames in the log
7262**   are checkpointed. This mode is the same as calling
7263**   sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
7266**   This mode blocks (calls the busy-handler callback) until there is no
7267**   database writer and all readers are reading from the most recent database
7268**   snapshot. It then checkpoints all frames in the log file and syncs the
7269**   database file. This call blocks database writers while it is running,
7270**   but not database readers.
7273**   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
7274**   checkpointing the log file it blocks (calls the busy-handler callback)
7275**   until all readers are reading from the database file only. This ensures
7276**   that the next client to write to the database file restarts the log file
7277**   from the beginning. This call blocks database writers while it is running,
7278**   but not database readers.
7279** </dl>
7281** If pnLog is not NULL, then *pnLog is set to the total number of frames in
7282** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
7283** the total number of checkpointed frames (including any that were already
7284** checkpointed when this function is called). *pnLog and *pnCkpt may be
7285** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
7286** If no values are available because of an error, they are both set to -1
7287** before returning to communicate this to the caller.
7289** All calls obtain an exclusive "checkpoint" lock on the database file. If
7290** any other process is running a checkpoint operation at the same time, the
7291** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
7292** busy-handler configured, it will not be invoked in this case.
7294** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
7295** "writer" lock on the database file. If the writer lock cannot be obtained
7296** immediately, and a busy-handler is configured, it is invoked and the writer
7297** lock retried until either the busy-handler returns 0 or the lock is
7298** successfully obtained. The busy-handler is also invoked while waiting for
7299** database readers as described above. If the busy-handler returns 0 before
7300** the writer lock is obtained or while waiting for database readers, the
7301** checkpoint operation proceeds from that point in the same way as
7302** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
7303** without blocking any further. SQLITE_BUSY is returned in this case.
7305** If parameter zDb is NULL or points to a zero length string, then the
7306** specified operation is attempted on all WAL databases. In this case the
7307** values written to output parameters *pnLog and *pnCkpt are undefined. If
7308** an SQLITE_BUSY error is encountered when processing one or more of the
7309** attached WAL databases, the operation is still attempted on any remaining
7310** attached databases and SQLITE_BUSY is returned to the caller. If any other
7311** error occurs while processing an attached database, processing is abandoned
7312** and the error code returned to the caller immediately. If no error
7313** (SQLITE_BUSY or otherwise) is encountered while processing the attached
7314** databases, SQLITE_OK is returned.
7316** If database zDb is the name of an attached database that is not in WAL
7317** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
7318** zDb is not NULL (or a zero length string) and is not the name of any
7319** attached database, SQLITE_ERROR is returned to the caller.
7321SQLITE_API int sqlite3_wal_checkpoint_v2(
7322  sqlite3 *db,                    /* Database handle */
7323  const char *zDb,                /* Name of attached database (or NULL) */
7324  int eMode,                      /* SQLITE_CHECKPOINT_* value */
7325  int *pnLog,                     /* OUT: Size of WAL log in frames */
7326  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
7330** CAPI3REF: Checkpoint operation parameters
7332** These constants can be used as the 3rd parameter to
7333** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
7334** documentation for additional information about the meaning and use of
7335** each of these values.
7342** CAPI3REF: Virtual Table Interface Configuration
7344** This function may be called by either the [xConnect] or [xCreate] method
7345** of a [virtual table] implementation to configure
7346** various facets of the virtual table interface.
7348** If this interface is invoked outside the context of an xConnect or
7349** xCreate virtual table method then the behavior is undefined.
7351** At present, there is only one option that may be configured using
7352** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options
7353** may be added in the future.
7355SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
7358** CAPI3REF: Virtual Table Configuration Options
7360** These macros define the various options to the
7361** [sqlite3_vtab_config()] interface that [virtual table] implementations
7362** can use to customize and optimize their behavior.
7364** <dl>
7366** <dd>Calls of the form
7367** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
7368** where X is an integer.  If X is zero, then the [virtual table] whose
7369** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
7370** support constraints.  In this configuration (which is the default) if
7371** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
7372** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
7373** specified as part of the users SQL statement, regardless of the actual
7374** ON CONFLICT mode specified.
7376** If X is non-zero, then the virtual table implementation guarantees
7377** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
7378** any modifications to internal or persistent data structures have been made.
7379** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
7380** is able to roll back a statement or database transaction, and abandon
7381** or continue processing the current SQL statement as appropriate.
7382** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
7383** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
7384** had been ABORT.
7386** Virtual table implementations that are required to handle OR REPLACE
7387** must do so within the [xUpdate] method. If a call to the
7388** [sqlite3_vtab_on_conflict()] function indicates that the current ON
7389** CONFLICT policy is REPLACE, the virtual table implementation should
7390** silently replace the appropriate rows within the xUpdate callback and
7391** return SQLITE_OK. Or, if this is not possible, it may return
7392** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
7393** constraint handling.
