/* ** 2001-09-15 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This header file defines the interface that the SQLite library ** presents to client programs. If a C-function, structure, datatype, ** or constant definition does not appear in this file, then it is ** not a published API of SQLite, is subject to change without ** notice, and should not be referenced by programs that use SQLite. ** ** Some of the definitions that are in this file are marked as ** "experimental". Experimental interfaces are normally new ** features recently added to SQLite. We do not anticipate changes ** to experimental interfaces but reserve the right to make minor changes ** if experience from use "in the wild" suggest such changes are prudent. ** ** The official C-language API documentation for SQLite is derived ** from comments in this file. This file is the authoritative source ** on how SQLite interfaces are supposed to operate. ** ** The name of this file under configuration management is "sqlite.h.in". ** The makefile makes some minor changes to this file (such as inserting ** the version number) and changes its name to "sqlite3.h" as ** part of the build process. */ #ifndef SQLITE3_H #define SQLITE3_H #include /* Needed for the definition of va_list */ /* ** Make sure we can call this stuff from C++. */ #ifdef __cplusplus extern "C" { #endif /* ** Provide the ability to override linkage features of the interface. */ #ifndef SQLITE_EXTERN # define SQLITE_EXTERN extern #endif #ifndef SQLITE_API # define SQLITE_API #endif #ifndef SQLITE_CDECL # define SQLITE_CDECL #endif #ifndef SQLITE_APICALL # define SQLITE_APICALL #endif #ifndef SQLITE_STDCALL # define SQLITE_STDCALL SQLITE_APICALL #endif #ifndef SQLITE_CALLBACK # define SQLITE_CALLBACK #endif #ifndef SQLITE_SYSAPI # define SQLITE_SYSAPI #endif /* ** These no-op macros are used in front of interfaces to mark those ** interfaces as either deprecated or experimental. New applications ** should not use deprecated interfaces - they are supported for backwards ** compatibility only. Application writers should be aware that ** experimental interfaces are subject to change in point releases. ** ** These macros used to resolve to various kinds of compiler magic that ** would generate warning messages when they were used. But that ** compiler magic ended up generating such a flurry of bug reports ** that we have taken it all out and gone back to using simple ** noop macros. */ #define SQLITE_DEPRECATED #define SQLITE_EXPERIMENTAL /* ** Ensure these symbols were not defined by some previous header file. */ #ifdef SQLITE_VERSION # undef SQLITE_VERSION #endif #ifdef SQLITE_VERSION_NUMBER # undef SQLITE_VERSION_NUMBER #endif /* ** CAPI3REF: Compile-Time Library Version Numbers ** ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header ** evaluates to a string literal that is the SQLite version in the ** format "X.Y.Z" where X is the major version number (always 3 for ** SQLite3) and Y is the minor version number and Z is the release number.)^ ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same ** numbers used in [SQLITE_VERSION].)^ ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also ** be larger than the release from which it is derived. Either Y will ** be held constant and Z will be incremented or else Y will be incremented ** and Z will be reset to zero. ** ** Since [version 3.6.18] ([dateof:3.6.18]), ** SQLite source code has been stored in the ** Fossil configuration management ** system. ^The SQLITE_SOURCE_ID macro evaluates to ** a string which identifies a particular check-in of SQLite ** within its configuration management system. ^The SQLITE_SOURCE_ID ** string contains the date and time of the check-in (UTC) and a SHA1 ** or SHA3-256 hash of the entire source tree. If the source code has ** been edited in any way since it was last checked in, then the last ** four hexadecimal digits of the hash may be modified. ** ** See also: [sqlite3_libversion()], ** [sqlite3_libversion_number()], [sqlite3_sourceid()], ** [sqlite_version()] and [sqlite_source_id()]. */ #define SQLITE_VERSION "3.36.0" #define SQLITE_VERSION_NUMBER 3036000 #define SQLITE_SOURCE_ID "2021-06-18 18:36:39 5c9a6c06871cb9fe42814af9c039eb6da5427a6ec28f187af7ebfb62eafa66e5" /* ** CAPI3REF: Run-Time Library Version Numbers ** KEYWORDS: sqlite3_version sqlite3_sourceid ** ** These interfaces provide the same information as the [SQLITE_VERSION], ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros ** but are associated with the library instead of the header file. ^(Cautious ** programmers might include assert() statements in their application to ** verify that values returned by these interfaces match the macros in ** the header, and thus ensure that the application is ** compiled with matching library and header files. ** **
** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
** 
)^ ** ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] ** macro. ^The sqlite3_libversion() function returns a pointer to the ** to the sqlite3_version[] string constant. The sqlite3_libversion() ** function is provided for use in DLLs since DLL users usually do not have ** direct access to string constants within the DLL. ^The ** sqlite3_libversion_number() function returns an integer equal to ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns ** a pointer to a string constant whose value is the same as the ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built ** using an edited copy of [the amalgamation], then the last four characters ** of the hash might be different from [SQLITE_SOURCE_ID].)^ ** ** See also: [sqlite_version()] and [sqlite_source_id()]. */ SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; SQLITE_API const char *sqlite3_libversion(void); SQLITE_API const char *sqlite3_sourceid(void); SQLITE_API int sqlite3_libversion_number(void); /* ** CAPI3REF: Run-Time Library Compilation Options Diagnostics ** ** ^The sqlite3_compileoption_used() function returns 0 or 1 ** indicating whether the specified option was defined at ** compile time. ^The SQLITE_ prefix may be omitted from the ** option name passed to sqlite3_compileoption_used(). ** ** ^The sqlite3_compileoption_get() function allows iterating ** over the list of options that were defined at compile time by ** returning the N-th compile time option string. ^If N is out of range, ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ ** prefix is omitted from any strings returned by ** sqlite3_compileoption_get(). ** ** ^Support for the diagnostic functions sqlite3_compileoption_used() ** and sqlite3_compileoption_get() may be omitted by specifying the ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. ** ** See also: SQL functions [sqlite_compileoption_used()] and ** [sqlite_compileoption_get()] and the [compile_options pragma]. */ #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS SQLITE_API int sqlite3_compileoption_used(const char *zOptName); SQLITE_API const char *sqlite3_compileoption_get(int N); #else # define sqlite3_compileoption_used(X) 0 # define sqlite3_compileoption_get(X) ((void*)0) #endif /* ** CAPI3REF: Test To See If The Library Is Threadsafe ** ** ^The sqlite3_threadsafe() function returns zero if and only if ** SQLite was compiled with mutexing code omitted due to the ** [SQLITE_THREADSAFE] compile-time option being set to 0. ** ** SQLite can be compiled with or without mutexes. When ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes ** are enabled and SQLite is threadsafe. When the ** [SQLITE_THREADSAFE] macro is 0, ** the mutexes are omitted. Without the mutexes, it is not safe ** to use SQLite concurrently from more than one thread. ** ** Enabling mutexes incurs a measurable performance penalty. ** So if speed is of utmost importance, it makes sense to disable ** the mutexes. But for maximum safety, mutexes should be enabled. ** ^The default behavior is for mutexes to be enabled. ** ** This interface can be used by an application to make sure that the ** version of SQLite that it is linking against was compiled with ** the desired setting of the [SQLITE_THREADSAFE] macro. ** ** This interface only reports on the compile-time mutex setting ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but ** can be fully or partially disabled using a call to [sqlite3_config()] ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the ** sqlite3_threadsafe() function shows only the compile-time setting of ** thread safety, not any run-time changes to that setting made by ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() ** is unchanged by calls to sqlite3_config().)^ ** ** See the [threading mode] documentation for additional information. */ SQLITE_API int sqlite3_threadsafe(void); /* ** CAPI3REF: Database Connection Handle ** KEYWORDS: {database connection} {database connections} ** ** Each open SQLite database is represented by a pointer to an instance of ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] ** and [sqlite3_close_v2()] are its destructors. There are many other ** interfaces (such as ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and ** [sqlite3_busy_timeout()] to name but three) that are methods on an ** sqlite3 object. */ typedef struct sqlite3 sqlite3; /* ** CAPI3REF: 64-Bit Integer Types ** KEYWORDS: sqlite_int64 sqlite_uint64 ** ** Because there is no cross-platform way to specify 64-bit integer types ** SQLite includes typedefs for 64-bit signed and unsigned integers. ** ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. ** The sqlite_int64 and sqlite_uint64 types are supported for backwards ** compatibility only. ** ** ^The sqlite3_int64 and sqlite_int64 types can store integer values ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The ** sqlite3_uint64 and sqlite_uint64 types can store integer values ** between 0 and +18446744073709551615 inclusive. */ #ifdef SQLITE_INT64_TYPE typedef SQLITE_INT64_TYPE sqlite_int64; # ifdef SQLITE_UINT64_TYPE typedef SQLITE_UINT64_TYPE sqlite_uint64; # else typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; # endif #elif defined(_MSC_VER) || defined(__BORLANDC__) typedef __int64 sqlite_int64; typedef unsigned __int64 sqlite_uint64; #else typedef long long int sqlite_int64; typedef unsigned long long int sqlite_uint64; #endif typedef sqlite_int64 sqlite3_int64; typedef sqlite_uint64 sqlite3_uint64; /* ** If compiling for a processor that lacks floating point support, ** substitute integer for floating-point. */ #ifdef SQLITE_OMIT_FLOATING_POINT # define double sqlite3_int64 #endif /* ** CAPI3REF: Closing A Database Connection ** DESTRUCTOR: sqlite3 ** ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors ** for the [sqlite3] object. ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if ** the [sqlite3] object is successfully destroyed and all associated ** resources are deallocated. ** ** Ideally, applications should [sqlite3_finalize | finalize] all ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated ** with the [sqlite3] object prior to attempting to close the object. ** ^If the database connection is associated with unfinalized prepared ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then ** sqlite3_close() will leave the database connection open and return ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, ** it returns [SQLITE_OK] regardless, but instead of deallocating the database ** connection immediately, it marks the database connection as an unusable ** "zombie" and makes arrangements to automatically deallocate the database ** connection after all prepared statements are finalized, all BLOB handles ** are closed, and all backups have finished. The sqlite3_close_v2() interface ** is intended for use with host languages that are garbage collected, and ** where the order in which destructors are called is arbitrary. ** ** ^If an [sqlite3] object is destroyed while a transaction is open, ** the transaction is automatically rolled back. ** ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] ** must be either a NULL ** pointer or an [sqlite3] object pointer obtained ** from [sqlite3_open()], [sqlite3_open16()], or ** [sqlite3_open_v2()], and not previously closed. ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer ** argument is a harmless no-op. */ SQLITE_API int sqlite3_close(sqlite3*); SQLITE_API int sqlite3_close_v2(sqlite3*); /* ** The type for a callback function. ** This is legacy and deprecated. It is included for historical ** compatibility and is not documented. */ typedef int (*sqlite3_callback)(void*,int,char**, char**); /* ** CAPI3REF: One-Step Query Execution Interface ** METHOD: sqlite3 ** ** The sqlite3_exec() interface is a convenience wrapper around ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], ** that allows an application to run multiple statements of SQL ** without having to use a lot of C code. ** ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, ** semicolon-separate SQL statements passed into its 2nd argument, ** in the context of the [database connection] passed in as its 1st ** argument. ^If the callback function of the 3rd argument to ** sqlite3_exec() is not NULL, then it is invoked for each result row ** coming out of the evaluated SQL statements. ^The 4th argument to ** sqlite3_exec() is relayed through to the 1st argument of each ** callback invocation. ^If the callback pointer to sqlite3_exec() ** is NULL, then no callback is ever invoked and result rows are ** ignored. ** ** ^If an error occurs while evaluating the SQL statements passed into ** sqlite3_exec(), then execution of the current statement stops and ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() ** is not NULL then any error message is written into memory obtained ** from [sqlite3_malloc()] and passed back through the 5th parameter. ** To avoid memory leaks, the application should invoke [sqlite3_free()] ** on error message strings returned through the 5th parameter of ** sqlite3_exec() after the error message string is no longer needed. ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to ** NULL before returning. ** ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() ** routine returns SQLITE_ABORT without invoking the callback again and ** without running any subsequent SQL statements. ** ** ^The 2nd argument to the sqlite3_exec() callback function is the ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() ** callback is an array of pointers to strings obtained as if from ** [sqlite3_column_text()], one for each column. ^If an element of a ** result row is NULL then the corresponding string pointer for the ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the ** sqlite3_exec() callback is an array of pointers to strings where each ** entry represents the name of corresponding result column as obtained ** from [sqlite3_column_name()]. ** ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer ** to an empty string, or a pointer that contains only whitespace and/or ** SQL comments, then no SQL statements are evaluated and the database ** is not changed. ** ** Restrictions: ** ** */ SQLITE_API int sqlite3_exec( sqlite3*, /* An open database */ const char *sql, /* SQL to be evaluated */ int (*callback)(void*,int,char**,char**), /* Callback function */ void *, /* 1st argument to callback */ char **errmsg /* Error msg written here */ ); /* ** CAPI3REF: Result Codes ** KEYWORDS: {result code definitions} ** ** Many SQLite functions return an integer result code from the set shown ** here in order to indicate success or failure. ** ** New error codes may be added in future versions of SQLite. ** ** See also: [extended result code definitions] */ #define SQLITE_OK 0 /* Successful result */ /* beginning-of-error-codes */ #define SQLITE_ERROR 1 /* Generic error */ #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ #define SQLITE_PERM 3 /* Access permission denied */ #define SQLITE_ABORT 4 /* Callback routine requested an abort */ #define SQLITE_BUSY 5 /* The database file is locked */ #define SQLITE_LOCKED 6 /* A table in the database is locked */ #define SQLITE_NOMEM 7 /* A malloc() failed */ #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ #define SQLITE_FULL 13 /* Insertion failed because database is full */ #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ #define SQLITE_EMPTY 16 /* Internal use only */ #define SQLITE_SCHEMA 17 /* The database schema changed */ #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ #define SQLITE_MISMATCH 20 /* Data type mismatch */ #define SQLITE_MISUSE 21 /* Library used incorrectly */ #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ #define SQLITE_AUTH 23 /* Authorization denied */ #define SQLITE_FORMAT 24 /* Not used */ #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ #define SQLITE_NOTADB 26 /* File opened that is not a database file */ #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ /* end-of-error-codes */ /* ** CAPI3REF: Extended Result Codes ** KEYWORDS: {extended result code definitions} ** ** In its default configuration, SQLite API routines return one of 30 integer ** [result codes]. However, experience has shown that many of ** these result codes are too coarse-grained. They do not provide as ** much information about problems as programmers might like. In an effort to ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] ** and later) include ** support for additional result codes that provide more detailed information ** about errors. These [extended result codes] are enabled or disabled ** on a per database connection basis using the ** [sqlite3_extended_result_codes()] API. Or, the extended code for ** the most recent error can be obtained using ** [sqlite3_extended_errcode()]. */ #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* ** CAPI3REF: Flags For File Open Operations ** ** These bit values are intended for use in the ** 3rd parameter to the [sqlite3_open_v2()] interface and ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. */ #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ /* Reserved: 0x00F00000 */ /* Legacy compatibility: */ #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ /* ** CAPI3REF: Device Characteristics ** ** The xDeviceCharacteristics method of the [sqlite3_io_methods] ** object returns an integer which is a vector of these ** bit values expressing I/O characteristics of the mass storage ** device that holds the file that the [sqlite3_io_methods] ** refers to. ** ** The SQLITE_IOCAP_ATOMIC property means that all writes of ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values ** mean that writes of blocks that are nnn bytes in size and ** are aligned to an address which is an integer multiple of ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means ** that when data is appended to a file, the data is appended ** first then the size of the file is extended, never the other ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that ** information is written to disk in the same order as calls ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that ** after reboot following a crash or power loss, the only bytes in a ** file that were written at the application level might have changed ** and that adjacent bytes, even bytes within the same sector are ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN ** flag indicates that a file cannot be deleted when open. The ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on ** read-only media and cannot be changed even by processes with ** elevated privileges. ** ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying ** filesystem supports doing multiple write operations atomically when those ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. */ #define SQLITE_IOCAP_ATOMIC 0x00000001 #define SQLITE_IOCAP_ATOMIC512 0x00000002 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 /* ** CAPI3REF: File Locking Levels ** ** SQLite uses one of these integer values as the second ** argument to calls it makes to the xLock() and xUnlock() methods ** of an [sqlite3_io_methods] object. */ #define SQLITE_LOCK_NONE 0 #define SQLITE_LOCK_SHARED 1 #define SQLITE_LOCK_RESERVED 2 #define SQLITE_LOCK_PENDING 3 #define SQLITE_LOCK_EXCLUSIVE 4 /* ** CAPI3REF: Synchronization Type Flags ** ** When SQLite invokes the xSync() method of an ** [sqlite3_io_methods] object it uses a combination of ** these integer values as the second argument. ** ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the ** sync operation only needs to flush data to mass storage. Inode ** information need not be flushed. If the lower four bits of the flag ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. ** If the lower four bits equal SQLITE_SYNC_FULL, that means ** to use Mac OS X style fullsync instead of fsync(). ** ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL ** settings. The [synchronous pragma] determines when calls to the ** xSync VFS method occur and applies uniformly across all platforms. ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how ** energetic or rigorous or forceful the sync operations are and ** only make a difference on Mac OSX for the default SQLite code. ** (Third-party VFS implementations might also make the distinction ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the ** operating systems natively supported by SQLite, only Mac OSX ** cares about the difference.) */ #define SQLITE_SYNC_NORMAL 0x00002 #define SQLITE_SYNC_FULL 0x00003 #define SQLITE_SYNC_DATAONLY 0x00010 /* ** CAPI3REF: OS Interface Open File Handle ** ** An [sqlite3_file] object represents an open file in the ** [sqlite3_vfs | OS interface layer]. Individual OS interface ** implementations will ** want to subclass this object by appending additional fields ** for their own use. The pMethods entry is a pointer to an ** [sqlite3_io_methods] object that defines methods for performing ** I/O operations on the open file. */ typedef struct sqlite3_file sqlite3_file; struct sqlite3_file { const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ }; /* ** CAPI3REF: OS Interface File Virtual Methods Object ** ** Every file opened by the [sqlite3_vfs.xOpen] method populates an ** [sqlite3_file] object (or, more commonly, a subclass of the ** [sqlite3_file] object) with a pointer to an instance of this object. ** This object defines the methods used to perform various operations ** against the open file represented by the [sqlite3_file] object. ** ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element ** to NULL. ** ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] ** flag may be ORed in to indicate that only the data of the file ** and not its inode needs to be synced. ** ** The integer values to xLock() and xUnlock() are one of ** ** xLock() increases the lock. xUnlock() decreases the lock. ** The xCheckReservedLock() method checks whether any database connection, ** either in this process or in some other process, is holding a RESERVED, ** PENDING, or EXCLUSIVE lock on the file. It returns true ** if such a lock exists and false otherwise. ** ** The xFileControl() method is a generic interface that allows custom ** VFS implementations to directly control an open file using the ** [sqlite3_file_control()] interface. The second "op" argument is an ** integer opcode. The third argument is a generic pointer intended to ** point to a structure that may contain arguments or space in which to ** write return values. Potential uses for xFileControl() might be ** functions to enable blocking locks with timeouts, to change the ** locking strategy (for example to use dot-file locks), to inquire ** about the status of a lock, or to break stale locks. The SQLite ** core reserves all opcodes less than 100 for its own use. ** A [file control opcodes | list of opcodes] less than 100 is available. ** Applications that define a custom xFileControl method should use opcodes ** greater than 100 to avoid conflicts. VFS implementations should ** return [SQLITE_NOTFOUND] for file control opcodes that they do not ** recognize. ** ** The xSectorSize() method returns the sector size of the ** device that underlies the file. The sector size is the ** minimum write that can be performed without disturbing ** other bytes in the file. The xDeviceCharacteristics() ** method returns a bit vector describing behaviors of the ** underlying device: ** ** ** ** The SQLITE_IOCAP_ATOMIC property means that all writes of ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values ** mean that writes of blocks that are nnn bytes in size and ** are aligned to an address which is an integer multiple of ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means ** that when data is appended to a file, the data is appended ** first then the size of the file is extended, never the other ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that ** information is written to disk in the same order as calls ** to xWrite(). ** ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill ** in the unread portions of the buffer with zeros. A VFS that ** fails to zero-fill short reads might seem to work. However, ** failure to zero-fill short reads will eventually lead to ** database corruption. */ typedef struct sqlite3_io_methods sqlite3_io_methods; struct sqlite3_io_methods { int iVersion; int (*xClose)(sqlite3_file*); int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); int (*xSync)(sqlite3_file*, int flags); int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); int (*xLock)(sqlite3_file*, int); int (*xUnlock)(sqlite3_file*, int); int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); int (*xFileControl)(sqlite3_file*, int op, void *pArg); int (*xSectorSize)(sqlite3_file*); int (*xDeviceCharacteristics)(sqlite3_file*); /* Methods above are valid for version 1 */ int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); void (*xShmBarrier)(sqlite3_file*); int (*xShmUnmap)(sqlite3_file*, int deleteFlag); /* Methods above are valid for version 2 */ int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); /* Methods above are valid for version 3 */ /* Additional methods may be added in future releases */ }; /* ** CAPI3REF: Standard File Control Opcodes ** KEYWORDS: {file control opcodes} {file control opcode} ** ** These integer constants are opcodes for the xFileControl method ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] ** interface. ** ** ** **
