michael@0: /* michael@0: ** 2001 September 15 michael@0: ** michael@0: ** The author disclaims copyright to this source code. In place of michael@0: ** a legal notice, here is a blessing: michael@0: ** michael@0: ** May you do good and not evil. michael@0: ** May you find forgiveness for yourself and forgive others. michael@0: ** May you share freely, never taking more than you give. michael@0: ** michael@0: ************************************************************************* michael@0: ** This header file defines the interface that the SQLite library michael@0: ** presents to client programs. If a C-function, structure, datatype, michael@0: ** or constant definition does not appear in this file, then it is michael@0: ** not a published API of SQLite, is subject to change without michael@0: ** notice, and should not be referenced by programs that use SQLite. michael@0: ** michael@0: ** Some of the definitions that are in this file are marked as michael@0: ** "experimental". Experimental interfaces are normally new michael@0: ** features recently added to SQLite. We do not anticipate changes michael@0: ** to experimental interfaces but reserve the right to make minor changes michael@0: ** if experience from use "in the wild" suggest such changes are prudent. michael@0: ** michael@0: ** The official C-language API documentation for SQLite is derived michael@0: ** from comments in this file. This file is the authoritative source michael@0: ** on how SQLite interfaces are suppose to operate. michael@0: ** michael@0: ** The name of this file under configuration management is "sqlite.h.in". michael@0: ** The makefile makes some minor changes to this file (such as inserting michael@0: ** the version number) and changes its name to "sqlite3.h" as michael@0: ** part of the build process. michael@0: */ michael@0: #ifndef _SQLITE3_H_ michael@0: #define _SQLITE3_H_ michael@0: #include /* Needed for the definition of va_list */ michael@0: michael@0: /* michael@0: ** Make sure we can call this stuff from C++. michael@0: */ michael@0: #ifdef __cplusplus michael@0: extern "C" { michael@0: #endif michael@0: michael@0: michael@0: /* michael@0: ** Add the ability to override 'extern' michael@0: */ michael@0: #ifndef SQLITE_EXTERN michael@0: # define SQLITE_EXTERN extern michael@0: #endif michael@0: michael@0: #ifndef SQLITE_API michael@0: # define SQLITE_API michael@0: #endif michael@0: michael@0: michael@0: /* michael@0: ** These no-op macros are used in front of interfaces to mark those michael@0: ** interfaces as either deprecated or experimental. New applications michael@0: ** should not use deprecated interfaces - they are support for backwards michael@0: ** compatibility only. Application writers should be aware that michael@0: ** experimental interfaces are subject to change in point releases. michael@0: ** michael@0: ** These macros used to resolve to various kinds of compiler magic that michael@0: ** would generate warning messages when they were used. But that michael@0: ** compiler magic ended up generating such a flurry of bug reports michael@0: ** that we have taken it all out and gone back to using simple michael@0: ** noop macros. michael@0: */ michael@0: #define SQLITE_DEPRECATED michael@0: #define SQLITE_EXPERIMENTAL michael@0: michael@0: /* michael@0: ** Ensure these symbols were not defined by some previous header file. michael@0: */ michael@0: #ifdef SQLITE_VERSION michael@0: # undef SQLITE_VERSION michael@0: #endif michael@0: #ifdef SQLITE_VERSION_NUMBER michael@0: # undef SQLITE_VERSION_NUMBER michael@0: #endif michael@0: michael@0: /* michael@0: ** CAPI3REF: Compile-Time Library Version Numbers michael@0: ** michael@0: ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header michael@0: ** evaluates to a string literal that is the SQLite version in the michael@0: ** format "X.Y.Z" where X is the major version number (always 3 for michael@0: ** SQLite3) and Y is the minor version number and Z is the release number.)^ michael@0: ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer michael@0: ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same michael@0: ** numbers used in [SQLITE_VERSION].)^ michael@0: ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also michael@0: ** be larger than the release from which it is derived. Either Y will michael@0: ** be held constant and Z will be incremented or else Y will be incremented michael@0: ** and Z will be reset to zero. michael@0: ** michael@0: ** Since version 3.6.18, SQLite source code has been stored in the michael@0: ** Fossil configuration management michael@0: ** system. ^The SQLITE_SOURCE_ID macro evaluates to michael@0: ** a string which identifies a particular check-in of SQLite michael@0: ** within its configuration management system. ^The SQLITE_SOURCE_ID michael@0: ** string contains the date and time of the check-in (UTC) and an SHA1 michael@0: ** hash of the entire source tree. michael@0: ** michael@0: ** See also: [sqlite3_libversion()], michael@0: ** [sqlite3_libversion_number()], [sqlite3_sourceid()], michael@0: ** [sqlite_version()] and [sqlite_source_id()]. michael@0: */ michael@0: #define SQLITE_VERSION "3.7.15" michael@0: #define SQLITE_VERSION_NUMBER 3007015 michael@0: #define SQLITE_SOURCE_ID "2012-12-12 13:36:53 cd0b37c52658bfdf992b1e3dc467bae1835a94ae" michael@0: michael@0: /* michael@0: ** CAPI3REF: Run-Time Library Version Numbers michael@0: ** KEYWORDS: sqlite3_version, sqlite3_sourceid michael@0: ** michael@0: ** These interfaces provide the same information as the [SQLITE_VERSION], michael@0: ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros michael@0: ** but are associated with the library instead of the header file. ^(Cautious michael@0: ** programmers might include assert() statements in their application to michael@0: ** verify that values returned by these interfaces match the macros in michael@0: ** the header, and thus insure that the application is michael@0: ** compiled with matching library and header files. michael@0: ** michael@0: ** 
michael@0: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
michael@0: ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
michael@0: ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
michael@0: **
)^ michael@0: ** michael@0: ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] michael@0: ** macro. ^The sqlite3_libversion() function returns a pointer to the michael@0: ** to the sqlite3_version[] string constant. The sqlite3_libversion() michael@0: ** function is provided for use in DLLs since DLL users usually do not have michael@0: ** direct access to string constants within the DLL. ^The michael@0: ** sqlite3_libversion_number() function returns an integer equal to michael@0: ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns michael@0: ** a pointer to a string constant whose value is the same as the michael@0: ** [SQLITE_SOURCE_ID] C preprocessor macro. michael@0: ** michael@0: ** See also: [sqlite_version()] and [sqlite_source_id()]. michael@0: */ michael@0: SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; michael@0: SQLITE_API const char *sqlite3_libversion(void); michael@0: SQLITE_API const char *sqlite3_sourceid(void); michael@0: SQLITE_API int sqlite3_libversion_number(void); michael@0: michael@0: /* michael@0: ** CAPI3REF: Run-Time Library Compilation Options Diagnostics michael@0: ** michael@0: ** ^The sqlite3_compileoption_used() function returns 0 or 1 michael@0: ** indicating whether the specified option was defined at michael@0: ** compile time. ^The SQLITE_ prefix may be omitted from the michael@0: ** option name passed to sqlite3_compileoption_used(). michael@0: ** michael@0: ** ^The sqlite3_compileoption_get() function allows iterating michael@0: ** over the list of options that were defined at compile time by michael@0: ** returning the N-th compile time option string. ^If N is out of range, michael@0: ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ michael@0: ** prefix is omitted from any strings returned by michael@0: ** sqlite3_compileoption_get(). michael@0: ** michael@0: ** ^Support for the diagnostic functions sqlite3_compileoption_used() michael@0: ** and sqlite3_compileoption_get() may be omitted by specifying the michael@0: ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. michael@0: ** michael@0: ** See also: SQL functions [sqlite_compileoption_used()] and michael@0: ** [sqlite_compileoption_get()] and the [compile_options pragma]. michael@0: */ michael@0: #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS michael@0: SQLITE_API int sqlite3_compileoption_used(const char *zOptName); michael@0: SQLITE_API const char *sqlite3_compileoption_get(int N); michael@0: #endif michael@0: michael@0: /* michael@0: ** CAPI3REF: Test To See If The Library Is Threadsafe michael@0: ** michael@0: ** ^The sqlite3_threadsafe() function returns zero if and only if michael@0: ** SQLite was compiled with mutexing code omitted due to the michael@0: ** [SQLITE_THREADSAFE] compile-time option being set to 0. michael@0: ** michael@0: ** SQLite can be compiled with or without mutexes. When michael@0: ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes michael@0: ** are enabled and SQLite is threadsafe. When the michael@0: ** [SQLITE_THREADSAFE] macro is 0, michael@0: ** the mutexes are omitted. Without the mutexes, it is not safe michael@0: ** to use SQLite concurrently from more than one thread. michael@0: ** michael@0: ** Enabling mutexes incurs a measurable performance penalty. michael@0: ** So if speed is of utmost importance, it makes sense to disable michael@0: ** the mutexes. But for maximum safety, mutexes should be enabled. michael@0: ** ^The default behavior is for mutexes to be enabled. michael@0: ** michael@0: ** This interface can be used by an application to make sure that the michael@0: ** version of SQLite that it is linking against was compiled with michael@0: ** the desired setting of the [SQLITE_THREADSAFE] macro. michael@0: ** michael@0: ** This interface only reports on the compile-time mutex setting michael@0: ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with michael@0: ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but michael@0: ** can be fully or partially disabled using a call to [sqlite3_config()] michael@0: ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], michael@0: ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the michael@0: ** sqlite3_threadsafe() function shows only the compile-time setting of michael@0: ** thread safety, not any run-time changes to that setting made by michael@0: ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() michael@0: ** is unchanged by calls to sqlite3_config().)^ michael@0: ** michael@0: ** See the [threading mode] documentation for additional information. michael@0: */ michael@0: SQLITE_API int sqlite3_threadsafe(void); michael@0: michael@0: /* michael@0: ** CAPI3REF: Database Connection Handle michael@0: ** KEYWORDS: {database connection} {database connections} michael@0: ** michael@0: ** Each open SQLite database is represented by a pointer to an instance of michael@0: ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 michael@0: ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and michael@0: ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] michael@0: ** and [sqlite3_close_v2()] are its destructors. There are many other michael@0: ** interfaces (such as michael@0: ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and michael@0: ** [sqlite3_busy_timeout()] to name but three) that are methods on an michael@0: ** sqlite3 object. michael@0: */ michael@0: typedef struct sqlite3 sqlite3; michael@0: michael@0: /* michael@0: ** CAPI3REF: 64-Bit Integer Types michael@0: ** KEYWORDS: sqlite_int64 sqlite_uint64 michael@0: ** michael@0: ** Because there is no cross-platform way to specify 64-bit integer types michael@0: ** SQLite includes typedefs for 64-bit signed and unsigned integers. michael@0: ** michael@0: ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. michael@0: ** The sqlite_int64 and sqlite_uint64 types are supported for backwards michael@0: ** compatibility only. michael@0: ** michael@0: ** ^The sqlite3_int64 and sqlite_int64 types can store integer values michael@0: ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The michael@0: ** sqlite3_uint64 and sqlite_uint64 types can store integer values michael@0: ** between 0 and +18446744073709551615 inclusive. michael@0: */ michael@0: #ifdef SQLITE_INT64_TYPE michael@0: typedef SQLITE_INT64_TYPE sqlite_int64; michael@0: typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; michael@0: #elif defined(_MSC_VER) || defined(__BORLANDC__) michael@0: typedef __int64 sqlite_int64; michael@0: typedef unsigned __int64 sqlite_uint64; michael@0: #else michael@0: typedef long long int sqlite_int64; michael@0: typedef unsigned long long int sqlite_uint64; michael@0: #endif michael@0: typedef sqlite_int64 sqlite3_int64; michael@0: typedef sqlite_uint64 sqlite3_uint64; michael@0: michael@0: /* michael@0: ** If compiling for a processor that lacks floating point support, michael@0: ** substitute integer for floating-point. michael@0: */ michael@0: #ifdef SQLITE_OMIT_FLOATING_POINT michael@0: # define double sqlite3_int64 michael@0: #endif michael@0: michael@0: /* michael@0: ** CAPI3REF: Closing A Database Connection michael@0: ** michael@0: ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors michael@0: ** for the [sqlite3] object. michael@0: ** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if michael@0: ** the [sqlite3] object is successfully destroyed and all associated michael@0: ** resources are deallocated. michael@0: ** michael@0: ** ^If the database connection is associated with unfinalized prepared michael@0: ** statements or unfinished sqlite3_backup objects then sqlite3_close() michael@0: ** will leave the database connection open and return [SQLITE_BUSY]. michael@0: ** ^If sqlite3_close_v2() is called with unfinalized prepared statements michael@0: ** and unfinished sqlite3_backups, then the database connection becomes michael@0: ** an unusable "zombie" which will automatically be deallocated when the michael@0: ** last prepared statement is finalized or the last sqlite3_backup is michael@0: ** finished. The sqlite3_close_v2() interface is intended for use with michael@0: ** host languages that are garbage collected, and where the order in which michael@0: ** destructors are called is arbitrary. michael@0: ** michael@0: ** Applications should [sqlite3_finalize | finalize] all [prepared statements], michael@0: ** [sqlite3_blob_close | close] all [BLOB handles], and michael@0: ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated michael@0: ** with the [sqlite3] object prior to attempting to close the object. ^If michael@0: ** sqlite3_close() is called on a [database connection] that still has michael@0: ** outstanding [prepared statements], [BLOB handles], and/or michael@0: ** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation michael@0: ** of resources is deferred until all [prepared statements], [BLOB handles], michael@0: ** and [sqlite3_backup] objects are also destroyed. michael@0: ** michael@0: ** ^If an [sqlite3] object is destroyed while a transaction is open, michael@0: ** the transaction is automatically rolled back. michael@0: ** michael@0: ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] michael@0: ** must be either a NULL michael@0: ** pointer or an [sqlite3] object pointer obtained michael@0: ** from [sqlite3_open()], [sqlite3_open16()], or michael@0: ** [sqlite3_open_v2()], and not previously closed. michael@0: ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer michael@0: ** argument is a harmless no-op. michael@0: */ michael@0: SQLITE_API int sqlite3_close(sqlite3*); michael@0: SQLITE_API int sqlite3_close_v2(sqlite3*); michael@0: michael@0: /* michael@0: ** The type for a callback function. michael@0: ** This is legacy and deprecated. It is included for historical michael@0: ** compatibility and is not documented. michael@0: */ michael@0: typedef int (*sqlite3_callback)(void*,int,char**, char**); michael@0: michael@0: /* michael@0: ** CAPI3REF: One-Step Query Execution Interface michael@0: ** michael@0: ** The sqlite3_exec() interface is a convenience wrapper around michael@0: ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], michael@0: ** that allows an application to run multiple statements of SQL michael@0: ** without having to use a lot of C code. michael@0: ** michael@0: ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, michael@0: ** semicolon-separate SQL statements passed into its 2nd argument, michael@0: ** in the context of the [database connection] passed in as its 1st michael@0: ** argument. ^If the callback function of the 3rd argument to michael@0: ** sqlite3_exec() is not NULL, then it is invoked for each result row michael@0: ** coming out of the evaluated SQL statements. ^The 4th argument to michael@0: ** sqlite3_exec() is relayed through to the 1st argument of each michael@0: ** callback invocation. ^If the callback pointer to sqlite3_exec() michael@0: ** is NULL, then no callback is ever invoked and result rows are michael@0: ** ignored. michael@0: ** michael@0: ** ^If an error occurs while evaluating the SQL statements passed into michael@0: ** sqlite3_exec(), then execution of the current statement stops and michael@0: ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() michael@0: ** is not NULL then any error message is written into memory obtained michael@0: ** from [sqlite3_malloc()] and passed back through the 5th parameter. michael@0: ** To avoid memory leaks, the application should invoke [sqlite3_free()] michael@0: ** on error message strings returned through the 5th parameter of michael@0: ** of sqlite3_exec() after the error message string is no longer needed. michael@0: ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors michael@0: ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to michael@0: ** NULL before returning. michael@0: ** michael@0: ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() michael@0: ** routine returns SQLITE_ABORT without invoking the callback again and michael@0: ** without running any subsequent SQL statements. michael@0: ** michael@0: ** ^The 2nd argument to the sqlite3_exec() callback function is the michael@0: ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() michael@0: ** callback is an array of pointers to strings obtained as if from michael@0: ** [sqlite3_column_text()], one for each column. ^If an element of a michael@0: ** result row is NULL then the corresponding string pointer for the michael@0: ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the michael@0: ** sqlite3_exec() callback is an array of pointers to strings where each michael@0: ** entry represents the name of corresponding result column as obtained michael@0: ** from [sqlite3_column_name()]. michael@0: ** michael@0: ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer michael@0: ** to an empty string, or a pointer that contains only whitespace and/or michael@0: ** SQL comments, then no SQL statements are evaluated and the database michael@0: ** is not changed. michael@0: ** michael@0: ** Restrictions: michael@0: ** michael@0: ** michael@0: */ michael@0: SQLITE_API int sqlite3_exec( michael@0: sqlite3*, /* An open database */ michael@0: const char *sql, /* SQL to be evaluated */ michael@0: int (*callback)(void*,int,char**,char**), /* Callback function */ michael@0: void *, /* 1st argument to callback */ michael@0: char **errmsg /* Error msg written here */ michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Result Codes michael@0: ** KEYWORDS: SQLITE_OK {error code} {error codes} michael@0: ** KEYWORDS: {result code} {result codes} michael@0: ** michael@0: ** Many SQLite functions return an integer result code from the set shown michael@0: ** here in order to indicate success or failure. michael@0: ** michael@0: ** New error codes may be added in future versions of SQLite. michael@0: ** michael@0: ** See also: [SQLITE_IOERR_READ | extended result codes], michael@0: ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. michael@0: */ michael@0: #define SQLITE_OK 0 /* Successful result */ michael@0: /* beginning-of-error-codes */ michael@0: #define SQLITE_ERROR 1 /* SQL error or missing database */ michael@0: #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ michael@0: #define SQLITE_PERM 3 /* Access permission denied */ michael@0: #define SQLITE_ABORT 4 /* Callback routine requested an abort */ michael@0: #define SQLITE_BUSY 5 /* The database file is locked */ michael@0: #define SQLITE_LOCKED 6 /* A table in the database is locked */ michael@0: #define SQLITE_NOMEM 7 /* A malloc() failed */ michael@0: #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ michael@0: #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ michael@0: #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ michael@0: #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ michael@0: #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ michael@0: #define SQLITE_FULL 13 /* Insertion failed because database is full */ michael@0: #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ michael@0: #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ michael@0: #define SQLITE_EMPTY 16 /* Database is empty */ michael@0: #define SQLITE_SCHEMA 17 /* The database schema changed */ michael@0: #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ michael@0: #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ michael@0: #define SQLITE_MISMATCH 20 /* Data type mismatch */ michael@0: #define SQLITE_MISUSE 21 /* Library used incorrectly */ michael@0: #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ michael@0: #define SQLITE_AUTH 23 /* Authorization denied */ michael@0: #define SQLITE_FORMAT 24 /* Auxiliary database format error */ michael@0: #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ michael@0: #define SQLITE_NOTADB 26 /* File opened that is not a database file */ michael@0: #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ michael@0: #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ michael@0: /* end-of-error-codes */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Extended Result Codes michael@0: ** KEYWORDS: {extended error code} {extended error codes} michael@0: ** KEYWORDS: {extended result code} {extended result codes} michael@0: ** michael@0: ** In its default configuration, SQLite API routines return one of 26 integer michael@0: ** [SQLITE_OK | result codes]. However, experience has shown that many of michael@0: ** these result codes are too coarse-grained. They do not provide as michael@0: ** much information about problems as programmers might like. In an effort to michael@0: ** address this, newer versions of SQLite (version 3.3.8 and later) include michael@0: ** support for additional result codes that provide more detailed information michael@0: ** about errors. The extended result codes are enabled or disabled michael@0: ** on a per database connection basis using the michael@0: ** [sqlite3_extended_result_codes()] API. michael@0: ** michael@0: ** Some of the available extended result codes are listed here. michael@0: ** One may expect the number of extended result codes will be expand michael@0: ** over time. Software that uses extended result codes should expect michael@0: ** to see new result codes in future releases of SQLite. michael@0: ** michael@0: ** The SQLITE_OK result code will never be extended. It will always michael@0: ** be exactly zero. michael@0: */ michael@0: #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) michael@0: #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) michael@0: #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) michael@0: #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) michael@0: #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) michael@0: #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) michael@0: #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) michael@0: #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) michael@0: #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) michael@0: #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) michael@0: #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) michael@0: #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) michael@0: #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) michael@0: #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) michael@0: #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) michael@0: #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) michael@0: #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) michael@0: #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) michael@0: #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) michael@0: #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) michael@0: #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) michael@0: #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) michael@0: #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) michael@0: #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) michael@0: #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) michael@0: #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) michael@0: #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) michael@0: #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) michael@0: #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) michael@0: #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) michael@0: #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) michael@0: #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) michael@0: michael@0: /* michael@0: ** CAPI3REF: Flags For File Open Operations michael@0: ** michael@0: ** These bit values are intended for use in the michael@0: ** 3rd parameter to the [sqlite3_open_v2()] interface and michael@0: ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. michael@0: */ michael@0: #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ michael@0: #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ michael@0: #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ michael@0: #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ michael@0: #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ michael@0: #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ michael@0: #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ michael@0: #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ michael@0: #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ michael@0: #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ michael@0: #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ michael@0: #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ michael@0: michael@0: /* Reserved: 0x00F00000 */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Device Characteristics michael@0: ** michael@0: ** The xDeviceCharacteristics method of the [sqlite3_io_methods] michael@0: ** object returns an integer which is a vector of these michael@0: ** bit values expressing I/O characteristics of the mass storage michael@0: ** device that holds the file that the [sqlite3_io_methods] michael@0: ** refers to. michael@0: ** michael@0: ** The SQLITE_IOCAP_ATOMIC property means that all writes of michael@0: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values michael@0: ** mean that writes of blocks that are nnn bytes in size and michael@0: ** are aligned to an address which is an integer multiple of michael@0: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means michael@0: ** that when data is appended to a file, the data is appended michael@0: ** first then the size of the file is extended, never the other michael@0: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that michael@0: ** information is written to disk in the same order as calls michael@0: ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that michael@0: ** after reboot following a crash or power loss, the only bytes in a michael@0: ** file that were written at the application level might have changed michael@0: ** and that adjacent bytes, even bytes within the same sector are michael@0: ** guaranteed to be unchanged. michael@0: */ michael@0: #define SQLITE_IOCAP_ATOMIC 0x00000001 michael@0: #define SQLITE_IOCAP_ATOMIC512 0x00000002 michael@0: #define SQLITE_IOCAP_ATOMIC1K 0x00000004 michael@0: #define SQLITE_IOCAP_ATOMIC2K 0x00000008 michael@0: #define SQLITE_IOCAP_ATOMIC4K 0x00000010 michael@0: #define SQLITE_IOCAP_ATOMIC8K 0x00000020 michael@0: #define SQLITE_IOCAP_ATOMIC16K 0x00000040 michael@0: #define SQLITE_IOCAP_ATOMIC32K 0x00000080 michael@0: #define SQLITE_IOCAP_ATOMIC64K 0x00000100 michael@0: #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 michael@0: #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 michael@0: #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 michael@0: #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 michael@0: michael@0: /* michael@0: ** CAPI3REF: File Locking Levels michael@0: ** michael@0: ** SQLite uses one of these integer values as the second michael@0: ** argument to calls it makes to the xLock() and xUnlock() methods michael@0: ** of an [sqlite3_io_methods] object. michael@0: */ michael@0: #define SQLITE_LOCK_NONE 0 michael@0: #define SQLITE_LOCK_SHARED 1 michael@0: #define SQLITE_LOCK_RESERVED 2 michael@0: #define SQLITE_LOCK_PENDING 3 michael@0: #define SQLITE_LOCK_EXCLUSIVE 4 michael@0: michael@0: /* michael@0: ** CAPI3REF: Synchronization Type Flags michael@0: ** michael@0: ** When SQLite invokes the xSync() method of an michael@0: ** [sqlite3_io_methods] object it uses a combination of michael@0: ** these integer values as the second argument. michael@0: ** michael@0: ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the michael@0: ** sync operation only needs to flush data to mass storage. Inode michael@0: ** information need not be flushed. If the lower four bits of the flag michael@0: ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. michael@0: ** If the lower four bits equal SQLITE_SYNC_FULL, that means michael@0: ** to use Mac OS X style fullsync instead of fsync(). michael@0: ** michael@0: ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags michael@0: ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL michael@0: ** settings. The [synchronous pragma] determines when calls to the michael@0: ** xSync VFS method occur and applies uniformly across all platforms. michael@0: ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how michael@0: ** energetic or rigorous or forceful the sync operations are and michael@0: ** only make a difference on Mac OSX for the default SQLite code. michael@0: ** (Third-party VFS implementations might also make the distinction michael@0: ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the michael@0: ** operating systems natively supported by SQLite, only Mac OSX michael@0: ** cares about the difference.) michael@0: */ michael@0: #define SQLITE_SYNC_NORMAL 0x00002 michael@0: #define SQLITE_SYNC_FULL 0x00003 michael@0: #define SQLITE_SYNC_DATAONLY 0x00010 michael@0: michael@0: /* michael@0: ** CAPI3REF: OS Interface Open File Handle michael@0: ** michael@0: ** An [sqlite3_file] object represents an open file in the michael@0: ** [sqlite3_vfs | OS interface layer]. Individual OS interface michael@0: ** implementations will michael@0: ** want to subclass this object by appending additional fields michael@0: ** for their own use. The pMethods entry is a pointer to an michael@0: ** [sqlite3_io_methods] object that defines methods for performing michael@0: ** I/O operations on the open file. michael@0: */ michael@0: typedef struct sqlite3_file sqlite3_file; michael@0: struct sqlite3_file { michael@0: const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: OS Interface File Virtual Methods Object michael@0: ** michael@0: ** Every file opened by the [sqlite3_vfs.xOpen] method populates an michael@0: ** [sqlite3_file] object (or, more commonly, a subclass of the michael@0: ** [sqlite3_file] object) with a pointer to an instance of this object. michael@0: ** This object defines the methods used to perform various operations michael@0: ** against the open file represented by the [sqlite3_file] object. michael@0: ** michael@0: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element michael@0: ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method michael@0: ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The michael@0: ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] michael@0: ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element michael@0: ** to NULL. michael@0: ** michael@0: ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or michael@0: ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). michael@0: ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] michael@0: ** flag may be ORed in to indicate that only the data of the file michael@0: ** and not its inode needs to be synced. michael@0: ** michael@0: ** The integer values to xLock() and xUnlock() are one of michael@0: ** michael@0: ** xLock() increases the lock. xUnlock() decreases the lock. michael@0: ** The xCheckReservedLock() method checks whether any database connection, michael@0: ** either in this process or in some other process, is holding a RESERVED, michael@0: ** PENDING, or EXCLUSIVE lock on the file. It returns true michael@0: ** if such a lock exists and false otherwise. michael@0: ** michael@0: ** The xFileControl() method is a generic interface that allows custom michael@0: ** VFS implementations to directly control an open file using the michael@0: ** [sqlite3_file_control()] interface. The second "op" argument is an michael@0: ** integer opcode. The third argument is a generic pointer intended