7394** </dl>
7399** CAPI3REF: Determine The Virtual Table Conflict Policy
7401** This function may only be called from within a call to the [xUpdate] method
7402** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
7403** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
7404** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
7405** of the SQL statement that triggered the call to the [xUpdate] method of the
7406** [virtual table].
7408SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
7411** CAPI3REF: Conflict resolution modes
7413** These constants are returned by [sqlite3_vtab_on_conflict()] to
7414** inform a [virtual table] implementation what the [ON CONFLICT] mode
7415** is for the SQL statement being evaluated.
7417** Note that the [SQLITE_IGNORE] constant is also used as a potential
7418** return value from the [sqlite3_set_authorizer()] callback and that
7419** [SQLITE_ABORT] is also a [result code].
7421#define SQLITE_ROLLBACK 1
7422/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
7423#define SQLITE_FAIL     3
7424/* #define SQLITE_ABORT 4  // Also an error code */
7425#define SQLITE_REPLACE  5
7430** Undo the hack that converts floating point types to integer for
7431** builds on processors without floating point support.
7434# undef double
7437#if 0
7438}  /* End of the 'extern "C"' block */
7440#endif /* _SQLITE3_H_ */
7443** 2010 August 30
7445** The author disclaims copyright to this source code.  In place of
7446** a legal notice, here is a blessing:
7448**    May you do good and not evil.
7449**    May you find forgiveness for yourself and forgive others.
7450**    May you share freely, never taking more than you give.
7455#ifndef _SQLITE3RTREE_H_
7456#define _SQLITE3RTREE_H_
7459#if 0
7460extern "C" {
7463typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
7466** Register a geometry callback named zGeom that can be used as part of an
7467** R-Tree geometry query as follows:
7469**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
7471SQLITE_API int sqlite3_rtree_geometry_callback(
7472  sqlite3 *db,
7473  const char *zGeom,
7475  int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes),
7477  int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes),
7479  void *pContext
7484** A pointer to a structure of the following type is passed as the first
7485** argument to callbacks registered using rtree_geometry_callback().
7487struct sqlite3_rtree_geometry {
7488  void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
7489  int nParam;                     /* Size of array aParam[] */
7490  double *aParam;                 /* Parameters passed to SQL geom function */
7491  void *pUser;                    /* Callback implementation user data */
7492  void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
7496#if 0
7497}  /* end of the 'extern "C"' block */
7500#endif  /* ifndef _SQLITE3RTREE_H_ */
7503/************** End of sqlite3.h *********************************************/
7504/************** Continuing where we left off in sqliteInt.h ******************/
7507** Include the configuration header output by 'configure' if we're using the
7508** autoconf-based build
7511#include "config.h"
7514/************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/
7515/************** Begin file sqliteLimit.h *************************************/
7517** 2007 May 7
7519** The author disclaims copyright to this source code.  In place of
7520** a legal notice, here is a blessing:
7522**    May you do good and not evil.
7523**    May you find forgiveness for yourself and forgive others.
7524**    May you share freely, never taking more than you give.
7528** This file defines various limits of what SQLite can process.
7532** The maximum length of a TEXT or BLOB in bytes.   This also
7533** limits the size of a row in a table or index.
7535** The hard limit is the ability of a 32-bit signed integer
7536** to count the size: 2^31-1 or 2147483647.
7539# define SQLITE_MAX_LENGTH 1000000000
7543** This is the maximum number of
7545**    * Columns in a table
7546**    * Columns in an index
7547**    * Columns in a view
7548**    * Terms in the SET clause of an UPDATE statement
7549**    * Terms in the result set of a SELECT statement
7550**    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.
7551**    * Terms in the VALUES clause of an INSERT statement
7553** The hard upper limit here is 32676.  Most database people will
7554** tell you that in a well-normalized database, you usually should
7555** not have more than a dozen or so columns in any table.  And if
7556** that is the case, there is no point in having more than a few
7557** dozen values in any of the other situations described above.
7560# define SQLITE_MAX_COLUMN 2000
7564** The maximum length of a single SQL statement in bytes.
7566** It used to be the case that setting this value to zero would
7567** turn the limit off.  That is no longer true.  It is not possible
7568** to turn this limit off.
7571# define SQLITE_MAX_SQL_LENGTH 1000000000
7575** The maximum depth of an expression tree. This is limited to
7576** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might
7577** want to place more severe limits on the complexity of an
7578** expression.
7580** A value of 0 used to mean that the limit was not enforced.
7581** But that is no longer true.  The limit is now strictly enforced
7582** at all times.
7585# define SQLITE_MAX_EXPR_DEPTH 1000
7589** The maximum number of terms in a compound SELECT statement.
7590** The code generator for compound SELECT statements does one
7591** level of recursion for each term.  A stack overflow can result
7592** if the number of terms is too large.  In practice, most SQL
7593** never has more than 3 or 4 terms.  Use a value of 0 to disable
7594** any limit on the number of terms in a compount SELECT.
7601** The maximum number of opcodes in a VDBE program.