  • [[SQLITE_FCNTL_EXTERNAL_READER]] ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect ** whether or not there is a database client in another process with a wal-mode ** transaction open on the database or not. It is only available on unix.The ** (void*) argument passed with this file-control should be a pointer to a ** value of type (int). The integer value is set to 1 if the database is a wal ** mode database and there exists at least one client in another process that ** currently has an SQL transaction open on the database. It is set to 0 if ** the database is not a wal-mode db, or if there is no such connection in any ** other process. This opcode cannot be used to detect transactions opened ** by clients within the current process, only within other processes. ** ** **
  • [[SQLITE_FCNTL_CKSM_FILE]] ** Used by the cksmvfs VFS module only. ** */ #define SQLITE_FCNTL_LOCKSTATE 1 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 #define SQLITE_FCNTL_LAST_ERRNO 4 #define SQLITE_FCNTL_SIZE_HINT 5 #define SQLITE_FCNTL_CHUNK_SIZE 6 #define SQLITE_FCNTL_FILE_POINTER 7 #define SQLITE_FCNTL_SYNC_OMITTED 8 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 #define SQLITE_FCNTL_PERSIST_WAL 10 #define SQLITE_FCNTL_OVERWRITE 11 #define SQLITE_FCNTL_VFSNAME 12 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 #define SQLITE_FCNTL_PRAGMA 14 #define SQLITE_FCNTL_BUSYHANDLER 15 #define SQLITE_FCNTL_TEMPFILENAME 16 #define SQLITE_FCNTL_MMAP_SIZE 18 #define SQLITE_FCNTL_TRACE 19 #define SQLITE_FCNTL_HAS_MOVED 20 #define SQLITE_FCNTL_SYNC 21 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 #define SQLITE_FCNTL_WAL_BLOCK 24 #define SQLITE_FCNTL_ZIPVFS 25 #define SQLITE_FCNTL_RBU 26 #define SQLITE_FCNTL_VFS_POINTER 27 #define SQLITE_FCNTL_JOURNAL_POINTER 28 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 #define SQLITE_FCNTL_PDB 30 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 #define SQLITE_FCNTL_DATA_VERSION 35 #define SQLITE_FCNTL_SIZE_LIMIT 36 #define SQLITE_FCNTL_CKPT_DONE 37 #define SQLITE_FCNTL_RESERVE_BYTES 38 #define SQLITE_FCNTL_CKPT_START 39 #define SQLITE_FCNTL_EXTERNAL_READER 40 #define SQLITE_FCNTL_CKSM_FILE 41 /* deprecated names */ #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO /* ** CAPI3REF: Mutex Handle ** ** The mutex module within SQLite defines [sqlite3_mutex] to be an ** abstract type for a mutex object. The SQLite core never looks ** at the internal representation of an [sqlite3_mutex]. It only ** deals with pointers to the [sqlite3_mutex] object. ** ** Mutexes are created using [sqlite3_mutex_alloc()]. */ typedef struct sqlite3_mutex sqlite3_mutex; /* ** CAPI3REF: Loadable Extension Thunk ** ** A pointer to the opaque sqlite3_api_routines structure is passed as ** the third parameter to entry points of [loadable extensions]. This ** structure must be typedefed in order to work around compiler warnings ** on some platforms. */ typedef struct sqlite3_api_routines sqlite3_api_routines; /* ** CAPI3REF: OS Interface Object ** ** An instance of the sqlite3_vfs object defines the interface between ** the SQLite core and the underlying operating system. The "vfs" ** in the name of the object stands for "virtual file system". See ** the [VFS | VFS documentation] for further information. ** ** The VFS interface is sometimes extended by adding new methods onto ** the end. Each time such an extension occurs, the iVersion field ** is incremented. The iVersion value started out as 1 in ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields ** may be appended to the sqlite3_vfs object and the iVersion value ** may increase again in future versions of SQLite. ** Note that due to an oversight, the structure ** of the sqlite3_vfs object changed in the transition from ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] ** and yet the iVersion field was not increased. ** ** The szOsFile field is the size of the subclassed [sqlite3_file] ** structure used by this VFS. mxPathname is the maximum length of ** a pathname in this VFS. ** ** Registered sqlite3_vfs objects are kept on a linked list formed by ** the pNext pointer. The [sqlite3_vfs_register()] ** and [sqlite3_vfs_unregister()] interfaces manage this list ** in a thread-safe way. The [sqlite3_vfs_find()] interface ** searches the list. Neither the application code nor the VFS ** implementation should use the pNext pointer. ** ** The pNext field is the only field in the sqlite3_vfs ** structure that SQLite will ever modify. SQLite will only access ** or modify this field while holding a particular static mutex. ** The application should never modify anything within the sqlite3_vfs ** object once the object has been registered. ** ** The zName field holds the name of the VFS module. The name must ** be unique across all VFS modules. ** ** [[sqlite3_vfs.xOpen]] ** ^SQLite guarantees that the zFilename parameter to xOpen ** is either a NULL pointer or string obtained ** from xFullPathname() with an optional suffix added. ** ^If a suffix is added to the zFilename parameter, it will ** consist of a single "-" character followed by no more than ** 11 alphanumeric and/or "-" characters. ** ^SQLite further guarantees that ** the string will be valid and unchanged until xClose() is ** called. Because of the previous sentence, ** the [sqlite3_file] can safely store a pointer to the ** filename if it needs to remember the filename for some reason. ** If the zFilename parameter to xOpen is a NULL pointer then xOpen ** must invent its own temporary name for the file. ^Whenever the ** xFilename parameter is NULL it will also be the case that the ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. ** ** The flags argument to xOpen() includes all bits set in ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] ** or [sqlite3_open16()] is used, then flags includes at least ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. ** If xOpen() opens a file read-only then it sets *pOutFlags to ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. ** ** ^(SQLite will also add one of the following flags to the xOpen() ** call, depending on the object being opened: ** ** )^ ** ** The file I/O implementation can use the object type flags to ** change the way it deals with files. For example, an application ** that does not care about crash recovery or rollback might make ** the open of a journal file a no-op. Writes to this journal would ** also be no-ops, and any attempt to read the journal would return ** SQLITE_IOERR. Or the implementation might recognize that a database ** file will be doing page-aligned sector reads and writes in a random ** order and set up its I/O subsystem accordingly. ** ** SQLite might also add one of the following flags to the xOpen method: ** ** ** ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] ** will be set for TEMP databases and their journals, transient ** databases, and subjournals. ** ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction ** with the [SQLITE_OPEN_CREATE] flag, which are both directly ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the ** SQLITE_OPEN_CREATE, is used to indicate that file should always ** be created, and that it is an error if it already exists. ** It is not used to indicate the file should be opened ** for exclusive access. ** ** ^At least szOsFile bytes of memory are allocated by SQLite ** to hold the [sqlite3_file] structure passed as the third ** argument to xOpen. The xOpen method does not have to ** allocate the structure; it should just fill it in. Note that ** the xOpen method must set the sqlite3_file.pMethods to either ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods ** element will be valid after xOpen returns regardless of the success ** or failure of the xOpen call. ** ** [[sqlite3_vfs.xAccess]] ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] ** to test whether a file is at least readable. The SQLITE_ACCESS_READ ** flag is never actually used and is not implemented in the built-in ** VFSes of SQLite. The file is named by the second argument and can be a ** directory. The xAccess method returns [SQLITE_OK] on success or some ** non-zero error code if there is an I/O error or if the name of ** the file given in the second argument is illegal. If SQLITE_OK ** is returned, then non-zero or zero is written into *pResOut to indicate ** whether or not the file is accessible. ** ** ^SQLite will always allocate at least mxPathname+1 bytes for the ** output buffer xFullPathname. The exact size of the output buffer ** is also passed as a parameter to both methods. If the output buffer ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is ** handled as a fatal error by SQLite, vfs implementations should endeavor ** to prevent this by setting mxPathname to a sufficiently large value. ** ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() ** interfaces are not strictly a part of the filesystem, but they are ** included in the VFS structure for completeness. ** The xRandomness() function attempts to return nBytes bytes ** of good-quality randomness into zOut. The return value is ** the actual number of bytes of randomness obtained. ** The xSleep() method causes the calling thread to sleep for at ** least the number of microseconds given. ^The xCurrentTime() ** method returns a Julian Day Number for the current date and time as ** a floating point value. ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian ** Day Number multiplied by 86400000 (the number of milliseconds in ** a 24-hour day). ** ^SQLite will use the xCurrentTimeInt64() method to get the current ** date and time if that method is available (if iVersion is 2 or ** greater and the function pointer is not NULL) and will fall back ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. ** ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces ** are not used by the SQLite core. These optional interfaces are provided ** by some VFSes to facilitate testing of the VFS code. By overriding ** system calls with functions under its control, a test program can ** simulate faults and error conditions that would otherwise be difficult ** or impossible to induce. The set of system calls that can be overridden ** varies from one VFS to another, and from one version of the same VFS to the ** next. Applications that use these interfaces must be prepared for any ** or all of these interfaces to be NULL or for their behavior to change ** from one release to the next. Applications must not attempt to access ** any of these methods if the iVersion of the VFS is less than 3. */ typedef struct sqlite3_vfs sqlite3_vfs; typedef void (*sqlite3_syscall_ptr)(void); struct sqlite3_vfs { int iVersion; /* Structure version number (currently 3) */ int szOsFile; /* Size of subclassed sqlite3_file */ int mxPathname; /* Maximum file pathname length */ sqlite3_vfs *pNext; /* Next registered VFS */ const char *zName; /* Name of this virtual file system */ void *pAppData; /* Pointer to application-specific data */ int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, int flags, int *pOutFlags); int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); void (*xDlClose)(sqlite3_vfs*, void*); int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); int (*xSleep)(sqlite3_vfs*, int microseconds); int (*xCurrentTime)(sqlite3_vfs*, double*); int (*xGetLastError)(sqlite3_vfs*, int, char *); /* ** The methods above are in version 1 of the sqlite_vfs object ** definition. Those that follow are added in version 2 or later */ int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); /* ** The methods above are in versions 1 and 2 of the sqlite_vfs object. ** Those below are for version 3 and greater. */ int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); /* ** The methods above are in versions 1 through 3 of the sqlite_vfs object. ** New fields may be appended in future versions. The iVersion ** value will increment whenever this happens. */ }; /* ** CAPI3REF: Flags for the xAccess VFS method ** ** These integer constants can be used as the third parameter to ** the xAccess method of an [sqlite3_vfs] object. They determine ** what kind of permissions the xAccess method is looking for. ** With SQLITE_ACCESS_EXISTS, the xAccess method ** simply checks whether the file exists. ** With SQLITE_ACCESS_READWRITE, the xAccess method ** checks whether the named directory is both readable and writable ** (in other words, if files can be added, removed, and renamed within ** the directory). ** The SQLITE_ACCESS_READWRITE constant is currently used only by the ** [temp_store_directory pragma], though this could change in a future ** release of SQLite. ** With SQLITE_ACCESS_READ, the xAccess method ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is ** currently unused, though it might be used in a future release of ** SQLite. */ #define SQLITE_ACCESS_EXISTS 0 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ #define SQLITE_ACCESS_READ 2 /* Unused */ /* ** CAPI3REF: Flags for the xShmLock VFS method ** ** These integer constants define the various locking operations ** allowed by the xShmLock method of [sqlite3_io_methods]. The ** following are the only legal combinations of flags to the ** xShmLock method: ** ** ** ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as ** was given on the corresponding lock. ** ** The xShmLock method can transition between unlocked and SHARED or ** between unlocked and EXCLUSIVE. It cannot transition between SHARED ** and EXCLUSIVE. */ #define SQLITE_SHM_UNLOCK 1 #define SQLITE_SHM_LOCK 2 #define SQLITE_SHM_SHARED 4 #define SQLITE_SHM_EXCLUSIVE 8 /* ** CAPI3REF: Maximum xShmLock index ** ** The xShmLock method on [sqlite3_io_methods] may use values ** between 0 and this upper bound as its "offset" argument. ** The SQLite core will never attempt to acquire or release a ** lock outside of this range */ #define SQLITE_SHM_NLOCK 8 /* ** CAPI3REF: Initialize The SQLite Library ** ** ^The sqlite3_initialize() routine initializes the ** SQLite library. ^The sqlite3_shutdown() routine ** deallocates any resources that were allocated by sqlite3_initialize(). ** These routines are designed to aid in process initialization and ** shutdown on embedded systems. Workstation applications using ** SQLite normally do not need to invoke either of these routines. ** ** A call to sqlite3_initialize() is an "effective" call if it is ** the first time sqlite3_initialize() is invoked during the lifetime of ** the process, or if it is the first time sqlite3_initialize() is invoked ** following a call to sqlite3_shutdown(). ^(Only an effective call ** of sqlite3_initialize() does any initialization. All other calls ** are harmless no-ops.)^ ** ** A call to sqlite3_shutdown() is an "effective" call if it is the first ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only ** an effective call to sqlite3_shutdown() does any deinitialization. ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ ** ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() ** is not. The sqlite3_shutdown() interface must only be called from a ** single thread. All open [database connections] must be closed and all ** other SQLite resources must be deallocated prior to invoking ** sqlite3_shutdown(). ** ** Among other things, ^sqlite3_initialize() will invoke ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() ** will invoke sqlite3_os_end(). ** ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. ** ^If for some reason, sqlite3_initialize() is unable to initialize ** the library (perhaps it is unable to allocate a needed resource such ** as a mutex) it returns an [error code] other than [SQLITE_OK]. ** ** ^The sqlite3_initialize() routine is called internally by many other ** SQLite interfaces so that an application usually does not need to ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] ** calls sqlite3_initialize() so the SQLite library will be automatically ** initialized when [sqlite3_open()] is called if it has not be initialized ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] ** compile-time option, then the automatic calls to sqlite3_initialize() ** are omitted and the application must call sqlite3_initialize() directly ** prior to using any other SQLite interface. For maximum portability, ** it is recommended that applications always invoke sqlite3_initialize() ** directly prior to using any other SQLite interface. Future releases ** of SQLite may require this. In other words, the behavior exhibited ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the ** default behavior in some future release of SQLite. ** ** The sqlite3_os_init() routine does operating-system specific ** initialization of the SQLite library. The sqlite3_os_end() ** routine undoes the effect of sqlite3_os_init(). Typical tasks ** performed by these routines include allocation or deallocation ** of static resources, initialization of global variables, ** setting up a default [sqlite3_vfs] module, or setting up ** a default configuration using [sqlite3_config()]. ** ** The application should never invoke either sqlite3_os_init() ** or sqlite3_os_end() directly. The application should only invoke ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() ** interface is called automatically by sqlite3_initialize() and ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate ** implementations for sqlite3_os_init() and sqlite3_os_end() ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. ** When [custom builds | built for other platforms] ** (using the [SQLITE_OS_OTHER=1] compile-time ** option) the application must supply a suitable implementation for ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied ** implementation of sqlite3_os_init() or sqlite3_os_end() ** must return [SQLITE_OK] on success and some other [error code] upon ** failure. */ SQLITE_API int sqlite3_initialize(void); SQLITE_API int sqlite3_shutdown(void); SQLITE_API int sqlite3_os_init(void); SQLITE_API int sqlite3_os_end(void); /* ** CAPI3REF: Configuring The SQLite Library ** ** The sqlite3_config() interface is used to make global configuration ** changes to SQLite in order to tune SQLite to the specific needs of ** the application. The default configuration is recommended for most ** applications and so this routine is usually not necessary. It is ** provided to support rare applications with unusual needs. ** ** The sqlite3_config() interface is not threadsafe. The application ** must ensure that no other SQLite interfaces are invoked by other ** threads while sqlite3_config() is running. ** ** The sqlite3_config() interface ** may only be invoked prior to library initialization using ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. ** Note, however, that ^sqlite3_config() can be called as part of the ** implementation of an application-defined [sqlite3_os_init()]. ** ** The first argument to sqlite3_config() is an integer ** [configuration option] that determines ** what property of SQLite is to be configured. Subsequent arguments ** vary depending on the [configuration option] ** in the first argument. ** ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. ** ^If the option is unknown or SQLite is unable to set the option ** then this routine returns a non-zero [error code]. */ SQLITE_API int sqlite3_config(int, ...); /* ** CAPI3REF: Configure database connections ** METHOD: sqlite3 ** ** The sqlite3_db_config() interface is used to make configuration ** changes to a [database connection]. The interface is similar to ** [sqlite3_config()] except that the changes apply to a single ** [database connection] (specified in the first argument). ** ** The second argument to sqlite3_db_config(D,V,...) is the ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code ** that indicates what aspect of the [database connection] is being configured. ** Subsequent arguments vary depending on the configuration verb. ** ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if ** the call is considered successful. */ SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); /* ** CAPI3REF: Memory Allocation Routines ** ** An instance of this object defines the interface between SQLite ** and low-level memory allocation routines. ** ** This object is used in only one place in the SQLite interface. ** A pointer to an instance of this object is the argument to ** [sqlite3_config()] when the configuration option is ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. ** By creating an instance of this object ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) ** during configuration, an application can specify an alternative ** memory allocation subsystem for SQLite to use for all of its ** dynamic memory needs. ** ** Note that SQLite comes with several [built-in memory allocators] ** that are perfectly adequate for the overwhelming majority of applications ** and that this object is only useful to a tiny minority of applications ** with specialized memory allocation requirements. This object is ** also used during testing of SQLite in order to specify an alternative ** memory allocator that simulates memory out-of-memory conditions in ** order to verify that SQLite recovers gracefully from such ** conditions. ** ** The xMalloc, xRealloc, and xFree methods must work like the ** malloc(), realloc() and free() functions from the standard C library. ** ^SQLite guarantees that the second argument to ** xRealloc is always a value returned by a prior call to xRoundup. ** ** xSize should return the allocated size of a memory allocation ** previously obtained from xMalloc or xRealloc. The allocated size ** is always at least as big as the requested size but may be larger. ** ** The xRoundup method returns what would be the allocated size of ** a memory allocation given a particular requested size. Most memory ** allocators round up memory allocations at least to the next multiple ** of 8. Some allocators round up to a larger multiple or to a power of 2. ** Every memory allocation request coming in through [sqlite3_malloc()] ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, ** that causes the corresponding memory allocation to fail. ** ** The xInit method initializes the memory allocator. For example, ** it might allocate any required mutexes or initialize internal data ** structures. The xShutdown method is invoked (indirectly) by ** [sqlite3_shutdown()] and should deallocate any resources acquired ** by xInit. The pAppData pointer is used as the only parameter to ** xInit and xShutdown. ** ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes ** the xInit method, so the xInit method need not be threadsafe. The ** xShutdown method is only called from [sqlite3_shutdown()] so it does ** not need to be threadsafe either. For all other methods, SQLite ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which ** it is by default) and so the methods are automatically serialized. ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other ** methods must be threadsafe or else make their own arrangements for ** serialization. ** ** SQLite will never invoke xInit() more than once without an intervening ** call to xShutdown(). */ typedef struct sqlite3_mem_methods sqlite3_mem_methods; struct sqlite3_mem_methods { void *(*xMalloc)(int); /* Memory allocation function */ void (*xFree)(void*); /* Free a prior allocation */ void *(*xRealloc)(void*,int); /* Resize an allocation */ int (*xSize)(void*); /* Return the size of an allocation */ int (*xRoundup)(int); /* Round up request size to allocation size */ int (*xInit)(void*); /* Initialize the memory allocator */ void (*xShutdown)(void*); /* Deinitialize the memory allocator */ void *pAppData; /* Argument to xInit() and xShutdown() */ }; /* ** CAPI3REF: Configuration Options ** KEYWORDS: {configuration option} ** ** These constants are the available integer configuration options that ** can be passed as the first argument to the [sqlite3_config()] interface. ** ** New configuration options may be added in future releases of SQLite. ** Existing configuration options might be discontinued. Applications ** should check the return code from [sqlite3_config()] to make sure that ** the call worked. The [sqlite3_config()] interface will return a ** non-zero [error code] if a discontinued or unsupported configuration option ** is invoked. ** **
    ** [[SQLITE_CONFIG_SINGLETHREAD]]
    SQLITE_CONFIG_SINGLETHREAD
    **
    There are no arguments to this option. ^This option sets the ** [threading mode] to Single-thread. In other words, it disables ** all mutexing and puts SQLite into a mode where it can only be used ** by a single thread. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** it is not possible to change the [threading mode] from its default ** value of Single-thread and so [sqlite3_config()] will return ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD ** configuration option.