to michael@0: ** point to a structure that may contain arguments or space in which to michael@0: ** write return values. Potential uses for xFileControl() might be michael@0: ** functions to enable blocking locks with timeouts, to change the michael@0: ** locking strategy (for example to use dot-file locks), to inquire michael@0: ** about the status of a lock, or to break stale locks. The SQLite michael@0: ** core reserves all opcodes less than 100 for its own use. michael@0: ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. michael@0: ** Applications that define a custom xFileControl method should use opcodes michael@0: ** greater than 100 to avoid conflicts. VFS implementations should michael@0: ** return [SQLITE_NOTFOUND] for file control opcodes that they do not michael@0: ** recognize. michael@0: ** michael@0: ** The xSectorSize() method returns the sector size of the michael@0: ** device that underlies the file. The sector size is the michael@0: ** minimum write that can be performed without disturbing michael@0: ** other bytes in the file. The xDeviceCharacteristics() michael@0: ** method returns a bit vector describing behaviors of the michael@0: ** underlying device: michael@0: ** michael@0: ** michael@0: ** michael@0: ** The SQLITE_IOCAP_ATOMIC property means that all writes of michael@0: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values michael@0: ** mean that writes of blocks that are nnn bytes in size and michael@0: ** are aligned to an address which is an integer multiple of michael@0: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means michael@0: ** that when data is appended to a file, the data is appended michael@0: ** first then the size of the file is extended, never the other michael@0: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that michael@0: ** information is written to disk in the same order as calls michael@0: ** to xWrite(). michael@0: ** michael@0: ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill michael@0: ** in the unread portions of the buffer with zeros. A VFS that michael@0: ** fails to zero-fill short reads might seem to work. However, michael@0: ** failure to zero-fill short reads will eventually lead to michael@0: ** database corruption. michael@0: */ michael@0: typedef struct sqlite3_io_methods sqlite3_io_methods; michael@0: struct sqlite3_io_methods { michael@0: int iVersion; michael@0: int (*xClose)(sqlite3_file*); michael@0: int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); michael@0: int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); michael@0: int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); michael@0: int (*xSync)(sqlite3_file*, int flags); michael@0: int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); michael@0: int (*xLock)(sqlite3_file*, int); michael@0: int (*xUnlock)(sqlite3_file*, int); michael@0: int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); michael@0: int (*xFileControl)(sqlite3_file*, int op, void *pArg); michael@0: int (*xSectorSize)(sqlite3_file*); michael@0: int (*xDeviceCharacteristics)(sqlite3_file*); michael@0: /* Methods above are valid for version 1 */ michael@0: int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); michael@0: int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); michael@0: void (*xShmBarrier)(sqlite3_file*); michael@0: int (*xShmUnmap)(sqlite3_file*, int deleteFlag); michael@0: /* Methods above are valid for version 2 */ michael@0: /* Additional methods may be added in future releases */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Standard File Control Opcodes michael@0: ** michael@0: ** These integer constants are opcodes for the xFileControl method michael@0: ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] michael@0: ** interface. michael@0: ** michael@0: ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This michael@0: ** opcode causes the xFileControl method to write the current state of michael@0: ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], michael@0: ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) michael@0: ** into an integer that the pArg argument points to. This capability michael@0: ** is used during testing and only needs to be supported when SQLITE_TEST michael@0: ** is defined. michael@0: ** michael@0: */ michael@0: #define SQLITE_FCNTL_LOCKSTATE 1 michael@0: #define SQLITE_GET_LOCKPROXYFILE 2 michael@0: #define SQLITE_SET_LOCKPROXYFILE 3 michael@0: #define SQLITE_LAST_ERRNO 4 michael@0: #define SQLITE_FCNTL_SIZE_HINT 5 michael@0: #define SQLITE_FCNTL_CHUNK_SIZE 6 michael@0: #define SQLITE_FCNTL_FILE_POINTER 7 michael@0: #define SQLITE_FCNTL_SYNC_OMITTED 8 michael@0: #define SQLITE_FCNTL_WIN32_AV_RETRY 9 michael@0: #define SQLITE_FCNTL_PERSIST_WAL 10 michael@0: #define SQLITE_FCNTL_OVERWRITE 11 michael@0: #define SQLITE_FCNTL_VFSNAME 12 michael@0: #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 michael@0: #define SQLITE_FCNTL_PRAGMA 14 michael@0: #define SQLITE_FCNTL_BUSYHANDLER 15 michael@0: #define SQLITE_FCNTL_TEMPFILENAME 16 michael@0: michael@0: /* michael@0: ** CAPI3REF: Mutex Handle michael@0: ** michael@0: ** The mutex module within SQLite defines [sqlite3_mutex] to be an michael@0: ** abstract type for a mutex object. The SQLite core never looks michael@0: ** at the internal representation of an [sqlite3_mutex]. It only michael@0: ** deals with pointers to the [sqlite3_mutex] object. michael@0: ** michael@0: ** Mutexes are created using [sqlite3_mutex_alloc()]. michael@0: */ michael@0: typedef struct sqlite3_mutex sqlite3_mutex; michael@0: michael@0: /* michael@0: ** CAPI3REF: OS Interface Object michael@0: ** michael@0: ** An instance of the sqlite3_vfs object defines the interface between michael@0: ** the SQLite core and the underlying operating system. The "vfs" michael@0: ** in the name of the object stands for "virtual file system". See michael@0: ** the [VFS | VFS documentation] for further information. michael@0: ** michael@0: ** The value of the iVersion field is initially 1 but may be larger in michael@0: ** future versions of SQLite. Additional fields may be appended to this michael@0: ** object when the iVersion value is increased. Note that the structure michael@0: ** of the sqlite3_vfs object changes in the transaction between michael@0: ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not michael@0: ** modified. michael@0: ** michael@0: ** The szOsFile field is the size of the subclassed [sqlite3_file] michael@0: ** structure used by this VFS. mxPathname is the maximum length of michael@0: ** a pathname in this VFS. michael@0: ** michael@0: ** Registered sqlite3_vfs objects are kept on a linked list formed by michael@0: ** the pNext pointer. The [sqlite3_vfs_register()] michael@0: ** and [sqlite3_vfs_unregister()] interfaces manage this list michael@0: ** in a thread-safe way. The [sqlite3_vfs_find()] interface michael@0: ** searches the list. Neither the application code nor the VFS michael@0: ** implementation should use the pNext pointer. michael@0: ** michael@0: ** The pNext field is the only field in the sqlite3_vfs michael@0: ** structure that SQLite will ever modify. SQLite will only access michael@0: ** or modify this field while holding a particular static mutex. michael@0: ** The application should never modify anything within the sqlite3_vfs michael@0: ** object once the object has been registered. michael@0: ** michael@0: ** The zName field holds the name of the VFS module. The name must michael@0: ** be unique across all VFS modules. michael@0: ** michael@0: ** [[sqlite3_vfs.xOpen]] michael@0: ** ^SQLite guarantees that the zFilename parameter to xOpen michael@0: ** is either a NULL pointer or string obtained michael@0: ** from xFullPathname() with an optional suffix added. michael@0: ** ^If a suffix is added to the zFilename parameter, it will michael@0: ** consist of a single "-" character followed by no more than michael@0: ** 11 alphanumeric and/or "-" characters. michael@0: ** ^SQLite further guarantees that michael@0: ** the string will be valid and unchanged until xClose() is michael@0: ** called. Because of the previous sentence, michael@0: ** the [sqlite3_file] can safely store a pointer to the michael@0: ** filename if it needs to remember the filename for some reason. michael@0: ** If the zFilename parameter to xOpen is a NULL pointer then xOpen michael@0: ** must invent its own temporary name for the file. ^Whenever the michael@0: ** xFilename parameter is NULL it will also be the case that the michael@0: ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. michael@0: ** michael@0: ** The flags argument to xOpen() includes all bits set in michael@0: ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] michael@0: ** or [sqlite3_open16()] is used, then flags includes at least michael@0: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. michael@0: ** If xOpen() opens a file read-only then it sets *pOutFlags to michael@0: ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. michael@0: ** michael@0: ** ^(SQLite will also add one of the following flags to the xOpen() michael@0: ** call, depending on the object being opened: michael@0: ** michael@0: ** )^ michael@0: ** michael@0: ** The file I/O implementation can use the object type flags to michael@0: ** change the way it deals with files. For example, an application michael@0: ** that does not care about crash recovery or rollback might make michael@0: ** the open of a journal file a no-op. Writes to this journal would michael@0: ** also be no-ops, and any attempt to read the journal would return michael@0: ** SQLITE_IOERR. Or the implementation might recognize that a database michael@0: ** file will be doing page-aligned sector reads and writes in a random michael@0: ** order and set up its I/O subsystem accordingly. michael@0: ** michael@0: ** SQLite might also add one of the following flags to the xOpen method: michael@0: ** michael@0: ** michael@0: ** michael@0: ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be michael@0: ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] michael@0: ** will be set for TEMP databases and their journals, transient michael@0: ** databases, and subjournals. michael@0: ** michael@0: ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction michael@0: ** with the [SQLITE_OPEN_CREATE] flag, which are both directly michael@0: ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() michael@0: ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the michael@0: ** SQLITE_OPEN_CREATE, is used to indicate that file should always michael@0: ** be created, and that it is an error if it already exists. michael@0: ** It is not used to indicate the file should be opened michael@0: ** for exclusive access. michael@0: ** michael@0: ** ^At least szOsFile bytes of memory are allocated by SQLite michael@0: ** to hold the [sqlite3_file] structure passed as the third michael@0: ** argument to xOpen. The xOpen method does not have to michael@0: ** allocate the structure; it should just fill it in. Note that michael@0: ** the xOpen method must set the sqlite3_file.pMethods to either michael@0: ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do michael@0: ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods michael@0: ** element will be valid after xOpen returns regardless of the success michael@0: ** or failure of the xOpen call. michael@0: ** michael@0: ** [[sqlite3_vfs.xAccess]] michael@0: ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] michael@0: ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to michael@0: ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] michael@0: ** to test whether a file is at least readable. The file can be a michael@0: ** directory. michael@0: ** michael@0: ** ^SQLite will always allocate at least mxPathname+1 bytes for the michael@0: ** output buffer xFullPathname. The exact size of the output buffer michael@0: ** is also passed as a parameter to both methods. If the output buffer michael@0: ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is michael@0: ** handled as a fatal error by SQLite, vfs implementations should endeavor michael@0: ** to prevent this by setting mxPathname to a sufficiently large value. michael@0: ** michael@0: ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() michael@0: ** interfaces are not strictly a part of the filesystem, but they are michael@0: ** included in the VFS structure for completeness. michael@0: ** The xRandomness() function attempts to return nBytes bytes michael@0: ** of good-quality randomness into zOut. The return value is michael@0: ** the actual number of bytes of randomness obtained. michael@0: ** The xSleep() method causes the calling thread to sleep for at michael@0: ** least the number of microseconds given. ^The xCurrentTime() michael@0: ** method returns a Julian Day Number for the current date and time as michael@0: ** a floating point value. michael@0: ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian michael@0: ** Day Number multiplied by 86400000 (the number of milliseconds in michael@0: ** a 24-hour day). michael@0: ** ^SQLite will use the xCurrentTimeInt64() method to get the current michael@0: ** date and time if that method is available (if iVersion is 2 or michael@0: ** greater and the function pointer is not NULL) and will fall back michael@0: ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. michael@0: ** michael@0: ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces michael@0: ** are not used by the SQLite core. These optional interfaces are provided michael@0: ** by some VFSes to facilitate testing of the VFS code. By overriding michael@0: ** system calls with functions under its control, a test program can michael@0: ** simulate faults and error conditions that would otherwise be difficult michael@0: ** or impossible to induce. The set of system calls that can be overridden michael@0: ** varies from one VFS to another, and from one version of the same VFS to the michael@0: ** next. Applications that use these interfaces must be prepared for any michael@0: ** or all of these interfaces to be NULL or for their behavior to change michael@0: ** from one release to the next. Applications must not attempt to access michael@0: ** any of these methods if the iVersion of the VFS is less than 3. michael@0: */ michael@0: typedef struct sqlite3_vfs sqlite3_vfs; michael@0: typedef void (*sqlite3_syscall_ptr)(void); michael@0: struct sqlite3_vfs { michael@0: int iVersion; /* Structure version number (currently 3) */ michael@0: int szOsFile; /* Size of subclassed sqlite3_file */ michael@0: int mxPathname; /* Maximum file pathname length */ michael@0: sqlite3_vfs *pNext; /* Next registered VFS */ michael@0: const char *zName; /* Name of this virtual file system */ michael@0: void *pAppData; /* Pointer to application-specific data */ michael@0: int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, michael@0: int flags, int *pOutFlags); michael@0: int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); michael@0: int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); michael@0: int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); michael@0: void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); michael@0: void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); michael@0: void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); michael@0: void (*xDlClose)(sqlite3_vfs*, void*); michael@0: int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); michael@0: int (*xSleep)(sqlite3_vfs*, int microseconds); michael@0: int (*xCurrentTime)(sqlite3_vfs*, double*); michael@0: int (*xGetLastError)(sqlite3_vfs*, int, char *); michael@0: /* michael@0: ** The methods above are in version 1 of the sqlite_vfs object michael@0: ** definition. Those that follow are added in version 2 or later michael@0: */ michael@0: int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); michael@0: /* michael@0: ** The methods above are in versions 1 and 2 of the sqlite_vfs object. michael@0: ** Those below are for version 3 and greater. michael@0: */ michael@0: int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); michael@0: sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); michael@0: const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); michael@0: /* michael@0: ** The methods above are in versions 1 through 3 of the sqlite_vfs object. michael@0: ** New fields may be appended in figure versions. The iVersion michael@0: ** value will increment whenever this happens. michael@0: */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Flags for the xAccess VFS method michael@0: ** michael@0: ** These integer constants can be used as the third parameter to michael@0: ** the xAccess method of an [sqlite3_vfs] object. They determine michael@0: ** what kind of permissions the xAccess method is looking for. michael@0: ** With SQLITE_ACCESS_EXISTS, the xAccess method michael@0: ** simply checks whether the file exists. michael@0: ** With SQLITE_ACCESS_READWRITE, the xAccess method michael@0: ** checks whether the named directory is both readable and writable michael@0: ** (in other words, if files can be added, removed, and renamed within michael@0: ** the directory). michael@0: ** The SQLITE_ACCESS_READWRITE constant is currently used only by the michael@0: ** [temp_store_directory pragma], though this could change in a future michael@0: ** release of SQLite. michael@0: ** With SQLITE_ACCESS_READ, the xAccess method michael@0: ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is michael@0: ** currently unused, though it might be used in a future release of michael@0: ** SQLite. michael@0: */ michael@0: #define SQLITE_ACCESS_EXISTS 0 michael@0: #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ michael@0: #define SQLITE_ACCESS_READ 2 /* Unused */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Flags for the xShmLock VFS method michael@0: ** michael@0: ** These integer constants define the various locking operations michael@0: ** allowed by the xShmLock method of [sqlite3_io_methods]. The michael@0: ** following are the only legal combinations of flags to the michael@0: ** xShmLock method: michael@0: ** michael@0: ** michael@0: ** michael@0: ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as michael@0: ** was given no the corresponding lock. michael@0: ** michael@0: ** The xShmLock method can transition between unlocked and SHARED or michael@0: ** between unlocked and EXCLUSIVE. It cannot transition between SHARED michael@0: ** and EXCLUSIVE. michael@0: */ michael@0: #define SQLITE_SHM_UNLOCK 1 michael@0: #define SQLITE_SHM_LOCK 2 michael@0: #define SQLITE_SHM_SHARED 4 michael@0: #define SQLITE_SHM_EXCLUSIVE 8 michael@0: michael@0: /* michael@0: ** CAPI3REF: Maximum xShmLock index michael@0: ** michael@0: ** The xShmLock method on [sqlite3_io_methods] may use values michael@0: ** between 0 and this upper bound as its "offset" argument. michael@0: ** The SQLite core will never attempt to acquire or release a michael@0: ** lock outside of this range michael@0: */ michael@0: #define SQLITE_SHM_NLOCK 8 michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Initialize The SQLite Library michael@0: ** michael@0: ** ^The sqlite3_initialize() routine initializes the michael@0: ** SQLite library. ^The sqlite3_shutdown() routine michael@0: ** deallocates any resources that were allocated by sqlite3_initialize(). michael@0: ** These routines are designed to aid in process initialization and michael@0: ** shutdown on embedded systems. Workstation applications using michael@0: ** SQLite normally do not need to invoke either of these routines. michael@0: ** michael@0: ** A call to sqlite3_initialize() is an "effective" call if it is michael@0: ** the first time sqlite3_initialize() is invoked during the lifetime of michael@0: ** the process, or if it is the first time sqlite3_initialize() is invoked michael@0: ** following a call to sqlite3_shutdown(). ^(Only an effective call michael@0: ** of sqlite3_initialize() does any initialization. All other calls michael@0: ** are harmless no-ops.)^ michael@0: ** michael@0: ** A call to sqlite3_shutdown() is an "effective" call if it is the first michael@0: ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only michael@0: ** an effective call to sqlite3_shutdown() does any deinitialization. michael@0: ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ michael@0: ** michael@0: ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() michael@0: ** is not. The sqlite3_shutdown() interface must only be called from a michael@0: ** single thread. All open [database connections] must be closed and all michael@0: ** other SQLite resources must be deallocated prior to invoking michael@0: ** sqlite3_shutdown(). michael@0: ** michael@0: ** Among other things, ^sqlite3_initialize() will invoke michael@0: ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() michael@0: ** will invoke sqlite3_os_end(). michael@0: ** michael@0: ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. michael@0: ** ^If for some reason, sqlite3_initialize() is unable to initialize michael@0: ** the library (perhaps it is unable to allocate a needed resource such michael@0: ** as a mutex) it returns an [error code] other than [SQLITE_OK]. michael@0: ** michael@0: ** ^The sqlite3_initialize() routine is called internally by many other michael@0: ** SQLite interfaces so that an application usually does not need to michael@0: ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] michael@0: ** calls sqlite3_initialize() so the SQLite library will be automatically michael@0: ** initialized when [sqlite3_open()] is called if it has not be initialized michael@0: ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] michael@0: ** compile-time option, then the automatic calls to sqlite3_initialize() michael@0: ** are omitted and the application must call sqlite3_initialize() directly michael@0: ** prior to using any other SQLite interface. For maximum portability, michael@0: ** it is recommended that applications always invoke sqlite3_initialize() michael@0: ** directly prior to using any other SQLite interface. Future releases michael@0: ** of SQLite may require this. In other words, the behavior exhibited michael@0: ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the michael@0: ** default behavior in some future release of SQLite. michael@0: ** michael@0: ** The sqlite3_os_init() routine does operating-system specific michael@0: ** initialization of the SQLite library. The sqlite3_os_end() michael@0: ** routine undoes the effect of sqlite3_os_init(). Typical tasks michael@0: ** performed by these routines include allocation or deallocation michael@0: ** of static resources, initialization of global variables, michael@0: ** setting up a default [sqlite3_vfs] module, or setting up michael@0: ** a default configuration using [sqlite3_config()]. michael@0: ** michael@0: ** The application should never invoke either sqlite3_os_init() michael@0: ** or sqlite3_os_end() directly. The application should only invoke michael@0: ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() michael@0: ** interface is called automatically by sqlite3_initialize() and michael@0: ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate michael@0: ** implementations for sqlite3_os_init() and sqlite3_os_end() michael@0: ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. michael@0: ** When [custom builds | built for other platforms] michael@0: ** (using the [SQLITE_OS_OTHER=1] compile-time michael@0: ** option) the application must supply a suitable implementation for michael@0: ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied michael@0: ** implementation of sqlite3_os_init() or sqlite3_os_end() michael@0: ** must return [SQLITE_OK] on success and some other [error code] upon michael@0: ** failure. michael@0: */ michael@0: SQLITE_API int sqlite3_initialize(void); michael@0: SQLITE_API int sqlite3_shutdown(void); michael@0: SQLITE_API int sqlite3_os_init(void); michael@0: SQLITE_API int sqlite3_os_end(void); michael@0: michael@0: /* michael@0: ** CAPI3REF: Configuring The SQLite Library michael@0: ** michael@0: ** The sqlite3_config() interface is used to make global configuration michael@0: ** changes to SQLite in order to tune SQLite to the specific needs of michael@0: ** the application. The default configuration is recommended for most michael@0: ** applications and so this routine is usually not necessary. It is michael@0: ** provided to support rare applications with unusual needs. michael@0: ** michael@0: ** The sqlite3_config() interface is not threadsafe. The application michael@0: ** must insure that no other SQLite interfaces are invoked by other michael@0: ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() michael@0: ** may only be invoked prior to library initialization using michael@0: ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. michael@0: ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before michael@0: ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. michael@0: ** Note, however, that ^sqlite3_config() can be called as part of the michael@0: ** implementation of an application-defined [sqlite3_os_init()]. michael@0: ** michael@0: ** The first argument to sqlite3_config() is an integer michael@0: ** [configuration option] that determines michael@0: ** what property of SQLite is to be configured. Subsequent arguments michael@0: ** vary depending on the [configuration option] michael@0: ** in the first argument. michael@0: ** michael@0: ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. michael@0: ** ^If the option is unknown or SQLite is unable to set the option michael@0: ** then this routine returns a non-zero [error code]. michael@0: */ michael@0: SQLITE_API int sqlite3_config(int, ...); michael@0: michael@0: /* michael@0: ** CAPI3REF: Configure database connections michael@0: ** michael@0: ** The sqlite3_db_config() interface is used to make configuration michael@0: ** changes to a [database connection]. The interface is similar to michael@0: ** [sqlite3_config()] except that the changes apply to a single michael@0: ** [database connection] (specified in the first argument). michael@0: ** michael@0: ** The second argument to sqlite3_db_config(D,V,...) is the michael@0: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code michael@0: ** that indicates what aspect of the [database connection] is being configured. michael@0: ** Subsequent arguments vary depending on the configuration verb. michael@0: ** michael@0: ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if michael@0: ** the call is considered successful. michael@0: */ michael@0: SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); michael@0: michael@0: /* michael@0: ** CAPI3REF: Memory Allocation Routines michael@0: ** michael@0: ** An instance of this object defines the interface between SQLite michael@0: ** and low-level memory allocation routines. michael@0: ** michael@0: ** This object is used in only one place in the SQLite interface. michael@0: ** A pointer to an instance of this object is the argument to michael@0: ** [sqlite3_config()] when the configuration option is michael@0: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. michael@0: ** By creating an instance of this object michael@0: ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) michael@0: ** during configuration, an application can specify an alternative michael@0: ** memory allocation subsystem for SQLite to use for all of its michael@0: ** dynamic memory needs. michael@0: ** michael@0: ** Note that SQLite comes with several [built-in memory allocators] michael@0: ** that are perfectly adequate for the overwhelming majority of applications michael@0: ** and that this object is only useful to a tiny minority of applications michael@0: ** with specialized memory allocation requirements. This object is michael@0: ** also used during testing of SQLite in order to specify an alternative michael@0: ** memory allocator that simulates memory out-of-memory conditions in michael@0: ** order to verify that SQLite recovers gracefully from such michael@0: ** conditions. michael@0: ** michael@0: ** The xMalloc, xRealloc, and xFree methods must work like the michael@0: ** malloc(), realloc() and free() functions from the standard C library. michael@0: ** ^SQLite guarantees that the second argument to michael@0: ** xRealloc is always a value returned by a prior call to xRoundup. michael@0: ** michael@0: ** xSize should return the allocated size of a memory allocation michael@0: ** previously obtained from xMalloc or xRealloc. The allocated size michael@0: ** is always at least as big as the requested size but may be larger. michael@0: ** michael@0: ** The xRoundup method returns what would be the allocated size of michael@0: ** a memory allocation given a particular requested size. Most memory michael@0: ** allocators round up memory allocations at least to the next multiple michael@0: ** of 8. Some allocators round up to a larger multiple or to a power of 2. michael@0: ** Every memory allocation request coming in through [sqlite3_malloc()] michael@0: ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, michael@0: ** that causes the corresponding memory allocation to fail. michael@0: ** michael@0: ** The xInit method initializes the memory allocator. (For example, michael@0: ** it might allocate any require mutexes or initialize internal data michael@0: ** structures. The xShutdown method is invoked (indirectly) by michael@0: ** [sqlite3_shutdown()] and should deallocate any resources acquired michael@0: ** by xInit. The pAppData pointer is used as the only parameter to michael@0: ** xInit and xShutdown. michael@0: ** michael@0: ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes michael@0: ** the xInit method, so the xInit method need not be threadsafe. The michael@0: ** xShutdown method is only called from [sqlite3_shutdown()] so it does michael@0: ** not need to be threadsafe either. For all other methods, SQLite michael@0: ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the michael@0: ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which michael@0: ** it is by default) and so the methods are automatically serialized. michael@0: ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other michael@0: ** methods must be threadsafe or else make their own arrangements for michael@0: ** serialization. michael@0: ** michael@0: ** SQLite will never invoke xInit() more than once without an intervening michael@0: ** call to xShutdown(). michael@0: */ michael@0: typedef struct sqlite3_mem_methods sqlite3_mem_methods; michael@0: struct sqlite3_mem_methods { michael@0: void *(*xMalloc)(int); /* Memory allocation function */ michael@0: void (*xFree)(void*); /* Free a prior allocation */ michael@0: void *(*xRealloc)(void*,int); /* Resize an allocation */ michael@0: int (*xSize)(void*); /* Return the size of an allocation */ michael@0: int (*xRoundup)(int); /* Round up request size to allocation size */ michael@0: int (*xInit)(void*); /* Initialize the memory allocator */ michael@0: void (*xShutdown)(void*); /* Deinitialize the memory allocator */ michael@0: void *pAppData; /* Argument to xInit() and xShutdown() */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Configuration Options michael@0: ** KEYWORDS: {configuration option} michael@0: ** michael@0: ** These constants are the available integer configuration options that michael@0: ** can be passed as the first argument to the [sqlite3_config()] interface. michael@0: ** michael@0: ** New configuration options may be added in future releases of SQLite. michael@0: ** Existing configuration options might be discontinued. Applications michael@0: ** should check the return code from [sqlite3_config()] to make sure that michael@0: ** the call worked. The [sqlite3_config()] interface will return a michael@0: ** non-zero [error code] if a discontinued or unsupported configuration option michael@0: ** is invoked. michael@0: ** michael@0: **
michael@0: ** [[SQLITE_CONFIG_SINGLETHREAD]]
SQLITE_CONFIG_SINGLETHREAD
michael@0: **
There are no arguments to this option. ^This option sets the michael@0: ** [threading mode] to Single-thread. In other words, it disables michael@0: ** all mutexing and puts SQLite into a mode where it can only be used michael@0: ** by a single thread. ^If SQLite is compiled with michael@0: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then michael@0: ** it is not possible to change the [threading mode] from its default michael@0: ** value of Single-thread and so [sqlite3_config()] will return michael@0: ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD michael@0: ** configuration option.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_MULTITHREAD]]
SQLITE_CONFIG_MULTITHREAD
michael@0: **
There are no arguments to this option. ^This option sets the michael@0: ** [threading mode] to Multi-thread. In other words, it disables michael@0: ** mutexing on [database connection] and [prepared statement] objects. michael@0: ** The application is responsible for serializing access to michael@0: ** [database connections] and [prepared statements]. But other mutexes michael@0: ** are enabled so that SQLite will be safe to use in a multi-threaded michael@0: ** environment as long as no two threads attempt to use the same michael@0: ** [database connection] at the same time. ^If SQLite is compiled with michael@0: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then michael@0: ** it is not possible to set the Multi-thread [threading mode] and michael@0: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the michael@0: ** SQLITE_CONFIG_MULTITHREAD configuration option.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_SERIALIZED]]
SQLITE_CONFIG_SERIALIZED
michael@0: **