7602** Not currently enforced.
7604#ifndef SQLITE_MAX_VDBE_OP
7605# define SQLITE_MAX_VDBE_OP 25000
7609** The maximum number of arguments to an SQL function.
7612# define SQLITE_MAX_FUNCTION_ARG 127
7616** The maximum number of in-memory pages to use for the main database
7617** table and for temporary tables.  The SQLITE_DEFAULT_CACHE_SIZE
7620# define SQLITE_DEFAULT_CACHE_SIZE  2000
7627** The default number of frames to accumulate in the log file before
7628** checkpointing the database in WAL mode.
7635** The maximum number of attached databases.  This must be between 0
7636** and 62.  The upper bound on 62 is because a 64-bit integer bitmap
7637** is used internally to track attached databases.
7640# define SQLITE_MAX_ATTACHED 10
7645** The maximum value of a ?nnn wildcard that the parser will accept.
7651/* Maximum page size.  The upper bound on this value is 65536.  This a limit
7652** imposed by the use of 16-bit offsets within each page.
7654** Earlier versions of SQLite allowed the user to change this value at
7655** compile time. This is no longer permitted, on the grounds that it creates
7656** a library that is technically incompatible with an SQLite library
7657** compiled with a different limit. If a process operating on a database
7658** with a page-size of 65536 bytes crashes, then an instance of SQLite
7659** compiled with the default page-size limit will not be able to rollback
7660** the aborted transaction. This could lead to database corruption.
7665#define SQLITE_MAX_PAGE_SIZE 65536
7669** The default size of a database page.
7672# define SQLITE_DEFAULT_PAGE_SIZE 1024
7680** Ordinarily, if no value is explicitly provided, SQLite creates databases
7681** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain
7682** device characteristics (sector-size and atomic write() support),
7683** SQLite may choose a larger value. This constant is the maximum value
7684** SQLite will choose on its own.
7696** Maximum number of pages in one database file.
7698** This is really just the default value for the max_page_count pragma.
7699** This value can be lowered (or raised) at run-time using that the
7700** max_page_count macro.
7703# define SQLITE_MAX_PAGE_COUNT 1073741823
7707** Maximum length (in bytes) of the pattern in a LIKE or GLOB
7708** operator.
7715** Maximum depth of recursion for triggers.
7717** A value of 1 means that a trigger program will not be able to itself
7718** fire any triggers. A value of 0 means that no trigger programs at all
7719** may be executed.
7722# define SQLITE_MAX_TRIGGER_DEPTH 1000
7725/************** End of sqliteLimit.h *****************************************/
7726/************** Continuing where we left off in sqliteInt.h ******************/
7728/* Disable nuisance warnings on Borland compilers */
7729#if defined(__BORLANDC__)
7730#pragma warn -rch /* unreachable code */
7731#pragma warn -ccc /* Condition is always true or false */
7732#pragma warn -aus /* Assigned value is never used */
7733#pragma warn -csu /* Comparing signed and unsigned */
7734#pragma warn -spa /* Suspicious pointer arithmetic */
7737/* Needed for various definitions... */
7738#ifndef _GNU_SOURCE
7739# define _GNU_SOURCE
7742#if defined(__OpenBSD__) && !defined(_BSD_SOURCE)
7743# define _BSD_SOURCE
7747** Include standard header files as necessary
7749#ifdef HAVE_STDINT_H
7750#include <stdint.h>
7752#ifdef HAVE_INTTYPES_H
7753#include <inttypes.h>
7757** The following macros are used to cast pointers to integers and
7758** integers to pointers.  The way you do this varies from one compiler
7759** to the next, so we have developed the following set of #if statements
7760** to generate appropriate macros for a wide range of compilers.
7762** The correct "ANSI" way to do this is to use the intptr_t type.
7763** Unfortunately, that typedef is not available on all compilers, or
7764** if it is available, it requires an #include of specific headers
7765** that vary from one machine to the next.
7767** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
7768** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
7769** So we have to define the macros in different ways depending on the
7770** compiler.
7772#if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
7773# define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
7774# define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
7775#elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
7776# define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
7777# define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
7778#elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
7779# define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
7780# define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
7781#else                          /* Generates a warning - but it always works */
7782# define SQLITE_INT_TO_PTR(X)  ((void*)(X))
7783# define SQLITE_PTR_TO_INT(X)  ((int)(X))
7787** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
7788** 0 means mutexes are permanently disable and the library is never
7789** threadsafe.  1 means the library is serialized which is the highest
7790** level of threadsafety.  2 means the library is multithreaded - multiple
7791** threads can use SQLite as long as no two threads try to use the same
7792** database connection at the same time.
7794** Older versions of SQLite used an optional THREADSAFE macro.
7795** We support that for legacy.
7797#if !defined(SQLITE_THREADSAFE)
7798# if defined(THREADSAFE)
7800# else
7801#   define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
7802# endif
7806** Powersafe overwrite is on by default.  But can be turned off using
7807** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.