    ** ** [[SQLITE_CONFIG_MULTITHREAD]]
    SQLITE_CONFIG_MULTITHREAD
    **
    There are no arguments to this option. ^This option sets the ** [threading mode] to Multi-thread. In other words, it disables ** mutexing on [database connection] and [prepared statement] objects. ** The application is responsible for serializing access to ** [database connections] and [prepared statements]. But other mutexes ** are enabled so that SQLite will be safe to use in a multi-threaded ** environment as long as no two threads attempt to use the same ** [database connection] at the same time. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** it is not possible to set the Multi-thread [threading mode] and ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the ** SQLITE_CONFIG_MULTITHREAD configuration option.
    ** ** [[SQLITE_CONFIG_SERIALIZED]]
    SQLITE_CONFIG_SERIALIZED
    **
    There are no arguments to this option. ^This option sets the ** [threading mode] to Serialized. In other words, this option enables ** all mutexes including the recursive ** mutexes on [database connection] and [prepared statement] objects. ** In this mode (which is the default when SQLite is compiled with ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access ** to [database connections] and [prepared statements] so that the ** application is free to use the same [database connection] or the ** same [prepared statement] in different threads at the same time. ** ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** it is not possible to set the Serialized [threading mode] and ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the ** SQLITE_CONFIG_SERIALIZED configuration option.
    ** ** [[SQLITE_CONFIG_MALLOC]]
    SQLITE_CONFIG_MALLOC
    **
    ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is ** a pointer to an instance of the [sqlite3_mem_methods] structure. ** The argument specifies ** alternative low-level memory allocation routines to be used in place of ** the memory allocation routines built into SQLite.)^ ^SQLite makes ** its own private copy of the content of the [sqlite3_mem_methods] structure ** before the [sqlite3_config()] call returns.
    ** ** [[SQLITE_CONFIG_GETMALLOC]]
    SQLITE_CONFIG_GETMALLOC
    **
    ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which ** is a pointer to an instance of the [sqlite3_mem_methods] structure. ** The [sqlite3_mem_methods] ** structure is filled with the currently defined memory allocation routines.)^ ** This option can be used to overload the default memory allocation ** routines with a wrapper that simulations memory allocation failure or ** tracks memory usage, for example.
    ** ** [[SQLITE_CONFIG_SMALL_MALLOC]]
    SQLITE_CONFIG_SMALL_MALLOC
    **
    ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of ** type int, interpreted as a boolean, which if true provides a hint to ** SQLite that it should avoid large memory allocations if possible. ** SQLite will run faster if it is free to make large memory allocations, ** but some application might prefer to run slower in exchange for ** guarantees about memory fragmentation that are possible if large ** allocations are avoided. This hint is normally off. **
    ** ** [[SQLITE_CONFIG_MEMSTATUS]]
    SQLITE_CONFIG_MEMSTATUS
    **
    ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, ** interpreted as a boolean, which enables or disables the collection of ** memory allocation statistics. ^(When memory allocation statistics are ** disabled, the following SQLite interfaces become non-operational: **
      **
    • [sqlite3_hard_heap_limit64()] **
    • [sqlite3_memory_used()] **
    • [sqlite3_memory_highwater()] **
    • [sqlite3_soft_heap_limit64()] **
    • [sqlite3_status64()] **
    )^ ** ^Memory allocation statistics are enabled by default unless SQLite is ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory ** allocation statistics are disabled by default. **
    ** ** [[SQLITE_CONFIG_SCRATCH]]
    SQLITE_CONFIG_SCRATCH
    **
    The SQLITE_CONFIG_SCRATCH option is no longer used. **
    ** ** [[SQLITE_CONFIG_PAGECACHE]]
    SQLITE_CONFIG_PAGECACHE
    **
    ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool ** that SQLite can use for the database page cache with the default page ** cache implementation. ** This configuration option is a no-op if an application-defined page ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to ** 8-byte aligned memory (pMem), the size of each page cache line (sz), ** and the number of cache lines (N). ** The sz argument should be the size of the largest database page ** (a power of two between 512 and 65536) plus some extra bytes for each ** page header. ^The number of extra bytes needed by the page header ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. ** ^It is harmless, apart from the wasted memory, ** for the sz parameter to be larger than necessary. The pMem ** argument must be either a NULL pointer or a pointer to an 8-byte ** aligned block of memory of at least sz*N bytes, otherwise ** subsequent behavior is undefined. ** ^When pMem is not NULL, SQLite will strive to use the memory provided ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if ** a page cache line is larger than sz bytes or if all of the pMem buffer ** is exhausted. ** ^If pMem is NULL and N is non-zero, then each database connection ** does an initial bulk allocation for page cache memory ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or ** of -1024*N bytes if N is negative, . ^If additional ** page cache memory is needed beyond what is provided by the initial ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each ** additional cache line.
    ** ** [[SQLITE_CONFIG_HEAP]]
    SQLITE_CONFIG_HEAP
    **
    ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer ** that SQLite will use for all of its dynamic memory allocation needs ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns ** [SQLITE_ERROR] if invoked otherwise. ** ^There are three arguments to SQLITE_CONFIG_HEAP: ** An 8-byte aligned pointer to the memory, ** the number of bytes in the memory buffer, and the minimum allocation size. ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts ** to using its default memory allocator (the system malloc() implementation), ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the ** memory pointer is not NULL then the alternative memory ** allocator is engaged to handle all of SQLites memory allocation needs. ** The first pointer (the memory pointer) must be aligned to an 8-byte ** boundary or subsequent behavior of SQLite will be undefined. ** The minimum allocation size is capped at 2**12. Reasonable values ** for the minimum allocation size are 2**5 through 2**8.
    ** ** [[SQLITE_CONFIG_MUTEX]]
    SQLITE_CONFIG_MUTEX
    **
    ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a ** pointer to an instance of the [sqlite3_mutex_methods] structure. ** The argument specifies alternative low-level mutex routines to be used ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of ** the content of the [sqlite3_mutex_methods] structure before the call to ** [sqlite3_config()] returns. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** the entire mutexing subsystem is omitted from the build and hence calls to ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will ** return [SQLITE_ERROR].
    ** ** [[SQLITE_CONFIG_GETMUTEX]]
    SQLITE_CONFIG_GETMUTEX
    **
    ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The ** [sqlite3_mutex_methods] ** structure is filled with the currently defined mutex routines.)^ ** This option can be used to overload the default mutex allocation ** routines with a wrapper used to track mutex usage for performance ** profiling or testing, for example. ^If SQLite is compiled with ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then ** the entire mutexing subsystem is omitted from the build and hence calls to ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will ** return [SQLITE_ERROR].
    ** ** [[SQLITE_CONFIG_LOOKASIDE]]
    SQLITE_CONFIG_LOOKASIDE
    **
    ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine ** the default size of lookaside memory on each [database connection]. ** The first argument is the ** size of each lookaside buffer slot and the second is the number of ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE ** sets the default lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] ** option to [sqlite3_db_config()] can be used to change the lookaside ** configuration on individual connections.)^
    ** ** [[SQLITE_CONFIG_PCACHE2]]
    SQLITE_CONFIG_PCACHE2
    **
    ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies ** the interface to a custom page cache implementation.)^ ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.
    ** ** [[SQLITE_CONFIG_GETPCACHE2]]
    SQLITE_CONFIG_GETPCACHE2
    **
    ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of ** the current page cache implementation into that object.)^
    ** ** [[SQLITE_CONFIG_LOG]]
    SQLITE_CONFIG_LOG
    **
    The SQLITE_CONFIG_LOG option is used to configure the SQLite ** global [error log]. ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a ** function with a call signature of void(*)(void*,int,const char*), ** and a pointer to void. ^If the function pointer is not NULL, it is ** invoked by [sqlite3_log()] to process each logging event. ^If the ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is ** passed through as the first parameter to the application-defined logger ** function whenever that function is invoked. ^The second parameter to ** the logger function is a copy of the first parameter to the corresponding ** [sqlite3_log()] call and is intended to be a [result code] or an ** [extended result code]. ^The third parameter passed to the logger is ** log message after formatting via [sqlite3_snprintf()]. ** The SQLite logging interface is not reentrant; the logger function ** supplied by the application must not invoke any SQLite interface. ** In a multi-threaded application, the application-defined logger ** function must be threadsafe.
    ** ** [[SQLITE_CONFIG_URI]]
    SQLITE_CONFIG_URI **
    ^(The SQLITE_CONFIG_URI option takes a single argument of type int. ** If non-zero, then URI handling is globally enabled. If the parameter is zero, ** then URI handling is globally disabled.)^ ^If URI handling is globally ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], ** [sqlite3_open16()] or ** specified as part of [ATTACH] commands are interpreted as URIs, regardless ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database ** connection is opened. ^If it is globally disabled, filenames are ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the ** database connection is opened. ^(By default, URI handling is globally ** disabled. The default value may be changed by compiling with the ** [SQLITE_USE_URI] symbol defined.)^ ** ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]]
    SQLITE_CONFIG_COVERING_INDEX_SCAN **
    ^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer ** argument which is interpreted as a boolean in order to enable or disable ** the use of covering indices for full table scans in the query optimizer. ** ^The default setting is determined ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" ** if that compile-time option is omitted. ** The ability to disable the use of covering indices for full table scans ** is because some incorrectly coded legacy applications might malfunction ** when the optimization is enabled. Providing the ability to ** disable the optimization allows the older, buggy application code to work ** without change even with newer versions of SQLite. ** ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] **
    SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE **
    These options are obsolete and should not be used by new code. ** They are retained for backwards compatibility but are now no-ops. **
    ** ** [[SQLITE_CONFIG_SQLLOG]] **
    SQLITE_CONFIG_SQLLOG **
    This option is only available if sqlite is compiled with the ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). ** The second should be of type (void*). The callback is invoked by the library ** in three separate circumstances, identified by the value passed as the ** fourth parameter. If the fourth parameter is 0, then the database connection ** passed as the second argument has just been opened. The third argument ** points to a buffer containing the name of the main database file. If the ** fourth parameter is 1, then the SQL statement that the third parameter ** points to has just been executed. Or, if the fourth parameter is 2, then ** the connection being passed as the second parameter is being closed. The ** third parameter is passed NULL In this case. An example of using this ** configuration option can be seen in the "test_sqllog.c" source file in ** the canonical SQLite source tree.
    ** ** [[SQLITE_CONFIG_MMAP_SIZE]] **
    SQLITE_CONFIG_MMAP_SIZE **
    ^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values ** that are the default mmap size limit (the default setting for ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. ** ^The default setting can be overridden by each database connection using ** either the [PRAGMA mmap_size] command, or by using the ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size ** will be silently truncated if necessary so that it does not exceed the ** compile-time maximum mmap size set by the ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ ** ^If either argument to this option is negative, then that argument is ** changed to its compile-time default. ** ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] **
    SQLITE_CONFIG_WIN32_HEAPSIZE **
    ^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value ** that specifies the maximum size of the created heap. ** ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] **
    SQLITE_CONFIG_PCACHE_HDRSZ **
    ^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which ** is a pointer to an integer and writes into that integer the number of extra ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. ** The amount of extra space required can change depending on the compiler, ** target platform, and SQLite version. ** ** [[SQLITE_CONFIG_PMASZ]] **
    SQLITE_CONFIG_PMASZ **
    ^The SQLITE_CONFIG_PMASZ option takes a single parameter which ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded ** sorter to that integer. The default minimum PMA Size is set by the ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched ** to help with sort operations when multithreaded sorting ** is enabled (using the [PRAGMA threads] command) and the amount of content ** to be sorted exceeds the page size times the minimum of the ** [PRAGMA cache_size] setting and this value. ** ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] **
    SQLITE_CONFIG_STMTJRNL_SPILL **
    ^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which ** becomes the [statement journal] spill-to-disk threshold. ** [Statement journals] are held in memory until their size (in bytes) ** exceeds this threshold, at which point they are written to disk. ** Or if the threshold is -1, statement journals are always held ** exclusively in memory. ** Since many statement journals never become large, setting the spill ** threshold to a value such as 64KiB can greatly reduce the amount of ** I/O required to support statement rollback. ** The default value for this setting is controlled by the ** [SQLITE_STMTJRNL_SPILL] compile-time option. ** ** [[SQLITE_CONFIG_SORTERREF_SIZE]] **
    SQLITE_CONFIG_SORTERREF_SIZE **
    The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter ** of type (int) - the new value of the sorter-reference size threshold. ** Usually, when SQLite uses an external sort to order records according ** to an ORDER BY clause, all fields required by the caller are present in the ** sorted records. However, if SQLite determines based on the declared type ** of a table column that its values are likely to be very large - larger ** than the configured sorter-reference size threshold - then a reference ** is stored in each sorted record and the required column values loaded ** from the database as records are returned in sorted order. The default ** value for this option is to never use this optimization. Specifying a ** negative value for this option restores the default behaviour. ** This option is only available if SQLite is compiled with the ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. ** ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] **
    SQLITE_CONFIG_MEMDB_MAXSIZE **
    The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter ** [sqlite3_int64] parameter which is the default maximum size for an in-memory ** database created using [sqlite3_deserialize()]. This default maximum ** size can be adjusted up or down for individual databases using the ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this ** configuration setting is never used, then the default maximum is determined ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that ** compile-time option is not set, then the default maximum is 1073741824. **
    */ #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ #define SQLITE_CONFIG_PCACHE 14 /* no-op */ #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ #define SQLITE_CONFIG_URI 17 /* int */ #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ /* ** CAPI3REF: Database Connection Configuration Options ** ** These constants are the available integer configuration options that ** can be passed as the second argument to the [sqlite3_db_config()] interface. ** ** New configuration options may be added in future releases of SQLite. ** Existing configuration options might be discontinued. Applications ** should check the return code from [sqlite3_db_config()] to make sure that ** the call worked. ^The [sqlite3_db_config()] interface will return a ** non-zero [error code] if a discontinued or unsupported configuration option ** is invoked. ** **
    ** [[SQLITE_DBCONFIG_LOOKASIDE]] **
    SQLITE_DBCONFIG_LOOKASIDE
    **
    ^This option takes three additional arguments that determine the ** [lookaside memory allocator] configuration for the [database connection]. ** ^The first argument (the third parameter to [sqlite3_db_config()] is a ** pointer to a memory buffer to use for lookaside memory. ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb ** may be NULL in which case SQLite will allocate the ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the ** size of each lookaside buffer slot. ^The third argument is the number of ** slots. The size of the buffer in the first argument must be greater than ** or equal to the product of the second and third arguments. The buffer ** must be aligned to an 8-byte boundary. ^If the second argument to ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally ** rounded down to the next smaller multiple of 8. ^(The lookaside memory ** configuration for a database connection can only be changed when that ** connection is not currently using lookaside memory, or in other words ** when the "current value" returned by ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. ** Any attempt to change the lookaside memory configuration when lookaside ** memory is in use leaves the configuration unchanged and returns ** [SQLITE_BUSY].)^
    ** ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] **
    SQLITE_DBCONFIG_ENABLE_FKEY
    **
    ^This option is used to enable or disable the enforcement of ** [foreign key constraints]. There should be two additional arguments. ** The first argument is an integer which is 0 to disable FK enforcement, ** positive to enable FK enforcement or negative to leave FK enforcement ** unchanged. The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether FK enforcement is off or on ** following this call. The second parameter may be a NULL pointer, in ** which case the FK enforcement setting is not reported back.
    ** ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] **
    SQLITE_DBCONFIG_ENABLE_TRIGGER
    **
    ^This option is used to enable or disable [CREATE TRIGGER | triggers]. ** There should be two additional arguments. ** The first argument is an integer which is 0 to disable triggers, ** positive to enable triggers or negative to leave the setting unchanged. ** The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether triggers are disabled or enabled ** following this call. The second parameter may be a NULL pointer, in ** which case the trigger setting is not reported back. ** **

    Originally this option disabled all triggers. ^(However, since ** SQLite version 3.35.0, TEMP triggers are still allowed even if ** this option is off. So, in other words, this option now only disables ** triggers in the main database schema or in the schemas of ATTACH-ed ** databases.)^

    ** ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] **
    SQLITE_DBCONFIG_ENABLE_VIEW
    **
    ^This option is used to enable or disable [CREATE VIEW | views]. ** There should be two additional arguments. ** The first argument is an integer which is 0 to disable views, ** positive to enable views or negative to leave the setting unchanged. ** The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether views are disabled or enabled ** following this call. The second parameter may be a NULL pointer, in ** which case the view setting is not reported back. ** **

    Originally this option disabled all views. ^(However, since ** SQLite version 3.35.0, TEMP views are still allowed even if ** this option is off. So, in other words, this option now only disables ** views in the main database schema or in the schemas of ATTACH-ed ** databases.)^

    ** ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] **
    SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER
    **
    ^This option is used to enable or disable the ** [fts3_tokenizer()] function which is part of the ** [FTS3] full-text search engine extension. ** There should be two additional arguments. ** The first argument is an integer which is 0 to disable fts3_tokenizer() or ** positive to enable fts3_tokenizer() or negative to leave the setting ** unchanged. ** The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled ** following this call. The second parameter may be a NULL pointer, in ** which case the new setting is not reported back.
    ** ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] **
    SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION
    **
    ^This option is used to enable or disable the [sqlite3_load_extension()] ** interface independently of the [load_extension()] SQL function. ** The [sqlite3_enable_load_extension()] API enables or disables both the ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. ** There should be two additional arguments. ** When the first argument to this interface is 1, then only the C-API is ** enabled and the SQL function remains disabled. If the first argument to ** this interface is 0, then both the C-API and the SQL function are disabled. ** If the first argument is -1, then no changes are made to state of either the ** C-API or the SQL function. ** The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface ** is disabled or enabled following this call. The second parameter may ** be a NULL pointer, in which case the new setting is not reported back. **
    ** ** [[SQLITE_DBCONFIG_MAINDBNAME]]
    SQLITE_DBCONFIG_MAINDBNAME
    **
    ^This option is used to change the name of the "main" database ** schema. ^The sole argument is a pointer to a constant UTF8 string ** which will become the new schema name in place of "main". ^SQLite ** does not make a copy of the new main schema name string, so the application ** must ensure that the argument passed into this DBCONFIG option is unchanged ** until after the database connection closes. **
    ** ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] **
    SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE
    **
    Usually, when a database in wal mode is closed or detached from a ** database handle, SQLite checks if this will mean that there are now no ** connections at all to the database. If so, it performs a checkpoint ** operation before closing the connection. This option may be used to ** override this behaviour. The first parameter passed to this operation ** is an integer - positive to disable checkpoints-on-close, or zero (the ** default) to enable them, and negative to leave the setting unchanged. ** The second parameter is a pointer to an integer ** into which is written 0 or 1 to indicate whether checkpoints-on-close ** have been disabled - 0 if they are not disabled, 1 if they are. **
    ** ** [[SQLITE_DBCONFIG_ENABLE_QPSG]]
    SQLITE_DBCONFIG_ENABLE_QPSG
    **
    ^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates ** the [query planner stability guarantee] (QPSG). When the QPSG is active, ** a single SQL query statement will always use the same algorithm regardless ** of values of [bound parameters].)^ The QPSG disables some query optimizations ** that look at the values of bound parameters, which can make some queries ** slower. But the QPSG has the advantage of more predictable behavior. With ** the QPSG active, SQLite will always use the same query plan in the field as ** was used during testing in the lab. ** The first argument to this setting is an integer which is 0 to disable ** the QPSG, positive to enable QPSG, or negative to leave the setting ** unchanged. The second parameter is a pointer to an integer into which ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled ** following this call. **
    ** ** [[SQLITE_DBCONFIG_TRIGGER_EQP]]
    SQLITE_DBCONFIG_TRIGGER_EQP
    **
    By default, the output of EXPLAIN QUERY PLAN commands does not ** include output for any operations performed by trigger programs. This ** option is used to set or clear (the default) a flag that governs this ** behavior. The first parameter passed to this operation is an integer - ** positive to enable output for trigger programs, or zero to disable it, ** or negative to leave the setting unchanged. ** The second parameter is a pointer to an integer into which is written ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if ** it is not disabled, 1 if it is. **
    ** ** [[SQLITE_DBCONFIG_RESET_DATABASE]]
    SQLITE_DBCONFIG_RESET_DATABASE
    **
    Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run ** [VACUUM] in order to reset a database back to an empty database ** with no schema and no content. The following process works even for ** a badly corrupted database file: **
      **
    1. If the database connection is newly opened, make sure it has read the ** database schema by preparing then discarding some query against the ** database, or calling sqlite3_table_column_metadata(), ignoring any ** errors. This step is only necessary if the application desires to keep ** the database in WAL mode after the reset if it was in WAL mode before ** the reset. **
    2. sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); **
    3. [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); **
    4. sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); **
    ** Because resetting a database is destructive and irreversible, the ** process requires the use of this obscure API and multiple steps to help ** ensure that it does not happen by accident. ** ** [[SQLITE_DBCONFIG_DEFENSIVE]]
    SQLITE_DBCONFIG_DEFENSIVE
    **
    The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the ** "defensive" flag for a database connection. When the defensive ** flag is enabled, language features that allow ordinary SQL to ** deliberately corrupt the database file are disabled. The disabled ** features include but are not limited to the following: **
      **
    • The [PRAGMA writable_schema=ON] statement. **
    • The [PRAGMA journal_mode=OFF] statement. **
    • Writes to the [sqlite_dbpage] virtual table. **
    • Direct writes to [shadow tables]. **
    **
    ** ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]]
    SQLITE_DBCONFIG_WRITABLE_SCHEMA
    **
    The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the ** "writable_schema" flag. This has the same effect and is logically equivalent ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. ** The first argument to this setting is an integer which is 0 to disable ** the writable_schema, positive to enable writable_schema, or negative to ** leave the setting unchanged. The second parameter is a pointer to an ** integer into which is written 0 or 1 to indicate whether the writable_schema ** is enabled or disabled following this call. **
    ** ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] **
    SQLITE_DBCONFIG_LEGACY_ALTER_TABLE
    **
    The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates ** the legacy behavior of the [ALTER TABLE RENAME] command such it ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for ** additional information. This feature can also be turned on and off ** using the [PRAGMA legacy_alter_table] statement. **
    ** ** [[SQLITE_DBCONFIG_DQS_DML]] **
    SQLITE_DBCONFIG_DQS_DML **
    The SQLITE_DBCONFIG_DQS_DML option activates or deactivates ** the legacy [double-quoted string literal] misfeature for DML statements ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The ** default value of this setting is determined by the [-DSQLITE_DQS] ** compile-time option. **
    ** ** [[SQLITE_DBCONFIG_DQS_DDL]] **
    SQLITE_DBCONFIG_DQS_DDL **
    The SQLITE_DBCONFIG_DQS option activates or deactivates ** the legacy [double-quoted string literal] misfeature for DDL statements, ** such as CREATE TABLE and CREATE INDEX. The ** default value of this setting is determined by the [-DSQLITE_DQS] ** compile-time option. **
    ** ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] **
    SQLITE_DBCONFIG_TRUSTED_SCHEMA **
    The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to ** assume that database schemas are untainted by malicious content. ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite ** takes additional defensive steps to protect the application from harm ** including: **
      **
    • Prohibit the use of SQL functions inside triggers, views, ** CHECK constraints, DEFAULT clauses, expression indexes, ** partial indexes, or generated columns ** unless those functions are tagged with [SQLITE_INNOCUOUS]. **
    • Prohibit the use of virtual tables inside of triggers or views ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. **
    ** This setting defaults to "on" for legacy compatibility, however ** all applications are advised to turn it off if possible. This setting ** can also be controlled using the [PRAGMA trusted_schema] statement. **
    ** ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] **
    SQLITE_DBCONFIG_LEGACY_FILE_FORMAT **
    The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates ** the legacy file format flag. When activated, this flag causes all newly ** created database file to have a schema format version number (the 4-byte ** integer found at offset 44 into the database header) of 1. This in turn ** means that the resulting database file will be readable and writable by ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, ** newly created databases are generally not understandable by SQLite versions ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there ** is now scarcely any need to generated database files that are compatible ** all the way back to version 3.0.0, and so this setting is of little ** practical use, but is provided so that SQLite can continue to claim the ** ability to generate new database files that are compatible with version ** 3.0.0. **

    Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, ** the [VACUUM] command will fail with an obscure error when attempting to ** process a table with generated columns and a descending index. This is ** not considered a bug since SQLite versions 3.3.0 and earlier do not support ** either generated columns or decending indexes. **

    **
    */ #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ /* ** CAPI3REF: Enable Or Disable Extended Result Codes ** METHOD: sqlite3 ** ** ^The sqlite3_extended_result_codes() routine enables or disables the ** [extended result codes] feature of SQLite. ^The extended result ** codes are disabled by default for historical compatibility. */ SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); /* ** CAPI3REF: Last Insert Rowid ** METHOD: sqlite3 ** ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) ** has a unique 64-bit signed ** integer key called the [ROWID | "rowid"]. ^The rowid is always available ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those ** names are not also used by explicitly declared columns. ^If ** the table has a column of type [INTEGER PRIMARY KEY] then that column ** is another alias for the rowid. ** ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of ** the most recent successful [INSERT] into a rowid table or [virtual table] ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred ** on the database connection D, then sqlite3_last_insert_rowid(D) returns ** zero. ** ** As well as being set automatically as rows are inserted into database ** tables, the value returned by this function may be set explicitly by ** [sqlite3_set_last_insert_rowid()] ** ** Some virtual table implementations may INSERT rows into rowid tables as ** part of committing a transaction (e.g. to flush data accumulated in memory ** to disk). In this case subsequent calls to this function return the rowid ** associated with these internal INSERT operations, which leads to ** unintuitive results. Virtual table implementations that do write to rowid ** tables in this way can avoid this problem by restoring the original ** rowid value using [sqlite3_set_last_insert_rowid()] before returning ** control to the user. ** ** ^(If an [INSERT] occurs within a trigger then this routine will ** return the [rowid] of the inserted row as long as the trigger is ** running. Once the trigger program ends, the value returned ** by this routine reverts to what it was before the trigger was fired.)^ ** ** ^An [INSERT] that fails due to a constraint violation is not a ** successful [INSERT] and does not change the value returned by this ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, ** and INSERT OR ABORT make no changes to the return value of this ** routine when their insertion fails. ^(When INSERT OR REPLACE ** encounters a constraint violation, it does not fail. The ** INSERT continues to completion after deleting rows that caused ** the constraint problem so INSERT OR REPLACE will always change ** the return value of this interface.)^ ** ** ^For the purposes of this routine, an [INSERT] is considered to ** be successful even if it is subsequently rolled back. ** ** This function is accessible to SQL statements via the ** [last_insert_rowid() SQL function]. ** ** If a separate thread performs a new [INSERT] on the same ** database connection while the [sqlite3_last_insert_rowid()] ** function is running and thus changes the last insert [rowid], ** then the value returned by [sqlite3_last_insert_rowid()] is ** unpredictable and might not equal either the old or the new ** last insert [rowid]. */ SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); /* ** CAPI3REF: Set the Last Insert Rowid value. ** METHOD: sqlite3 ** ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to ** set the value returned by calling sqlite3_last_insert_rowid(D) to R ** without inserting a row into the database. */ SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); /* ** CAPI3REF: Count The Number Of Rows Modified ** METHOD: sqlite3 ** ** ^This function returns the number of rows modified, inserted or ** deleted by the most recently completed INSERT, UPDATE or DELETE ** statement on the database connection specified by the only parameter. ** ^Executing any other type of SQL statement does not modify the value ** returned by this function. ** ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], ** [foreign key actions] or [REPLACE] constraint resolution are not counted. ** ** Changes to a view that are intercepted by ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or ** DELETE statement run on a view is always zero. Only changes made to real ** tables are counted. ** ** Things are more complicated if the sqlite3_changes() function is ** executed while a trigger program is running. This may happen if the ** program uses the [changes() SQL function], or if some other callback ** function invokes sqlite3_changes() directly. Essentially: ** ** ** ** ^This means that if the changes() SQL function (or similar) is used ** by the first INSERT, UPDATE or DELETE statement within a trigger, it ** returns the value as set when the calling statement began executing. ** ^If it is used by the second or subsequent such statement within a trigger ** program, the value returned reflects the number of rows modified by the ** previous INSERT, UPDATE or DELETE statement within the same trigger. ** ** If a separate thread makes changes on the same database connection ** while [sqlite3_changes()] is running then the value returned ** is unpredictable and not meaningful. ** ** See also: ** */ SQLITE_API int sqlite3_changes(sqlite3*); /* ** CAPI3REF: Total Number Of Rows Modified ** METHOD: sqlite3 ** ** ^This function returns the total number of rows inserted, modified or ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed ** since the database connection was opened, including those executed as ** part of trigger programs. ^Executing any other type of SQL statement ** does not affect the value returned by sqlite3_total_changes(). ** ** ^Changes made as part of [foreign key actions] are included in the ** count, but those made as part of REPLACE constraint resolution are ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers ** are not counted. ** ** The [sqlite3_total_changes(D)] interface only reports the number ** of rows that changed due to SQL statement run against database ** connection D. Any changes by other database connections are ignored. ** To detect changes against a database file from other database ** connections use the [PRAGMA data_version] command or the ** [SQLITE_FCNTL_DATA_VERSION] [file control]. ** ** If a separate thread makes changes on the same database connection ** while [sqlite3_total_changes()] is running then the value ** returned is unpredictable and not meaningful. ** ** See also: ** */ SQLITE_API int sqlite3_total_changes(sqlite3*); /* ** CAPI3REF: Interrupt A Long-Running Query ** METHOD: sqlite3 ** ** ^This function causes any pending database operation to abort and ** return at its earliest opportunity. This routine is typically ** called in response to a user action such as pressing "Cancel" ** or Ctrl-C where the user wants a long query operation to halt ** immediately. ** ** ^It is safe to call this routine from a thread different from the ** thread that is currently running the database operation. But it ** is not safe to call this routine with a [database connection] that ** is closed or might close before sqlite3_interrupt() returns. ** ** ^If an SQL operation is very nearly finished at the time when ** sqlite3_interrupt() is called, then it might not have an opportunity ** to be interrupted and might continue to completion. ** ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE ** that is inside an explicit transaction, then the entire transaction ** will be rolled back automatically. ** ** ^The sqlite3_interrupt(D) call is in effect until all currently running ** SQL statements on [database connection] D complete. ^Any new SQL statements ** that are started after the sqlite3_interrupt() call and before the ** running statement count reaches zero are interrupted as if they had been ** running prior to the sqlite3_interrupt() call. ^New SQL statements ** that are started after the running statement count reaches zero are ** not effected by the sqlite3_interrupt(). ** ^A call to sqlite3_interrupt(D) that occurs when there are no running ** SQL statements is a no-op and has no effect on SQL statements ** that are started after the sqlite3_interrupt() call returns. */ SQLITE_API void sqlite3_interrupt(sqlite3*); /* ** CAPI3REF: Determine If An SQL Statement Is Complete ** ** These routines are useful during command-line input to determine if the ** currently entered text seems to form a complete SQL statement or ** if additional input is needed before sending the text into ** SQLite for parsing. ^These routines return 1 if the input string ** appears to be a complete SQL statement. ^A statement is judged to be ** complete if it ends with a semicolon token and is not a prefix of a ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within ** string literals or quoted identifier names or comments are not ** independent tokens (they are part of the token in which they are ** embedded) and thus do not count as a statement terminator. ^Whitespace ** and comments that follow the final semicolon are ignored. ** ** ^These routines return 0 if the statement is incomplete. ^If a ** memory allocation fails, then SQLITE_NOMEM is returned. ** ** ^These routines do not parse the SQL statements thus ** will not detect syntactically incorrect SQL. ** ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked ** automatically by sqlite3_complete16(). If that initialization fails, ** then the return value from sqlite3_complete16() will be non-zero ** regardless of whether or not the input SQL is complete.)^ ** ** The input to [sqlite3_complete()] must be a zero-terminated ** UTF-8 string. ** ** The input to [sqlite3_complete16()] must be a zero-terminated ** UTF-16 string in native byte order. */ SQLITE_API int sqlite3_complete(const char *sql); SQLITE_API int sqlite3_complete16(const void *sql); /* ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors ** KEYWORDS: {busy-handler callback} {busy handler} ** METHOD: sqlite3 ** ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X ** that might be invoked with argument P whenever ** an attempt is made to access a database table associated with ** [database connection] D when another thread ** or process has the table locked. ** The sqlite3_busy_handler() interface is used to implement ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. ** ** ^If the busy callback is NULL, then [SQLITE_BUSY] ** is returned immediately upon encountering the lock. ^If the busy callback ** is not NULL, then the callback might be invoked with two arguments. ** ** ^The first argument to the busy handler is a copy of the void* pointer which ** is the third argument to sqlite3_busy_handler(). ^The second argument to ** the busy handler callback is the number of times that the busy handler has ** been invoked previously for the same locking event. ^If the ** busy callback returns 0, then no additional attempts are made to ** access the database and [SQLITE_BUSY] is returned ** to the application. ** ^If the callback returns non-zero, then another attempt ** is made to access the database and the cycle repeats. ** ** The presence of a busy handler does not guarantee that it will be invoked ** when there is lock contention. ^If SQLite determines that invoking the busy ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] ** to the application instead of invoking the ** busy handler. ** Consider a scenario where one process is holding a read lock that ** it is trying to promote to a reserved lock and ** a second process is holding a reserved lock that it is trying ** to promote to an exclusive lock. The first process cannot proceed ** because it is blocked by the second and the second process cannot ** proceed because it is blocked by the first. If both processes ** invoke the busy handlers, neither will make any progress. Therefore, ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this ** will induce the first process to release its read lock and allow ** the second process to proceed. ** ** ^The default busy callback is NULL. ** ** ^(There can only be a single busy handler defined for each ** [database connection]. Setting a new busy handler clears any ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] ** or evaluating [PRAGMA busy_timeout=N] will change the ** busy handler and thus clear any previously set busy handler. ** ** The busy callback should not take any actions which modify the ** database connection that invoked the busy handler. In other words, ** the busy handler is not reentrant. Any such actions ** result in undefined behavior. ** ** A busy handler must not close the database connection ** or [prepared statement] that invoked the busy handler. */ SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); /* ** CAPI3REF: Set A Busy Timeout ** METHOD: sqlite3 ** ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps ** for a specified amount of time when a table is locked. ^The handler ** will sleep multiple times until at least "ms" milliseconds of sleeping ** have accumulated. ^After at least "ms" milliseconds of sleeping, ** the handler returns 0 which causes [sqlite3_step()] to return ** [SQLITE_BUSY]. ** ** ^Calling this routine with an argument less than or equal to zero ** turns off all busy handlers. ** ** ^(There can only be a single busy handler for a particular ** [database connection] at any given moment. If another busy handler ** was defined (using [sqlite3_busy_handler()]) prior to calling ** this routine, that other busy handler is cleared.)^ ** ** See also: [PRAGMA busy_timeout] */ SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); /* ** CAPI3REF: Convenience Routines For Running Queries ** METHOD: sqlite3 ** ** This is a legacy interface that is preserved for backwards compatibility. ** Use of this interface is not recommended. ** ** Definition: A result table is memory data structure created by the ** [sqlite3_get_table()] interface. A result table records the ** complete query results from one or more queries. ** ** The table conceptually has a number of rows and columns. But ** these numbers are not part of the result table itself. These ** numbers are obtained separately. Let N be the number of rows ** and M be the number of columns. ** ** A result table is an array of pointers to zero-terminated UTF-8 strings. ** There are (N+1)*M elements in the array. The first M pointers point ** to zero-terminated strings that contain the names of the columns. ** The remaining entries all point to query results. NULL values result ** in NULL pointers. All other values are in their UTF-8 zero-terminated ** string representation as returned by [sqlite3_column_text()]. ** ** A result table might consist of one or more memory allocations. ** It is not safe to pass a result table directly to [sqlite3_free()]. ** A result table should be deallocated using [sqlite3_free_table()]. ** ** ^(As an example of the result table format, suppose a query result ** is as follows: ** **
    **        Name        | Age
    **        -----------------------
    **        Alice       | 43
    **        Bob         | 28
    **        Cindy       | 21
    ** 
    ** ** There are two columns (M==2) and three rows (N==3). Thus the ** result table has 8 entries. Suppose the result table is stored ** in an array named azResult. Then azResult holds this content: ** **
    **        azResult[0] = "Name";
    **        azResult[1] = "Age";
    **        azResult[2] = "Alice";
    **        azResult[3] = "43";
    **        azResult[4] = "Bob";
    **        azResult[5] = "28";
    **        azResult[6] = "Cindy";
    **        azResult[7] = "21";
    ** 