There are no arguments to this option. ^This option sets the michael@0: ** [threading mode] to Serialized. In other words, this option enables michael@0: ** all mutexes including the recursive michael@0: ** mutexes on [database connection] and [prepared statement] objects. michael@0: ** In this mode (which is the default when SQLite is compiled with michael@0: ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access michael@0: ** to [database connections] and [prepared statements] so that the michael@0: ** application is free to use the same [database connection] or the michael@0: ** same [prepared statement] in different threads at the same time. michael@0: ** ^If SQLite is compiled with michael@0: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then michael@0: ** it is not possible to set the Serialized [threading mode] and michael@0: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the michael@0: ** SQLITE_CONFIG_SERIALIZED configuration option.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_MALLOC]]
SQLITE_CONFIG_MALLOC
michael@0: **
^(This option takes a single argument which is a pointer to an michael@0: ** instance of the [sqlite3_mem_methods] structure. The argument specifies michael@0: ** alternative low-level memory allocation routines to be used in place of michael@0: ** the memory allocation routines built into SQLite.)^ ^SQLite makes michael@0: ** its own private copy of the content of the [sqlite3_mem_methods] structure michael@0: ** before the [sqlite3_config()] call returns.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_GETMALLOC]]
SQLITE_CONFIG_GETMALLOC
michael@0: **
^(This option takes a single argument which is a pointer to an michael@0: ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] michael@0: ** structure is filled with the currently defined memory allocation routines.)^ michael@0: ** This option can be used to overload the default memory allocation michael@0: ** routines with a wrapper that simulations memory allocation failure or michael@0: ** tracks memory usage, for example.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_MEMSTATUS]]
SQLITE_CONFIG_MEMSTATUS
michael@0: **
^This option takes single argument of type int, interpreted as a michael@0: ** boolean, which enables or disables the collection of memory allocation michael@0: ** statistics. ^(When memory allocation statistics are disabled, the michael@0: ** following SQLite interfaces become non-operational: michael@0: **
    michael@0: **
  • [sqlite3_memory_used()] michael@0: **
  • [sqlite3_memory_highwater()] michael@0: **
  • [sqlite3_soft_heap_limit64()] michael@0: **
  • [sqlite3_status()] michael@0: **
)^ michael@0: ** ^Memory allocation statistics are enabled by default unless SQLite is michael@0: ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory michael@0: ** allocation statistics are disabled by default. michael@0: **
michael@0: ** michael@0: ** [[SQLITE_CONFIG_SCRATCH]]
SQLITE_CONFIG_SCRATCH
michael@0: **
^This option specifies a static memory buffer that SQLite can use for michael@0: ** scratch memory. There are three arguments: A pointer an 8-byte michael@0: ** aligned memory buffer from which the scratch allocations will be michael@0: ** drawn, the size of each scratch allocation (sz), michael@0: ** and the maximum number of scratch allocations (N). The sz michael@0: ** argument must be a multiple of 16. michael@0: ** The first argument must be a pointer to an 8-byte aligned buffer michael@0: ** of at least sz*N bytes of memory. michael@0: ** ^SQLite will use no more than two scratch buffers per thread. So michael@0: ** N should be set to twice the expected maximum number of threads. michael@0: ** ^SQLite will never require a scratch buffer that is more than 6 michael@0: ** times the database page size. ^If SQLite needs needs additional michael@0: ** scratch memory beyond what is provided by this configuration option, then michael@0: ** [sqlite3_malloc()] will be used to obtain the memory needed.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_PAGECACHE]]
SQLITE_CONFIG_PAGECACHE
michael@0: **
^This option specifies a static memory buffer that SQLite can use for michael@0: ** the database page cache with the default page cache implementation. michael@0: ** This configuration should not be used if an application-define page michael@0: ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. michael@0: ** There are three arguments to this option: A pointer to 8-byte aligned michael@0: ** memory, the size of each page buffer (sz), and the number of pages (N). michael@0: ** The sz argument should be the size of the largest database page michael@0: ** (a power of two between 512 and 32768) plus a little extra for each michael@0: ** page header. ^The page header size is 20 to 40 bytes depending on michael@0: ** the host architecture. ^It is harmless, apart from the wasted memory, michael@0: ** to make sz a little too large. The first michael@0: ** argument should point to an allocation of at least sz*N bytes of memory. michael@0: ** ^SQLite will use the memory provided by the first argument to satisfy its michael@0: ** memory needs for the first N pages that it adds to cache. ^If additional michael@0: ** page cache memory is needed beyond what is provided by this option, then michael@0: ** SQLite goes to [sqlite3_malloc()] for the additional storage space. michael@0: ** The pointer in the first argument must michael@0: ** be aligned to an 8-byte boundary or subsequent behavior of SQLite michael@0: ** will be undefined.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_HEAP]]
SQLITE_CONFIG_HEAP
michael@0: **
^This option specifies a static memory buffer that SQLite will use michael@0: ** for all of its dynamic memory allocation needs beyond those provided michael@0: ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. michael@0: ** There are three arguments: An 8-byte aligned pointer to the memory, michael@0: ** the number of bytes in the memory buffer, and the minimum allocation size. michael@0: ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts michael@0: ** to using its default memory allocator (the system malloc() implementation), michael@0: ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the michael@0: ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or michael@0: ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory michael@0: ** allocator is engaged to handle all of SQLites memory allocation needs. michael@0: ** The first pointer (the memory pointer) must be aligned to an 8-byte michael@0: ** boundary or subsequent behavior of SQLite will be undefined. michael@0: ** The minimum allocation size is capped at 2**12. Reasonable values michael@0: ** for the minimum allocation size are 2**5 through 2**8.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_MUTEX]]
SQLITE_CONFIG_MUTEX
michael@0: **
^(This option takes a single argument which is a pointer to an michael@0: ** instance of the [sqlite3_mutex_methods] structure. The argument specifies michael@0: ** alternative low-level mutex routines to be used in place michael@0: ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the michael@0: ** content of the [sqlite3_mutex_methods] structure before the call to michael@0: ** [sqlite3_config()] returns. ^If SQLite is compiled with michael@0: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then michael@0: ** the entire mutexing subsystem is omitted from the build and hence calls to michael@0: ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will michael@0: ** return [SQLITE_ERROR].
michael@0: ** michael@0: ** [[SQLITE_CONFIG_GETMUTEX]]
SQLITE_CONFIG_GETMUTEX
michael@0: **
^(This option takes a single argument which is a pointer to an michael@0: ** instance of the [sqlite3_mutex_methods] structure. The michael@0: ** [sqlite3_mutex_methods] michael@0: ** structure is filled with the currently defined mutex routines.)^ michael@0: ** This option can be used to overload the default mutex allocation michael@0: ** routines with a wrapper used to track mutex usage for performance michael@0: ** profiling or testing, for example. ^If SQLite is compiled with michael@0: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then michael@0: ** the entire mutexing subsystem is omitted from the build and hence calls to michael@0: ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will michael@0: ** return [SQLITE_ERROR].
michael@0: ** michael@0: ** [[SQLITE_CONFIG_LOOKASIDE]]
SQLITE_CONFIG_LOOKASIDE
michael@0: **
^(This option takes two arguments that determine the default michael@0: ** memory allocation for the lookaside memory allocator on each michael@0: ** [database connection]. The first argument is the michael@0: ** size of each lookaside buffer slot and the second is the number of michael@0: ** slots allocated to each database connection.)^ ^(This option sets the michael@0: ** default lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] michael@0: ** verb to [sqlite3_db_config()] can be used to change the lookaside michael@0: ** configuration on individual connections.)^
michael@0: ** michael@0: ** [[SQLITE_CONFIG_PCACHE2]]
SQLITE_CONFIG_PCACHE2
michael@0: **
^(This option takes a single argument which is a pointer to michael@0: ** an [sqlite3_pcache_methods2] object. This object specifies the interface michael@0: ** to a custom page cache implementation.)^ ^SQLite makes a copy of the michael@0: ** object and uses it for page cache memory allocations.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_GETPCACHE2]]
SQLITE_CONFIG_GETPCACHE2
michael@0: **
^(This option takes a single argument which is a pointer to an michael@0: ** [sqlite3_pcache_methods2] object. SQLite copies of the current michael@0: ** page cache implementation into that object.)^
michael@0: ** michael@0: ** [[SQLITE_CONFIG_LOG]]
SQLITE_CONFIG_LOG
michael@0: **
^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a michael@0: ** function with a call signature of void(*)(void*,int,const char*), michael@0: ** and a pointer to void. ^If the function pointer is not NULL, it is michael@0: ** invoked by [sqlite3_log()] to process each logging event. ^If the michael@0: ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. michael@0: ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is michael@0: ** passed through as the first parameter to the application-defined logger michael@0: ** function whenever that function is invoked. ^The second parameter to michael@0: ** the logger function is a copy of the first parameter to the corresponding michael@0: ** [sqlite3_log()] call and is intended to be a [result code] or an michael@0: ** [extended result code]. ^The third parameter passed to the logger is michael@0: ** log message after formatting via [sqlite3_snprintf()]. michael@0: ** The SQLite logging interface is not reentrant; the logger function michael@0: ** supplied by the application must not invoke any SQLite interface. michael@0: ** In a multi-threaded application, the application-defined logger michael@0: ** function must be threadsafe.
michael@0: ** michael@0: ** [[SQLITE_CONFIG_URI]]
SQLITE_CONFIG_URI michael@0: **
This option takes a single argument of type int. If non-zero, then michael@0: ** URI handling is globally enabled. If the parameter is zero, then URI handling michael@0: ** is globally disabled. If URI handling is globally enabled, all filenames michael@0: ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or michael@0: ** specified as part of [ATTACH] commands are interpreted as URIs, regardless michael@0: ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database michael@0: ** connection is opened. If it is globally disabled, filenames are michael@0: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the michael@0: ** database connection is opened. By default, URI handling is globally michael@0: ** disabled. The default value may be changed by compiling with the michael@0: ** [SQLITE_USE_URI] symbol defined. michael@0: ** michael@0: ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]]
SQLITE_CONFIG_COVERING_INDEX_SCAN michael@0: **
This option takes a single integer argument which is interpreted as michael@0: ** a boolean in order to enable or disable the use of covering indices for michael@0: ** full table scans in the query optimizer. The default setting is determined michael@0: ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" michael@0: ** if that compile-time option is omitted. michael@0: ** The ability to disable the use of covering indices for full table scans michael@0: ** is because some incorrectly coded legacy applications might malfunction michael@0: ** malfunction when the optimization is enabled. Providing the ability to michael@0: ** disable the optimization allows the older, buggy application code to work michael@0: ** without change even with newer versions of SQLite. michael@0: ** michael@0: ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] michael@0: **
SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE michael@0: **
These options are obsolete and should not be used by new code. michael@0: ** They are retained for backwards compatibility but are now no-ops. michael@0: **
michael@0: ** michael@0: ** [[SQLITE_CONFIG_SQLLOG]] michael@0: **
SQLITE_CONFIG_SQLLOG michael@0: **
This option is only available if sqlite is compiled with the michael@0: ** SQLITE_ENABLE_SQLLOG pre-processor macro defined. The first argument should michael@0: ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). michael@0: ** The second should be of type (void*). The callback is invoked by the library michael@0: ** in three separate circumstances, identified by the value passed as the michael@0: ** fourth parameter. If the fourth parameter is 0, then the database connection michael@0: ** passed as the second argument has just been opened. The third argument michael@0: ** points to a buffer containing the name of the main database file. If the michael@0: ** fourth parameter is 1, then the SQL statement that the third parameter michael@0: ** points to has just been executed. Or, if the fourth parameter is 2, then michael@0: ** the connection being passed as the second parameter is being closed. The michael@0: ** third parameter is passed NULL In this case. michael@0: ** michael@0: */ michael@0: #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ michael@0: #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ michael@0: #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ michael@0: #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ michael@0: #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ michael@0: #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ michael@0: #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ michael@0: #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ michael@0: #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ michael@0: #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ michael@0: #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ michael@0: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ michael@0: #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ michael@0: #define SQLITE_CONFIG_PCACHE 14 /* no-op */ michael@0: #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ michael@0: #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ michael@0: #define SQLITE_CONFIG_URI 17 /* int */ michael@0: #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ michael@0: #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ michael@0: #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ michael@0: #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Database Connection Configuration Options michael@0: ** michael@0: ** These constants are the available integer configuration options that michael@0: ** can be passed as the second argument to the [sqlite3_db_config()] interface. michael@0: ** michael@0: ** New configuration options may be added in future releases of SQLite. michael@0: ** Existing configuration options might be discontinued. Applications michael@0: ** should check the return code from [sqlite3_db_config()] to make sure that michael@0: ** the call worked. ^The [sqlite3_db_config()] interface will return a michael@0: ** non-zero [error code] if a discontinued or unsupported configuration option michael@0: ** is invoked. michael@0: ** michael@0: **
michael@0: **
SQLITE_DBCONFIG_LOOKASIDE
michael@0: **
^This option takes three additional arguments that determine the michael@0: ** [lookaside memory allocator] configuration for the [database connection]. michael@0: ** ^The first argument (the third parameter to [sqlite3_db_config()] is a michael@0: ** pointer to a memory buffer to use for lookaside memory. michael@0: ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb michael@0: ** may be NULL in which case SQLite will allocate the michael@0: ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the michael@0: ** size of each lookaside buffer slot. ^The third argument is the number of michael@0: ** slots. The size of the buffer in the first argument must be greater than michael@0: ** or equal to the product of the second and third arguments. The buffer michael@0: ** must be aligned to an 8-byte boundary. ^If the second argument to michael@0: ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally michael@0: ** rounded down to the next smaller multiple of 8. ^(The lookaside memory michael@0: ** configuration for a database connection can only be changed when that michael@0: ** connection is not currently using lookaside memory, or in other words michael@0: ** when the "current value" returned by michael@0: ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. michael@0: ** Any attempt to change the lookaside memory configuration when lookaside michael@0: ** memory is in use leaves the configuration unchanged and returns michael@0: ** [SQLITE_BUSY].)^
michael@0: ** michael@0: **
SQLITE_DBCONFIG_ENABLE_FKEY
michael@0: **
^This option is used to enable or disable the enforcement of michael@0: ** [foreign key constraints]. There should be two additional arguments. michael@0: ** The first argument is an integer which is 0 to disable FK enforcement, michael@0: ** positive to enable FK enforcement or negative to leave FK enforcement michael@0: ** unchanged. The second parameter is a pointer to an integer into which michael@0: ** is written 0 or 1 to indicate whether FK enforcement is off or on michael@0: ** following this call. The second parameter may be a NULL pointer, in michael@0: ** which case the FK enforcement setting is not reported back.
michael@0: ** michael@0: **
SQLITE_DBCONFIG_ENABLE_TRIGGER
michael@0: **
^This option is used to enable or disable [CREATE TRIGGER | triggers]. michael@0: ** There should be two additional arguments. michael@0: ** The first argument is an integer which is 0 to disable triggers, michael@0: ** positive to enable triggers or negative to leave the setting unchanged. michael@0: ** The second parameter is a pointer to an integer into which michael@0: ** is written 0 or 1 to indicate whether triggers are disabled or enabled michael@0: ** following this call. The second parameter may be a NULL pointer, in michael@0: ** which case the trigger setting is not reported back.
michael@0: ** michael@0: **
michael@0: */ michael@0: #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ michael@0: #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ michael@0: #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Enable Or Disable Extended Result Codes michael@0: ** michael@0: ** ^The sqlite3_extended_result_codes() routine enables or disables the michael@0: ** [extended result codes] feature of SQLite. ^The extended result michael@0: ** codes are disabled by default for historical compatibility. michael@0: */ michael@0: SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); michael@0: michael@0: /* michael@0: ** CAPI3REF: Last Insert Rowid michael@0: ** michael@0: ** ^Each entry in an SQLite table has a unique 64-bit signed michael@0: ** integer key called the [ROWID | "rowid"]. ^The rowid is always available michael@0: ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those michael@0: ** names are not also used by explicitly declared columns. ^If michael@0: ** the table has a column of type [INTEGER PRIMARY KEY] then that column michael@0: ** is another alias for the rowid. michael@0: ** michael@0: ** ^This routine returns the [rowid] of the most recent michael@0: ** successful [INSERT] into the database from the [database connection] michael@0: ** in the first argument. ^As of SQLite version 3.7.7, this routines michael@0: ** records the last insert rowid of both ordinary tables and [virtual tables]. michael@0: ** ^If no successful [INSERT]s michael@0: ** have ever occurred on that database connection, zero is returned. michael@0: ** michael@0: ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] michael@0: ** method, then this routine will return the [rowid] of the inserted michael@0: ** row as long as the trigger or virtual table method is running. michael@0: ** But once the trigger or virtual table method ends, the value returned michael@0: ** by this routine reverts to what it was before the trigger or virtual michael@0: ** table method began.)^ michael@0: ** michael@0: ** ^An [INSERT] that fails due to a constraint violation is not a michael@0: ** successful [INSERT] and does not change the value returned by this michael@0: ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, michael@0: ** and INSERT OR ABORT make no changes to the return value of this michael@0: ** routine when their insertion fails. ^(When INSERT OR REPLACE michael@0: ** encounters a constraint violation, it does not fail. The michael@0: ** INSERT continues to completion after deleting rows that caused michael@0: ** the constraint problem so INSERT OR REPLACE will always change michael@0: ** the return value of this interface.)^ michael@0: ** michael@0: ** ^For the purposes of this routine, an [INSERT] is considered to michael@0: ** be successful even if it is subsequently rolled back. michael@0: ** michael@0: ** This function is accessible to SQL statements via the michael@0: ** [last_insert_rowid() SQL function]. michael@0: ** michael@0: ** If a separate thread performs a new [INSERT] on the same michael@0: ** database connection while the [sqlite3_last_insert_rowid()] michael@0: ** function is running and thus changes the last insert [rowid], michael@0: ** then the value returned by [sqlite3_last_insert_rowid()] is michael@0: ** unpredictable and might not equal either the old or the new michael@0: ** last insert [rowid]. michael@0: */ michael@0: SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Count The Number Of Rows Modified michael@0: ** michael@0: ** ^This function returns the number of database rows that were changed michael@0: ** or inserted or deleted by the most recently completed SQL statement michael@0: ** on the [database connection] specified by the first parameter. michael@0: ** ^(Only changes that are directly specified by the [INSERT], [UPDATE], michael@0: ** or [DELETE] statement are counted. Auxiliary changes caused by michael@0: ** triggers or [foreign key actions] are not counted.)^ Use the michael@0: ** [sqlite3_total_changes()] function to find the total number of changes michael@0: ** including changes caused by triggers and foreign key actions. michael@0: ** michael@0: ** ^Changes to a view that are simulated by an [INSTEAD OF trigger] michael@0: ** are not counted. Only real table changes are counted. michael@0: ** michael@0: ** ^(A "row change" is a change to a single row of a single table michael@0: ** caused by an INSERT, DELETE, or UPDATE statement. Rows that michael@0: ** are changed as side effects of [REPLACE] constraint resolution, michael@0: ** rollback, ABORT processing, [DROP TABLE], or by any other michael@0: ** mechanisms do not count as direct row changes.)^ michael@0: ** michael@0: ** A "trigger context" is a scope of execution that begins and michael@0: ** ends with the script of a [CREATE TRIGGER | trigger]. michael@0: ** Most SQL statements are michael@0: ** evaluated outside of any trigger. This is the "top level" michael@0: ** trigger context. If a trigger fires from the top level, a michael@0: ** new trigger context is entered for the duration of that one michael@0: ** trigger. Subtriggers create subcontexts for their duration. michael@0: ** michael@0: ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does michael@0: ** not create a new trigger context. michael@0: ** michael@0: ** ^This function returns the number of direct row changes in the michael@0: ** most recent INSERT, UPDATE, or DELETE statement within the same michael@0: ** trigger context. michael@0: ** michael@0: ** ^Thus, when called from the top level, this function returns the michael@0: ** number of changes in the most recent INSERT, UPDATE, or DELETE michael@0: ** that also occurred at the top level. ^(Within the body of a trigger, michael@0: ** the sqlite3_changes() interface can be called to find the number of michael@0: ** changes in the most recently completed INSERT, UPDATE, or DELETE michael@0: ** statement within the body of the same trigger. michael@0: ** However, the number returned does not include changes michael@0: ** caused by subtriggers since those have their own context.)^ michael@0: ** michael@0: ** See also the [sqlite3_total_changes()] interface, the michael@0: ** [count_changes pragma], and the [changes() SQL function]. michael@0: ** michael@0: ** If a separate thread makes changes on the same database connection michael@0: ** while [sqlite3_changes()] is running then the value returned michael@0: ** is unpredictable and not meaningful. michael@0: */ michael@0: SQLITE_API int sqlite3_changes(sqlite3*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Total Number Of Rows Modified michael@0: ** michael@0: ** ^This function returns the number of row changes caused by [INSERT], michael@0: ** [UPDATE] or [DELETE] statements since the [database connection] was opened. michael@0: ** ^(The count returned by sqlite3_total_changes() includes all changes michael@0: ** from all [CREATE TRIGGER | trigger] contexts and changes made by michael@0: ** [foreign key actions]. However, michael@0: ** the count does not include changes used to implement [REPLACE] constraints, michael@0: ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The michael@0: ** count does not include rows of views that fire an [INSTEAD OF trigger], michael@0: ** though if the INSTEAD OF trigger makes changes of its own, those changes michael@0: ** are counted.)^ michael@0: ** ^The sqlite3_total_changes() function counts the changes as soon as michael@0: ** the statement that makes them is completed (when the statement handle michael@0: ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). michael@0: ** michael@0: ** See also the [sqlite3_changes()] interface, the michael@0: ** [count_changes pragma], and the [total_changes() SQL function]. michael@0: ** michael@0: ** If a separate thread makes changes on the same database connection michael@0: ** while [sqlite3_total_changes()] is running then the value michael@0: ** returned is unpredictable and not meaningful. michael@0: */ michael@0: SQLITE_API int sqlite3_total_changes(sqlite3*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Interrupt A Long-Running Query michael@0: ** michael@0: ** ^This function causes any pending database operation to abort and michael@0: ** return at its earliest opportunity. This routine is typically michael@0: ** called in response to a user action such as pressing "Cancel" michael@0: ** or Ctrl-C where the user wants a long query operation to halt michael@0: ** immediately. michael@0: ** michael@0: ** ^It is safe to call this routine from a thread different from the michael@0: ** thread that is currently running the database operation. But it michael@0: ** is not safe to call this routine with a [database connection] that michael@0: ** is closed or might close before sqlite3_interrupt() returns. michael@0: ** michael@0: ** ^If an SQL operation is very nearly finished at the time when michael@0: ** sqlite3_interrupt() is called, then it might not have an opportunity michael@0: ** to be interrupted and might continue to completion. michael@0: ** michael@0: ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. michael@0: ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE michael@0: ** that is inside an explicit transaction, then the entire transaction michael@0: ** will be rolled back automatically. michael@0: ** michael@0: ** ^The sqlite3_interrupt(D) call is in effect until all currently running michael@0: ** SQL statements on [database connection] D complete. ^Any new SQL statements michael@0: ** that are started after the sqlite3_interrupt() call and before the michael@0: ** running statements reaches zero are interrupted as if they had been michael@0: ** running prior to the sqlite3_interrupt() call. ^New SQL statements michael@0: ** that are started after the running statement count reaches zero are michael@0: ** not effected by the sqlite3_interrupt(). michael@0: ** ^A call to sqlite3_interrupt(D) that occurs when there are no running michael@0: ** SQL statements is a no-op and has no effect on SQL statements michael@0: ** that are started after the sqlite3_interrupt() call returns. michael@0: ** michael@0: ** If the database connection closes while [sqlite3_interrupt()] michael@0: ** is running then bad things will likely happen. michael@0: */ michael@0: SQLITE_API void sqlite3_interrupt(sqlite3*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Determine If An SQL Statement Is Complete michael@0: ** michael@0: ** These routines are useful during command-line input to determine if the michael@0: ** currently entered text seems to form a complete SQL statement or michael@0: ** if additional input is needed before sending the text into michael@0: ** SQLite for parsing. ^These routines return 1 if the input string michael@0: ** appears to be a complete SQL statement. ^A statement is judged to be michael@0: ** complete if it ends with a semicolon token and is not a prefix of a michael@0: ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within michael@0: ** string literals or quoted identifier names or comments are not michael@0: ** independent tokens (they are part of the token in which they are michael@0: ** embedded) and thus do not count as a statement terminator. ^Whitespace michael@0: ** and comments that follow the final semicolon are ignored. michael@0: ** michael@0: ** ^These routines return 0 if the statement is incomplete. ^If a michael@0: ** memory allocation fails, then SQLITE_NOMEM is returned. michael@0: ** michael@0: ** ^These routines do not parse the SQL statements thus michael@0: ** will not detect syntactically incorrect SQL. michael@0: ** michael@0: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior michael@0: ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked michael@0: ** automatically by sqlite3_complete16(). If that initialization fails, michael@0: ** then the return value from sqlite3_complete16() will be non-zero michael@0: ** regardless of whether or not the input SQL is complete.)^ michael@0: ** michael@0: ** The input to [sqlite3_complete()] must be a zero-terminated michael@0: ** UTF-8 string. michael@0: ** michael@0: ** The input to [sqlite3_complete16()] must be a zero-terminated michael@0: ** UTF-16 string in native byte order. michael@0: */ michael@0: SQLITE_API int sqlite3_complete(const char *sql); michael@0: SQLITE_API int sqlite3_complete16(const void *sql); michael@0: michael@0: /* michael@0: ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors michael@0: ** michael@0: ** ^This routine sets a callback function that might be invoked whenever michael@0: ** an attempt is made to open a database table that another thread michael@0: ** or process has locked. michael@0: ** michael@0: ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] michael@0: ** is returned immediately upon encountering the lock. ^If the busy callback michael@0: ** is not NULL, then the callback might be invoked with two arguments. michael@0: ** michael@0: ** ^The first argument to the busy handler is a copy of the void* pointer which michael@0: ** is the third argument to sqlite3_busy_handler(). ^The second argument to michael@0: ** the busy handler callback is the number of times that the busy handler has michael@0: ** been invoked for this locking event. ^If the michael@0: ** busy callback returns 0, then no additional attempts are made to michael@0: ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. michael@0: ** ^If the callback returns non-zero, then another attempt michael@0: ** is made to open the database for reading and the cycle repeats. michael@0: ** michael@0: ** The presence of a busy handler does not guarantee that it will be invoked michael@0: ** when there is lock contention. ^If SQLite determines that invoking the busy michael@0: ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] michael@0: ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. michael@0: ** Consider a scenario where one process is holding a read lock that michael@0: ** it is trying to promote to a reserved lock and michael@0: ** a second process is holding a reserved lock that it is trying michael@0: ** to promote to an exclusive lock. The first process cannot proceed michael@0: ** because it is blocked by the second and the second process cannot michael@0: ** proceed because it is blocked by the first. If both processes michael@0: ** invoke the busy handlers, neither will make any progress. Therefore, michael@0: ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this michael@0: ** will induce the first process to release its read lock and allow michael@0: ** the second process to proceed. michael@0: ** michael@0: ** ^The default busy callback is NULL. michael@0: ** michael@0: ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] michael@0: ** when SQLite is in the middle of a large transaction where all the michael@0: ** changes will not fit into the in-memory cache. SQLite will michael@0: ** already hold a RESERVED lock on the database file, but it needs michael@0: ** to promote this lock to EXCLUSIVE so that it can spill cache michael@0: ** pages into the database file without harm to concurrent michael@0: ** readers. ^If it is unable to promote the lock, then the in-memory michael@0: ** cache will be left in an inconsistent state and so the error michael@0: ** code is promoted from the relatively benign [SQLITE_BUSY] to michael@0: ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion michael@0: ** forces an automatic rollback of the changes. See the michael@0: ** michael@0: ** CorruptionFollowingBusyError wiki page for a discussion of why michael@0: ** this is important. michael@0: ** michael@0: ** ^(There can only be a single busy handler defined for each michael@0: ** [database connection]. Setting a new busy handler clears any michael@0: ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] michael@0: ** will also set or clear the busy handler. michael@0: ** michael@0: ** The busy callback should not take any actions which modify the michael@0: ** database connection that invoked the busy handler. Any such actions michael@0: ** result in undefined behavior. michael@0: ** michael@0: ** A busy handler must not close the database connection michael@0: ** or [prepared statement] that invoked the busy handler. michael@0: */ michael@0: SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Set A Busy Timeout michael@0: ** michael@0: ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps michael@0: ** for a specified amount of time when a table is locked. ^The handler michael@0: ** will sleep multiple times until at least "ms" milliseconds of sleeping michael@0: ** have accumulated. ^After at least "ms" milliseconds of sleeping, michael@0: ** the handler returns 0 which causes [sqlite3_step()] to return michael@0: ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. michael@0: ** michael@0: ** ^Calling this routine with an argument less than or equal to zero michael@0: ** turns off all busy handlers. michael@0: ** michael@0: ** ^(There can only be a single busy handler for a particular michael@0: ** [database connection] any any given moment. If another busy handler michael@0: ** was defined (using [sqlite3_busy_handler()]) prior to calling michael@0: ** this routine, that other busy handler is cleared.)^ michael@0: */ michael@0: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); michael@0: michael@0: /* michael@0: ** CAPI3REF: Convenience Routines For Running Queries michael@0: ** michael@0: ** This is a legacy interface that is preserved for backwards compatibility. michael@0: ** Use of this interface is not recommended. michael@0: ** michael@0: ** Definition: A result table is memory data structure created by the michael@0: ** [sqlite3_get_table()] interface. A result table records the michael@0: ** complete query results from one or more queries. michael@0: ** michael@0: ** The table conceptually has a number of rows and columns. But michael@0: ** these numbers are not part of the result table itself. These michael@0: ** numbers are obtained separately. Let N be the number of rows michael@0: ** and M be the number of columns. michael@0: ** michael@0: ** A result table is an array of pointers to zero-terminated UTF-8 strings. michael@0: ** There are (N+1)*M elements in the array. The first M pointers point michael@0: ** to zero-terminated strings that contain the names of the columns. michael@0: ** The remaining entries all point to query results. NULL values result michael@0: ** in NULL pointers. All other values are in their UTF-8 zero-terminated michael@0: ** string representation as returned by [sqlite3_column_text()]. michael@0: ** michael@0: ** A result table might consist of one or more memory allocations. michael@0: ** It is not safe to pass a result table directly to [sqlite3_free()]. michael@0: ** A result table should be deallocated using [sqlite3_free_table()]. michael@0: ** michael@0: ** ^(As an example of the result table format, suppose a query result michael@0: ** is as follows: michael@0: ** michael@0: ** 
michael@0: **        Name        | Age
michael@0: **        -----------------------
michael@0: **        Alice       | 43
michael@0: **        Bob         | 28
michael@0: **        Cindy       | 21
michael@0: **
michael@0: ** michael@0: ** There are two column (M==2) and three rows (N==3). Thus the michael@0: ** result table has 8 entries. Suppose the result table is stored michael@0: ** in an array names azResult. Then azResult holds this content: michael@0: ** michael@0: ** 
michael@0: **        azResult[0] = "Name";
michael@0: **        azResult[1] = "Age";
michael@0: **        azResult[2] = "Alice";
michael@0: **        azResult[3] = "43";
michael@0: **        azResult[4] = "Bob";
michael@0: **        azResult[5] = "28";
michael@0: **        azResult[6] = "Cindy";
michael@0: **        azResult[7] = "21";
michael@0: **
)^ michael@0: ** michael@0: ** ^The sqlite3_get_table() function evaluates one or more michael@0: ** semicolon-separated SQL statements in the zero-terminated UTF-8 michael@0: ** string of its 2nd parameter and returns a result table to the michael@0: ** pointer given in its 3rd parameter. michael@0: ** michael@0: ** After the application has finished with the result from sqlite3_get_table(), michael@0: ** it must pass the result table pointer to sqlite3_free_table() in order to michael@0: ** release the memory that was malloced. Because of the way the michael@0: ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling michael@0: ** function must not try to call [sqlite3_free()] directly. Only michael@0: ** [sqlite3_free_table()] is able to release the memory properly and safely. michael@0: ** michael@0: ** The sqlite3_get_table() interface is implemented as a wrapper around michael@0: ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access michael@0: ** to any internal data structures of SQLite. It uses only the public michael@0: ** interface defined here. As a consequence, errors that occur in the michael@0: ** wrapper layer outside of the internal [sqlite3_exec()] call are not michael@0: ** reflected in subsequent calls to [sqlite3_errcode()] or michael@0: ** [sqlite3_errmsg()]. michael@0: */ michael@0: SQLITE_API int sqlite3_get_table( michael@0: sqlite3 *db, /* An open database */ michael@0: const char *zSql, /* SQL to be evaluated */ michael@0: char ***pazResult, /* Results of the query */ michael@0: int *pnRow, /* Number of result rows written here */ michael@0: int *pnColumn, /* Number of result columns written here */ michael@0: char **pzErrmsg /* Error msg written here */ michael@0: ); michael@0: SQLITE_API void sqlite3_free_table(char **result); michael@0: michael@0: /* michael@0: ** CAPI3REF: Formatted String Printing Functions michael@0: ** michael@0: ** These routines are work-alikes of the "printf()" family of functions michael@0: ** from the standard C library. michael@0: ** michael@0: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their michael@0: ** results into memory obtained from [sqlite3_malloc()]. michael@0: ** The strings returned by these two routines should be michael@0: ** released by [sqlite3_free()]. ^Both routines return a michael@0: ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough michael@0: ** memory to hold the resulting string. michael@0: ** michael@0: ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from michael@0: ** the standard C library. The result is written into the michael@0: ** buffer supplied as the second parameter whose size is given by michael@0: ** the first parameter. Note that the order of the michael@0: ** first two parameters is reversed from snprintf().)^ This is an michael@0: ** historical accident that cannot be fixed without breaking michael@0: ** backwards compatibility. ^(Note also that sqlite3_snprintf() michael@0: ** returns a pointer to its buffer instead of the number of michael@0: ** characters actually written into the buffer.)^ We admit that michael@0: ** the number of characters written would be a more useful return michael@0: ** value but we cannot change the implementation of sqlite3_snprintf() michael@0: ** now without breaking compatibility. michael@0: ** michael@0: ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() michael@0: ** guarantees that the buffer is always zero-terminated. ^The first michael@0: ** parameter "n" is the total size of the buffer, including space for michael@0: ** the zero terminator. So the longest string that can be completely michael@0: ** written will be n-1 characters. michael@0: ** michael@0: ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). michael@0: ** michael@0: ** These routines all implement some additional formatting michael@0: ** options that are useful for constructing SQL statements. michael@0: ** All of the usual printf() formatting options apply. In addition, there michael@0: ** is are "%q", "%Q", and "%z" options. michael@0: ** michael@0: ** ^(The %q option works like %s in that it substitutes a nul-terminated michael@0: ** string from the argument list. But %q also doubles every '\'' character. michael@0: ** %q is designed for use inside a string literal.)^ By doubling each '\'' michael@0: ** character it escapes that character and allows it to be inserted into michael@0: ** the string. michael@0: ** michael@0: ** For example, assume the string variable zText contains text as follows: michael@0: ** michael@0: ** 
michael@0: **  char *zText = "It's a happy day!";
michael@0: **
michael@0: ** michael@0: ** One can use this text in an SQL statement as follows: michael@0: ** michael@0: ** 
michael@0: **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
michael@0: **  sqlite3_exec(db, zSQL, 0, 0, 0);
michael@0: **  sqlite3_free(zSQL);
michael@0: **
michael@0: ** michael@0: ** Because the %q format string is used, the '\'' character in zText michael@0: ** is escaped and the SQL generated is as follows: michael@0: ** michael@0: ** 
michael@0: **  INSERT INTO table1 VALUES('It''s a happy day!')
michael@0: **
michael@0: ** michael@0: ** This is correct. Had we used %s instead of %q, the generated SQL michael@0: ** would have looked like this: michael@0: ** michael@0: ** 
michael@0: **  INSERT INTO table1 VALUES('It's a happy day!');
michael@0: **
michael@0: ** michael@0: ** This second example is an SQL syntax error. As a general rule you should michael@0: ** always use %q instead of %s when inserting text into a string literal. michael@0: ** michael@0: ** ^(The %Q option works like %q except it also adds single quotes around michael@0: ** the outside of the total string. Additionally, if the parameter in the michael@0: ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without michael@0: ** single quotes).)^ So, for example, one could say: michael@0: ** michael@0: ** 
michael@0: **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
michael@0: **  sqlite3_exec(db, zSQL, 0, 0, 0);
michael@0: **  sqlite3_free(zSQL);
michael@0: **
michael@0: ** michael@0: ** The code above will render a correct SQL statement in the zSQL michael@0: ** variable even if the zText variable is a NULL pointer. michael@0: ** michael@0: ** ^(The "%z" formatting option works like "%s" but with the michael@0: ** addition that after the string has been read and copied into michael@0: ** the result, [sqlite3_free()] is called on the input string.)^ michael@0: */ michael@0: SQLITE_API char *sqlite3_mprintf(const char*,...); michael@0: SQLITE_API char *sqlite3_vmprintf(const char*, va_list); michael@0: SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); michael@0: SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); michael@0: michael@0: /* michael@0: ** CAPI3REF: Memory Allocation Subsystem michael@0: ** michael@0: ** The SQLite core uses these three routines for all of its own michael@0: ** internal memory allocation needs. "Core" in the previous sentence michael@0: ** does not include operating-system specific VFS implementation. The michael@0: ** Windows VFS uses native malloc() and free() for some operations. michael@0: ** michael@0: ** ^The sqlite3_malloc() routine returns a pointer to a block michael@0: ** of memory at least N bytes in length, where N is the parameter. michael@0: ** ^If sqlite3_malloc() is unable to obtain sufficient free michael@0: ** memory, it returns a NULL pointer. ^If the parameter N to michael@0: ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns michael@0: ** a NULL pointer. michael@0: ** michael@0: ** ^Calling sqlite3_free() with a pointer previously returned michael@0: ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so michael@0: ** that it might be reused. ^The sqlite3_free() routine is michael@0: ** a no-op if is called with a NULL pointer. Passing a NULL pointer michael@0: ** to sqlite3_free() is harmless. After being freed, memory michael@0: ** should neither be read nor written. Even reading previously freed michael@0: ** memory might result in a segmentation fault or other severe error. michael@0: ** Memory corruption, a segmentation fault, or other severe error michael@0: ** might result if sqlite3_free() is called with a non-NULL pointer that michael@0: ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). michael@0: ** michael@0: ** ^(The sqlite3_realloc() interface attempts to resize a michael@0: ** prior memory allocation to be at least N bytes, where N is the michael@0: ** second parameter. The memory allocation to be resized is the first michael@0: ** parameter.)^ ^ If the first parameter to sqlite3_realloc() michael@0: ** is a NULL pointer then its behavior is identical to calling michael@0: ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). michael@0: ** ^If the second parameter to sqlite3_realloc() is zero or michael@0: ** negative then the behavior is exactly the same as calling michael@0: ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). michael@0: ** ^sqlite3_realloc() returns a pointer to a memory allocation michael@0: ** of at least N bytes in size or NULL if sufficient memory is unavailable. michael@0: ** ^If M is the size of the prior allocation, then min(N,M) bytes michael@0: ** of the prior allocation are copied into the beginning of buffer returned michael@0: ** by sqlite3_realloc() and the prior allocation is freed. michael@0: ** ^If sqlite3_realloc() returns NULL, then the prior allocation michael@0: ** is not freed. michael@0: ** michael@0: ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() michael@0: ** is always aligned to at least an 8 byte boundary, or to a michael@0: ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time michael@0: ** option is used. michael@0: ** michael@0: ** In SQLite version 3.5.0 and 3.5.1, it was possible to define michael@0: ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in michael@0: ** implementation of these routines to be omitted. That capability michael@0: ** is no longer provided. Only built-in memory allocators can be used. michael@0: ** michael@0: ** Prior to SQLite version 3.7.10, the Windows OS interface layer called michael@0: ** the system malloc() and free() directly when converting michael@0: ** filenames between the UTF-8 encoding used by SQLite michael@0: ** and whatever filename encoding is used by the particular Windows michael@0: ** installation. Memory allocation errors were detected, but michael@0: ** they were reported back as [SQLITE_CANTOPEN] or michael@0: ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. michael@0: ** michael@0: ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] michael@0: ** must be either NULL or else pointers obtained from a prior michael@0: ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have michael@0: ** not yet been released. michael@0: ** michael@0: ** The application must not read or write any part of michael@0: ** a block of memory after it has been released using michael@0: ** [sqlite3_free()] or [sqlite3_realloc()]. michael@0: */ michael@0: SQLITE_API void *sqlite3_malloc(int); michael@0: SQLITE_API void *sqlite3_realloc(void*, int); michael@0: SQLITE_API void sqlite3_free(void*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Memory Allocator Statistics michael@0: ** michael@0: ** SQLite provides these two interfaces for reporting on the status michael@0: ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] michael@0: ** routines, which form the built-in memory allocation subsystem. michael@0: ** michael@0: ** ^The [sqlite3_memory_used()] routine returns the number of bytes michael@0: ** of memory currently outstanding (malloced but not freed). michael@0: ** ^The [sqlite3_memory_highwater()] routine returns the maximum michael@0: ** value of [sqlite3_memory_used()] since the high-water mark michael@0: ** was last reset. ^The values returned by [sqlite3_memory_used()] and michael@0: ** [sqlite3_memory_highwater()] include any overhead michael@0: ** added by SQLite in its implementation of [sqlite3_malloc()], michael@0: ** but not overhead added by the any underlying system library michael@0: ** routines that [sqlite3_malloc()] may call. michael@0: ** michael@0: ** ^The memory high-water mark is reset to the current value of michael@0: ** [sqlite3_memory_used()] if and only if the parameter to michael@0: ** [sqlite3_memory_highwater()] is true. ^The value returned michael@0: ** by [sqlite3_memory_highwater(1)] is the high-water mark michael@0: ** prior to the reset. michael@0: */ michael@0: SQLITE_API sqlite3_int64 sqlite3_memory_used(void); michael@0: SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); michael@0: michael@0: /* michael@0: ** CAPI3REF: Pseudo-Random Number Generator michael@0: ** michael@0: ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to michael@0: ** select random [ROWID | ROWIDs] when inserting new records into a table that michael@0: ** already uses the largest possible [ROWID]. The PRNG is also used for michael@0: ** the build-in random() and randomblob() SQL functions. This interface allows michael@0: ** applications to access the same PRNG for other purposes. michael@0: ** michael@0: ** ^A call to this routine stores N bytes of randomness into buffer P. michael@0: ** michael@0: ** ^The first time this routine is invoked (either internally or by michael@0: ** the application) the PRNG is seeded using randomness obtained michael@0: ** from the xRandomness method of the default [sqlite3_vfs] object. michael@0: ** ^On all subsequent invocations, the pseudo-randomness is generated michael@0: ** internally and without recourse to the [sqlite3_vfs] xRandomness michael@0: ** method. michael@0: */ michael@0: SQLITE_API void sqlite3_randomness(int N, void *P); michael@0: michael@0: /* michael@0: ** CAPI3REF: Compile-Time Authorization Callbacks michael@0: ** michael@0: ** ^This routine registers an authorizer callback with a particular michael@0: ** [database connection], supplied in the first argument. michael@0: ** ^The authorizer callback is invoked as SQL statements are being compiled michael@0: ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], michael@0: ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various michael@0: ** points during the compilation process, as logic is being created michael@0: ** to perform various actions, the authorizer callback is invoked to michael@0: ** see if those actions are allowed. ^The authorizer callback should michael@0: ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the michael@0: ** specific action but allow the SQL statement to continue to be michael@0: ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be michael@0: ** rejected with an error. ^If the authorizer callback returns michael@0: ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] michael@0: ** then the [sqlite3_prepare_v2()] or equivalent call that triggered michael@0: ** the authorizer will fail with an error message. michael@0: ** michael@0: ** When the callback returns [SQLITE_OK], that means the operation michael@0: ** requested is ok. ^When the callback returns [SQLITE_DENY], the michael@0: ** [sqlite3_prepare_v2()] or equivalent call that triggered the michael@0: ** authorizer will fail with an error message explaining that michael@0: ** access is denied. michael@0: ** michael@0: ** ^The first parameter to the authorizer callback is a copy of the third michael@0: ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter michael@0: ** to the callback is an integer [SQLITE_COPY | action code] that specifies michael@0: ** the particular action to be authorized. ^The third through sixth parameters michael@0: ** to the callback are zero-terminated strings that contain additional michael@0: ** details about the action to be authorized. michael@0: ** michael@0: ** ^If the action code is [SQLITE_READ] michael@0: ** and the callback returns [SQLITE_IGNORE] then the michael@0: ** [prepared statement] statement is constructed to substitute michael@0: ** a NULL value in place of the table column that would have michael@0: ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] michael@0: ** return can be used to deny an untrusted user access to individual michael@0: ** columns of a table. michael@0: ** ^If the action code is [SQLITE_DELETE] and the callback returns michael@0: ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the michael@0: ** [truncate optimization] is disabled and all rows are deleted individually. michael@0: ** michael@0: ** An authorizer is used when [sqlite3_prepare | preparing] michael@0: ** SQL statements from an untrusted source, to ensure that the SQL statements michael@0: ** do not try to access data they are not allowed to see, or that they do not michael@0: ** try to execute malicious statements that damage the database. For michael@0: ** example, an application may allow a user to enter arbitrary michael@0: ** SQL queries for evaluation by a database. But the application does michael@0: ** not want the user to be able to make arbitrary changes to the michael@0: ** database. An authorizer could then be put in place while the michael@0: ** user-entered SQL is being [sqlite3_prepare | prepared] that michael@0: ** disallows everything except [SELECT] statements. michael@0: ** michael@0: ** Applications that need to process SQL from untrusted sources michael@0: ** might also consider lowering resource limits using [sqlite3_limit()] michael@0: ** and limiting database size using the [max_page_count] [PRAGMA] michael@0: ** in addition to using an authorizer. michael@0: ** michael@0: ** ^(Only a single authorizer can be in place on a database connection michael@0: ** at a time. Each call to sqlite3_set_authorizer overrides the michael@0: ** previous call.)^ ^Disable the authorizer by installing a NULL callback. michael@0: ** The authorizer is disabled by default. michael@0: ** michael@0: ** The authorizer callback must not do anything that will modify michael@0: ** the database connection that invoked the authorizer callback. michael@0: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their michael@0: ** database connections for the meaning of "modify" in this paragraph. michael@0: ** michael@0: ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the michael@0: ** statement might be re-prepared during [sqlite3_step()] due to a michael@0: ** schema change. Hence, the application should ensure that the michael@0: ** correct authorizer callback remains in place during the [sqlite3_step()]. michael@0: ** michael@0: ** ^Note that the authorizer callback is invoked only during michael@0: ** [sqlite3_prepare()] or its variants. Authorization is not michael@0: ** performed during statement evaluation in [sqlite3_step()], unless michael@0: ** as stated in the previous paragraph, sqlite3_step() invokes michael@0: ** sqlite3_prepare_v2() to reprepare a statement after a schema change. michael@0: */ michael@0: SQLITE_API int sqlite3_set_authorizer( michael@0: sqlite3*, michael@0: int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), michael@0: void *pUserData michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Authorizer Return Codes michael@0: ** michael@0: ** The [sqlite3_set_authorizer | authorizer callback function] must michael@0: ** return either [SQLITE_OK] or one of these two constants in order michael@0: ** to signal SQLite whether or not the action is permitted. See the michael@0: ** [sqlite3_set_authorizer | authorizer documentation] for additional michael@0: ** information. michael@0: ** michael@0: ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] michael@0: ** from the [sqlite3_vtab_on_conflict()] interface. michael@0: */ michael@0: #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ michael@0: #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Authorizer Action Codes michael@0: ** michael@0: ** The [sqlite3_set_authorizer()] interface registers a callback function michael@0: ** that is invoked to authorize certain SQL statement actions. The michael@0: ** second parameter to the callback is an integer code that specifies michael@0: ** what action is being authorized. These are the integer action codes that michael@0: ** the authorizer callback may be passed. michael@0: ** michael@0: ** These action code values signify what kind of operation is to be michael@0: ** authorized. The 3rd and 4th parameters to the authorization michael@0: ** callback function will be parameters or NULL depending on which of these michael@0: ** codes is used as the second parameter. ^(The 5th parameter to the michael@0: ** authorizer callback is the name of the database ("main", "temp", michael@0: ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback michael@0: ** is the name of the inner-most trigger or view that is responsible for michael@0: ** the access attempt or NULL if this access attempt is directly from michael@0: ** top-level SQL code. michael@0: */ michael@0: /******************************************* 3rd ************ 4th ***********/ michael@0: #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ michael@0: #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ michael@0: #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ michael@0: #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ michael@0: #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ michael@0: #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ michael@0: #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ michael@0: #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ michael@0: #define SQLITE_DELETE 9 /* Table Name NULL */ michael@0: #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ michael@0: #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ michael@0: #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ michael@0: #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ michael@0: #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ michael@0: #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ michael@0: #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ michael@0: #define SQLITE_DROP_VIEW 17 /* View Name NULL */ michael@0: #define SQLITE_INSERT 18 /* Table Name NULL */ michael@0: #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ michael@0: #define SQLITE_READ 20 /* Table Name Column Name */ michael@0: #define SQLITE_SELECT 21 /* NULL NULL */ michael@0: #define SQLITE_TRANSACTION 22 /* Operation NULL */ michael@0: #define SQLITE_UPDATE 23 /* Table Name Column Name */ michael@0: #define SQLITE_ATTACH 24 /* Filename NULL */ michael@0: #define SQLITE_DETACH 25 /* Database Name NULL */ michael@0: #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ michael@0: #define SQLITE_REINDEX 27 /* Index Name NULL */ michael@0: #define SQLITE_ANALYZE 28 /* Table Name NULL */ michael@0: #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ michael@0: #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ michael@0: #define SQLITE_FUNCTION 31 /* NULL Function Name */ michael@0: #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ michael@0: #define SQLITE_COPY 0 /* No longer used */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Tracing And Profiling Functions michael@0: ** michael@0: ** These routines register callback functions that can be used for michael@0: ** tracing and profiling the execution of SQL statements. michael@0: ** michael@0: ** ^The callback function registered by sqlite3_trace() is invoked at michael@0: ** various times when an SQL statement is being run by [sqlite3_step()]. michael@0: ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the michael@0: ** SQL statement text as the statement first begins executing. michael@0: ** ^(Additional sqlite3_trace() callbacks might occur michael@0: ** as each triggered subprogram is entered. The callbacks for triggers michael@0: ** contain a UTF-8 SQL comment that identifies the trigger.)^ michael@0: ** michael@0: ** ^The callback function registered by sqlite3_profile() is invoked michael@0: ** as each SQL statement finishes. ^The profile callback contains michael@0: ** the original statement text and an estimate of wall-clock time michael@0: ** of how long that statement took to run. ^The profile callback michael@0: ** time is in units of nanoseconds, however the current implementation michael@0: ** is only capable of millisecond resolution so the six least significant michael@0: ** digits in the time are meaningless. Future versions of SQLite michael@0: ** might provide greater resolution on the profiler callback. The michael@0: ** sqlite3_profile() function is considered experimental and is michael@0: ** subject to change in future versions of SQLite. michael@0: */ michael@0: SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); michael@0: SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, michael@0: void(*xProfile)(void*,const char*,sqlite3_uint64), void*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Query Progress Callbacks michael@0: ** michael@0: ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback michael@0: ** function X to be invoked periodically during long running calls to michael@0: ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for michael@0: ** database connection D. An example use for this michael@0: ** interface is to keep a GUI updated during a large query. michael@0: ** michael@0: ** ^The parameter P is passed through as the only parameter to the michael@0: ** callback function X. ^The parameter N is the number of michael@0: ** [virtual machine instructions] that are evaluated between successive michael@0: ** invocations of the callback X. michael@0: ** michael@0: ** ^Only a single progress handler may be defined at one time per michael@0: ** [database connection]; setting a new progress handler cancels the michael@0: ** old one. ^Setting parameter X to NULL disables the progress handler. michael@0: ** ^The progress handler is also disabled by setting N to a value less michael@0: ** than 1. michael@0: ** michael@0: ** ^If the progress callback returns non-zero, the operation is michael@0: ** interrupted. This feature can be used to implement a michael@0: ** "Cancel" button on a GUI progress dialog box. michael@0: ** michael@0: ** The progress handler callback must not do anything that will modify michael@0: ** the database connection that invoked the progress handler. michael@0: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their michael@0: ** database connections for the meaning of "modify" in this paragraph. michael@0: ** michael@0: */ michael@0: SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Opening A New Database Connection michael@0: ** michael@0: ** ^These routines open an SQLite database file as specified by the michael@0: ** filename argument. ^The filename argument is interpreted as UTF-8 for michael@0: ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte michael@0: ** order for sqlite3_open16(). ^(A [database connection] handle is usually michael@0: ** returned in *ppDb, even if an error occurs. The only exception is that michael@0: ** if SQLite is unable to allocate memory to hold the [sqlite3] object, michael@0: ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] michael@0: ** object.)^ ^(If the database is opened (and/or created) successfully, then michael@0: ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The michael@0: ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain michael@0: ** an English language description of the error following a failure of any michael@0: ** of the sqlite3_open() routines. michael@0: ** michael@0: ** ^The default encoding for the database will be UTF-8 if michael@0: ** sqlite3_open() or sqlite3_open_v2() is called and michael@0: ** UTF-16 in the native byte order if sqlite3_open16() is used. michael@0: ** michael@0: ** Whether or not an error occurs when it is opened, resources michael@0: ** associated with the [database connection] handle should be released by michael@0: ** passing it to [sqlite3_close()] when it is no longer required. michael@0: ** michael@0: ** The sqlite3_open_v2() interface works like sqlite3_open() michael@0: ** except that it accepts two additional parameters for additional control michael@0: ** over the new database connection. ^(The flags parameter to michael@0: ** sqlite3_open_v2() can take one of michael@0: ** the following three values, optionally combined with the michael@0: ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], michael@0: ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ michael@0: ** michael@0: **
michael@0: ** ^(
[SQLITE_OPEN_READONLY]
michael@0: **
The database is opened in read-only mode. If the database does not michael@0: ** already exist, an error is returned.