    )^ ** ** ^The sqlite3_get_table() function evaluates one or more ** semicolon-separated SQL statements in the zero-terminated UTF-8 ** string of its 2nd parameter and returns a result table to the ** pointer given in its 3rd parameter. ** ** After the application has finished with the result from sqlite3_get_table(), ** it must pass the result table pointer to sqlite3_free_table() in order to ** release the memory that was malloced. Because of the way the ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling ** function must not try to call [sqlite3_free()] directly. Only ** [sqlite3_free_table()] is able to release the memory properly and safely. ** ** The sqlite3_get_table() interface is implemented as a wrapper around ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access ** to any internal data structures of SQLite. It uses only the public ** interface defined here. As a consequence, errors that occur in the ** wrapper layer outside of the internal [sqlite3_exec()] call are not ** reflected in subsequent calls to [sqlite3_errcode()] or ** [sqlite3_errmsg()]. */ SQLITE_API int sqlite3_get_table( sqlite3 *db, /* An open database */ const char *zSql, /* SQL to be evaluated */ char ***pazResult, /* Results of the query */ int *pnRow, /* Number of result rows written here */ int *pnColumn, /* Number of result columns written here */ char **pzErrmsg /* Error msg written here */ ); SQLITE_API void sqlite3_free_table(char **result); /* ** CAPI3REF: Formatted String Printing Functions ** ** These routines are work-alikes of the "printf()" family of functions ** from the standard C library. ** These routines understand most of the common formatting options from ** the standard library printf() ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). ** See the [built-in printf()] documentation for details. ** ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their ** results into memory obtained from [sqlite3_malloc64()]. ** The strings returned by these two routines should be ** released by [sqlite3_free()]. ^Both routines return a ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough ** memory to hold the resulting string. ** ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from ** the standard C library. The result is written into the ** buffer supplied as the second parameter whose size is given by ** the first parameter. Note that the order of the ** first two parameters is reversed from snprintf().)^ This is an ** historical accident that cannot be fixed without breaking ** backwards compatibility. ^(Note also that sqlite3_snprintf() ** returns a pointer to its buffer instead of the number of ** characters actually written into the buffer.)^ We admit that ** the number of characters written would be a more useful return ** value but we cannot change the implementation of sqlite3_snprintf() ** now without breaking compatibility. ** ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() ** guarantees that the buffer is always zero-terminated. ^The first ** parameter "n" is the total size of the buffer, including space for ** the zero terminator. So the longest string that can be completely ** written will be n-1 characters. ** ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). ** ** See also: [built-in printf()], [printf() SQL function] */ SQLITE_API char *sqlite3_mprintf(const char*,...); SQLITE_API char *sqlite3_vmprintf(const char*, va_list); SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); /* ** CAPI3REF: Memory Allocation Subsystem ** ** The SQLite core uses these three routines for all of its own ** internal memory allocation needs. "Core" in the previous sentence ** does not include operating-system specific [VFS] implementation. The ** Windows VFS uses native malloc() and free() for some operations. ** ** ^The sqlite3_malloc() routine returns a pointer to a block ** of memory at least N bytes in length, where N is the parameter. ** ^If sqlite3_malloc() is unable to obtain sufficient free ** memory, it returns a NULL pointer. ^If the parameter N to ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns ** a NULL pointer. ** ** ^The sqlite3_malloc64(N) routine works just like ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead ** of a signed 32-bit integer. ** ** ^Calling sqlite3_free() with a pointer previously returned ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so ** that it might be reused. ^The sqlite3_free() routine is ** a no-op if is called with a NULL pointer. Passing a NULL pointer ** to sqlite3_free() is harmless. After being freed, memory ** should neither be read nor written. Even reading previously freed ** memory might result in a segmentation fault or other severe error. ** Memory corruption, a segmentation fault, or other severe error ** might result if sqlite3_free() is called with a non-NULL pointer that ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). ** ** ^The sqlite3_realloc(X,N) interface attempts to resize a ** prior memory allocation X to be at least N bytes. ** ^If the X parameter to sqlite3_realloc(X,N) ** is a NULL pointer then its behavior is identical to calling ** sqlite3_malloc(N). ** ^If the N parameter to sqlite3_realloc(X,N) is zero or ** negative then the behavior is exactly the same as calling ** sqlite3_free(X). ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation ** of at least N bytes in size or NULL if insufficient memory is available. ** ^If M is the size of the prior allocation, then min(N,M) bytes ** of the prior allocation are copied into the beginning of buffer returned ** by sqlite3_realloc(X,N) and the prior allocation is freed. ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the ** prior allocation is not freed. ** ** ^The sqlite3_realloc64(X,N) interfaces works the same as ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead ** of a 32-bit signed integer. ** ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then ** sqlite3_msize(X) returns the size of that memory allocation in bytes. ** ^The value returned by sqlite3_msize(X) might be larger than the number ** of bytes requested when X was allocated. ^If X is a NULL pointer then ** sqlite3_msize(X) returns zero. If X points to something that is not ** the beginning of memory allocation, or if it points to a formerly ** valid memory allocation that has now been freed, then the behavior ** of sqlite3_msize(X) is undefined and possibly harmful. ** ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), ** sqlite3_malloc64(), and sqlite3_realloc64() ** is always aligned to at least an 8 byte boundary, or to a ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time ** option is used. ** ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] ** must be either NULL or else pointers obtained from a prior ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have ** not yet been released. ** ** The application must not read or write any part of ** a block of memory after it has been released using ** [sqlite3_free()] or [sqlite3_realloc()]. */ SQLITE_API void *sqlite3_malloc(int); SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); SQLITE_API void *sqlite3_realloc(void*, int); SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); SQLITE_API void sqlite3_free(void*); SQLITE_API sqlite3_uint64 sqlite3_msize(void*); /* ** CAPI3REF: Memory Allocator Statistics ** ** SQLite provides these two interfaces for reporting on the status ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] ** routines, which form the built-in memory allocation subsystem. ** ** ^The [sqlite3_memory_used()] routine returns the number of bytes ** of memory currently outstanding (malloced but not freed). ** ^The [sqlite3_memory_highwater()] routine returns the maximum ** value of [sqlite3_memory_used()] since the high-water mark ** was last reset. ^The values returned by [sqlite3_memory_used()] and ** [sqlite3_memory_highwater()] include any overhead ** added by SQLite in its implementation of [sqlite3_malloc()], ** but not overhead added by the any underlying system library ** routines that [sqlite3_malloc()] may call. ** ** ^The memory high-water mark is reset to the current value of ** [sqlite3_memory_used()] if and only if the parameter to ** [sqlite3_memory_highwater()] is true. ^The value returned ** by [sqlite3_memory_highwater(1)] is the high-water mark ** prior to the reset. */ SQLITE_API sqlite3_int64 sqlite3_memory_used(void); SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); /* ** CAPI3REF: Pseudo-Random Number Generator ** ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to ** select random [ROWID | ROWIDs] when inserting new records into a table that ** already uses the largest possible [ROWID]. The PRNG is also used for ** the built-in random() and randomblob() SQL functions. This interface allows ** applications to access the same PRNG for other purposes. ** ** ^A call to this routine stores N bytes of randomness into buffer P. ** ^The P parameter can be a NULL pointer. ** ** ^If this routine has not been previously called or if the previous ** call had N less than one or a NULL pointer for P, then the PRNG is ** seeded using randomness obtained from the xRandomness method of ** the default [sqlite3_vfs] object. ** ^If the previous call to this routine had an N of 1 or more and a ** non-NULL P then the pseudo-randomness is generated ** internally and without recourse to the [sqlite3_vfs] xRandomness ** method. */ SQLITE_API void sqlite3_randomness(int N, void *P); /* ** CAPI3REF: Compile-Time Authorization Callbacks ** METHOD: sqlite3 ** KEYWORDS: {authorizer callback} ** ** ^This routine registers an authorizer callback with a particular ** [database connection], supplied in the first argument. ** ^The authorizer callback is invoked as SQL statements are being compiled ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], ** and [sqlite3_prepare16_v3()]. ^At various ** points during the compilation process, as logic is being created ** to perform various actions, the authorizer callback is invoked to ** see if those actions are allowed. ^The authorizer callback should ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the ** specific action but allow the SQL statement to continue to be ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be ** rejected with an error. ^If the authorizer callback returns ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] ** then the [sqlite3_prepare_v2()] or equivalent call that triggered ** the authorizer will fail with an error message. ** ** When the callback returns [SQLITE_OK], that means the operation ** requested is ok. ^When the callback returns [SQLITE_DENY], the ** [sqlite3_prepare_v2()] or equivalent call that triggered the ** authorizer will fail with an error message explaining that ** access is denied. ** ** ^The first parameter to the authorizer callback is a copy of the third ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter ** to the callback is an integer [SQLITE_COPY | action code] that specifies ** the particular action to be authorized. ^The third through sixth parameters ** to the callback are either NULL pointers or zero-terminated strings ** that contain additional details about the action to be authorized. ** Applications must always be prepared to encounter a NULL pointer in any ** of the third through the sixth parameters of the authorization callback. ** ** ^If the action code is [SQLITE_READ] ** and the callback returns [SQLITE_IGNORE] then the ** [prepared statement] statement is constructed to substitute ** a NULL value in place of the table column that would have ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] ** return can be used to deny an untrusted user access to individual ** columns of a table. ** ^When a table is referenced by a [SELECT] but no column values are ** extracted from that table (for example in a query like ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback ** is invoked once for that table with a column name that is an empty string. ** ^If the action code is [SQLITE_DELETE] and the callback returns ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the ** [truncate optimization] is disabled and all rows are deleted individually. ** ** An authorizer is used when [sqlite3_prepare | preparing] ** SQL statements from an untrusted source, to ensure that the SQL statements ** do not try to access data they are not allowed to see, or that they do not ** try to execute malicious statements that damage the database. For ** example, an application may allow a user to enter arbitrary ** SQL queries for evaluation by a database. But the application does ** not want the user to be able to make arbitrary changes to the ** database. An authorizer could then be put in place while the ** user-entered SQL is being [sqlite3_prepare | prepared] that ** disallows everything except [SELECT] statements. ** ** Applications that need to process SQL from untrusted sources ** might also consider lowering resource limits using [sqlite3_limit()] ** and limiting database size using the [max_page_count] [PRAGMA] ** in addition to using an authorizer. ** ** ^(Only a single authorizer can be in place on a database connection ** at a time. Each call to sqlite3_set_authorizer overrides the ** previous call.)^ ^Disable the authorizer by installing a NULL callback. ** The authorizer is disabled by default. ** ** The authorizer callback must not do anything that will modify ** the database connection that invoked the authorizer callback. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their ** database connections for the meaning of "modify" in this paragraph. ** ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the ** statement might be re-prepared during [sqlite3_step()] due to a ** schema change. Hence, the application should ensure that the ** correct authorizer callback remains in place during the [sqlite3_step()]. ** ** ^Note that the authorizer callback is invoked only during ** [sqlite3_prepare()] or its variants. Authorization is not ** performed during statement evaluation in [sqlite3_step()], unless ** as stated in the previous paragraph, sqlite3_step() invokes ** sqlite3_prepare_v2() to reprepare a statement after a schema change. */ SQLITE_API int sqlite3_set_authorizer( sqlite3*, int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), void *pUserData ); /* ** CAPI3REF: Authorizer Return Codes ** ** The [sqlite3_set_authorizer | authorizer callback function] must ** return either [SQLITE_OK] or one of these two constants in order ** to signal SQLite whether or not the action is permitted. See the ** [sqlite3_set_authorizer | authorizer documentation] for additional ** information. ** ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] ** returned from the [sqlite3_vtab_on_conflict()] interface. */ #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ /* ** CAPI3REF: Authorizer Action Codes ** ** The [sqlite3_set_authorizer()] interface registers a callback function ** that is invoked to authorize certain SQL statement actions. The ** second parameter to the callback is an integer code that specifies ** what action is being authorized. These are the integer action codes that ** the authorizer callback may be passed. ** ** These action code values signify what kind of operation is to be ** authorized. The 3rd and 4th parameters to the authorization ** callback function will be parameters or NULL depending on which of these ** codes is used as the second parameter. ^(The 5th parameter to the ** authorizer callback is the name of the database ("main", "temp", ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback ** is the name of the inner-most trigger or view that is responsible for ** the access attempt or NULL if this access attempt is directly from ** top-level SQL code. */ /******************************************* 3rd ************ 4th ***********/ #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ #define SQLITE_DELETE 9 /* Table Name NULL */ #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ #define SQLITE_DROP_VIEW 17 /* View Name NULL */ #define SQLITE_INSERT 18 /* Table Name NULL */ #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ #define SQLITE_READ 20 /* Table Name Column Name */ #define SQLITE_SELECT 21 /* NULL NULL */ #define SQLITE_TRANSACTION 22 /* Operation NULL */ #define SQLITE_UPDATE 23 /* Table Name Column Name */ #define SQLITE_ATTACH 24 /* Filename NULL */ #define SQLITE_DETACH 25 /* Database Name NULL */ #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ #define SQLITE_REINDEX 27 /* Index Name NULL */ #define SQLITE_ANALYZE 28 /* Table Name NULL */ #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ #define SQLITE_FUNCTION 31 /* NULL Function Name */ #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ #define SQLITE_COPY 0 /* No longer used */ #define SQLITE_RECURSIVE 33 /* NULL NULL */ /* ** CAPI3REF: Tracing And Profiling Functions ** METHOD: sqlite3 ** ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface ** instead of the routines described here. ** ** These routines register callback functions that can be used for ** tracing and profiling the execution of SQL statements. ** ** ^The callback function registered by sqlite3_trace() is invoked at ** various times when an SQL statement is being run by [sqlite3_step()]. ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the ** SQL statement text as the statement first begins executing. ** ^(Additional sqlite3_trace() callbacks might occur ** as each triggered subprogram is entered. The callbacks for triggers ** contain a UTF-8 SQL comment that identifies the trigger.)^ ** ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit ** the length of [bound parameter] expansion in the output of sqlite3_trace(). ** ** ^The callback function registered by sqlite3_profile() is invoked ** as each SQL statement finishes. ^The profile callback contains ** the original statement text and an estimate of wall-clock time ** of how long that statement took to run. ^The profile callback ** time is in units of nanoseconds, however the current implementation ** is only capable of millisecond resolution so the six least significant ** digits in the time are meaningless. Future versions of SQLite ** might provide greater resolution on the profiler callback. Invoking ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the ** profile callback. */ SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, void(*xProfile)(void*,const char*,sqlite3_uint64), void*); /* ** CAPI3REF: SQL Trace Event Codes ** KEYWORDS: SQLITE_TRACE ** ** These constants identify classes of events that can be monitored ** using the [sqlite3_trace_v2()] tracing logic. The M argument ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of ** the following constants. ^The first argument to the trace callback ** is one of the following constants. ** ** New tracing constants may be added in future releases. ** ** ^A trace callback has four arguments: xCallback(T,C,P,X). ** ^The T argument is one of the integer type codes above. ** ^The C argument is a copy of the context pointer passed in as the ** fourth argument to [sqlite3_trace_v2()]. ** The P and X arguments are pointers whose meanings depend on T. ** **
    ** [[SQLITE_TRACE_STMT]]
    SQLITE_TRACE_STMT
    **
    ^An SQLITE_TRACE_STMT callback is invoked when a prepared statement ** first begins running and possibly at other times during the ** execution of the prepared statement, such as at the start of each ** trigger subprogram. ^The P argument is a pointer to the ** [prepared statement]. ^The X argument is a pointer to a string which ** is the unexpanded SQL text of the prepared statement or an SQL comment ** that indicates the invocation of a trigger. ^The callback can compute ** the same text that would have been returned by the legacy [sqlite3_trace()] ** interface by using the X argument when X begins with "--" and invoking ** [sqlite3_expanded_sql(P)] otherwise. ** ** [[SQLITE_TRACE_PROFILE]]
    SQLITE_TRACE_PROFILE
    **
    ^An SQLITE_TRACE_PROFILE callback provides approximately the same ** information as is provided by the [sqlite3_profile()] callback. ** ^The P argument is a pointer to the [prepared statement] and the ** X argument points to a 64-bit integer which is the estimated of ** the number of nanosecond that the prepared statement took to run. ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. ** ** [[SQLITE_TRACE_ROW]]
    SQLITE_TRACE_ROW
    **
    ^An SQLITE_TRACE_ROW callback is invoked whenever a prepared ** statement generates a single row of result. ** ^The P argument is a pointer to the [prepared statement] and the ** X argument is unused. ** ** [[SQLITE_TRACE_CLOSE]]
    SQLITE_TRACE_CLOSE
    **
    ^An SQLITE_TRACE_CLOSE callback is invoked when a database ** connection closes. ** ^The P argument is a pointer to the [database connection] object ** and the X argument is unused. **
    */ #define SQLITE_TRACE_STMT 0x01 #define SQLITE_TRACE_PROFILE 0x02 #define SQLITE_TRACE_ROW 0x04 #define SQLITE_TRACE_CLOSE 0x08 /* ** CAPI3REF: SQL Trace Hook ** METHOD: sqlite3 ** ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback ** function X against [database connection] D, using property mask M ** and context pointer P. ^If the X callback is ** NULL or if the M mask is zero, then tracing is disabled. The ** M argument should be the bitwise OR-ed combination of ** zero or more [SQLITE_TRACE] constants. ** ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). ** ** ^The X callback is invoked whenever any of the events identified by ** mask M occur. ^The integer return value from the callback is currently ** ignored, though this may change in future releases. Callback ** implementations should return zero to ensure future compatibility. ** ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). ** ^The T argument is one of the [SQLITE_TRACE] ** constants to indicate why the callback was invoked. ** ^The C argument is a copy of the context pointer. ** The P and X arguments are pointers whose meanings depend on T. ** ** The sqlite3_trace_v2() interface is intended to replace the legacy ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which ** are deprecated. */ SQLITE_API int sqlite3_trace_v2( sqlite3*, unsigned uMask, int(*xCallback)(unsigned,void*,void*,void*), void *pCtx ); /* ** CAPI3REF: Query Progress Callbacks ** METHOD: sqlite3 ** ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback ** function X to be invoked periodically during long running calls to ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for ** database connection D. An example use for this ** interface is to keep a GUI updated during a large query. ** ** ^The parameter P is passed through as the only parameter to the ** callback function X. ^The parameter N is the approximate number of ** [virtual machine instructions] that are evaluated between successive ** invocations of the callback X. ^If N is less than one then the progress ** handler is disabled. ** ** ^Only a single progress handler may be defined at one time per ** [database connection]; setting a new progress handler cancels the ** old one. ^Setting parameter X to NULL disables the progress handler. ** ^The progress handler is also disabled by setting N to a value less ** than 1. ** ** ^If the progress callback returns non-zero, the operation is ** interrupted. This feature can be used to implement a ** "Cancel" button on a GUI progress dialog box. ** ** The progress handler callback must not do anything that will modify ** the database connection that invoked the progress handler. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their ** database connections for the meaning of "modify" in this paragraph. ** */ SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); /* ** CAPI3REF: Opening A New Database Connection ** CONSTRUCTOR: sqlite3 ** ** ^These routines open an SQLite database file as specified by the ** filename argument. ^The filename argument is interpreted as UTF-8 for ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte ** order for sqlite3_open16(). ^(A [database connection] handle is usually ** returned in *ppDb, even if an error occurs. The only exception is that ** if SQLite is unable to allocate memory to hold the [sqlite3] object, ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] ** object.)^ ^(If the database is opened (and/or created) successfully, then ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain ** an English language description of the error following a failure of any ** of the sqlite3_open() routines. ** ** ^The default encoding will be UTF-8 for databases created using ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases ** created using sqlite3_open16() will be UTF-16 in the native byte order. ** ** Whether or not an error occurs when it is opened, resources ** associated with the [database connection] handle should be released by ** passing it to [sqlite3_close()] when it is no longer required. ** ** The sqlite3_open_v2() interface works like sqlite3_open() ** except that it accepts two additional parameters for additional control ** over the new database connection. ^(The flags parameter to ** sqlite3_open_v2() must include, at a minimum, one of the following ** three flag combinations:)^ ** **
    ** ^(
    [SQLITE_OPEN_READONLY]
    **
    The database is opened in read-only mode. If the database does not ** already exist, an error is returned.
    )^ ** ** ^(
    [SQLITE_OPEN_READWRITE]
    **
    The database is opened for reading and writing if possible, or reading ** only if the file is write protected by the operating system. In either ** case the database must already exist, otherwise an error is returned.
    )^ ** ** ^(
    [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]
    **
    The database is opened for reading and writing, and is created if ** it does not already exist. This is the behavior that is always used for ** sqlite3_open() and sqlite3_open16().
    )^ **
    ** ** In addition to the required flags, the following optional flags are ** also supported: ** **
    ** ^(
    [SQLITE_OPEN_URI]
    **
    The filename can be interpreted as a URI if this flag is set.