)^ michael@0: ** michael@0: ** ^(
[SQLITE_OPEN_READWRITE]
michael@0: **
The database is opened for reading and writing if possible, or reading michael@0: ** only if the file is write protected by the operating system. In either michael@0: ** case the database must already exist, otherwise an error is returned.
)^ michael@0: ** michael@0: ** ^(
[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]
michael@0: **
The database is opened for reading and writing, and is created if michael@0: ** it does not already exist. This is the behavior that is always used for michael@0: ** sqlite3_open() and sqlite3_open16().
)^ michael@0: **
michael@0: ** michael@0: ** If the 3rd parameter to sqlite3_open_v2() is not one of the michael@0: ** combinations shown above optionally combined with other michael@0: ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] michael@0: ** then the behavior is undefined. michael@0: ** michael@0: ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection michael@0: ** opens in the multi-thread [threading mode] as long as the single-thread michael@0: ** mode has not been set at compile-time or start-time. ^If the michael@0: ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens michael@0: ** in the serialized [threading mode] unless single-thread was michael@0: ** previously selected at compile-time or start-time. michael@0: ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be michael@0: ** eligible to use [shared cache mode], regardless of whether or not shared michael@0: ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The michael@0: ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not michael@0: ** participate in [shared cache mode] even if it is enabled. michael@0: ** michael@0: ** ^The fourth parameter to sqlite3_open_v2() is the name of the michael@0: ** [sqlite3_vfs] object that defines the operating system interface that michael@0: ** the new database connection should use. ^If the fourth parameter is michael@0: ** a NULL pointer then the default [sqlite3_vfs] object is used. michael@0: ** michael@0: ** ^If the filename is ":memory:", then a private, temporary in-memory database michael@0: ** is created for the connection. ^This in-memory database will vanish when michael@0: ** the database connection is closed. Future versions of SQLite might michael@0: ** make use of additional special filenames that begin with the ":" character. michael@0: ** It is recommended that when a database filename actually does begin with michael@0: ** a ":" character you should prefix the filename with a pathname such as michael@0: ** "./" to avoid ambiguity. michael@0: ** michael@0: ** ^If the filename is an empty string, then a private, temporary michael@0: ** on-disk database will be created. ^This private database will be michael@0: ** automatically deleted as soon as the database connection is closed. michael@0: ** michael@0: ** [[URI filenames in sqlite3_open()]]

URI Filenames

michael@0: ** michael@0: ** ^If [URI filename] interpretation is enabled, and the filename argument michael@0: ** begins with "file:", then the filename is interpreted as a URI. ^URI michael@0: ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is michael@0: ** set in the fourth argument to sqlite3_open_v2(), or if it has michael@0: ** been enabled globally using the [SQLITE_CONFIG_URI] option with the michael@0: ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. michael@0: ** As of SQLite version 3.7.7, URI filename interpretation is turned off michael@0: ** by default, but future releases of SQLite might enable URI filename michael@0: ** interpretation by default. See "[URI filenames]" for additional michael@0: ** information. michael@0: ** michael@0: ** URI filenames are parsed according to RFC 3986. ^If the URI contains an michael@0: ** authority, then it must be either an empty string or the string michael@0: ** "localhost". ^If the authority is not an empty string or "localhost", an michael@0: ** error is returned to the caller. ^The fragment component of a URI, if michael@0: ** present, is ignored. michael@0: ** michael@0: ** ^SQLite uses the path component of the URI as the name of the disk file michael@0: ** which contains the database. ^If the path begins with a '/' character, michael@0: ** then it is interpreted as an absolute path. ^If the path does not begin michael@0: ** with a '/' (meaning that the authority section is omitted from the URI) michael@0: ** then the path is interpreted as a relative path. michael@0: ** ^On windows, the first component of an absolute path michael@0: ** is a drive specification (e.g. "C:"). michael@0: ** michael@0: ** [[core URI query parameters]] michael@0: ** The query component of a URI may contain parameters that are interpreted michael@0: ** either by SQLite itself, or by a [VFS | custom VFS implementation]. michael@0: ** SQLite interprets the following three query parameters: michael@0: ** michael@0: ** michael@0: ** michael@0: ** ^Specifying an unknown parameter in the query component of a URI is not an michael@0: ** error. Future versions of SQLite might understand additional query michael@0: ** parameters. See "[query parameters with special meaning to SQLite]" for michael@0: ** additional information. michael@0: ** michael@0: ** [[URI filename examples]]

URI filename examples

michael@0: ** michael@0: ** michael@0: **
URI filenames Results michael@0: **
file:data.db michael@0: ** Open the file "data.db" in the current directory. michael@0: **
file:/home/fred/data.db
michael@0: ** file:///home/fred/data.db
michael@0: ** file://localhost/home/fred/data.db
michael@0: ** Open the database file "/home/fred/data.db". michael@0: **
file://darkstar/home/fred/data.db michael@0: ** An error. "darkstar" is not a recognized authority. michael@0: **
michael@0: ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db michael@0: ** Windows only: Open the file "data.db" on fred's desktop on drive michael@0: ** C:. Note that the %20 escaping in this example is not strictly michael@0: ** necessary - space characters can be used literally michael@0: ** in URI filenames. michael@0: **
file:data.db?mode=ro&cache=private michael@0: ** Open file "data.db" in the current directory for read-only access. michael@0: ** Regardless of whether or not shared-cache mode is enabled by michael@0: ** default, use a private cache. michael@0: **
file:/home/fred/data.db?vfs=unix-nolock michael@0: ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". michael@0: **
file:data.db?mode=readonly michael@0: ** An error. "readonly" is not a valid option for the "mode" parameter. michael@0: **
michael@0: ** michael@0: ** ^URI hexadecimal escape sequences (%HH) are supported within the path and michael@0: ** query components of a URI. A hexadecimal escape sequence consists of a michael@0: ** percent sign - "%" - followed by exactly two hexadecimal digits michael@0: ** specifying an octet value. ^Before the path or query components of a michael@0: ** URI filename are interpreted, they are encoded using UTF-8 and all michael@0: ** hexadecimal escape sequences replaced by a single byte containing the michael@0: ** corresponding octet. If this process generates an invalid UTF-8 encoding, michael@0: ** the results are undefined. michael@0: ** michael@0: ** Note to Windows users: The encoding used for the filename argument michael@0: ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever michael@0: ** codepage is currently defined. Filenames containing international michael@0: ** characters must be converted to UTF-8 prior to passing them into michael@0: ** sqlite3_open() or sqlite3_open_v2(). michael@0: ** michael@0: ** Note to Windows Runtime users: The temporary directory must be set michael@0: ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various michael@0: ** features that require the use of temporary files may fail. michael@0: ** michael@0: ** See also: [sqlite3_temp_directory] michael@0: */ michael@0: SQLITE_API int sqlite3_open( michael@0: const char *filename, /* Database filename (UTF-8) */ michael@0: sqlite3 **ppDb /* OUT: SQLite db handle */ michael@0: ); michael@0: SQLITE_API int sqlite3_open16( michael@0: const void *filename, /* Database filename (UTF-16) */ michael@0: sqlite3 **ppDb /* OUT: SQLite db handle */ michael@0: ); michael@0: SQLITE_API int sqlite3_open_v2( michael@0: const char *filename, /* Database filename (UTF-8) */ michael@0: sqlite3 **ppDb, /* OUT: SQLite db handle */ michael@0: int flags, /* Flags */ michael@0: const char *zVfs /* Name of VFS module to use */ michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Obtain Values For URI Parameters michael@0: ** michael@0: ** These are utility routines, useful to VFS implementations, that check michael@0: ** to see if a database file was a URI that contained a specific query michael@0: ** parameter, and if so obtains the value of that query parameter. michael@0: ** michael@0: ** If F is the database filename pointer passed into the xOpen() method of michael@0: ** a VFS implementation when the flags parameter to xOpen() has one or michael@0: ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and michael@0: ** P is the name of the query parameter, then michael@0: ** sqlite3_uri_parameter(F,P) returns the value of the P michael@0: ** parameter if it exists or a NULL pointer if P does not appear as a michael@0: ** query parameter on F. If P is a query parameter of F michael@0: ** has no explicit value, then sqlite3_uri_parameter(F,P) returns michael@0: ** a pointer to an empty string. michael@0: ** michael@0: ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean michael@0: ** parameter and returns true (1) or false (0) according to the value michael@0: ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the michael@0: ** value of query parameter P is one of "yes", "true", or "on" in any michael@0: ** case or if the value begins with a non-zero number. The michael@0: ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of michael@0: ** query parameter P is one of "no", "false", or "off" in any case or michael@0: ** if the value begins with a numeric zero. If P is not a query michael@0: ** parameter on F or if the value of P is does not match any of the michael@0: ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). michael@0: ** michael@0: ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a michael@0: ** 64-bit signed integer and returns that integer, or D if P does not michael@0: ** exist. If the value of P is something other than an integer, then michael@0: ** zero is returned. michael@0: ** michael@0: ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and michael@0: ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and michael@0: ** is not a database file pathname pointer that SQLite passed into the xOpen michael@0: ** VFS method, then the behavior of this routine is undefined and probably michael@0: ** undesirable. michael@0: */ michael@0: SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); michael@0: SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); michael@0: SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Error Codes And Messages michael@0: ** michael@0: ** ^The sqlite3_errcode() interface returns the numeric [result code] or michael@0: ** [extended result code] for the most recent failed sqlite3_* API call michael@0: ** associated with a [database connection]. If a prior API call failed michael@0: ** but the most recent API call succeeded, the return value from michael@0: ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() michael@0: ** interface is the same except that it always returns the michael@0: ** [extended result code] even when extended result codes are michael@0: ** disabled. michael@0: ** michael@0: ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language michael@0: ** text that describes the error, as either UTF-8 or UTF-16 respectively. michael@0: ** ^(Memory to hold the error message string is managed internally. michael@0: ** The application does not need to worry about freeing the result. michael@0: ** However, the error string might be overwritten or deallocated by michael@0: ** subsequent calls to other SQLite interface functions.)^ michael@0: ** michael@0: ** ^The sqlite3_errstr() interface returns the English-language text michael@0: ** that describes the [result code], as UTF-8. michael@0: ** ^(Memory to hold the error message string is managed internally michael@0: ** and must not be freed by the application)^. michael@0: ** michael@0: ** When the serialized [threading mode] is in use, it might be the michael@0: ** case that a second error occurs on a separate thread in between michael@0: ** the time of the first error and the call to these interfaces. michael@0: ** When that happens, the second error will be reported since these michael@0: ** interfaces always report the most recent result. To avoid michael@0: ** this, each thread can obtain exclusive use of the [database connection] D michael@0: ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning michael@0: ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after michael@0: ** all calls to the interfaces listed here are completed. michael@0: ** michael@0: ** If an interface fails with SQLITE_MISUSE, that means the interface michael@0: ** was invoked incorrectly by the application. In that case, the michael@0: ** error code and message may or may not be set. michael@0: */ michael@0: SQLITE_API int sqlite3_errcode(sqlite3 *db); michael@0: SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); michael@0: SQLITE_API const char *sqlite3_errmsg(sqlite3*); michael@0: SQLITE_API const void *sqlite3_errmsg16(sqlite3*); michael@0: SQLITE_API const char *sqlite3_errstr(int); michael@0: michael@0: /* michael@0: ** CAPI3REF: SQL Statement Object michael@0: ** KEYWORDS: {prepared statement} {prepared statements} michael@0: ** michael@0: ** An instance of this object represents a single SQL statement. michael@0: ** This object is variously known as a "prepared statement" or a michael@0: ** "compiled SQL statement" or simply as a "statement". michael@0: ** michael@0: ** The life of a statement object goes something like this: michael@0: ** michael@0: **
    michael@0: **
  1. Create the object using [sqlite3_prepare_v2()] or a related michael@0: ** function. michael@0: **
  2. Bind values to [host parameters] using the sqlite3_bind_*() michael@0: ** interfaces. michael@0: **
  3. Run the SQL by calling [sqlite3_step()] one or more times. michael@0: **
  4. Reset the statement using [sqlite3_reset()] then go back michael@0: ** to step 2. Do this zero or more times. michael@0: **
  5. Destroy the object using [sqlite3_finalize()]. michael@0: **
michael@0: ** michael@0: ** Refer to documentation on individual methods above for additional michael@0: ** information. michael@0: */ michael@0: typedef struct sqlite3_stmt sqlite3_stmt; michael@0: michael@0: /* michael@0: ** CAPI3REF: Run-time Limits michael@0: ** michael@0: ** ^(This interface allows the size of various constructs to be limited michael@0: ** on a connection by connection basis. The first parameter is the michael@0: ** [database connection] whose limit is to be set or queried. The michael@0: ** second parameter is one of the [limit categories] that define a michael@0: ** class of constructs to be size limited. The third parameter is the michael@0: ** new limit for that construct.)^ michael@0: ** michael@0: ** ^If the new limit is a negative number, the limit is unchanged. michael@0: ** ^(For each limit category SQLITE_LIMIT_NAME there is a michael@0: ** [limits | hard upper bound] michael@0: ** set at compile-time by a C preprocessor macro called michael@0: ** [limits | SQLITE_MAX_NAME]. michael@0: ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ michael@0: ** ^Attempts to increase a limit above its hard upper bound are michael@0: ** silently truncated to the hard upper bound. michael@0: ** michael@0: ** ^Regardless of whether or not the limit was changed, the michael@0: ** [sqlite3_limit()] interface returns the prior value of the limit. michael@0: ** ^Hence, to find the current value of a limit without changing it, michael@0: ** simply invoke this interface with the third parameter set to -1. michael@0: ** michael@0: ** Run-time limits are intended for use in applications that manage michael@0: ** both their own internal database and also databases that are controlled michael@0: ** by untrusted external sources. An example application might be a michael@0: ** web browser that has its own databases for storing history and michael@0: ** separate databases controlled by JavaScript applications downloaded michael@0: ** off the Internet. The internal databases can be given the michael@0: ** large, default limits. Databases managed by external sources can michael@0: ** be given much smaller limits designed to prevent a denial of service michael@0: ** attack. Developers might also want to use the [sqlite3_set_authorizer()] michael@0: ** interface to further control untrusted SQL. The size of the database michael@0: ** created by an untrusted script can be contained using the michael@0: ** [max_page_count] [PRAGMA]. michael@0: ** michael@0: ** New run-time limit categories may be added in future releases. michael@0: */ michael@0: SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); michael@0: michael@0: /* michael@0: ** CAPI3REF: Run-Time Limit Categories michael@0: ** KEYWORDS: {limit category} {*limit categories} michael@0: ** michael@0: ** These constants define various performance limits michael@0: ** that can be lowered at run-time using [sqlite3_limit()]. michael@0: ** The synopsis of the meanings of the various limits is shown below. michael@0: ** Additional information is available at [limits | Limits in SQLite]. michael@0: ** michael@0: **
michael@0: ** [[SQLITE_LIMIT_LENGTH]] ^(
SQLITE_LIMIT_LENGTH
michael@0: **
The maximum size of any string or BLOB or table row, in bytes.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(
SQLITE_LIMIT_SQL_LENGTH
michael@0: **
The maximum length of an SQL statement, in bytes.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_COLUMN]] ^(
SQLITE_LIMIT_COLUMN
michael@0: **
The maximum number of columns in a table definition or in the michael@0: ** result set of a [SELECT] or the maximum number of columns in an index michael@0: ** or in an ORDER BY or GROUP BY clause.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(
SQLITE_LIMIT_EXPR_DEPTH
michael@0: **
The maximum depth of the parse tree on any expression.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(
SQLITE_LIMIT_COMPOUND_SELECT
michael@0: **
The maximum number of terms in a compound SELECT statement.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_VDBE_OP]] ^(
SQLITE_LIMIT_VDBE_OP
michael@0: **
The maximum number of instructions in a virtual machine program michael@0: ** used to implement an SQL statement. This limit is not currently michael@0: ** enforced, though that might be added in some future release of michael@0: ** SQLite.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(
SQLITE_LIMIT_FUNCTION_ARG
michael@0: **
The maximum number of arguments on a function.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_ATTACHED]] ^(
SQLITE_LIMIT_ATTACHED
michael@0: **
The maximum number of [ATTACH | attached databases].)^
michael@0: ** michael@0: ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] michael@0: ** ^(
SQLITE_LIMIT_LIKE_PATTERN_LENGTH
michael@0: **
The maximum length of the pattern argument to the [LIKE] or michael@0: ** [GLOB] operators.
)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] michael@0: ** ^(
SQLITE_LIMIT_VARIABLE_NUMBER
michael@0: **
The maximum index number of any [parameter] in an SQL statement.)^ michael@0: ** michael@0: ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(
SQLITE_LIMIT_TRIGGER_DEPTH
michael@0: **
The maximum depth of recursion for triggers.
)^ michael@0: **
michael@0: */ michael@0: #define SQLITE_LIMIT_LENGTH 0 michael@0: #define SQLITE_LIMIT_SQL_LENGTH 1 michael@0: #define SQLITE_LIMIT_COLUMN 2 michael@0: #define SQLITE_LIMIT_EXPR_DEPTH 3 michael@0: #define SQLITE_LIMIT_COMPOUND_SELECT 4 michael@0: #define SQLITE_LIMIT_VDBE_OP 5 michael@0: #define SQLITE_LIMIT_FUNCTION_ARG 6 michael@0: #define SQLITE_LIMIT_ATTACHED 7 michael@0: #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 michael@0: #define SQLITE_LIMIT_VARIABLE_NUMBER 9 michael@0: #define SQLITE_LIMIT_TRIGGER_DEPTH 10 michael@0: michael@0: /* michael@0: ** CAPI3REF: Compiling An SQL Statement michael@0: ** KEYWORDS: {SQL statement compiler} michael@0: ** michael@0: ** To execute an SQL query, it must first be compiled into a byte-code michael@0: ** program using one of these routines. michael@0: ** michael@0: ** The first argument, "db", is a [database connection] obtained from a michael@0: ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or michael@0: ** [sqlite3_open16()]. The database connection must not have been closed. michael@0: ** michael@0: ** The second argument, "zSql", is the statement to be compiled, encoded michael@0: ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() michael@0: ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() michael@0: ** use UTF-16. michael@0: ** michael@0: ** ^If the nByte argument is less than zero, then zSql is read up to the michael@0: ** first zero terminator. ^If nByte is non-negative, then it is the maximum michael@0: ** number of bytes read from zSql. ^When nByte is non-negative, the michael@0: ** zSql string ends at either the first '\000' or '\u0000' character or michael@0: ** the nByte-th byte, whichever comes first. If the caller knows michael@0: ** that the supplied string is nul-terminated, then there is a small michael@0: ** performance advantage to be gained by passing an nByte parameter that michael@0: ** is equal to the number of bytes in the input string including michael@0: ** the nul-terminator bytes as this saves SQLite from having to michael@0: ** make a copy of the input string. michael@0: ** michael@0: ** ^If pzTail is not NULL then *pzTail is made to point to the first byte michael@0: ** past the end of the first SQL statement in zSql. These routines only michael@0: ** compile the first statement in zSql, so *pzTail is left pointing to michael@0: ** what remains uncompiled. michael@0: ** michael@0: ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be michael@0: ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set michael@0: ** to NULL. ^If the input text contains no SQL (if the input is an empty michael@0: ** string or a comment) then *ppStmt is set to NULL. michael@0: ** The calling procedure is responsible for deleting the compiled michael@0: ** SQL statement using [sqlite3_finalize()] after it has finished with it. michael@0: ** ppStmt may not be NULL. michael@0: ** michael@0: ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; michael@0: ** otherwise an [error code] is returned. michael@0: ** michael@0: ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are michael@0: ** recommended for all new programs. The two older interfaces are retained michael@0: ** for backwards compatibility, but their use is discouraged. michael@0: ** ^In the "v2" interfaces, the prepared statement michael@0: ** that is returned (the [sqlite3_stmt] object) contains a copy of the michael@0: ** original SQL text. This causes the [sqlite3_step()] interface to michael@0: ** behave differently in three ways: michael@0: ** michael@0: **
    michael@0: **
  1. michael@0: ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it michael@0: ** always used to do, [sqlite3_step()] will automatically recompile the SQL michael@0: ** statement and try to run it again. michael@0: **
    2. michael@0: ** michael@0: **
  2. michael@0: ** ^When an error occurs, [sqlite3_step()] will return one of the detailed michael@0: ** [error codes] or [extended error codes]. ^The legacy behavior was that michael@0: ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code michael@0: ** and the application would have to make a second call to [sqlite3_reset()] michael@0: ** in order to find the underlying cause of the problem. With the "v2" prepare michael@0: ** interfaces, the underlying reason for the error is returned immediately. michael@0: **
    3. michael@0: ** michael@0: **
  3. michael@0: ** ^If the specific value bound to [parameter | host parameter] in the michael@0: ** WHERE clause might influence the choice of query plan for a statement, michael@0: ** then the statement will be automatically recompiled, as if there had been michael@0: ** a schema change, on the first [sqlite3_step()] call following any change michael@0: ** to the [sqlite3_bind_text | bindings] of that [parameter]. michael@0: ** ^The specific value of WHERE-clause [parameter] might influence the michael@0: ** choice of query plan if the parameter is the left-hand side of a [LIKE] michael@0: ** or [GLOB] operator or if the parameter is compared to an indexed column michael@0: ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. michael@0: ** the michael@0: **
    4. michael@0: **
michael@0: */ michael@0: SQLITE_API int sqlite3_prepare( michael@0: sqlite3 *db, /* Database handle */ michael@0: const char *zSql, /* SQL statement, UTF-8 encoded */ michael@0: int nByte, /* Maximum length of zSql in bytes. */ michael@0: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ michael@0: const char **pzTail /* OUT: Pointer to unused portion of zSql */ michael@0: ); michael@0: SQLITE_API int sqlite3_prepare_v2( michael@0: sqlite3 *db, /* Database handle */ michael@0: const char *zSql, /* SQL statement, UTF-8 encoded */ michael@0: int nByte, /* Maximum length of zSql in bytes. */ michael@0: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ michael@0: const char **pzTail /* OUT: Pointer to unused portion of zSql */ michael@0: ); michael@0: SQLITE_API int sqlite3_prepare16( michael@0: sqlite3 *db, /* Database handle */ michael@0: const void *zSql, /* SQL statement, UTF-16 encoded */ michael@0: int nByte, /* Maximum length of zSql in bytes. */ michael@0: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ michael@0: const void **pzTail /* OUT: Pointer to unused portion of zSql */ michael@0: ); michael@0: SQLITE_API int sqlite3_prepare16_v2( michael@0: sqlite3 *db, /* Database handle */ michael@0: const void *zSql, /* SQL statement, UTF-16 encoded */ michael@0: int nByte, /* Maximum length of zSql in bytes. */ michael@0: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ michael@0: const void **pzTail /* OUT: Pointer to unused portion of zSql */ michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Retrieving Statement SQL michael@0: ** michael@0: ** ^This interface can be used to retrieve a saved copy of the original michael@0: ** SQL text used to create a [prepared statement] if that statement was michael@0: ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. michael@0: */ michael@0: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); michael@0: michael@0: /* michael@0: ** CAPI3REF: Determine If An SQL Statement Writes The Database michael@0: ** michael@0: ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if michael@0: ** and only if the [prepared statement] X makes no direct changes to michael@0: ** the content of the database file. michael@0: ** michael@0: ** Note that [application-defined SQL functions] or michael@0: ** [virtual tables] might change the database indirectly as a side effect. michael@0: ** ^(For example, if an application defines a function "eval()" that michael@0: ** calls [sqlite3_exec()], then the following SQL statement would michael@0: ** change the database file through side-effects: michael@0: ** michael@0: ** 
michael@0: **    SELECT eval('DELETE FROM t1') FROM t2;
michael@0: **
michael@0: ** michael@0: ** But because the [SELECT] statement does not change the database file michael@0: ** directly, sqlite3_stmt_readonly() would still return true.)^ michael@0: ** michael@0: ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], michael@0: ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, michael@0: ** since the statements themselves do not actually modify the database but michael@0: ** rather they control the timing of when other statements modify the michael@0: ** database. ^The [ATTACH] and [DETACH] statements also cause michael@0: ** sqlite3_stmt_readonly() to return true since, while those statements michael@0: ** change the configuration of a database connection, they do not make michael@0: ** changes to the content of the database files on disk. michael@0: */ michael@0: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); michael@0: michael@0: /* michael@0: ** CAPI3REF: Determine If A Prepared Statement Has Been Reset michael@0: ** michael@0: ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the michael@0: ** [prepared statement] S has been stepped at least once using michael@0: ** [sqlite3_step(S)] but has not run to completion and/or has not michael@0: ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) michael@0: ** interface returns false if S is a NULL pointer. If S is not a michael@0: ** NULL pointer and is not a pointer to a valid [prepared statement] michael@0: ** object, then the behavior is undefined and probably undesirable. michael@0: ** michael@0: ** This interface can be used in combination [sqlite3_next_stmt()] michael@0: ** to locate all prepared statements associated with a database michael@0: ** connection that are in need of being reset. This can be used, michael@0: ** for example, in diagnostic routines to search for prepared michael@0: ** statements that are holding a transaction open. michael@0: */ michael@0: SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Dynamically Typed Value Object michael@0: ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} michael@0: ** michael@0: ** SQLite uses the sqlite3_value object to represent all values michael@0: ** that can be stored in a database table. SQLite uses dynamic typing michael@0: ** for the values it stores. ^Values stored in sqlite3_value objects michael@0: ** can be integers, floating point values, strings, BLOBs, or NULL. michael@0: ** michael@0: ** An sqlite3_value object may be either "protected" or "unprotected". michael@0: ** Some interfaces require a protected sqlite3_value. Other interfaces michael@0: ** will accept either a protected or an unprotected sqlite3_value. michael@0: ** Every interface that accepts sqlite3_value arguments specifies michael@0: ** whether or not it requires a protected sqlite3_value. michael@0: ** michael@0: ** The terms "protected" and "unprotected" refer to whether or not michael@0: ** a mutex is held. An internal mutex is held for a protected michael@0: ** sqlite3_value object but no mutex is held for an unprotected michael@0: ** sqlite3_value object. If SQLite is compiled to be single-threaded michael@0: ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) michael@0: ** or if SQLite is run in one of reduced mutex modes michael@0: ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] michael@0: ** then there is no distinction between protected and unprotected michael@0: ** sqlite3_value objects and they can be used interchangeably. However, michael@0: ** for maximum code portability it is recommended that applications michael@0: ** still make the distinction between protected and unprotected michael@0: ** sqlite3_value objects even when not strictly required. michael@0: ** michael@0: ** ^The sqlite3_value objects that are passed as parameters into the michael@0: ** implementation of [application-defined SQL functions] are protected. michael@0: ** ^The sqlite3_value object returned by michael@0: ** [sqlite3_column_value()] is unprotected. michael@0: ** Unprotected sqlite3_value objects may only be used with michael@0: ** [sqlite3_result_value()] and [sqlite3_bind_value()]. michael@0: ** The [sqlite3_value_blob | sqlite3_value_type()] family of michael@0: ** interfaces require protected sqlite3_value objects. michael@0: */ michael@0: typedef struct Mem sqlite3_value; michael@0: michael@0: /* michael@0: ** CAPI3REF: SQL Function Context Object michael@0: ** michael@0: ** The context in which an SQL function executes is stored in an michael@0: ** sqlite3_context object. ^A pointer to an sqlite3_context object michael@0: ** is always first parameter to [application-defined SQL functions]. michael@0: ** The application-defined SQL function implementation will pass this michael@0: ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], michael@0: ** [sqlite3_aggregate_context()], [sqlite3_user_data()], michael@0: ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], michael@0: ** and/or [sqlite3_set_auxdata()]. michael@0: */ michael@0: typedef struct sqlite3_context sqlite3_context; michael@0: michael@0: /* michael@0: ** CAPI3REF: Binding Values To Prepared Statements michael@0: ** KEYWORDS: {host parameter} {host parameters} {host parameter name} michael@0: ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} michael@0: ** michael@0: ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, michael@0: ** literals may be replaced by a [parameter] that matches one of following michael@0: ** templates: michael@0: ** michael@0: ** michael@0: ** michael@0: ** In the templates above, NNN represents an integer literal, michael@0: ** and VVV represents an alphanumeric identifier.)^ ^The values of these michael@0: ** parameters (also called "host parameter names" or "SQL parameters") michael@0: ** can be set using the sqlite3_bind_*() routines defined here. michael@0: ** michael@0: ** ^The first argument to the sqlite3_bind_*() routines is always michael@0: ** a pointer to the [sqlite3_stmt] object returned from michael@0: ** [sqlite3_prepare_v2()] or its variants. michael@0: ** michael@0: ** ^The second argument is the index of the SQL parameter to be set. michael@0: ** ^The leftmost SQL parameter has an index of 1. ^When the same named michael@0: ** SQL parameter is used more than once, second and subsequent michael@0: ** occurrences have the same index as the first occurrence. michael@0: ** ^The index for named parameters can be looked up using the michael@0: ** [sqlite3_bind_parameter_index()] API if desired. ^The index michael@0: ** for "?NNN" parameters is the value of NNN. michael@0: ** ^The NNN value must be between 1 and the [sqlite3_limit()] michael@0: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). michael@0: ** michael@0: ** ^The third argument is the value to bind to the parameter. michael@0: ** michael@0: ** ^(In those routines that have a fourth argument, its value is the michael@0: ** number of bytes in the parameter. To be clear: the value is the michael@0: ** number of bytes in the value, not the number of characters.)^ michael@0: ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() michael@0: ** is negative, then the length of the string is michael@0: ** the number of bytes up to the first zero terminator. michael@0: ** If the fourth parameter to sqlite3_bind_blob() is negative, then michael@0: ** the behavior is undefined. michael@0: ** If a non-negative fourth parameter is provided to sqlite3_bind_text() michael@0: ** or sqlite3_bind_text16() then that parameter must be the byte offset michael@0: ** where the NUL terminator would occur assuming the string were NUL michael@0: ** terminated. If any NUL characters occur at byte offsets less than michael@0: ** the value of the fourth parameter then the resulting string value will michael@0: ** contain embedded NULs. The result of expressions involving strings michael@0: ** with embedded NULs is undefined. michael@0: ** michael@0: ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and michael@0: ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or michael@0: ** string after SQLite has finished with it. ^The destructor is called michael@0: ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), michael@0: ** sqlite3_bind_text(), or sqlite3_bind_text16() fails. michael@0: ** ^If the fifth argument is michael@0: ** the special value [SQLITE_STATIC], then SQLite assumes that the michael@0: ** information is in static, unmanaged space and does not need to be freed. michael@0: ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then michael@0: ** SQLite makes its own private copy of the data immediately, before michael@0: ** the sqlite3_bind_*() routine returns. michael@0: ** michael@0: ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that michael@0: ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory michael@0: ** (just an integer to hold its size) while it is being processed. michael@0: ** Zeroblobs are intended to serve as placeholders for BLOBs whose michael@0: ** content is later written using michael@0: ** [sqlite3_blob_open | incremental BLOB I/O] routines. michael@0: ** ^A negative value for the zeroblob results in a zero-length BLOB. michael@0: ** michael@0: ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer michael@0: ** for the [prepared statement] or with a prepared statement for which michael@0: ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], michael@0: ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() michael@0: ** routine is passed a [prepared statement] that has been finalized, the michael@0: ** result is undefined and probably harmful. michael@0: ** michael@0: ** ^Bindings are not cleared by the [sqlite3_reset()] routine. michael@0: ** ^Unbound parameters are interpreted as NULL. michael@0: ** michael@0: ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an michael@0: ** [error code] if anything goes wrong. michael@0: ** ^[SQLITE_RANGE] is returned if the parameter michael@0: ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. michael@0: ** michael@0: ** See also: [sqlite3_bind_parameter_count()], michael@0: ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. michael@0: */ michael@0: SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); michael@0: SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); michael@0: SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); michael@0: SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); michael@0: SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); michael@0: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); michael@0: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); michael@0: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); michael@0: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); michael@0: michael@0: /* michael@0: ** CAPI3REF: Number Of SQL Parameters michael@0: ** michael@0: ** ^This routine can be used to find the number of [SQL parameters] michael@0: ** in a [prepared statement]. SQL parameters are tokens of the michael@0: ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as michael@0: ** placeholders for values that are [sqlite3_bind_blob | bound] michael@0: ** to the parameters at a later time. michael@0: ** michael@0: ** ^(This routine actually returns the index of the largest (rightmost) michael@0: ** parameter. For all forms except ?NNN, this will correspond to the michael@0: ** number of unique parameters. If parameters of the ?NNN form are used, michael@0: ** there may be gaps in the list.)^ michael@0: ** michael@0: ** See also: [sqlite3_bind_blob|sqlite3_bind()], michael@0: ** [sqlite3_bind_parameter_name()], and michael@0: ** [sqlite3_bind_parameter_index()]. michael@0: */ michael@0: SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Name Of A Host Parameter michael@0: ** michael@0: ** ^The sqlite3_bind_parameter_name(P,N) interface returns michael@0: ** the name of the N-th [SQL parameter] in the [prepared statement] P. michael@0: ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" michael@0: ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" michael@0: ** respectively. michael@0: ** In other words, the initial ":" or "$" or "@" or "?" michael@0: ** is included as part of the name.)^ michael@0: ** ^Parameters of the form "?" without a following integer have no name michael@0: ** and are referred to as "nameless" or "anonymous parameters". michael@0: ** michael@0: ** ^The first host parameter has an index of 1, not 0. michael@0: ** michael@0: ** ^If the value N is out of range or if the N-th parameter is michael@0: ** nameless, then NULL is returned. ^The returned string is michael@0: ** always in UTF-8 encoding even if the named parameter was michael@0: ** originally specified as UTF-16 in [sqlite3_prepare16()] or michael@0: ** [sqlite3_prepare16_v2()]. michael@0: ** michael@0: ** See also: [sqlite3_bind_blob|sqlite3_bind()], michael@0: ** [sqlite3_bind_parameter_count()], and michael@0: ** [sqlite3_bind_parameter_index()]. michael@0: */ michael@0: SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); michael@0: michael@0: /* michael@0: ** CAPI3REF: Index Of A Parameter With A Given Name michael@0: ** michael@0: ** ^Return the index of an SQL parameter given its name. ^The michael@0: ** index value returned is suitable for use as the second michael@0: ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero michael@0: ** is returned if no matching parameter is found. ^The parameter michael@0: ** name must be given in UTF-8 even if the original statement michael@0: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. michael@0: ** michael@0: ** See also: [sqlite3_bind_blob|sqlite3_bind()], michael@0: ** [sqlite3_bind_parameter_count()], and michael@0: ** [sqlite3_bind_parameter_index()]. michael@0: */ michael@0: SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); michael@0: michael@0: /* michael@0: ** CAPI3REF: Reset All Bindings On A Prepared Statement michael@0: ** michael@0: ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset michael@0: ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. michael@0: ** ^Use this routine to reset all host parameters to NULL. michael@0: */ michael@0: SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Number Of Columns In A Result Set michael@0: ** michael@0: ** ^Return the number of columns in the result set returned by the michael@0: ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL michael@0: ** statement that does not return data (for example an [UPDATE]). michael@0: ** michael@0: ** See also: [sqlite3_data_count()] michael@0: */ michael@0: SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); michael@0: michael@0: /* michael@0: ** CAPI3REF: Column Names In A Result Set michael@0: ** michael@0: ** ^These routines return the name assigned to a particular column michael@0: ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() michael@0: ** interface returns a pointer to a zero-terminated UTF-8 string michael@0: ** and sqlite3_column_name16() returns a pointer to a zero-terminated michael@0: ** UTF-16 string. ^The first parameter is the [prepared statement] michael@0: ** that implements the [SELECT] statement. ^The second parameter is the michael@0: ** column number. ^The leftmost column is number 0. michael@0: ** michael@0: ** ^The returned string pointer is valid until either the [prepared statement] michael@0: ** is destroyed by [sqlite3_finalize()] or until the statement is automatically michael@0: ** reprepared by the first call to [sqlite3_step()] for a particular run michael@0: ** or until the next call to michael@0: ** sqlite3_column_name() or sqlite3_column_name16() on the same column. michael@0: ** michael@0: ** ^If sqlite3_malloc() fails during the processing of either routine michael@0: ** (for example during a conversion from UTF-8 to UTF-16) then a michael@0: ** NULL pointer is returned. michael@0: ** michael@0: ** ^The name of a result column is the value of the "AS" clause for michael@0: ** that column, if there is an AS clause. If there is no AS clause michael@0: ** then the name of the column is unspecified and may change from michael@0: ** one release of SQLite to the next. michael@0: */ michael@0: SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); michael@0: SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); michael@0: michael@0: /* michael@0: ** CAPI3REF: Source Of Data In A Query Result michael@0: ** michael@0: ** ^These routines provide a means to determine the database, table, and michael@0: ** table column that is the origin of a particular result column in michael@0: ** [SELECT] statement. michael@0: ** ^The name of the database or table or column can be returned as michael@0: ** either a UTF-8 or UTF-16 string. ^The _database_ routines return michael@0: ** the database name, the _table_ routines return the table name, and michael@0: ** the origin_ routines return the column name. michael@0: ** ^The returned string is valid until the [prepared statement] is destroyed michael@0: ** using [sqlite3_finalize()] or until the statement is automatically michael@0: ** reprepared by the first call to [sqlite3_step()] for a particular run michael@0: ** or until the same information is requested michael@0: ** again in a different encoding. michael@0: ** michael@0: ** ^The names returned are the original un-aliased names of the michael@0: ** database, table, and column. michael@0: ** michael@0: ** ^The first argument to these interfaces is a [prepared statement]. michael@0: ** ^These functions return information about the Nth result column returned by michael@0: ** the statement, where N is the second function argument. michael@0: ** ^The left-most column is column 0 for these routines. michael@0: ** michael@0: ** ^If the Nth column returned by the statement is an expression or michael@0: ** subquery and is not a column value, then all of these functions return michael@0: ** NULL. ^These routine might also return NULL if a memory allocation error michael@0: ** occurs. ^Otherwise, they return the name of the attached database, table, michael@0: ** or column that query result column was extracted from. michael@0: ** michael@0: ** ^As with all other SQLite APIs, those whose names end with "16" return michael@0: ** UTF-16 encoded strings and the other functions return UTF-8. michael@0: ** michael@0: ** ^These APIs are only available if the library was compiled with the michael@0: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. michael@0: ** michael@0: ** If two or more threads call one or more of these routines against the same michael@0: ** prepared statement and column at the same time then the results are michael@0: ** undefined. michael@0: ** michael@0: ** If two or more threads call one or more michael@0: ** [sqlite3_column_database_name | column metadata interfaces] michael@0: ** for the same [prepared statement] and result column michael@0: ** at the same time then the results are undefined. michael@0: */ michael@0: SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); michael@0: SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); michael@0: SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); michael@0: SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); michael@0: SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); michael@0: SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); michael@0: michael@0: /* michael@0: ** CAPI3REF: Declared Datatype Of A Query Result michael@0: ** michael@0: ** ^(The first parameter is a [prepared statement]. michael@0: ** If this statement is a [SELECT] statement and the Nth column of the michael@0: ** returned result set of that [SELECT] is a table column (not an michael@0: ** expression or subquery) then the declared type of the table michael@0: ** column is returned.)^ ^If the Nth column of the result set is an michael@0: ** expression or subquery, then a NULL pointer is returned. michael@0: ** ^The returned string is always UTF-8 encoded. michael@0: ** michael@0: ** ^(For example, given the database schema: michael@0: ** michael@0: ** CREATE TABLE t1(c1 VARIANT); michael@0: ** michael@0: ** and the following statement to be compiled: michael@0: ** michael@0: ** SELECT c1 + 1, c1 FROM t1; michael@0: ** michael@0: ** this routine would return the string "VARIANT" for the second result michael@0: ** column (i==1), and a NULL pointer for the first result column (i==0).)^ michael@0: ** michael@0: ** ^SQLite uses dynamic run-time typing. ^So just because a column michael@0: ** is declared to contain a particular type does not mean that the michael@0: ** data stored in that column is of the declared type. SQLite is michael@0: ** strongly typed, but the typing is dynamic not static. ^Type michael@0: ** is associated with individual values, not with the containers michael@0: ** used to hold those values. michael@0: */ michael@0: SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); michael@0: SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); michael@0: michael@0: /* michael@0: ** CAPI3REF: Evaluate An SQL Statement michael@0: ** michael@0: ** After a [prepared statement] has been prepared using either michael@0: ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy michael@0: ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function michael@0: ** must be called one or more times to evaluate the statement. michael@0: ** michael@0: ** The details of the behavior of the sqlite3_step() interface depend michael@0: ** on whether the statement was prepared using the newer "v2" interface michael@0: ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy michael@0: ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the michael@0: ** new "v2" interface is recommended for new applications but the legacy michael@0: ** interface will continue to be supported. michael@0: ** michael@0: ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], michael@0: ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. michael@0: ** ^With the "v2" interface, any of the other [result codes] or michael@0: ** [extended result codes] might be returned as well. michael@0: ** michael@0: ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the michael@0: ** database locks it needs to do its job. ^If the statement is a [COMMIT] michael@0: ** or occurs outside of an explicit transaction, then you can retry the michael@0: ** statement. If the statement is not a [COMMIT] and occurs within an michael@0: ** explicit transaction then you should rollback the transaction before michael@0: ** continuing. michael@0: ** michael@0: ** ^[SQLITE_DONE] means that the statement has finished executing michael@0: ** successfully. sqlite3_step() should not be called again on this virtual michael@0: ** machine without first calling [sqlite3_reset()] to reset the virtual michael@0: ** machine back to its initial state. michael@0: ** michael@0: ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] michael@0: ** is returned each time a new row of data is ready for processing by the michael@0: ** caller. The values may be accessed using the [column access functions]. michael@0: ** sqlite3_step() is called again to retrieve the next row of data. michael@0: ** michael@0: ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint michael@0: ** violation) has occurred. sqlite3_step() should not be called again on michael@0: ** the VM. More information may be found by calling [sqlite3_errmsg()]. michael@0: ** ^With the legacy interface, a more specific error code (for example, michael@0: ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) michael@0: ** can be obtained by calling [sqlite3_reset()] on the michael@0: ** [prepared statement]. ^In the "v2" interface, michael@0: ** the more specific error code is returned directly by sqlite3_step(). michael@0: ** michael@0: ** [SQLITE_MISUSE] means that the this routine was called inappropriately. michael@0: ** Perhaps it was called on a [prepared statement] that has michael@0: ** already been [sqlite3_finalize | finalized] or on one that had michael@0: ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could michael@0: ** be the case that the same database connection is being used by two or michael@0: ** more threads at the same moment in time. michael@0: ** michael@0: ** For all versions of SQLite up to and including 3.6.23.1, a call to michael@0: ** [sqlite3_reset()] was required after sqlite3_step() returned anything michael@0: ** other than [SQLITE_ROW] before any subsequent invocation of michael@0: ** sqlite3_step(). Failure to reset the prepared statement using michael@0: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from michael@0: ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began michael@0: ** calling [sqlite3_reset()] automatically in this circumstance rather michael@0: ** than returning [SQLITE_MISUSE]. This is not considered a compatibility michael@0: ** break because any application that ever receives an SQLITE_MISUSE error michael@0: ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option michael@0: ** can be used to restore the legacy behavior. michael@0: ** michael@0: ** Goofy Interface Alert: In the legacy interface, the sqlite3_step() michael@0: ** API always returns a generic error code, [SQLITE_ERROR], following any michael@0: ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call michael@0: ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the michael@0: ** specific [error codes] that better describes the error. michael@0: ** We admit that this is a goofy design. The problem has been fixed michael@0: ** with the "v2" interface. If you prepare all of your SQL statements michael@0: ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead michael@0: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, michael@0: ** then the more specific [error codes] are returned directly michael@0: ** by sqlite3_step(). The use of the "v2" interface is recommended. michael@0: */ michael@0: SQLITE_API int sqlite3_step(sqlite3_stmt*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Number of columns in a result set michael@0: ** michael@0: ** ^The sqlite3_data_count(P) interface returns the number of columns in the michael@0: ** current row of the result set of [prepared statement] P. michael@0: ** ^If prepared statement P does not have results ready to return michael@0: ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of michael@0: ** interfaces) then sqlite3_data_count(P) returns 0. michael@0: ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. michael@0: ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to michael@0: ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) michael@0: ** will return non-zero if previous call to [sqlite3_step](P) returned michael@0: ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] michael@0: ** where it always returns zero since each step of that multi-step michael@0: ** pragma returns 0 columns of data. michael@0: ** michael@0: ** See also: [sqlite3_column_count()] michael@0: */ michael@0: SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); michael@0: michael@0: /* michael@0: ** CAPI3REF: Fundamental Datatypes michael@0: ** KEYWORDS: SQLITE_TEXT michael@0: ** michael@0: ** ^(Every value in SQLite has one of five fundamental datatypes: michael@0: ** michael@0: ** )^ michael@0: ** michael@0: ** These constants are codes for each of those types. michael@0: ** michael@0: ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 michael@0: ** for a completely different meaning. Software that links against both michael@0: ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not michael@0: ** SQLITE_TEXT. michael@0: */ michael@0: #define SQLITE_INTEGER 1 michael@0: #define SQLITE_FLOAT 2 michael@0: #define SQLITE_BLOB 4 michael@0: #define SQLITE_NULL 5 michael@0: #ifdef SQLITE_TEXT michael@0: # undef SQLITE_TEXT michael@0: #else michael@0: # define SQLITE_TEXT 3 michael@0: #endif michael@0: #define SQLITE3_TEXT 3 michael@0: michael@0: /* michael@0: ** CAPI3REF: Result Values From A Query michael@0: ** KEYWORDS: {column access functions} michael@0: ** michael@0: ** These routines form the "result set" interface. michael@0: ** michael@0: ** ^These routines return information about a single column of the current michael@0: ** result row of a query. ^In every case the first argument is a pointer michael@0: ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] michael@0: ** that was returned from [sqlite3_prepare_v2()] or one of its variants) michael@0: ** and the second argument is the index of the column for which information michael@0: ** should be returned. ^The leftmost column of the result set has the index 0. michael@0: ** ^The number of columns in the result can be determined using michael@0: ** [sqlite3_column_count()]. michael@0: ** michael@0: ** If the SQL statement does not currently point to a valid row, or if the michael@0: ** column index is out of range, the result is undefined. michael@0: ** These routines may only be called when the most recent call to michael@0: ** [sqlite3_step()] has returned [SQLITE_ROW] and neither michael@0: ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. michael@0: ** If any of these routines are called after [sqlite3_reset()] or michael@0: ** [sqlite3_finalize()] or after [sqlite3_step()] has returned michael@0: ** something other than [SQLITE_ROW], the results are undefined. michael@0: ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] michael@0: ** are called from a different thread while any of these routines michael@0: ** are pending, then the results are undefined. michael@0: ** michael@0: ** ^The sqlite3_column_type() routine returns the michael@0: ** [SQLITE_INTEGER | datatype code] for the initial data type michael@0: ** of the result column. ^The returned value is one of [SQLITE_INTEGER], michael@0: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value michael@0: ** returned by sqlite3_column_type() is only meaningful if no type michael@0: ** conversions have occurred as described below. After a type conversion, michael@0: ** the value returned by sqlite3_column_type() is undefined. Future michael@0: ** versions of SQLite may change the behavior of sqlite3_column_type() michael@0: ** following a type conversion. michael@0: ** michael@0: ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() michael@0: ** routine returns the number of bytes in that BLOB or string. michael@0: ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts michael@0: ** the string to UTF-8 and then returns the number of bytes. michael@0: ** ^If the result is a numeric value then sqlite3_column_bytes() uses michael@0: ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns michael@0: ** the number of bytes in that string. michael@0: ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. michael@0: ** michael@0: ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() michael@0: ** routine returns the number of bytes in that BLOB or string. michael@0: ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts michael@0: ** the string to UTF-16 and then returns the number of bytes. michael@0: ** ^If the result is a numeric value then sqlite3_column_bytes16() uses michael@0: ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns michael@0: ** the number of bytes in that string. michael@0: ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. michael@0: ** michael@0: ** ^The values returned by [sqlite3_column_bytes()] and michael@0: ** [sqlite3_column_bytes16()] do not include the zero terminators at the end michael@0: ** of the string. ^For clarity: the values returned by michael@0: ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of michael@0: ** bytes in the string, not the number of characters. michael@0: ** michael@0: ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), michael@0: ** even empty strings, are always zero-terminated. ^The return michael@0: ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. michael@0: ** michael@0: ** ^The object returned by [sqlite3_column_value()] is an michael@0: ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object michael@0: ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. michael@0: ** If the [unprotected sqlite3_value] object returned by michael@0: ** [sqlite3_column_value()] is used in any other way, including calls michael@0: ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], michael@0: ** or [sqlite3_value_bytes()], then the behavior is undefined. michael@0: ** michael@0: ** These routines attempt to convert the value where appropriate. ^For michael@0: ** example, if the internal representation is FLOAT and a text result michael@0: ** is requested, [sqlite3_snprintf()] is used internally to perform the michael@0: ** conversion automatically. ^(The following table details the conversions michael@0: ** that are applied: michael@0: ** michael@0: **
michael@0: ** michael@0: **
Internal
Type 		Requested
Type 		Conversion michael@0: ** michael@0: **
NULL INTEGER Result is 0 michael@0: **
NULL FLOAT Result is 0.0 michael@0: **
NULL TEXT Result is NULL pointer michael@0: **
NULL BLOB Result is NULL pointer michael@0: **
INTEGER FLOAT Convert from integer to float michael@0: **
INTEGER TEXT ASCII rendering of the integer michael@0: **
INTEGER BLOB Same as INTEGER->TEXT michael@0: **
FLOAT INTEGER Convert from float to integer michael@0: **
FLOAT TEXT ASCII rendering of the float michael@0: **
FLOAT BLOB Same as FLOAT->TEXT michael@0: **
TEXT INTEGER Use atoi() michael@0: **
TEXT FLOAT Use atof() michael@0: **
TEXT BLOB No change michael@0: **
BLOB INTEGER Convert to TEXT then use atoi() michael@0: **
BLOB FLOAT Convert to TEXT then use atof() michael@0: **
BLOB TEXT Add a zero terminator if needed michael@0: **
michael@0: **
)^ michael@0: ** michael@0: ** The table above makes reference to standard C library functions atoi() michael@0: ** and atof(). SQLite does not really use these functions. It has its michael@0: ** own equivalent internal routines. The atoi() and atof() names are michael@0: ** used in the table for brevity and because they are familiar to most michael@0: ** C programmers. michael@0: ** michael@0: ** Note that when type conversions occur, pointers returned by prior michael@0: ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or michael@0: ** sqlite3_column_text16() may be invalidated. michael@0: ** Type conversions and pointer invalidations might occur michael@0: ** in the following cases: michael@0: ** michael@0: ** michael@0: ** michael@0: ** ^Conversions between UTF-16be and UTF-16le are always done in place and do michael@0: ** not invalidate a prior pointer, though of course the content of the buffer michael@0: ** that the prior pointer references will have been modified. Other kinds michael@0: ** of conversion are done in place when it is possible, but sometimes they michael@0: ** are not possible and in those cases prior pointers are invalidated. michael@0: ** michael@0: ** The safest and easiest to remember policy is to invoke these routines michael@0: ** in one of the following ways: michael@0: ** michael@0: ** michael@0: ** michael@0: ** In other words, you should call sqlite3_column_text(), michael@0: ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result michael@0: ** into the desired format, then invoke sqlite3_column_bytes() or michael@0: ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls michael@0: ** to sqlite3_column_text() or sqlite3_column_blob() with calls to michael@0: ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() michael@0: ** with calls to sqlite3_column_bytes(). michael@0: ** michael@0: ** ^The pointers returned are valid until a type conversion occurs as michael@0: ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or michael@0: ** [sqlite3_finalize()] is called. ^The memory space used to hold strings michael@0: ** and BLOBs is freed automatically. Do not pass the pointers returned michael@0: ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into michael@0: ** [sqlite3_free()]. michael@0: ** michael@0: ** ^(If a memory allocation error occurs during the evaluation of any michael@0: ** of these routines, a default value is returned. The default value michael@0: ** is either the integer 0, the floating point number 0.0, or a NULL michael@0: ** pointer. Subsequent calls to [sqlite3_errcode()] will return michael@0: ** [SQLITE_NOMEM].)^ michael@0: */ michael@0: SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); michael@0: SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); michael@0: SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); michael@0: SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); michael@0: SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); michael@0: SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); michael@0: SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); michael@0: SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); michael@0: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); michael@0: SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); michael@0: michael@0: /* michael@0: ** CAPI3REF: Destroy A Prepared Statement Object michael@0: ** michael@0: ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. michael@0: ** ^If the most recent evaluation of the statement encountered no errors michael@0: ** or if the statement is never been evaluated, then sqlite3_finalize() returns michael@0: ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then michael@0: ** sqlite3_finalize(S) returns the appropriate [error code] or michael@0: ** [extended error code]. michael@0: ** michael@0: ** ^The sqlite3_finalize(S) routine can be called at any point during michael@0: ** the life cycle of [prepared statement] S: michael@0: ** before statement S is ever evaluated, after michael@0: ** one or more calls to [sqlite3_reset()], or after any call michael@0: ** to [sqlite3_step()] regardless of whether or not the statement has michael@0: ** completed execution. michael@0: ** michael@0: ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. michael@0: ** michael@0: ** The application must finalize every [prepared statement] in order to avoid michael@0: ** resource leaks. It is a grievous error for the application to try to use michael@0: ** a prepared statement after it has been finalized. Any use of a prepared michael@0: ** statement after it has been finalized can result in undefined and michael@0: ** undesirable behavior such as segfaults and heap corruption. michael@0: */ michael@0: SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); michael@0: michael@0: /* michael@0: ** CAPI3REF: Reset A Prepared Statement Object michael@0: ** michael@0: ** The sqlite3_reset() function is called to reset a [prepared statement] michael@0: ** object back to its initial state, ready to be re-executed. michael@0: ** ^Any SQL statement variables that had values bound to them using michael@0: ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. michael@0: ** Use [sqlite3_clear_bindings()] to reset the bindings. michael@0: ** michael@0: ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S michael@0: ** back to the beginning of its program. michael@0: ** michael@0: ** ^If the most recent call to [sqlite3_step(S)] for the michael@0: ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], michael@0: ** or if [sqlite3_step(S)] has never before been called on S, michael@0: ** then [sqlite3_reset(S)] returns [SQLITE_OK]. michael@0: ** michael@0: ** ^If the most recent call to [sqlite3_step(S)] for the michael@0: ** [prepared statement] S indicated an error, then michael@0: ** [sqlite3_reset(S)] returns an appropriate [error code]. michael@0: ** michael@0: ** ^The [sqlite3_reset(S)] interface does not change the values michael@0: ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. michael@0: */ michael@0: SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); michael@0: michael@0: /* michael@0: ** CAPI3REF: Create Or Redefine SQL Functions michael@0: ** KEYWORDS: {function creation routines} michael@0: ** KEYWORDS: {application-defined SQL function} michael@0: ** KEYWORDS: {application-defined SQL functions} michael@0: ** michael@0: ** ^These functions (collectively known as "function creation routines") michael@0: ** are used to add SQL functions or aggregates or to redefine the behavior michael@0: ** of existing SQL functions or aggregates. The only differences between michael@0: ** these routines are the text encoding expected for michael@0: ** the second parameter (the name of the function being created) michael@0: ** and the presence or absence of a destructor callback for michael@0: ** the application data pointer. michael@0: ** michael@0: ** ^The first parameter is the [database connection] to which the SQL michael@0: ** function is to be added. ^If an application uses more than one database michael@0: ** connection then application-defined SQL functions must be added michael@0: ** to each database connection separately. michael@0: ** michael@0: ** ^The second parameter is the name of the SQL function to be created or michael@0: ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 michael@0: ** representation, exclusive of the zero-terminator. ^Note that the name michael@0: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. michael@0: ** ^Any attempt to create a function with a longer name michael@0: ** will result in [SQLITE_MISUSE] being returned. michael@0: ** michael@0: ** ^The third parameter (nArg) michael@0: ** is the number of arguments that the SQL function or michael@0: ** aggregate takes. ^If this parameter is -1, then the SQL function or michael@0: ** aggregate may take any number of arguments between 0 and the limit michael@0: ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third michael@0: ** parameter is less than -1 or greater than 127 then the behavior is michael@0: ** undefined. michael@0: ** michael@0: ** ^The fourth parameter, eTextRep, specifies what michael@0: ** [SQLITE_UTF8 | text encoding] this SQL function prefers for michael@0: ** its parameters. Every SQL function implementation must be able to work michael@0: ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be michael@0: ** more efficient with one encoding than another. ^An application may michael@0: ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple michael@0: ** times with the same function but with different values of eTextRep. michael@0: ** ^When multiple implementations of the same function are available, SQLite michael@0: ** will pick the one that involves the least amount of data conversion. michael@0: ** If there is only a single implementation which does not care what text michael@0: ** encoding is used, then the fourth argument should be [SQLITE_ANY]. michael@0: ** michael@0: ** ^(The fifth parameter is an arbitrary pointer. The implementation of the michael@0: ** function can gain access to this pointer using [sqlite3_user_data()].)^ michael@0: ** michael@0: ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are michael@0: ** pointers to C-language functions that implement the SQL function or michael@0: ** aggregate. ^A scalar SQL function requires an implementation of the xFunc michael@0: ** callback only; NULL pointers must be passed as the xStep and xFinal michael@0: ** parameters. ^An aggregate SQL function requires an implementation of xStep michael@0: ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing michael@0: ** SQL function or aggregate, pass NULL pointers for all three function michael@0: ** callbacks. michael@0: ** michael@0: ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, michael@0: ** then it is destructor for the application data pointer. michael@0: ** The destructor is invoked when the function is deleted, either by being michael@0: ** overloaded or when the database connection closes.)^ michael@0: ** ^The destructor is also invoked if the call to michael@0: ** sqlite3_create_function_v2() fails. michael@0: ** ^When the destructor callback of the tenth parameter is invoked, it michael@0: ** is passed a single argument which is a copy of the application data michael@0: ** pointer which was the fifth parameter to sqlite3_create_function_v2(). michael@0: ** michael@0: ** ^It is permitted to register multiple implementations of the same michael@0: ** functions with the same name but with either differing numbers of michael@0: ** arguments or differing preferred text encodings. ^SQLite will use michael@0: ** the implementation that most closely matches the way in which the michael@0: ** SQL function is used. ^A function implementation with a non-negative michael@0: ** nArg parameter is a better match than a function implementation with michael@0: ** a negative nArg. ^A function where the preferred text encoding michael@0: ** matches the database encoding is a better michael@0: ** match than a function where the encoding is different. michael@0: ** ^A function where the encoding difference is between UTF16le and UTF16be michael@0: ** is a closer match than a function where the encoding difference is michael@0: ** between UTF8 and UTF16. michael@0: ** michael@0: ** ^Built-in functions may be overloaded by new application-defined functions. michael@0: ** michael@0: ** ^An application-defined function is permitted to call other michael@0: ** SQLite interfaces. However, such calls must not michael@0: ** close the database connection nor finalize or reset the prepared michael@0: ** statement in which the function is running. michael@0: */ michael@0: SQLITE_API int sqlite3_create_function( michael@0: sqlite3 *db, michael@0: const char *zFunctionName, michael@0: int nArg, michael@0: int eTextRep, michael@0: void *pApp, michael@0: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), michael@0: void (*xStep)(sqlite3_context*,int,sqlite3_value**), michael@0: void (*xFinal)(sqlite3_context*) michael@0: ); michael@0: SQLITE_API int sqlite3_create_function16( michael@0: sqlite3 *db, michael@0: const void *zFunctionName, michael@0: int nArg, michael@0: int eTextRep, michael@0: void *pApp, michael@0: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), michael@0: void (*xStep)(sqlite3_context*,int,sqlite3_value**), michael@0: void (*xFinal)(sqlite3_context*) michael@0: ); michael@0: SQLITE_API int sqlite3_create_function_v2( michael@0: sqlite3 *db, michael@0: const char *zFunctionName, michael@0: int nArg, michael@0: int eTextRep, michael@0: void *pApp, michael@0: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), michael@0: void (*xStep)(sqlite3_context*,int,sqlite3_value**), michael@0: void (*xFinal)(sqlite3_context*), michael@0: void(*xDestroy)(void*) michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Text Encodings michael@0: ** michael@0: ** These constant define integer codes that represent the various michael@0: ** text encodings supported by SQLite. michael@0: */ michael@0: #define SQLITE_UTF8 1 michael@0: #define SQLITE_UTF16LE 2 michael@0: #define SQLITE_UTF16BE 3 michael@0: #define SQLITE_UTF16 4 /* Use native byte order */ michael@0: #define SQLITE_ANY 5 /* sqlite3_create_function only */ michael@0: #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Deprecated Functions michael@0: ** DEPRECATED michael@0: ** michael@0: ** These functions are [deprecated]. In order to maintain michael@0: ** backwards compatibility with older code, these functions continue michael@0: ** to be supported. However, new applications should avoid michael@0: ** the use of these functions. To help encourage people to avoid michael@0: ** using these functions, we are not going to tell you what they do. michael@0: */ michael@0: #ifndef SQLITE_OMIT_DEPRECATED michael@0: SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); michael@0: SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); michael@0: SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); michael@0: SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); michael@0: SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); michael@0: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); michael@0: #endif michael@0: michael@0: /* michael@0: ** CAPI3REF: Obtaining SQL Function Parameter Values michael@0: ** michael@0: ** The C-language implementation of SQL functions and aggregates uses michael@0: ** this set of interface routines to access the parameter values on michael@0: ** the function or aggregate. michael@0: ** michael@0: ** The xFunc (for scalar functions) or xStep (for aggregates) parameters michael@0: ** to [sqlite3_create_function()] and [sqlite3_create_function16()] michael@0: ** define callbacks that implement the SQL functions and aggregates. michael@0: ** The 3rd parameter to these callbacks is an array of pointers to michael@0: ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for michael@0: ** each parameter to the SQL function. These routines are used to michael@0: ** extract values from the [sqlite3_value] objects. michael@0: ** michael@0: ** These routines work only with [protected sqlite3_value] objects. michael@0: ** Any attempt to use these routines on an [unprotected sqlite3_value] michael@0: ** object results in undefined behavior. michael@0: ** michael@0: ** ^These routines work just like the corresponding [column access functions] michael@0: ** except that these routines take a single [protected sqlite3_value] object michael@0: ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. michael@0: ** michael@0: ** ^The sqlite3_value_text16() interface extracts a UTF-16 string michael@0: ** in the native byte-order of the host machine. ^The michael@0: ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces michael@0: ** extract UTF-16 strings as big-endian and little-endian respectively. michael@0: ** michael@0: ** ^(The sqlite3_value_numeric_type() interface attempts to apply michael@0: ** numeric affinity to the value. This means that an attempt is michael@0: ** made to convert the value to an integer or floating point. If michael@0: ** such a conversion is possible without loss of information (in other michael@0: ** words, if the value is a string that looks like a number) michael@0: ** then the conversion is performed. Otherwise no conversion occurs. michael@0: ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ michael@0: ** michael@0: ** Please pay particular attention to the fact that the pointer returned michael@0: ** from [sqlite3_value_blob()], [sqlite3_value_text()], or michael@0: ** [sqlite3_value_text16()] can be invalidated by a subsequent call to michael@0: ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], michael@0: ** or [sqlite3_value_text16()]. michael@0: ** michael@0: ** These routines must be called from the same thread as michael@0: ** the SQL function that supplied the [sqlite3_value*] parameters. michael@0: */ michael@0: SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); michael@0: SQLITE_API int sqlite3_value_bytes(sqlite3_value*); michael@0: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); michael@0: SQLITE_API double sqlite3_value_double(sqlite3_value*); michael@0: SQLITE_API int sqlite3_value_int(sqlite3_value*); michael@0: SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); michael@0: SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); michael@0: SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); michael@0: SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); michael@0: SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); michael@0: SQLITE_API int sqlite3_value_type(sqlite3_value*); michael@0: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Obtain Aggregate Function Context michael@0: ** michael@0: ** Implementations of aggregate SQL functions use this michael@0: ** routine to allocate memory for storing their state. michael@0: ** michael@0: ** ^The first time the sqlite3_aggregate_context(C,N) routine is called michael@0: ** for a particular aggregate function, SQLite michael@0: ** allocates N of memory, zeroes out that memory, and returns a pointer michael@0: ** to the new memory. ^On second and subsequent calls to michael@0: ** sqlite3_aggregate_context() for the same aggregate function instance, michael@0: ** the same buffer is returned. Sqlite3_aggregate_context() is normally michael@0: ** called once for each invocation of the xStep callback and then one michael@0: ** last time when the xFinal callback is invoked. ^(When no rows match michael@0: ** an aggregate query, the xStep() callback of the aggregate function michael@0: ** implementation is never called and xFinal() is called exactly once. michael@0: ** In those cases, sqlite3_aggregate_context() might be called for the michael@0: ** first time from within xFinal().)^ michael@0: ** michael@0: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is michael@0: ** less than or equal to zero or if a memory allocate error occurs. michael@0: ** michael@0: ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is michael@0: ** determined by the N parameter on first successful call. Changing the michael@0: ** value of N in subsequent call to sqlite3_aggregate_context() within michael@0: ** the same aggregate function instance will not resize the memory michael@0: ** allocation.)^ michael@0: ** michael@0: ** ^SQLite automatically frees the memory allocated by michael@0: ** sqlite3_aggregate_context() when the aggregate query concludes. michael@0: ** michael@0: ** The first parameter must be a copy of the michael@0: ** [sqlite3_context | SQL function context] that is the first parameter michael@0: ** to the xStep or xFinal callback routine that implements the aggregate michael@0: ** function. michael@0: ** michael@0: ** This routine must be called from the same thread in which michael@0: ** the aggregate SQL function is running. michael@0: */ michael@0: SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); michael@0: michael@0: /* michael@0: ** CAPI3REF: User Data For Functions michael@0: ** michael@0: ** ^The sqlite3_user_data() interface returns a copy of michael@0: ** the pointer that was the pUserData parameter (the 5th parameter) michael@0: ** of the [sqlite3_create_function()] michael@0: ** and [sqlite3_create_function16()] routines that originally michael@0: ** registered the application defined function. michael@0: ** michael@0: ** This routine must be called from the same thread in which michael@0: ** the application-defined function is running. michael@0: */ michael@0: SQLITE_API void *sqlite3_user_data(sqlite3_context*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Database Connection For Functions michael@0: ** michael@0: ** ^The sqlite3_context_db_handle() interface returns a copy of michael@0: ** the pointer to the [database connection] (the 1st parameter) michael@0: ** of the [sqlite3_create_function()] michael@0: ** and [sqlite3_create_function16()] routines that originally michael@0: ** registered the application defined function. michael@0: */ michael@0: SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Function Auxiliary Data michael@0: ** michael@0: ** The following two functions may be used by scalar SQL functions to michael@0: ** associate metadata with argument values. If the same value is passed to michael@0: ** multiple invocations of the same SQL function during query execution, under michael@0: ** some circumstances the associated metadata may be preserved. This may michael@0: ** be used, for example, to add a regular-expression matching scalar michael@0: ** function. The compiled version of the regular expression is stored as michael@0: ** metadata associated with the SQL value passed as the regular expression michael@0: ** pattern. The compiled regular expression can be reused on multiple michael@0: ** invocations of the same function so that the original pattern string michael@0: ** does not need to be recompiled on each invocation. michael@0: ** michael@0: ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata michael@0: ** associated by the sqlite3_set_auxdata() function with the Nth argument michael@0: ** value to the application-defined function. ^If no metadata has been ever michael@0: ** been set for the Nth argument of the function, or if the corresponding michael@0: ** function parameter has changed since the meta-data was set, michael@0: ** then sqlite3_get_auxdata() returns a NULL pointer. michael@0: ** michael@0: ** ^The sqlite3_set_auxdata() interface saves the metadata michael@0: ** pointed to by its 3rd parameter as the metadata for the N-th michael@0: ** argument of the application-defined function. Subsequent michael@0: ** calls to sqlite3_get_auxdata() might return this data, if it has michael@0: ** not been destroyed. michael@0: ** ^If it is not NULL, SQLite will invoke the destructor michael@0: ** function given by the 4th parameter to sqlite3_set_auxdata() on michael@0: ** the metadata when the corresponding function parameter changes michael@0: ** or when the SQL statement completes, whichever comes first. michael@0: ** michael@0: ** SQLite is free to call the destructor and drop metadata on any michael@0: ** parameter of any function at any time. ^The only guarantee is that michael@0: ** the destructor will be called before the metadata is dropped. michael@0: ** michael@0: ** ^(In practice, metadata is preserved between function calls for michael@0: ** expressions that are constant at compile time. This includes literal michael@0: ** values and [parameters].)