    )^ ** ** ^(
    [SQLITE_OPEN_MEMORY]
    **
    The database will be opened as an in-memory database. The database ** is named by the "filename" argument for the purposes of cache-sharing, ** if shared cache mode is enabled, but the "filename" is otherwise ignored. **
    )^ ** ** ^(
    [SQLITE_OPEN_NOMUTEX]
    **
    The new database connection will use the "multi-thread" ** [threading mode].)^ This means that separate threads are allowed ** to use SQLite at the same time, as long as each thread is using ** a different [database connection]. ** ** ^(
    [SQLITE_OPEN_FULLMUTEX]
    **
    The new database connection will use the "serialized" ** [threading mode].)^ This means the multiple threads can safely ** attempt to use the same database connection at the same time. ** (Mutexes will block any actual concurrency, but in this mode ** there is no harm in trying.) ** ** ^(
    [SQLITE_OPEN_SHAREDCACHE]
    **
    The database is opened [shared cache] enabled, overriding ** the default shared cache setting provided by ** [sqlite3_enable_shared_cache()].)^ ** ** ^(
    [SQLITE_OPEN_PRIVATECACHE]
    **
    The database is opened [shared cache] disabled, overriding ** the default shared cache setting provided by ** [sqlite3_enable_shared_cache()].)^ ** ** [[OPEN_NOFOLLOW]] ^(
    [SQLITE_OPEN_NOFOLLOW]
    **
    The database filename is not allowed to be a symbolic link
    **
    )^ ** ** If the 3rd parameter to sqlite3_open_v2() is not one of the ** required combinations shown above optionally combined with other ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] ** then the behavior is undefined. ** ** ^The fourth parameter to sqlite3_open_v2() is the name of the ** [sqlite3_vfs] object that defines the operating system interface that ** the new database connection should use. ^If the fourth parameter is ** a NULL pointer then the default [sqlite3_vfs] object is used. ** ** ^If the filename is ":memory:", then a private, temporary in-memory database ** is created for the connection. ^This in-memory database will vanish when ** the database connection is closed. Future versions of SQLite might ** make use of additional special filenames that begin with the ":" character. ** It is recommended that when a database filename actually does begin with ** a ":" character you should prefix the filename with a pathname such as ** "./" to avoid ambiguity. ** ** ^If the filename is an empty string, then a private, temporary ** on-disk database will be created. ^This private database will be ** automatically deleted as soon as the database connection is closed. ** ** [[URI filenames in sqlite3_open()]]

    URI Filenames

    ** ** ^If [URI filename] interpretation is enabled, and the filename argument ** begins with "file:", then the filename is interpreted as a URI. ^URI ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is ** set in the third argument to sqlite3_open_v2(), or if it has ** been enabled globally using the [SQLITE_CONFIG_URI] option with the ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. ** URI filename interpretation is turned off ** by default, but future releases of SQLite might enable URI filename ** interpretation by default. See "[URI filenames]" for additional ** information. ** ** URI filenames are parsed according to RFC 3986. ^If the URI contains an ** authority, then it must be either an empty string or the string ** "localhost". ^If the authority is not an empty string or "localhost", an ** error is returned to the caller. ^The fragment component of a URI, if ** present, is ignored. ** ** ^SQLite uses the path component of the URI as the name of the disk file ** which contains the database. ^If the path begins with a '/' character, ** then it is interpreted as an absolute path. ^If the path does not begin ** with a '/' (meaning that the authority section is omitted from the URI) ** then the path is interpreted as a relative path. ** ^(On windows, the first component of an absolute path ** is a drive specification (e.g. "C:").)^ ** ** [[core URI query parameters]] ** The query component of a URI may contain parameters that are interpreted ** either by SQLite itself, or by a [VFS | custom VFS implementation]. ** SQLite and its built-in [VFSes] interpret the ** following query parameters: ** ** ** ** ^Specifying an unknown parameter in the query component of a URI is not an ** error. Future versions of SQLite might understand additional query ** parameters. See "[query parameters with special meaning to SQLite]" for ** additional information. ** ** [[URI filename examples]]

    URI filename examples

    ** ** **
    URI filenames Results **
    file:data.db ** Open the file "data.db" in the current directory. **
    file:/home/fred/data.db
    ** file:///home/fred/data.db
    ** file://localhost/home/fred/data.db
    ** Open the database file "/home/fred/data.db". **
    file://darkstar/home/fred/data.db ** An error. "darkstar" is not a recognized authority. **
    ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db ** Windows only: Open the file "data.db" on fred's desktop on drive ** C:. Note that the %20 escaping in this example is not strictly ** necessary - space characters can be used literally ** in URI filenames. **
    file:data.db?mode=ro&cache=private ** Open file "data.db" in the current directory for read-only access. ** Regardless of whether or not shared-cache mode is enabled by ** default, use a private cache. **
    file:/home/fred/data.db?vfs=unix-dotfile ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" ** that uses dot-files in place of posix advisory locking. **
    file:data.db?mode=readonly ** An error. "readonly" is not a valid option for the "mode" parameter. ** Use "ro" instead: "file:data.db?mode=ro". **
    ** ** ^URI hexadecimal escape sequences (%HH) are supported within the path and ** query components of a URI. A hexadecimal escape sequence consists of a ** percent sign - "%" - followed by exactly two hexadecimal digits ** specifying an octet value. ^Before the path or query components of a ** URI filename are interpreted, they are encoded using UTF-8 and all ** hexadecimal escape sequences replaced by a single byte containing the ** corresponding octet. If this process generates an invalid UTF-8 encoding, ** the results are undefined. ** ** Note to Windows users: The encoding used for the filename argument ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever ** codepage is currently defined. Filenames containing international ** characters must be converted to UTF-8 prior to passing them into ** sqlite3_open() or sqlite3_open_v2(). ** ** Note to Windows Runtime users: The temporary directory must be set ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various ** features that require the use of temporary files may fail. ** ** See also: [sqlite3_temp_directory] */ SQLITE_API int sqlite3_open( const char *filename, /* Database filename (UTF-8) */ sqlite3 **ppDb /* OUT: SQLite db handle */ ); SQLITE_API int sqlite3_open16( const void *filename, /* Database filename (UTF-16) */ sqlite3 **ppDb /* OUT: SQLite db handle */ ); SQLITE_API int sqlite3_open_v2( const char *filename, /* Database filename (UTF-8) */ sqlite3 **ppDb, /* OUT: SQLite db handle */ int flags, /* Flags */ const char *zVfs /* Name of VFS module to use */ ); /* ** CAPI3REF: Obtain Values For URI Parameters ** ** These are utility routines, useful to [VFS|custom VFS implementations], ** that check if a database file was a URI that contained a specific query ** parameter, and if so obtains the value of that query parameter. ** ** The first parameter to these interfaces (hereafter referred to ** as F) must be one of: ** ** If the F parameter is not one of the above, then the behavior is ** undefined and probably undesirable. Older versions of SQLite were ** more tolerant of invalid F parameters than newer versions. ** ** If F is a suitable filename (as described in the previous paragraph) ** and if P is the name of the query parameter, then ** sqlite3_uri_parameter(F,P) returns the value of the P ** parameter if it exists or a NULL pointer if P does not appear as a ** query parameter on F. If P is a query parameter of F and it ** has no explicit value, then sqlite3_uri_parameter(F,P) returns ** a pointer to an empty string. ** ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean ** parameter and returns true (1) or false (0) according to the value ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the ** value of query parameter P is one of "yes", "true", or "on" in any ** case or if the value begins with a non-zero number. The ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of ** query parameter P is one of "no", "false", or "off" in any case or ** if the value begins with a numeric zero. If P is not a query ** parameter on F or if the value of P does not match any of the ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). ** ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a ** 64-bit signed integer and returns that integer, or D if P does not ** exist. If the value of P is something other than an integer, then ** zero is returned. ** ** The sqlite3_uri_key(F,N) returns a pointer to the name (not ** the value) of the N-th query parameter for filename F, or a NULL ** pointer if N is less than zero or greater than the number of query ** parameters minus 1. The N value is zero-based so N should be 0 to obtain ** the name of the first query parameter, 1 for the second parameter, and ** so forth. ** ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and ** is not a database file pathname pointer that the SQLite core passed ** into the xOpen VFS method, then the behavior of this routine is undefined ** and probably undesirable. ** ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F ** parameter can also be the name of a rollback journal file or WAL file ** in addition to the main database file. Prior to version 3.31.0, these ** routines would only work if F was the name of the main database file. ** When the F parameter is the name of the rollback journal or WAL file, ** it has access to all the same query parameters as were found on the ** main database file. ** ** See the [URI filename] documentation for additional information. */ SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); /* ** CAPI3REF: Translate filenames ** ** These routines are available to [VFS|custom VFS implementations] for ** translating filenames between the main database file, the journal file, ** and the WAL file. ** ** If F is the name of an sqlite database file, journal file, or WAL file ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) ** returns the name of the corresponding database file. ** ** If F is the name of an sqlite database file, journal file, or WAL file ** passed by the SQLite core into the VFS, or if F is a database filename ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) ** returns the name of the corresponding rollback journal file. ** ** If F is the name of an sqlite database file, journal file, or WAL file ** that was passed by the SQLite core into the VFS, or if F is a database ** filename obtained from [sqlite3_db_filename()], then ** sqlite3_filename_wal(F) returns the name of the corresponding ** WAL file. ** ** In all of the above, if F is not the name of a database, journal or WAL ** filename passed into the VFS from the SQLite core and F is not the ** return value from [sqlite3_db_filename()], then the result is ** undefined and is likely a memory access violation. */ SQLITE_API const char *sqlite3_filename_database(const char*); SQLITE_API const char *sqlite3_filename_journal(const char*); SQLITE_API const char *sqlite3_filename_wal(const char*); /* ** CAPI3REF: Database File Corresponding To A Journal ** ** ^If X is the name of a rollback or WAL-mode journal file that is ** passed into the xOpen method of [sqlite3_vfs], then ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] ** object that represents the main database file. ** ** This routine is intended for use in custom [VFS] implementations ** only. It is not a general-purpose interface. ** The argument sqlite3_file_object(X) must be a filename pointer that ** has been passed into [sqlite3_vfs].xOpen method where the ** flags parameter to xOpen contains one of the bits ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use ** of this routine results in undefined and probably undesirable ** behavior. */ SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); /* ** CAPI3REF: Create and Destroy VFS Filenames ** ** These interfces are provided for use by [VFS shim] implementations and ** are not useful outside of that context. ** ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of ** database filename D with corresponding journal file J and WAL file W and ** with N URI parameters key/values pairs in the array P. The result from ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that ** is safe to pass to routines like: ** ** If a memory allocation error occurs, sqlite3_create_filename() might ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) ** must be released by a corresponding call to sqlite3_free_filename(Y). ** ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array ** of 2*N pointers to strings. Each pair of pointers in this array corresponds ** to a key and value for a query parameter. The P parameter may be a NULL ** pointer if N is zero. None of the 2*N pointers in the P array may be ** NULL pointers and key pointers should not be empty strings. ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may ** be NULL pointers, though they can be empty strings. ** ** The sqlite3_free_filename(Y) routine releases a memory allocation ** previously obtained from sqlite3_create_filename(). Invoking ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. ** ** If the Y parameter to sqlite3_free_filename(Y) is anything other ** than a NULL pointer or a pointer previously acquired from ** sqlite3_create_filename(), then bad things such as heap ** corruption or segfaults may occur. The value Y should not be ** used again after sqlite3_free_filename(Y) has been called. This means ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, ** then the corresponding [sqlite3_module.xClose() method should also be ** invoked prior to calling sqlite3_free_filename(Y). */ SQLITE_API char *sqlite3_create_filename( const char *zDatabase, const char *zJournal, const char *zWal, int nParam, const char **azParam ); SQLITE_API void sqlite3_free_filename(char*); /* ** CAPI3REF: Error Codes And Messages ** METHOD: sqlite3 ** ** ^If the most recent sqlite3_* API call associated with ** [database connection] D failed, then the sqlite3_errcode(D) interface ** returns the numeric [result code] or [extended result code] for that ** API call. ** ^The sqlite3_extended_errcode() ** interface is the same except that it always returns the ** [extended result code] even when extended result codes are ** disabled. ** ** The values returned by sqlite3_errcode() and/or ** sqlite3_extended_errcode() might change with each API call. ** Except, there are some interfaces that are guaranteed to never ** change the value of the error code. The error-code preserving ** interfaces are: ** ** ** ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language ** text that describes the error, as either UTF-8 or UTF-16 respectively. ** ^(Memory to hold the error message string is managed internally. ** The application does not need to worry about freeing the result. ** However, the error string might be overwritten or deallocated by ** subsequent calls to other SQLite interface functions.)^ ** ** ^The sqlite3_errstr() interface returns the English-language text ** that describes the [result code], as UTF-8. ** ^(Memory to hold the error message string is managed internally ** and must not be freed by the application)^. ** ** When the serialized [threading mode] is in use, it might be the ** case that a second error occurs on a separate thread in between ** the time of the first error and the call to these interfaces. ** When that happens, the second error will be reported since these ** interfaces always report the most recent result. To avoid ** this, each thread can obtain exclusive use of the [database connection] D ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after ** all calls to the interfaces listed here are completed. ** ** If an interface fails with SQLITE_MISUSE, that means the interface ** was invoked incorrectly by the application. In that case, the ** error code and message may or may not be set. */ SQLITE_API int sqlite3_errcode(sqlite3 *db); SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); SQLITE_API const char *sqlite3_errmsg(sqlite3*); SQLITE_API const void *sqlite3_errmsg16(sqlite3*); SQLITE_API const char *sqlite3_errstr(int); /* ** CAPI3REF: Prepared Statement Object ** KEYWORDS: {prepared statement} {prepared statements} ** ** An instance of this object represents a single SQL statement that ** has been compiled into binary form and is ready to be evaluated. ** ** Think of each SQL statement as a separate computer program. The ** original SQL text is source code. A prepared statement object ** is the compiled object code. All SQL must be converted into a ** prepared statement before it can be run. ** ** The life-cycle of a prepared statement object usually goes like this: ** **
      **
    1. Create the prepared statement object using [sqlite3_prepare_v2()]. **
    2. Bind values to [parameters] using the sqlite3_bind_*() ** interfaces. **
    3. Run the SQL by calling [sqlite3_step()] one or more times. **
    4. Reset the prepared statement using [sqlite3_reset()] then go back ** to step 2. Do this zero or more times. **
    5. Destroy the object using [sqlite3_finalize()]. **
    */ typedef struct sqlite3_stmt sqlite3_stmt; /* ** CAPI3REF: Run-time Limits ** METHOD: sqlite3 ** ** ^(This interface allows the size of various constructs to be limited ** on a connection by connection basis. The first parameter is the ** [database connection] whose limit is to be set or queried. The ** second parameter is one of the [limit categories] that define a ** class of constructs to be size limited. The third parameter is the ** new limit for that construct.)^ ** ** ^If the new limit is a negative number, the limit is unchanged. ** ^(For each limit category SQLITE_LIMIT_NAME there is a ** [limits | hard upper bound] ** set at compile-time by a C preprocessor macro called ** [limits | SQLITE_MAX_NAME]. ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ ** ^Attempts to increase a limit above its hard upper bound are ** silently truncated to the hard upper bound. ** ** ^Regardless of whether or not the limit was changed, the ** [sqlite3_limit()] interface returns the prior value of the limit. ** ^Hence, to find the current value of a limit without changing it, ** simply invoke this interface with the third parameter set to -1. ** ** Run-time limits are intended for use in applications that manage ** both their own internal database and also databases that are controlled ** by untrusted external sources. An example application might be a ** web browser that has its own databases for storing history and ** separate databases controlled by JavaScript applications downloaded ** off the Internet. The internal databases can be given the ** large, default limits. Databases managed by external sources can ** be given much smaller limits designed to prevent a denial of service ** attack. Developers might also want to use the [sqlite3_set_authorizer()] ** interface to further control untrusted SQL. The size of the database ** created by an untrusted script can be contained using the ** [max_page_count] [PRAGMA]. ** ** New run-time limit categories may be added in future releases. */ SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); /* ** CAPI3REF: Run-Time Limit Categories ** KEYWORDS: {limit category} {*limit categories} ** ** These constants define various performance limits ** that can be lowered at run-time using [sqlite3_limit()]. ** The synopsis of the meanings of the various limits is shown below. ** Additional information is available at [limits | Limits in SQLite]. ** **
    ** [[SQLITE_LIMIT_LENGTH]] ^(
    SQLITE_LIMIT_LENGTH
    **
    The maximum size of any string or BLOB or table row, in bytes.
    )^ ** ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(
    SQLITE_LIMIT_SQL_LENGTH
    **
    The maximum length of an SQL statement, in bytes.
    )^ ** ** [[SQLITE_LIMIT_COLUMN]] ^(
    SQLITE_LIMIT_COLUMN
    **
    The maximum number of columns in a table definition or in the ** result set of a [SELECT] or the maximum number of columns in an index ** or in an ORDER BY or GROUP BY clause.
    )^ ** ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(
    SQLITE_LIMIT_EXPR_DEPTH
    **
    The maximum depth of the parse tree on any expression.
    )^ ** ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(
    SQLITE_LIMIT_COMPOUND_SELECT
    **
    The maximum number of terms in a compound SELECT statement.
    )^ ** ** [[SQLITE_LIMIT_VDBE_OP]] ^(
    SQLITE_LIMIT_VDBE_OP
    **
    The maximum number of instructions in a virtual machine program ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or ** the equivalent tries to allocate space for more than this many opcodes ** in a single prepared statement, an SQLITE_NOMEM error is returned.
    )^ ** ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(
    SQLITE_LIMIT_FUNCTION_ARG
    **
    The maximum number of arguments on a function.
    )^ ** ** [[SQLITE_LIMIT_ATTACHED]] ^(
    SQLITE_LIMIT_ATTACHED
    **
    The maximum number of [ATTACH | attached databases].)^
    ** ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] ** ^(
    SQLITE_LIMIT_LIKE_PATTERN_LENGTH
    **
    The maximum length of the pattern argument to the [LIKE] or ** [GLOB] operators.
    )^ ** ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] ** ^(
    SQLITE_LIMIT_VARIABLE_NUMBER
    **
    The maximum index number of any [parameter] in an SQL statement.)^ ** ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(
    SQLITE_LIMIT_TRIGGER_DEPTH
    **
    The maximum depth of recursion for triggers.
    )^ ** ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(
    SQLITE_LIMIT_WORKER_THREADS
    **
    The maximum number of auxiliary worker threads that a single ** [prepared statement] may start.
    )^ **
    */ #define SQLITE_LIMIT_LENGTH 0 #define SQLITE_LIMIT_SQL_LENGTH 1 #define SQLITE_LIMIT_COLUMN 2 #define SQLITE_LIMIT_EXPR_DEPTH 3 #define SQLITE_LIMIT_COMPOUND_SELECT 4 #define SQLITE_LIMIT_VDBE_OP 5 #define SQLITE_LIMIT_FUNCTION_ARG 6 #define SQLITE_LIMIT_ATTACHED 7 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 #define SQLITE_LIMIT_WORKER_THREADS 11 /* ** CAPI3REF: Prepare Flags ** ** These constants define various flags that can be passed into ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and ** [sqlite3_prepare16_v3()] interfaces. ** ** New flags may be added in future releases of SQLite. ** **
    ** [[SQLITE_PREPARE_PERSISTENT]] ^(
    SQLITE_PREPARE_PERSISTENT
    **
    The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner ** that the prepared statement will be retained for a long time and ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] ** and [sqlite3_prepare16_v3()] assume that the prepared statement will ** be used just once or at most a few times and then destroyed using ** [sqlite3_finalize()] relatively soon. The current implementation acts ** on this hint by avoiding the use of [lookaside memory] so as not to ** deplete the limited store of lookaside memory. Future versions of ** SQLite may act on this hint differently. ** ** [[SQLITE_PREPARE_NORMALIZE]]
    SQLITE_PREPARE_NORMALIZE
    **
    The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used ** to be required for any prepared statement that wanted to use the ** [sqlite3_normalized_sql()] interface. However, the ** [sqlite3_normalized_sql()] interface is now available to all ** prepared statements, regardless of whether or not they use this ** flag. ** ** [[SQLITE_PREPARE_NO_VTAB]]
    SQLITE_PREPARE_NO_VTAB
    **
    The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler ** to return an error (error code SQLITE_ERROR) if the statement uses ** any virtual tables. **
    */ #define SQLITE_PREPARE_PERSISTENT 0x01 #define SQLITE_PREPARE_NORMALIZE 0x02 #define SQLITE_PREPARE_NO_VTAB 0x04 /* ** CAPI3REF: Compiling An SQL Statement ** KEYWORDS: {SQL statement compiler} ** METHOD: sqlite3 ** CONSTRUCTOR: sqlite3_stmt ** ** To execute an SQL statement, it must first be compiled into a byte-code ** program using one of these routines. Or, in other words, these routines ** are constructors for the [prepared statement] object. ** ** The preferred routine to use is [sqlite3_prepare_v2()]. The ** [sqlite3_prepare()] interface is legacy and should be avoided. ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used ** for special purposes. ** ** The use of the UTF-8 interfaces is preferred, as SQLite currently ** does all parsing using UTF-8. The UTF-16 interfaces are provided ** as a convenience. The UTF-16 interfaces work by converting the ** input text into UTF-8, then invoking the corresponding UTF-8 interface. ** ** The first argument, "db", is a [database connection] obtained from a ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or ** [sqlite3_open16()]. The database connection must not have been closed. ** ** The second argument, "zSql", is the statement to be compiled, encoded ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), ** and sqlite3_prepare_v3() ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), ** and sqlite3_prepare16_v3() use UTF-16. ** ** ^If the nByte argument is negative, then zSql is read up to the ** first zero terminator. ^If nByte is positive, then it is the ** number of bytes read from zSql. ^If nByte is zero, then no prepared ** statement is generated. ** If the caller knows that the supplied string is nul-terminated, then ** there is a small performance advantage to passing an nByte parameter that ** is the number of bytes in the input string including ** the nul-terminator. ** ** ^If pzTail is not NULL then *pzTail is made to point to the first byte ** past the end of the first SQL statement in zSql. These routines only ** compile the first statement in zSql, so *pzTail is left pointing to ** what remains uncompiled. ** ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set ** to NULL. ^If the input text contains no SQL (if the input is an empty ** string or a comment) then *ppStmt is set to NULL. ** The calling procedure is responsible for deleting the compiled ** SQL statement using [sqlite3_finalize()] after it has finished with it. ** ppStmt may not be NULL. ** ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; ** otherwise an [error code] is returned. ** ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) ** are retained for backwards compatibility, but their use is discouraged. ** ^In the "vX" interfaces, the prepared statement ** that is returned (the [sqlite3_stmt] object) contains a copy of the ** original SQL text. This causes the [sqlite3_step()] interface to ** behave differently in three ways: ** **
      **
    1. ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it ** always used to do, [sqlite3_step()] will automatically recompile the SQL ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] ** retries will occur before sqlite3_step() gives up and returns an error. **
    2. ** **
    3. ** ^When an error occurs, [sqlite3_step()] will return one of the detailed ** [error codes] or [extended error codes]. ^The legacy behavior was that ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code ** and the application would have to make a second call to [sqlite3_reset()] ** in order to find the underlying cause of the problem. With the "v2" prepare ** interfaces, the underlying reason for the error is returned immediately. **
    4. ** **
    5. ** ^If the specific value bound to a [parameter | host parameter] in the ** WHERE clause might influence the choice of query plan for a statement, ** then the statement will be automatically recompiled, as if there had been ** a schema change, on the first [sqlite3_step()] call following any change ** to the [sqlite3_bind_text | bindings] of that [parameter]. ** ^The specific value of a WHERE-clause [parameter] might influence the ** choice of query plan if the parameter is the left-hand side of a [LIKE] ** or [GLOB] operator or if the parameter is compared to an indexed column ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. **
    6. **
    ** **

    ^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having ** the extra prepFlags parameter, which is a bit array consisting of zero or ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The ** sqlite3_prepare_v2() interface works exactly the same as ** sqlite3_prepare_v3() with a zero prepFlags parameter. */ SQLITE_API int sqlite3_prepare( sqlite3 *db, /* Database handle */ const char *zSql, /* SQL statement, UTF-8 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const char **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare_v2( sqlite3 *db, /* Database handle */ const char *zSql, /* SQL statement, UTF-8 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const char **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare_v3( sqlite3 *db, /* Database handle */ const char *zSql, /* SQL statement, UTF-8 encoded */ int nByte, /* Maximum length of zSql in bytes. */ unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const char **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare16( sqlite3 *db, /* Database handle */ const void *zSql, /* SQL statement, UTF-16 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const void **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare16_v2( sqlite3 *db, /* Database handle */ const void *zSql, /* SQL statement, UTF-16 encoded */ int nByte, /* Maximum length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const void **pzTail /* OUT: Pointer to unused portion of zSql */ ); SQLITE_API int sqlite3_prepare16_v3( sqlite3 *db, /* Database handle */ const void *zSql, /* SQL statement, UTF-16 encoded */ int nByte, /* Maximum length of zSql in bytes. */ unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ sqlite3_stmt **ppStmt, /* OUT: Statement handle */ const void **pzTail /* OUT: Pointer to unused portion of zSql */ ); /* ** CAPI3REF: Retrieving Statement SQL ** METHOD: sqlite3_stmt ** ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 ** SQL text used to create [prepared statement] P if P was ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 ** string containing the SQL text of prepared statement P with ** [bound parameters] expanded. ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 ** string containing the normalized SQL text of prepared statement P. The ** semantics used to normalize a SQL statement are unspecified and subject ** to change. At a minimum, literal values will be replaced with suitable ** placeholders. ** ** ^(For example, if a prepared statement is created using the SQL ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 ** and parameter :xyz is unbound, then sqlite3_sql() will return ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() ** will return "SELECT 2345,NULL".)^ ** ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory ** is available to hold the result, or if the result would exceed the ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. ** ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time ** option causes sqlite3_expanded_sql() to always return NULL. ** ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) ** are managed by SQLite and are automatically freed when the prepared ** statement is finalized. ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, ** is obtained from [sqlite3_malloc()] and must be free by the application ** by passing it to [sqlite3_free()]. */ SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); /* ** CAPI3REF: Determine If An SQL Statement Writes The Database ** METHOD: sqlite3_stmt ** ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if ** and only if the [prepared statement] X makes no direct changes to ** the content of the database file. ** ** Note that [application-defined SQL functions] or ** [virtual tables] might change the database indirectly as a side effect. ** ^(For example, if an application defines a function "eval()" that ** calls [sqlite3_exec()], then the following SQL statement would ** change the database file through side-effects: ** **

    **    SELECT eval('DELETE FROM t1') FROM t2;
    ** 
    ** ** But because the [SELECT] statement does not change the database file ** directly, sqlite3_stmt_readonly() would still return true.)^ ** ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, ** since the statements themselves do not actually modify the database but ** rather they control the timing of when other statements modify the ** database. ^The [ATTACH] and [DETACH] statements also cause ** sqlite3_stmt_readonly() to return true since, while those statements ** change the configuration of a database connection, they do not make ** changes to the content of the database files on disk. ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so ** sqlite3_stmt_readonly() returns false for those commands. ** ** ^This routine returns false if there is any possibility that the ** statement might change the database file. ^A false return does ** not guarantee that the statement will change the database file. ** ^For example, an UPDATE statement might have a WHERE clause that ** makes it a no-op, but the sqlite3_stmt_readonly() result would still ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a ** read-only no-op if the table already exists, but ** sqlite3_stmt_readonly() still returns false for such a statement. */ SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); /* ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement ** METHOD: sqlite3_stmt ** ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the ** prepared statement S is an EXPLAIN statement, or 2 if the ** statement S is an EXPLAIN QUERY PLAN. ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is ** an ordinary statement or a NULL pointer. */ SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); /* ** CAPI3REF: Determine If A Prepared Statement Has Been Reset ** METHOD: sqlite3_stmt ** ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the ** [prepared statement] S has been stepped at least once using ** [sqlite3_step(S)] but has neither run to completion (returned ** [SQLITE_DONE] from [sqlite3_step(S)]) nor ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) ** interface returns false if S is a NULL pointer. If S is not a ** NULL pointer and is not a pointer to a valid [prepared statement] ** object, then the behavior is undefined and probably undesirable. ** ** This interface can be used in combination [sqlite3_next_stmt()] ** to locate all prepared statements associated with a database ** connection that are in need of being reset. This can be used, ** for example, in diagnostic routines to search for prepared ** statements that are holding a transaction open. */ SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); /* ** CAPI3REF: Dynamically Typed Value Object ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} ** ** SQLite uses the sqlite3_value object to represent all values ** that can be stored in a database table. SQLite uses dynamic typing ** for the values it stores. ^Values stored in sqlite3_value objects ** can be integers, floating point values, strings, BLOBs, or NULL. ** ** An sqlite3_value object may be either "protected" or "unprotected". ** Some interfaces require a protected sqlite3_value. Other interfaces ** will accept either a protected or an unprotected sqlite3_value. ** Every interface that accepts sqlite3_value arguments specifies ** whether or not it requires a protected sqlite3_value. The ** [sqlite3_value_dup()] interface can be used to construct a new ** protected sqlite3_value from an unprotected sqlite3_value. ** ** The terms "protected" and "unprotected" refer to whether or not ** a mutex is held. An internal mutex is held for a protected ** sqlite3_value object but no mutex is held for an unprotected ** sqlite3_value object. If SQLite is compiled to be single-threaded ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) ** or if SQLite is run in one of reduced mutex modes ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] ** then there is no distinction between protected and unprotected ** sqlite3_value objects and they can be used interchangeably. However, ** for maximum code portability it is recommended that applications ** still make the distinction between protected and unprotected ** sqlite3_value objects even when not strictly required. ** ** ^The sqlite3_value objects that are passed as parameters into the ** implementation of [application-defined SQL functions] are protected. ** ^The sqlite3_value object returned by ** [sqlite3_column_value()] is unprotected. ** Unprotected sqlite3_value objects may only be used as arguments ** to [sqlite3_result_value()], [sqlite3_bind_value()], and ** [sqlite3_value_dup()]. ** The [sqlite3_value_blob | sqlite3_value_type()] family of ** interfaces require protected sqlite3_value objects. */ typedef struct sqlite3_value sqlite3_value; /* ** CAPI3REF: SQL Function Context Object ** ** The context in which an SQL function executes is stored in an ** sqlite3_context object. ^A pointer to an sqlite3_context object ** is always first parameter to [application-defined SQL functions]. ** The application-defined SQL function implementation will pass this ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], ** [sqlite3_aggregate_context()], [sqlite3_user_data()], ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], ** and/or [sqlite3_set_auxdata()]. */ typedef struct sqlite3_context sqlite3_context; /* ** CAPI3REF: Binding Values To Prepared Statements ** KEYWORDS: {host parameter} {host parameters} {host parameter name} ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} ** METHOD: sqlite3_stmt ** ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, ** literals may be replaced by a [parameter] that matches one of following ** templates: ** ** ** ** In the templates above, NNN represents an integer literal, ** and VVV represents an alphanumeric identifier.)^ ^The values of these ** parameters (also called "host parameter names" or "SQL parameters") ** can be set using the sqlite3_bind_*() routines defined here. ** ** ^The first argument to the sqlite3_bind_*() routines is always ** a pointer to the [sqlite3_stmt] object returned from ** [sqlite3_prepare_v2()] or its variants. ** ** ^The second argument is the index of the SQL parameter to be set. ** ^The leftmost SQL parameter has an index of 1. ^When the same named ** SQL parameter is used more than once, second and subsequent ** occurrences have the same index as the first occurrence. ** ^The index for named parameters can be looked up using the ** [sqlite3_bind_parameter_index()] API if desired. ^The index ** for "?NNN" parameters is the value of NNN. ** ^The NNN value must be between 1 and the [sqlite3_limit()] ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). ** ** ^The third argument is the value to bind to the parameter. ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter ** is ignored and the end result is the same as sqlite3_bind_null(). ** ^If the third parameter to sqlite3_bind_text() is not NULL, then ** it should be a pointer to well-formed UTF8 text. ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then ** it should be a pointer to well-formed UTF16 text. ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then ** it should be a pointer to a well-formed unicode string that is ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 ** otherwise. ** ** [[byte-order determination rules]] ^The byte-order of ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) ** found in first character, which is removed, or in the absence of a BOM ** the byte order is the native byte order of the host ** machine for sqlite3_bind_text16() or the byte order specified in ** the 6th parameter for sqlite3_bind_text64().)^ ** ^If UTF16 input text contains invalid unicode ** characters, then SQLite might change those invalid characters ** into the unicode replacement character: U+FFFD. ** ** ^(In those routines that have a fourth argument, its value is the ** number of bytes in the parameter. To be clear: the value is the ** number of bytes in the value, not the number of characters.)^ ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() ** is negative, then the length of the string is ** the number of bytes up to the first zero terminator. ** If the fourth parameter to sqlite3_bind_blob() is negative, then ** the behavior is undefined. ** If a non-negative fourth parameter is provided to sqlite3_bind_text() ** or sqlite3_bind_text16() or sqlite3_bind_text64() then ** that parameter must be the byte offset ** where the NUL terminator would occur assuming the string were NUL ** terminated. If any NUL characters occurs at byte offsets less than ** the value of the fourth parameter then the resulting string value will ** contain embedded NULs. The result of expressions involving strings ** with embedded NULs is undefined. ** ** ^The fifth argument to the BLOB and string binding interfaces controls ** or indicates the lifetime of the object referenced by the third parameter. ** These three options exist: ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished ** with it may be passed. ^It is called to dispose of the BLOB or string even ** if the call to the bind API fails, except the destructor is not called if ** the third parameter is a NULL pointer or the fourth parameter is negative. ** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that ** the application remains responsible for disposing of the object. ^In this ** case, the object and the provided pointer to it must remain valid until ** either the prepared statement is finalized or the same SQL parameter is ** bound to something else, whichever occurs sooner. ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the ** object is to be copied prior to the return from sqlite3_bind_*(). ^The ** object and pointer to it must remain valid until then. ^SQLite will then ** manage the lifetime of its private copy. ** ** ^The sixth argument to sqlite3_bind_text64() must be one of ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] ** to specify the encoding of the text in the third parameter. If ** the sixth argument to sqlite3_bind_text64() is not one of the ** allowed values shown above, or if the text encoding is different ** from the encoding specified by the sixth parameter, then the behavior ** is undefined. ** ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory ** (just an integer to hold its size) while it is being processed. ** Zeroblobs are intended to serve as placeholders for BLOBs whose ** content is later written using ** [sqlite3_blob_open | incremental BLOB I/O] routines. ** ^A negative value for the zeroblob results in a zero-length BLOB. ** ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in ** [prepared statement] S to have an SQL value of NULL, but to also be ** associated with the pointer P of type T. ^D is either a NULL pointer or ** a pointer to a destructor function for P. ^SQLite will invoke the ** destructor D with a single argument of P when it is finished using ** P. The T parameter should be a static string, preferably a string ** literal. The sqlite3_bind_pointer() routine is part of the ** [pointer passing interface] added for SQLite 3.20.0. ** ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer ** for the [prepared statement] or with a prepared statement for which ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() ** routine is passed a [prepared statement] that has been finalized, the ** result is undefined and probably harmful. ** ** ^Bindings are not cleared by the [sqlite3_reset()] routine. ** ^Unbound parameters are interpreted as NULL. ** ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an ** [error code] if anything goes wrong. ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or ** [SQLITE_MAX_LENGTH]. ** ^[SQLITE_RANGE] is returned if the parameter ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. ** ** See also: [sqlite3_bind_parameter_count()], ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. */ SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, void(*)(void*)); SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, void(*)(void*), unsigned char encoding); SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); /* ** CAPI3REF: Number Of SQL Parameters ** METHOD: sqlite3_stmt ** ** ^This routine can be used to find the number of [SQL parameters] ** in a [prepared statement]. SQL parameters are tokens of the ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as ** placeholders for values that are [sqlite3_bind_blob | bound] ** to the parameters at a later time. ** ** ^(This routine actually returns the index of the largest (rightmost) ** parameter. For all forms except ?NNN, this will correspond to the ** number of unique parameters. If parameters of the ?NNN form are used, ** there may be gaps in the list.)^ ** ** See also: [sqlite3_bind_blob|sqlite3_bind()], ** [sqlite3_bind_parameter_name()], and ** [sqlite3_bind_parameter_index()]. */ SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); /* ** CAPI3REF: Name Of A Host Parameter ** METHOD: sqlite3_stmt ** ** ^The sqlite3_bind_parameter_name(P,N) interface returns ** the name of the N-th [SQL parameter] in the [prepared statement] P. ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" ** respectively. ** In other words, the initial ":" or "$" or "@" or "?" ** is included as part of the name.)^ ** ^Parameters of the form "?" without a following integer have no name ** and are referred to as "nameless" or "anonymous parameters". ** ** ^The first host parameter has an index of 1, not 0. ** ** ^If the value N is out of range or if the N-th parameter is ** nameless, then NULL is returned. ^The returned string is ** always in UTF-8 encoding even if the named parameter was ** originally specified as UTF-16 in [sqlite3_prepare16()], ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. ** ** See also: [sqlite3_bind_blob|sqlite3_bind()], ** [sqlite3_bind_parameter_count()], and ** [sqlite3_bind_parameter_index()]. */ SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); /* ** CAPI3REF: Index Of A Parameter With A Given Name ** METHOD: sqlite3_stmt ** ** ^Return the index of an SQL parameter given its name. ^The ** index value returned is suitable for use as the second ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero ** is returned if no matching parameter is found. ^The parameter ** name must be given in UTF-8 even if the original statement ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or ** [sqlite3_prepare16_v3()]. ** ** See also: [sqlite3_bind_blob|sqlite3_bind()], ** [sqlite3_bind_parameter_count()], and ** [sqlite3_bind_parameter_name()]. */ SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); /* ** CAPI3REF: Reset All Bindings On A Prepared Statement ** METHOD: sqlite3_stmt ** ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. ** ^Use this routine to reset all host parameters to NULL. */ SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); /* ** CAPI3REF: Number Of Columns In A Result Set ** METHOD: sqlite3_stmt ** ** ^Return the number of columns in the result set returned by the ** [prepared statement]. ^If this routine returns 0, that means the ** [prepared statement] returns no data (for example an [UPDATE]). ** ^However, just because this routine returns a positive number does not ** mean that one or more rows of data will be returned. ^A SELECT statement ** will always have a positive sqlite3_column_count() but depending on the ** WHERE clause constraints and the table content, it might return no rows. ** ** See also: [sqlite3_data_count()] */ SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); /* ** CAPI3REF: Column Names In A Result Set ** METHOD: sqlite3_stmt ** ** ^These routines return the name assigned to a particular column ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() ** interface returns a pointer to a zero-terminated UTF-8 string ** and sqlite3_column_name16() returns a pointer to a zero-terminated ** UTF-16 string. ^The first parameter is the [prepared statement] ** that implements the [SELECT] statement. ^The second parameter is the ** column number. ^The leftmost column is number 0. ** ** ^The returned string pointer is valid until either the [prepared statement] ** is destroyed by [sqlite3_finalize()] or until the statement is automatically ** reprepared by the first call to [sqlite3_step()] for a particular run ** or until the next call to ** sqlite3_column_name() or sqlite3_column_name16() on the same column. ** ** ^If sqlite3_malloc() fails during the processing of either routine ** (for example during a conversion from UTF-8 to UTF-16) then a ** NULL pointer is returned. ** ** ^The name of a result column is the value of the "AS" clause for ** that column, if there is an AS clause. If there is no AS clause ** then the name of the column is unspecified and may change from ** one release of SQLite to the next. */ SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); /* ** CAPI3REF: Source Of Data In A Query Result ** METHOD: sqlite3_stmt ** ** ^These routines provide a means to determine the database, table, and ** table column that is the origin of a particular result column in ** [SELECT] statement. ** ^The name of the database or table or column can be returned as ** either a UTF-8 or UTF-16 string. ^The _database_ routines return ** the database name, the _table_ routines return the table name, and ** the origin_ routines return the column name. ** ^The returned string is valid until the [prepared statement] is destroyed ** using [sqlite3_finalize()] or until the statement is automatically ** reprepared by the first call to [sqlite3_step()] for a particular run ** or until the same information is requested ** again in a different encoding. ** ** ^The names returned are the original un-aliased names of the ** database, table, and column. ** ** ^The first argument to these interfaces is a [prepared statement]. ** ^These functions return information about the Nth result column returned by ** the statement, where N is the second function argument. ** ^The left-most column is column 0 for these routines. ** ** ^If the Nth column returned by the statement is an expression or ** subquery and is not a column value, then all of these functions return ** NULL. ^These routines might also return NULL if a memory allocation error ** occurs. ^Otherwise, they return the name of the attached database, table, ** or column that query result column was extracted from. ** ** ^As with all other SQLite APIs, those whose names end with "16" return ** UTF-16 encoded strings and the other functions return UTF-8. ** ** ^These APIs are only available if the library was compiled with the ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. ** ** If two or more threads call one or more ** [sqlite3_column_database_name | column metadata interfaces] ** for the same [prepared statement] and result column ** at the same time then the results are undefined. */ SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); /* ** CAPI3REF: Declared Datatype Of A Query Result ** METHOD: sqlite3_stmt ** ** ^(The first parameter is a [prepared statement]. ** If this statement is a [SELECT] statement and the Nth column of the ** returned result set of that [SELECT] is a table column (not an ** expression or subquery) then the declared type of the table ** column is returned.)^ ^If the Nth column of the result set is an ** expression or subquery, then a NULL pointer is returned. ** ^The returned string is always UTF-8 encoded. ** ** ^(For example, given the database schema: ** ** CREATE TABLE t1(c1 VARIANT); ** ** and the following statement to be compiled: ** ** SELECT c1 + 1, c1 FROM t1; ** ** this routine would return the string "VARIANT" for the second result ** column (i==1), and a NULL pointer for the first result column (i==0).)^ ** ** ^SQLite uses dynamic run-time typing. ^So just because a column ** is declared to contain a particular type does not mean that the ** data stored in that column is of the declared type. SQLite is ** strongly typed, but the typing is dynamic not static. ^Type ** is associated with individual values, not with the containers ** used to hold those values. */ SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); /* ** CAPI3REF: Evaluate An SQL Statement ** METHOD: sqlite3_stmt ** ** After a [prepared statement] has been prepared using any of ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], ** or [sqlite3_prepare16_v3()] or one of the legacy ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function ** must be called one or more times to evaluate the statement. ** ** The details of the behavior of the sqlite3_step() interface depend ** on whether the statement was prepared using the newer "vX" interfaces ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], ** [sqlite3_prepare16_v2()] or the older legacy ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the ** new "vX" interface is recommended for new applications but the legacy ** interface will continue to be supported. ** ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. ** ^With the "v2" interface, any of the other [result codes] or ** [extended result codes] might be returned as well. ** ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the ** database locks it needs to do its job. ^If the statement is a [COMMIT] ** or occurs outside of an explicit transaction, then you can retry the ** statement. If the statement is not a [COMMIT] and occurs within an ** explicit transaction then you should rollback the transaction before ** continuing. ** ** ^[SQLITE_DONE] means that the statement has finished executing ** successfully. sqlite3_step() should not be called again on this virtual ** machine without first calling [sqlite3_reset()] to reset the virtual ** machine back to its initial state. ** ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] ** is returned each time a new row of data is ready for processing by the ** caller. The values may be accessed using the [column access functions]. ** sqlite3_step() is called again to retrieve the next row of data. ** ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint ** violation) has occurred. sqlite3_step() should not be called again on ** the VM. More information may be found by calling [sqlite3_errmsg()]. ** ^With the legacy interface, a more specific error code (for example, ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) ** can be obtained by calling [sqlite3_reset()] on the ** [prepared statement]. ^In the "v2" interface, ** the more specific error code is returned directly by sqlite3_step(). ** ** [SQLITE_MISUSE] means that the this routine was called inappropriately. ** Perhaps it was called on a [prepared statement] that has ** already been [sqlite3_finalize | finalized] or on one that had ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could ** be the case that the same database connection is being used by two or ** more threads at the same moment in time. ** ** For all versions of SQLite up to and including 3.6.23.1, a call to ** [sqlite3_reset()] was required after sqlite3_step() returned anything ** other than [SQLITE_ROW] before any subsequent invocation of ** sqlite3_step(). Failure to reset the prepared statement using ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], ** sqlite3_step() began ** calling [sqlite3_reset()] automatically in this circumstance rather ** than returning [SQLITE_MISUSE]. This is not considered a compatibility ** break because any application that ever receives an SQLITE_MISUSE error ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option ** can be used to restore the legacy behavior. ** ** Goofy Interface Alert: In the legacy interface, the sqlite3_step() ** API always returns a generic error code, [SQLITE_ERROR], following any ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the ** specific [error codes] that better describes the error. ** We admit that this is a goofy design. The problem has been fixed ** with the "v2" interface. If you prepare all of your SQL statements ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, ** then the more specific [error codes] are returned directly ** by sqlite3_step(). The use of the "vX" interfaces is recommended. */ SQLITE_API int sqlite3_step(sqlite3_stmt*); /* ** CAPI3REF: Number of columns in a result set ** METHOD: sqlite3_stmt ** ** ^The sqlite3_data_count(P) interface returns the number of columns in the ** current row of the result set of [prepared statement] P. ** ^If prepared statement P does not have results ready to return ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of ** interfaces) then sqlite3_data_count(P) returns 0. ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) ** will return non-zero if previous call to [sqlite3_step](P) returned ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] ** where it always returns zero since each step of that multi-step ** pragma returns 0 columns of data. ** ** See also: [sqlite3_column_count()] */ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); /* ** CAPI3REF: Fundamental Datatypes ** KEYWORDS: SQLITE_TEXT ** ** ^(Every value in SQLite has one of five fundamental datatypes: ** ** )^ ** ** These constants are codes for each of those types. ** ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 ** for a completely different meaning. Software that links against both ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not ** SQLITE_TEXT. */ #define SQLITE_INTEGER 1 #define SQLITE_FLOAT 2 #define SQLITE_BLOB 4 #define SQLITE_NULL 5 #ifdef SQLITE_TEXT # undef SQLITE_TEXT #else # define SQLITE_TEXT 3 #endif #define SQLITE3_TEXT 3 /* ** CAPI3REF: Result Values From A Query ** KEYWORDS: {column access functions} ** METHOD: sqlite3_stmt ** ** Summary: **
    **
    sqlite3_column_blobBLOB result **
    sqlite3_column_doubleREAL result **
    sqlite3_column_int32-bit INTEGER result **
    sqlite3_column_int6464-bit INTEGER result **
    sqlite3_column_textUTF-8 TEXT result **
    sqlite3_column_text16UTF-16 TEXT result **
    sqlite3_column_valueThe result as an ** [sqlite3_value|unprotected sqlite3_value] object. **
        **
    sqlite3_column_bytesSize of a BLOB ** or a UTF-8 TEXT result in bytes **
    sqlite3_column_bytes16   ** →  Size of UTF-16 ** TEXT in bytes **
    sqlite3_column_typeDefault ** datatype of the result **
    ** ** Details: ** ** ^These routines return information about a single column of the current ** result row of a query. ^In every case the first argument is a pointer ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] ** that was returned from [sqlite3_prepare_v2()] or one of its variants) ** and the second argument is the index of the column for which information ** should be returned. ^The leftmost column of the result set has the index 0. ** ^The number of columns in the result can be determined using ** [sqlite3_column_count()]. ** ** If the SQL statement does not currently point to a valid row, or if the ** column index is out of range, the result is undefined. ** These routines may only be called when the most recent call to ** [sqlite3_step()] has returned [SQLITE_ROW] and neither ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. ** If any of these routines are called after [sqlite3_reset()] or ** [sqlite3_finalize()] or after [sqlite3_step()] has returned ** something other than [SQLITE_ROW], the results are undefined. ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] ** are called from a different thread while any of these routines ** are pending, then the results are undefined. ** ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) ** each return the value of a result column in a specific data format. If ** the result column is not initially in the requested format (for example, ** if the query returns an integer but the sqlite3_column_text() interface ** is used to extract the value) then an automatic type conversion is performed. ** ** ^The sqlite3_column_type() routine returns the ** [SQLITE_INTEGER | datatype code] for the initial data type ** of the result column. ^The returned value is one of [SQLITE_INTEGER], ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. ** The return value of sqlite3_column_type() can be used to decide which ** of the first six interface should be used to extract the column value. ** The value returned by sqlite3_column_type() is only meaningful if no ** automatic type conversions have occurred for the value in question. ** After a type conversion, the result of calling sqlite3_column_type() ** is undefined, though harmless. Future ** versions of SQLite may change the behavior of sqlite3_column_type() ** following a type conversion. ** ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() ** or sqlite3_column_bytes16() interfaces can be used to determine the size ** of that BLOB or string. ** ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() ** routine returns the number of bytes in that BLOB or string. ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts ** the string to UTF-8 and then returns the number of bytes. ** ^If the result is a numeric value then sqlite3_column_bytes() uses ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns ** the number of bytes in that string. ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. ** ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() ** routine returns the number of bytes in that BLOB or string. ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts ** the string to UTF-16 and then returns the number of bytes. ** ^If the result is a numeric value then sqlite3_column_bytes16() uses ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns ** the number of bytes in that string. ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. ** ** ^The values returned by [sqlite3_column_bytes()] and ** [sqlite3_column_bytes16()] do not include the zero terminators at the end ** of the string. ^For clarity: the values returned by ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of ** bytes in the string, not the number of characters. ** ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), ** even empty strings, are always zero-terminated. ^The return ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. ** ** Warning: ^The object returned by [sqlite3_column_value()] is an ** [unprotected sqlite3_value] object. In a multithreaded environment, ** an unprotected sqlite3_value object may only be used safely with ** [sqlite3_bind_value()] and [sqlite3_result_value()]. ** If the [unprotected sqlite3_value] object returned by ** [sqlite3_column_value()] is used in any other way, including calls ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], ** or [sqlite3_value_bytes()], the behavior is not threadsafe. ** Hence, the sqlite3_column_value() interface ** is normally only useful within the implementation of ** [application-defined SQL functions] or [virtual tables], not within ** top-level application code. ** ** The these routines may attempt to convert the datatype of the result. ** ^For example, if the internal representation is FLOAT and a text result ** is requested, [sqlite3_snprintf()] is used internally to perform the ** conversion automatically. ^(The following table details the conversions ** that are applied: ** **
    ** **
    Internal
    Type
    Requested
    Type
    Conversion ** **
    NULL INTEGER Result is 0 **
    NULL FLOAT Result is 0.0 **
    NULL TEXT Result is a NULL pointer **
    NULL BLOB Result is a NULL pointer **
    INTEGER FLOAT Convert from integer to float **
    INTEGER TEXT ASCII rendering of the integer **
    INTEGER BLOB Same as INTEGER->TEXT **
    FLOAT INTEGER [CAST] to INTEGER **
    FLOAT TEXT ASCII rendering of the float **
    FLOAT BLOB [CAST] to BLOB **
    TEXT INTEGER [CAST] to INTEGER **
    TEXT FLOAT [CAST] to REAL **
    TEXT BLOB No change **
    BLOB INTEGER [CAST] to INTEGER **
    BLOB FLOAT [CAST] to REAL **
    BLOB TEXT Add a zero terminator if needed **
    **
    )^ ** ** Note that when type conversions occur, pointers returned by prior ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or ** sqlite3_column_text16() may be invalidated. ** Type conversions and pointer invalidations might occur ** in the following cases: ** ** ** ** ^Conversions between UTF-16be and UTF-16le are always done in place and do ** not invalidate a prior pointer, though of course the content of the buffer ** that the prior pointer references will have been modified. Other kinds ** of conversion are done in place when it is possible, but sometimes they ** are not possible and in those cases prior pointers are invalidated. ** ** The safest policy is to invoke these routines ** in one of the following ways: ** ** ** ** In other words, you should call sqlite3_column_text(), ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result ** into the desired format, then invoke sqlite3_column_bytes() or ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls ** to sqlite3_column_text() or sqlite3_column_blob() with calls to ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() ** with calls to sqlite3_column_bytes(). ** ** ^The pointers returned are valid until a type conversion occurs as ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or ** [sqlite3_finalize()] is called. ^The memory space used to hold strings ** and BLOBs is freed automatically. Do not pass the pointers returned ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into ** [sqlite3_free()]. ** ** As long as the input parameters are correct, these routines will only ** fail if an out-of-memory error occurs during a format conversion. ** Only the following subset of interfaces are subject to out-of-memory ** errors: ** ** ** ** If an out-of-memory error occurs, then the return value from these ** routines is the same as if the column had contained an SQL NULL value. ** Valid SQL NULL returns can be distinguished from out-of-memory errors ** by invoking the [sqlite3_errcode()] immediately after the suspect ** return value is obtained and before any ** other SQLite interface is called on the same [database connection]. */ SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); /* ** CAPI3REF: Destroy A Prepared Statement Object ** DESTRUCTOR: sqlite3_stmt ** ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. ** ^If the most recent evaluation of the statement encountered no errors ** or if the statement is never been evaluated, then sqlite3_finalize() returns ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then ** sqlite3_finalize(S) returns the appropriate [error code] or ** [extended error code]. ** ** ^The sqlite3_finalize(S) routine can be called at any point during ** the life cycle of [prepared statement] S: ** before statement S is ever evaluated, after ** one or more calls to [sqlite3_reset()], or after any call ** to [sqlite3_step()] regardless of whether or not the statement has ** completed execution. ** ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. ** ** The application must finalize every [prepared statement] in order to avoid ** resource leaks. It is a grievous error for the application to try to use ** a prepared statement after it has been finalized. Any use of a prepared ** statement after it has been finalized can result in undefined and ** undesirable behavior such as segfaults and heap corruption. */ SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); /* ** CAPI3REF: Reset A Prepared Statement Object ** METHOD: sqlite3_stmt ** ** The sqlite3_reset() function is called to reset a [prepared statement] ** object back to its initial state, ready to be re-executed. ** ^Any SQL statement variables that had values bound to them using ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. ** Use [sqlite3_clear_bindings()] to reset the bindings. ** ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S ** back to the beginning of its program. ** ** ^If the most recent call to [sqlite3_step(S)] for the ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], ** or if [sqlite3_step(S)] has never before been called on S, ** then [sqlite3_reset(S)] returns [SQLITE_OK]. ** ** ^If the most recent call to [sqlite3_step(S)] for the ** [prepared statement] S indicated an error, then ** [sqlite3_reset(S)] returns an appropriate [error code]. ** ** ^The [sqlite3_reset(S)] interface does not change the values ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. */ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); /* ** CAPI3REF: Create Or Redefine SQL Functions ** KEYWORDS: {function creation routines} ** METHOD: sqlite3 ** ** ^These functions (collectively known as "function creation routines") ** are used to add SQL functions or aggregates or to redefine the behavior ** of existing SQL functions or aggregates. The only differences between ** the three "sqlite3_create_function*" routines are the text encoding ** expected for the second parameter (the name of the function being ** created) and the presence or absence of a destructor callback for ** the application data pointer. Function sqlite3_create_window_function() ** is similar, but allows the user to supply the extra callback functions ** needed by [aggregate window functions]. ** ** ^The first parameter is the [database connection] to which the SQL ** function is to be added. ^If an application uses more than one database ** connection then application-defined SQL functions must be added ** to each database connection separately. ** ** ^The second parameter is the name of the SQL function to be created or ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 ** representation, exclusive of the zero-terminator. ^Note that the name ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. ** ^Any attempt to create a function with a longer name ** will result in [SQLITE_MISUSE] being returned. ** ** ^The third parameter (nArg) ** is the number of arguments that the SQL function or ** aggregate takes. ^If this parameter is -1, then the SQL function or ** aggregate may take any number of arguments between 0 and the limit ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third ** parameter is less than -1 or greater than 127 then the behavior is ** undefined. ** ** ^The fourth parameter, eTextRep, specifies what ** [SQLITE_UTF8 | text encoding] this SQL function prefers for ** its parameters. The application should set this parameter to ** [SQLITE_UTF16LE] if the function implementation invokes ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the ** implementation invokes [sqlite3_value_text16be()] on an input, or ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] ** otherwise. ^The same SQL function may be registered multiple times using ** different preferred text encodings, with different implementations for ** each encoding. ** ^When multiple implementations of the same function are available, SQLite ** will pick the one that involves the least amount of data conversion. ** ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] ** to signal that the function will always return the same result given ** the same inputs within a single SQL statement. Most SQL functions are ** deterministic. The built-in [random()] SQL function is an example of a ** function that is not deterministic. The SQLite query planner is able to ** perform additional optimizations on deterministic functions, so use ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. ** ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] ** flag, which if present prevents the function from being invoked from ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, ** index expressions, or the WHERE clause of partial indexes. ** ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for ** all application-defined SQL functions that do not need to be ** used inside of triggers, view, CHECK constraints, or other elements of ** the database schema. This flags is especially recommended for SQL ** functions that have side effects or reveal internal application state. ** Without this flag, an attacker might be able to modify the schema of ** a database file to include invocations of the function with parameters ** chosen by the attacker, which the application will then execute when ** the database file is opened and read. ** ** ^(The fifth parameter is an arbitrary pointer. The implementation of the ** function can gain access to this pointer using [sqlite3_user_data()].)^ ** ** ^The sixth, seventh and eighth parameters passed to the three ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are ** pointers to C-language functions that implement the SQL function or ** aggregate. ^A scalar SQL function requires an implementation of the xFunc ** callback only; NULL pointers must be passed as the xStep and xFinal ** parameters. ^An aggregate SQL function requires an implementation of xStep ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing ** SQL function or aggregate, pass NULL pointers for all three function ** callbacks. ** ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue ** and xInverse) passed to sqlite3_create_window_function are pointers to ** C-language callbacks that implement the new function. xStep and xFinal ** must both be non-NULL. xValue and xInverse may either both be NULL, in ** which case a regular aggregate function is created, or must both be ** non-NULL, in which case the new function may be used as either an aggregate ** or aggregate window function. More details regarding the implementation ** of aggregate window functions are ** [user-defined window functions|available here]. ** ** ^(If the final parameter to sqlite3_create_function_v2() or ** sqlite3_create_window_function() is not NULL, then it is destructor for ** the application data pointer. The destructor is invoked when the function ** is deleted, either by being overloaded or when the database connection ** closes.)^ ^The destructor is also invoked if the call to ** sqlite3_create_function_v2() fails. ^When the destructor callback is ** invoked, it is passed a single argument which is a copy of the application ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). ** ** ^It is permitted to register multiple implementations of the same ** functions with the same name but with either differing numbers of ** arguments or differing preferred text encodings. ^SQLite will use ** the implementation that most closely matches the way in which the ** SQL function is used. ^A function implementation with a non-negative ** nArg parameter is a better match than a function implementation with ** a negative nArg. ^A function where the preferred text encoding ** matches the database encoding is a better ** match than a function where the encoding is different. ** ^A function where the encoding difference is between UTF16le and UTF16be ** is a closer match than a function where the encoding difference is ** between UTF8 and UTF16. ** ** ^Built-in functions may be overloaded by new application-defined functions. ** ** ^An application-defined function is permitted to call other ** SQLite interfaces. However, such calls must not ** close the database connection nor finalize or reset the prepared ** statement in which the function is running. */ SQLITE_API int sqlite3_create_function( sqlite3 *db, const char *zFunctionName, int nArg, int eTextRep, void *pApp, void (*xFunc)(sqlite3_context*,int,sqlite3_value**), void (*xStep)(sqlite3_context*,int,sqlite3_value**), void (*xFinal)(sqlite3_context*) ); SQLITE_API int sqlite3_create_function16( sqlite3 *db, const void *zFunctionName, int nArg, int eTextRep, void *pApp, void (*xFunc)(sqlite3_context*,int,sqlite3_value**), void (*xStep)(sqlite3_context*,int,sqlite3_value**), void (*xFinal)(sqlite3_context*) ); SQLITE_API int sqlite3_create_function_v2( sqlite3 *db, const char *zFunctionName, int nArg, int eTextRep, void *pApp, void (*xFunc)(sqlite3_context*,int,sqlite3_value**), void (*xStep)(sqlite3_context*,int,sqlite3_value**), void (*xFinal)(sqlite3_context*), void(*xDestroy)(void*) ); SQLITE_API int sqlite3_create_window_function( sqlite3 *db, const char *zFunctionName, int nArg, int eTextRep, void *pApp, void (*xStep)(sqlite3_context*,int,sqlite3_value**), void (*xFinal)(sqlite3_context*), void (*xValue)(sqlite3_context*), void (*xInverse)(sqlite3_context*,int,sqlite3_value**), void(*xDestroy)(void*) ); /* ** CAPI3REF: Text Encodings ** ** These constant define integer codes that represent the various ** text encodings supported by SQLite. */ #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ #define SQLITE_UTF16 4 /* Use native byte order */ #define SQLITE_ANY 5 /* Deprecated */ #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ /* ** CAPI3REF: Function Flags ** ** These constants may be ORed together with the ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument ** to [sqlite3_create_function()], [sqlite3_create_function16()], or ** [sqlite3_create_function_v2()]. ** **
    ** [[SQLITE_DETERMINISTIC]]
    SQLITE_DETERMINISTIC
    ** The SQLITE_DETERMINISTIC flag means that the new function always gives ** the same output when the input parameters are the same. ** The [abs|abs() function] is deterministic, for example, but ** [randomblob|randomblob()] is not. Functions must ** be deterministic in order to be used in certain contexts such as ** with the WHERE clause of [partial indexes] or in [generated columns]. ** SQLite might also optimize deterministic functions by factoring them ** out of inner loops. **
    ** ** [[SQLITE_DIRECTONLY]]
    SQLITE_DIRECTONLY
    ** The SQLITE_DIRECTONLY flag means that the function may only be invoked ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in ** schema structures such as [CHECK constraints], [DEFAULT clauses], ** [expression indexes], [partial indexes], or [generated columns]. ** The SQLITE_DIRECTONLY flags is a security feature which is recommended ** for all [application-defined SQL functions], and especially for functions ** that have side-effects or that could potentially leak sensitive ** information. **
    ** ** [[SQLITE_INNOCUOUS]]