^ michael@0: ** michael@0: ** These routines must be called from the same thread in which michael@0: ** the SQL function is running. michael@0: */ michael@0: SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); michael@0: SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Constants Defining Special Destructor Behavior michael@0: ** michael@0: ** These are special values for the destructor that is passed in as the michael@0: ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor michael@0: ** argument is SQLITE_STATIC, it means that the content pointer is constant michael@0: ** and will never change. It does not need to be destroyed. ^The michael@0: ** SQLITE_TRANSIENT value means that the content will likely change in michael@0: ** the near future and that SQLite should make its own private copy of michael@0: ** the content before returning. michael@0: ** michael@0: ** The typedef is necessary to work around problems in certain michael@0: ** C++ compilers. See ticket #2191. michael@0: */ michael@0: typedef void (*sqlite3_destructor_type)(void*); michael@0: #define SQLITE_STATIC ((sqlite3_destructor_type)0) michael@0: #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) michael@0: michael@0: /* michael@0: ** CAPI3REF: Setting The Result Of An SQL Function michael@0: ** michael@0: ** These routines are used by the xFunc or xFinal callbacks that michael@0: ** implement SQL functions and aggregates. See michael@0: ** [sqlite3_create_function()] and [sqlite3_create_function16()] michael@0: ** for additional information. michael@0: ** michael@0: ** These functions work very much like the [parameter binding] family of michael@0: ** functions used to bind values to host parameters in prepared statements. michael@0: ** Refer to the [SQL parameter] documentation for additional information. michael@0: ** michael@0: ** ^The sqlite3_result_blob() interface sets the result from michael@0: ** an application-defined function to be the BLOB whose content is pointed michael@0: ** to by the second parameter and which is N bytes long where N is the michael@0: ** third parameter. michael@0: ** michael@0: ** ^The sqlite3_result_zeroblob() interfaces set the result of michael@0: ** the application-defined function to be a BLOB containing all zero michael@0: ** bytes and N bytes in size, where N is the value of the 2nd parameter. michael@0: ** michael@0: ** ^The sqlite3_result_double() interface sets the result from michael@0: ** an application-defined function to be a floating point value specified michael@0: ** by its 2nd argument. michael@0: ** michael@0: ** ^The sqlite3_result_error() and sqlite3_result_error16() functions michael@0: ** cause the implemented SQL function to throw an exception. michael@0: ** ^SQLite uses the string pointed to by the michael@0: ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() michael@0: ** as the text of an error message. ^SQLite interprets the error michael@0: ** message string from sqlite3_result_error() as UTF-8. ^SQLite michael@0: ** interprets the string from sqlite3_result_error16() as UTF-16 in native michael@0: ** byte order. ^If the third parameter to sqlite3_result_error() michael@0: ** or sqlite3_result_error16() is negative then SQLite takes as the error michael@0: ** message all text up through the first zero character. michael@0: ** ^If the third parameter to sqlite3_result_error() or michael@0: ** sqlite3_result_error16() is non-negative then SQLite takes that many michael@0: ** bytes (not characters) from the 2nd parameter as the error message. michael@0: ** ^The sqlite3_result_error() and sqlite3_result_error16() michael@0: ** routines make a private copy of the error message text before michael@0: ** they return. Hence, the calling function can deallocate or michael@0: ** modify the text after they return without harm. michael@0: ** ^The sqlite3_result_error_code() function changes the error code michael@0: ** returned by SQLite as a result of an error in a function. ^By default, michael@0: ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() michael@0: ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. michael@0: ** michael@0: ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an michael@0: ** error indicating that a string or BLOB is too long to represent. michael@0: ** michael@0: ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an michael@0: ** error indicating that a memory allocation failed. michael@0: ** michael@0: ** ^The sqlite3_result_int() interface sets the return value michael@0: ** of the application-defined function to be the 32-bit signed integer michael@0: ** value given in the 2nd argument. michael@0: ** ^The sqlite3_result_int64() interface sets the return value michael@0: ** of the application-defined function to be the 64-bit signed integer michael@0: ** value given in the 2nd argument. michael@0: ** michael@0: ** ^The sqlite3_result_null() interface sets the return value michael@0: ** of the application-defined function to be NULL. michael@0: ** michael@0: ** ^The sqlite3_result_text(), sqlite3_result_text16(), michael@0: ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces michael@0: ** set the return value of the application-defined function to be michael@0: ** a text string which is represented as UTF-8, UTF-16 native byte order, michael@0: ** UTF-16 little endian, or UTF-16 big endian, respectively. michael@0: ** ^SQLite takes the text result from the application from michael@0: ** the 2nd parameter of the sqlite3_result_text* interfaces. michael@0: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces michael@0: ** is negative, then SQLite takes result text from the 2nd parameter michael@0: ** through the first zero character. michael@0: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces michael@0: ** is non-negative, then as many bytes (not characters) of the text michael@0: ** pointed to by the 2nd parameter are taken as the application-defined michael@0: ** function result. If the 3rd parameter is non-negative, then it michael@0: ** must be the byte offset into the string where the NUL terminator would michael@0: ** appear if the string where NUL terminated. If any NUL characters occur michael@0: ** in the string at a byte offset that is less than the value of the 3rd michael@0: ** parameter, then the resulting string will contain embedded NULs and the michael@0: ** result of expressions operating on strings with embedded NULs is undefined. michael@0: ** ^If the 4th parameter to the sqlite3_result_text* interfaces michael@0: ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that michael@0: ** function as the destructor on the text or BLOB result when it has michael@0: ** finished using that result. michael@0: ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to michael@0: ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite michael@0: ** assumes that the text or BLOB result is in constant space and does not michael@0: ** copy the content of the parameter nor call a destructor on the content michael@0: ** when it has finished using that result. michael@0: ** ^If the 4th parameter to the sqlite3_result_text* interfaces michael@0: ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT michael@0: ** then SQLite makes a copy of the result into space obtained from michael@0: ** from [sqlite3_malloc()] before it returns. michael@0: ** michael@0: ** ^The sqlite3_result_value() interface sets the result of michael@0: ** the application-defined function to be a copy the michael@0: ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The michael@0: ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] michael@0: ** so that the [sqlite3_value] specified in the parameter may change or michael@0: ** be deallocated after sqlite3_result_value() returns without harm. michael@0: ** ^A [protected sqlite3_value] object may always be used where an michael@0: ** [unprotected sqlite3_value] object is required, so either michael@0: ** kind of [sqlite3_value] object can be used with this interface. michael@0: ** michael@0: ** If these routines are called from within the different thread michael@0: ** than the one containing the application-defined function that received michael@0: ** the [sqlite3_context] pointer, the results are undefined. michael@0: */ michael@0: SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); michael@0: SQLITE_API void sqlite3_result_double(sqlite3_context*, double); michael@0: SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); michael@0: SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); michael@0: SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); michael@0: SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); michael@0: SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); michael@0: SQLITE_API void sqlite3_result_int(sqlite3_context*, int); michael@0: SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); michael@0: SQLITE_API void sqlite3_result_null(sqlite3_context*); michael@0: SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); michael@0: SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); michael@0: SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); michael@0: SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); michael@0: SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); michael@0: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); michael@0: michael@0: /* michael@0: ** CAPI3REF: Define New Collating Sequences michael@0: ** michael@0: ** ^These functions add, remove, or modify a [collation] associated michael@0: ** with the [database connection] specified as the first argument. michael@0: ** michael@0: ** ^The name of the collation is a UTF-8 string michael@0: ** for sqlite3_create_collation() and sqlite3_create_collation_v2() michael@0: ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). michael@0: ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are michael@0: ** considered to be the same name. michael@0: ** michael@0: ** ^(The third argument (eTextRep) must be one of the constants: michael@0: ** )^ michael@0: ** ^The eTextRep argument determines the encoding of strings passed michael@0: ** to the collating function callback, xCallback. michael@0: ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep michael@0: ** force strings to be UTF16 with native byte order. michael@0: ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin michael@0: ** on an even byte address. michael@0: ** michael@0: ** ^The fourth argument, pArg, is an application data pointer that is passed michael@0: ** through as the first argument to the collating function callback. michael@0: ** michael@0: ** ^The fifth argument, xCallback, is a pointer to the collating function. michael@0: ** ^Multiple collating functions can be registered using the same name but michael@0: ** with different eTextRep parameters and SQLite will use whichever michael@0: ** function requires the least amount of data transformation. michael@0: ** ^If the xCallback argument is NULL then the collating function is michael@0: ** deleted. ^When all collating functions having the same name are deleted, michael@0: ** that collation is no longer usable. michael@0: ** michael@0: ** ^The collating function callback is invoked with a copy of the pArg michael@0: ** application data pointer and with two strings in the encoding specified michael@0: ** by the eTextRep argument. The collating function must return an michael@0: ** integer that is negative, zero, or positive michael@0: ** if the first string is less than, equal to, or greater than the second, michael@0: ** respectively. A collating function must always return the same answer michael@0: ** given the same inputs. If two or more collating functions are registered michael@0: ** to the same collation name (using different eTextRep values) then all michael@0: ** must give an equivalent answer when invoked with equivalent strings. michael@0: ** The collating function must obey the following properties for all michael@0: ** strings A, B, and C: michael@0: ** michael@0: **
    michael@0: **
  1. If A==B then B==A. michael@0: **
  2. If A==B and B==C then A==C. michael@0: **
  3. If A<B THEN B>A. michael@0: **
  4. If A<B and B<C then A<C. michael@0: **
michael@0: ** michael@0: ** If a collating function fails any of the above constraints and that michael@0: ** collating function is registered and used, then the behavior of SQLite michael@0: ** is undefined. michael@0: ** michael@0: ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() michael@0: ** with the addition that the xDestroy callback is invoked on pArg when michael@0: ** the collating function is deleted. michael@0: ** ^Collating functions are deleted when they are overridden by later michael@0: ** calls to the collation creation functions or when the michael@0: ** [database connection] is closed using [sqlite3_close()]. michael@0: ** michael@0: ** ^The xDestroy callback is not called if the michael@0: ** sqlite3_create_collation_v2() function fails. Applications that invoke michael@0: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should michael@0: ** check the return code and dispose of the application data pointer michael@0: ** themselves rather than expecting SQLite to deal with it for them. michael@0: ** This is different from every other SQLite interface. The inconsistency michael@0: ** is unfortunate but cannot be changed without breaking backwards michael@0: ** compatibility. michael@0: ** michael@0: ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. michael@0: */ michael@0: SQLITE_API int sqlite3_create_collation( michael@0: sqlite3*, michael@0: const char *zName, michael@0: int eTextRep, michael@0: void *pArg, michael@0: int(*xCompare)(void*,int,const void*,int,const void*) michael@0: ); michael@0: SQLITE_API int sqlite3_create_collation_v2( michael@0: sqlite3*, michael@0: const char *zName, michael@0: int eTextRep, michael@0: void *pArg, michael@0: int(*xCompare)(void*,int,const void*,int,const void*), michael@0: void(*xDestroy)(void*) michael@0: ); michael@0: SQLITE_API int sqlite3_create_collation16( michael@0: sqlite3*, michael@0: const void *zName, michael@0: int eTextRep, michael@0: void *pArg, michael@0: int(*xCompare)(void*,int,const void*,int,const void*) michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Collation Needed Callbacks michael@0: ** michael@0: ** ^To avoid having to register all collation sequences before a database michael@0: ** can be used, a single callback function may be registered with the michael@0: ** [database connection] to be invoked whenever an undefined collation michael@0: ** sequence is required. michael@0: ** michael@0: ** ^If the function is registered using the sqlite3_collation_needed() API, michael@0: ** then it is passed the names of undefined collation sequences as strings michael@0: ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, michael@0: ** the names are passed as UTF-16 in machine native byte order. michael@0: ** ^A call to either function replaces the existing collation-needed callback. michael@0: ** michael@0: ** ^(When the callback is invoked, the first argument passed is a copy michael@0: ** of the second argument to sqlite3_collation_needed() or michael@0: ** sqlite3_collation_needed16(). The second argument is the database michael@0: ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], michael@0: ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation michael@0: ** sequence function required. The fourth parameter is the name of the michael@0: ** required collation sequence.)^ michael@0: ** michael@0: ** The callback function should register the desired collation using michael@0: ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or michael@0: ** [sqlite3_create_collation_v2()]. michael@0: */ michael@0: SQLITE_API int sqlite3_collation_needed( michael@0: sqlite3*, michael@0: void*, michael@0: void(*)(void*,sqlite3*,int eTextRep,const char*) michael@0: ); michael@0: SQLITE_API int sqlite3_collation_needed16( michael@0: sqlite3*, michael@0: void*, michael@0: void(*)(void*,sqlite3*,int eTextRep,const void*) michael@0: ); michael@0: michael@0: #ifdef SQLITE_HAS_CODEC michael@0: /* michael@0: ** Specify the key for an encrypted database. This routine should be michael@0: ** called right after sqlite3_open(). michael@0: ** michael@0: ** The code to implement this API is not available in the public release michael@0: ** of SQLite. michael@0: */ michael@0: SQLITE_API int sqlite3_key( michael@0: sqlite3 *db, /* Database to be rekeyed */ michael@0: const void *pKey, int nKey /* The key */ michael@0: ); michael@0: michael@0: /* michael@0: ** Change the key on an open database. If the current database is not michael@0: ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the michael@0: ** database is decrypted. michael@0: ** michael@0: ** The code to implement this API is not available in the public release michael@0: ** of SQLite. michael@0: */ michael@0: SQLITE_API int sqlite3_rekey( michael@0: sqlite3 *db, /* Database to be rekeyed */ michael@0: const void *pKey, int nKey /* The new key */ michael@0: ); michael@0: michael@0: /* michael@0: ** Specify the activation key for a SEE database. Unless michael@0: ** activated, none of the SEE routines will work. michael@0: */ michael@0: SQLITE_API void sqlite3_activate_see( michael@0: const char *zPassPhrase /* Activation phrase */ michael@0: ); michael@0: #endif michael@0: michael@0: #ifdef SQLITE_ENABLE_CEROD michael@0: /* michael@0: ** Specify the activation key for a CEROD database. Unless michael@0: ** activated, none of the CEROD routines will work. michael@0: */ michael@0: SQLITE_API void sqlite3_activate_cerod( michael@0: const char *zPassPhrase /* Activation phrase */ michael@0: ); michael@0: #endif michael@0: michael@0: /* michael@0: ** CAPI3REF: Suspend Execution For A Short Time michael@0: ** michael@0: ** The sqlite3_sleep() function causes the current thread to suspend execution michael@0: ** for at least a number of milliseconds specified in its parameter. michael@0: ** michael@0: ** If the operating system does not support sleep requests with michael@0: ** millisecond time resolution, then the time will be rounded up to michael@0: ** the nearest second. The number of milliseconds of sleep actually michael@0: ** requested from the operating system is returned. michael@0: ** michael@0: ** ^SQLite implements this interface by calling the xSleep() michael@0: ** method of the default [sqlite3_vfs] object. If the xSleep() method michael@0: ** of the default VFS is not implemented correctly, or not implemented at michael@0: ** all, then the behavior of sqlite3_sleep() may deviate from the description michael@0: ** in the previous paragraphs. michael@0: */ michael@0: SQLITE_API int sqlite3_sleep(int); michael@0: michael@0: /* michael@0: ** CAPI3REF: Name Of The Folder Holding Temporary Files michael@0: ** michael@0: ** ^(If this global variable is made to point to a string which is michael@0: ** the name of a folder (a.k.a. directory), then all temporary files michael@0: ** created by SQLite when using a built-in [sqlite3_vfs | VFS] michael@0: ** will be placed in that directory.)^ ^If this variable michael@0: ** is a NULL pointer, then SQLite performs a search for an appropriate michael@0: ** temporary file directory. michael@0: ** michael@0: ** It is not safe to read or modify this variable in more than one michael@0: ** thread at a time. It is not safe to read or modify this variable michael@0: ** if a [database connection] is being used at the same time in a separate michael@0: ** thread. michael@0: ** It is intended that this variable be set once michael@0: ** as part of process initialization and before any SQLite interface michael@0: ** routines have been called and that this variable remain unchanged michael@0: ** thereafter. michael@0: ** michael@0: ** ^The [temp_store_directory pragma] may modify this variable and cause michael@0: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, michael@0: ** the [temp_store_directory pragma] always assumes that any string michael@0: ** that this variable points to is held in memory obtained from michael@0: ** [sqlite3_malloc] and the pragma may attempt to free that memory michael@0: ** using [sqlite3_free]. michael@0: ** Hence, if this variable is modified directly, either it should be michael@0: ** made NULL or made to point to memory obtained from [sqlite3_malloc] michael@0: ** or else the use of the [temp_store_directory pragma] should be avoided. michael@0: ** michael@0: ** Note to Windows Runtime users: The temporary directory must be set michael@0: ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various michael@0: ** features that require the use of temporary files may fail. Here is an michael@0: ** example of how to do this using C++ with the Windows Runtime: michael@0: ** michael@0: ** 
michael@0: ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
michael@0: **       TemporaryFolder->Path->Data();
michael@0: ** char zPathBuf[MAX_PATH + 1];
michael@0: ** memset(zPathBuf, 0, sizeof(zPathBuf));
michael@0: ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
michael@0: **       NULL, NULL);
michael@0: ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
michael@0: **
michael@0: */ michael@0: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; michael@0: michael@0: /* michael@0: ** CAPI3REF: Name Of The Folder Holding Database Files michael@0: ** michael@0: ** ^(If this global variable is made to point to a string which is michael@0: ** the name of a folder (a.k.a. directory), then all database files michael@0: ** specified with a relative pathname and created or accessed by michael@0: ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed michael@0: ** to be relative to that directory.)^ ^If this variable is a NULL michael@0: ** pointer, then SQLite assumes that all database files specified michael@0: ** with a relative pathname are relative to the current directory michael@0: ** for the process. Only the windows VFS makes use of this global michael@0: ** variable; it is ignored by the unix VFS. michael@0: ** michael@0: ** Changing the value of this variable while a database connection is michael@0: ** open can result in a corrupt database. michael@0: ** michael@0: ** It is not safe to read or modify this variable in more than one michael@0: ** thread at a time. It is not safe to read or modify this variable michael@0: ** if a [database connection] is being used at the same time in a separate michael@0: ** thread. michael@0: ** It is intended that this variable be set once michael@0: ** as part of process initialization and before any SQLite interface michael@0: ** routines have been called and that this variable remain unchanged michael@0: ** thereafter. michael@0: ** michael@0: ** ^The [data_store_directory pragma] may modify this variable and cause michael@0: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, michael@0: ** the [data_store_directory pragma] always assumes that any string michael@0: ** that this variable points to is held in memory obtained from michael@0: ** [sqlite3_malloc] and the pragma may attempt to free that memory michael@0: ** using [sqlite3_free]. michael@0: ** Hence, if this variable is modified directly, either it should be michael@0: ** made NULL or made to point to memory obtained from [sqlite3_malloc] michael@0: ** or else the use of the [data_store_directory pragma] should be avoided. michael@0: */ michael@0: SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; michael@0: michael@0: /* michael@0: ** CAPI3REF: Test For Auto-Commit Mode michael@0: ** KEYWORDS: {autocommit mode} michael@0: ** michael@0: ** ^The sqlite3_get_autocommit() interface returns non-zero or michael@0: ** zero if the given database connection is or is not in autocommit mode, michael@0: ** respectively. ^Autocommit mode is on by default. michael@0: ** ^Autocommit mode is disabled by a [BEGIN] statement. michael@0: ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. michael@0: ** michael@0: ** If certain kinds of errors occur on a statement within a multi-statement michael@0: ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], michael@0: ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the michael@0: ** transaction might be rolled back automatically. The only way to michael@0: ** find out whether SQLite automatically rolled back the transaction after michael@0: ** an error is to use this function. michael@0: ** michael@0: ** If another thread changes the autocommit status of the database michael@0: ** connection while this routine is running, then the return value michael@0: ** is undefined. michael@0: */ michael@0: SQLITE_API int sqlite3_get_autocommit(sqlite3*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Find The Database Handle Of A Prepared Statement michael@0: ** michael@0: ** ^The sqlite3_db_handle interface returns the [database connection] handle michael@0: ** to which a [prepared statement] belongs. ^The [database connection] michael@0: ** returned by sqlite3_db_handle is the same [database connection] michael@0: ** that was the first argument michael@0: ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to michael@0: ** create the statement in the first place. michael@0: */ michael@0: SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Return The Filename For A Database Connection michael@0: ** michael@0: ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename michael@0: ** associated with database N of connection D. ^The main database file michael@0: ** has the name "main". If there is no attached database N on the database michael@0: ** connection D, or if database N is a temporary or in-memory database, then michael@0: ** a NULL pointer is returned. michael@0: ** michael@0: ** ^The filename returned by this function is the output of the michael@0: ** xFullPathname method of the [VFS]. ^In other words, the filename michael@0: ** will be an absolute pathname, even if the filename used michael@0: ** to open the database originally was a URI or relative pathname. michael@0: */ michael@0: SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); michael@0: michael@0: /* michael@0: ** CAPI3REF: Determine if a database is read-only michael@0: ** michael@0: ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N michael@0: ** of connection D is read-only, 0 if it is read/write, or -1 if N is not michael@0: ** the name of a database on connection D. michael@0: */ michael@0: SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); michael@0: michael@0: /* michael@0: ** CAPI3REF: Find the next prepared statement michael@0: ** michael@0: ** ^This interface returns a pointer to the next [prepared statement] after michael@0: ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL michael@0: ** then this interface returns a pointer to the first prepared statement michael@0: ** associated with the database connection pDb. ^If no prepared statement michael@0: ** satisfies the conditions of this routine, it returns NULL. michael@0: ** michael@0: ** The [database connection] pointer D in a call to michael@0: ** [sqlite3_next_stmt(D,S)] must refer to an open database michael@0: ** connection and in particular must not be a NULL pointer. michael@0: */ michael@0: SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); michael@0: michael@0: /* michael@0: ** CAPI3REF: Commit And Rollback Notification Callbacks michael@0: ** michael@0: ** ^The sqlite3_commit_hook() interface registers a callback michael@0: ** function to be invoked whenever a transaction is [COMMIT | committed]. michael@0: ** ^Any callback set by a previous call to sqlite3_commit_hook() michael@0: ** for the same database connection is overridden. michael@0: ** ^The sqlite3_rollback_hook() interface registers a callback michael@0: ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. michael@0: ** ^Any callback set by a previous call to sqlite3_rollback_hook() michael@0: ** for the same database connection is overridden. michael@0: ** ^The pArg argument is passed through to the callback. michael@0: ** ^If the callback on a commit hook function returns non-zero, michael@0: ** then the commit is converted into a rollback. michael@0: ** michael@0: ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions michael@0: ** return the P argument from the previous call of the same function michael@0: ** on the same [database connection] D, or NULL for michael@0: ** the first call for each function on D. michael@0: ** michael@0: ** The commit and rollback hook callbacks are not reentrant. michael@0: ** The callback implementation must not do anything that will modify michael@0: ** the database connection that invoked the callback. Any actions michael@0: ** to modify the database connection must be deferred until after the michael@0: ** completion of the [sqlite3_step()] call that triggered the commit michael@0: ** or rollback hook in the first place. michael@0: ** Note that running any other SQL statements, including SELECT statements, michael@0: ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify michael@0: ** the database connections for the meaning of "modify" in this paragraph. michael@0: ** michael@0: ** ^Registering a NULL function disables the callback. michael@0: ** michael@0: ** ^When the commit hook callback routine returns zero, the [COMMIT] michael@0: ** operation is allowed to continue normally. ^If the commit hook michael@0: ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. michael@0: ** ^The rollback hook is invoked on a rollback that results from a commit michael@0: ** hook returning non-zero, just as it would be with any other rollback. michael@0: ** michael@0: ** ^For the purposes of this API, a transaction is said to have been michael@0: ** rolled back if an explicit "ROLLBACK" statement is executed, or michael@0: ** an error or constraint causes an implicit rollback to occur. michael@0: ** ^The rollback callback is not invoked if a transaction is michael@0: ** automatically rolled back because the database connection is closed. michael@0: ** michael@0: ** See also the [sqlite3_update_hook()] interface. michael@0: */ michael@0: SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); michael@0: SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Data Change Notification Callbacks michael@0: ** michael@0: ** ^The sqlite3_update_hook() interface registers a callback function michael@0: ** with the [database connection] identified by the first argument michael@0: ** to be invoked whenever a row is updated, inserted or deleted. michael@0: ** ^Any callback set by a previous call to this function michael@0: ** for the same database connection is overridden. michael@0: ** michael@0: ** ^The second argument is a pointer to the function to invoke when a michael@0: ** row is updated, inserted or deleted. michael@0: ** ^The first argument to the callback is a copy of the third argument michael@0: ** to sqlite3_update_hook(). michael@0: ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], michael@0: ** or [SQLITE_UPDATE], depending on the operation that caused the callback michael@0: ** to be invoked. michael@0: ** ^The third and fourth arguments to the callback contain pointers to the michael@0: ** database and table name containing the affected row. michael@0: ** ^The final callback parameter is the [rowid] of the row. michael@0: ** ^In the case of an update, this is the [rowid] after the update takes place. michael@0: ** michael@0: ** ^(The update hook is not invoked when internal system tables are michael@0: ** modified (i.e. sqlite_master and sqlite_sequence).)^ michael@0: ** michael@0: ** ^In the current implementation, the update hook michael@0: ** is not invoked when duplication rows are deleted because of an michael@0: ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook michael@0: ** invoked when rows are deleted using the [truncate optimization]. michael@0: ** The exceptions defined in this paragraph might change in a future michael@0: ** release of SQLite. michael@0: ** michael@0: ** The update hook implementation must not do anything that will modify michael@0: ** the database connection that invoked the update hook. Any actions michael@0: ** to modify the database connection must be deferred until after the michael@0: ** completion of the [sqlite3_step()] call that triggered the update hook. michael@0: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their michael@0: ** database connections for the meaning of "modify" in this paragraph. michael@0: ** michael@0: ** ^The sqlite3_update_hook(D,C,P) function michael@0: ** returns the P argument from the previous call michael@0: ** on the same [database connection] D, or NULL for michael@0: ** the first call on D. michael@0: ** michael@0: ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] michael@0: ** interfaces. michael@0: */ michael@0: SQLITE_API void *sqlite3_update_hook( michael@0: sqlite3*, michael@0: void(*)(void *,int ,char const *,char const *,sqlite3_int64), michael@0: void* michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Enable Or Disable Shared Pager Cache michael@0: ** michael@0: ** ^(This routine enables or disables the sharing of the database cache michael@0: ** and schema data structures between [database connection | connections] michael@0: ** to the same database. Sharing is enabled if the argument is true michael@0: ** and disabled if the argument is false.)^ michael@0: ** michael@0: ** ^Cache sharing is enabled and disabled for an entire process. michael@0: ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, michael@0: ** sharing was enabled or disabled for each thread separately. michael@0: ** michael@0: ** ^(The cache sharing mode set by this interface effects all subsequent michael@0: ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. michael@0: ** Existing database connections continue use the sharing mode michael@0: ** that was in effect at the time they were opened.)^ michael@0: ** michael@0: ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled michael@0: ** successfully. An [error code] is returned otherwise.)^ michael@0: ** michael@0: ** ^Shared cache is disabled by default. But this might change in michael@0: ** future releases of SQLite. Applications that care about shared michael@0: ** cache setting should set it explicitly. michael@0: ** michael@0: ** This interface is threadsafe on processors where writing a michael@0: ** 32-bit integer is atomic. michael@0: ** michael@0: ** See Also: [SQLite Shared-Cache Mode] michael@0: */ michael@0: SQLITE_API int sqlite3_enable_shared_cache(int); michael@0: michael@0: /* michael@0: ** CAPI3REF: Attempt To Free Heap Memory michael@0: ** michael@0: ** ^The sqlite3_release_memory() interface attempts to free N bytes michael@0: ** of heap memory by deallocating non-essential memory allocations michael@0: ** held by the database library. Memory used to cache database michael@0: ** pages to improve performance is an example of non-essential memory. michael@0: ** ^sqlite3_release_memory() returns the number of bytes actually freed, michael@0: ** which might be more or less than the amount requested. michael@0: ** ^The sqlite3_release_memory() routine is a no-op returning zero michael@0: ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. michael@0: ** michael@0: ** See also: [sqlite3_db_release_memory()] michael@0: */ michael@0: SQLITE_API int sqlite3_release_memory(int); michael@0: michael@0: /* michael@0: ** CAPI3REF: Free Memory Used By A Database Connection michael@0: ** michael@0: ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap michael@0: ** memory as possible from database connection D. Unlike the michael@0: ** [sqlite3_release_memory()] interface, this interface is effect even michael@0: ** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is michael@0: ** omitted. michael@0: ** michael@0: ** See also: [sqlite3_release_memory()] michael@0: */ michael@0: SQLITE_API int sqlite3_db_release_memory(sqlite3*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Impose A Limit On Heap Size michael@0: ** michael@0: ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the michael@0: ** soft limit on the amount of heap memory that may be allocated by SQLite. michael@0: ** ^SQLite strives to keep heap memory utilization below the soft heap michael@0: ** limit by reducing the number of pages held in the page cache michael@0: ** as heap memory usages approaches the limit. michael@0: ** ^The soft heap limit is "soft" because even though SQLite strives to stay michael@0: ** below the limit, it will exceed the limit rather than generate michael@0: ** an [SQLITE_NOMEM] error. In other words, the soft heap limit michael@0: ** is advisory only. michael@0: ** michael@0: ** ^The return value from sqlite3_soft_heap_limit64() is the size of michael@0: ** the soft heap limit prior to the call, or negative in the case of an michael@0: ** error. ^If the argument N is negative michael@0: ** then no change is made to the soft heap limit. Hence, the current michael@0: ** size of the soft heap limit can be determined by invoking michael@0: ** sqlite3_soft_heap_limit64() with a negative argument. michael@0: ** michael@0: ** ^If the argument N is zero then the soft heap limit is disabled. michael@0: ** michael@0: ** ^(The soft heap limit is not enforced in the current implementation michael@0: ** if one or more of following conditions are true: michael@0: ** michael@0: ** )^ michael@0: ** michael@0: ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced michael@0: ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] michael@0: ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], michael@0: ** the soft heap limit is enforced on every memory allocation. Without michael@0: ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced michael@0: ** when memory is allocated by the page cache. Testing suggests that because michael@0: ** the page cache is the predominate memory user in SQLite, most michael@0: ** applications will achieve adequate soft heap limit enforcement without michael@0: ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. michael@0: ** michael@0: ** The circumstances under which SQLite will enforce the soft heap limit may michael@0: ** changes in future releases of SQLite. michael@0: */ michael@0: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); michael@0: michael@0: /* michael@0: ** CAPI3REF: Deprecated Soft Heap Limit Interface michael@0: ** DEPRECATED michael@0: ** michael@0: ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] michael@0: ** interface. This routine is provided for historical compatibility michael@0: ** only. All new applications should use the michael@0: ** [sqlite3_soft_heap_limit64()] interface rather than this one. michael@0: */ michael@0: SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Extract Metadata About A Column Of A Table michael@0: ** michael@0: ** ^This routine returns metadata about a specific column of a specific michael@0: ** database table accessible using the [database connection] handle michael@0: ** passed as the first function argument. michael@0: ** michael@0: ** ^The column is identified by the second, third and fourth parameters to michael@0: ** this function. ^The second parameter is either the name of the database michael@0: ** (i.e. "main", "temp", or an attached database) containing the specified michael@0: ** table or NULL. ^If it is NULL, then all attached databases are searched michael@0: ** for the table using the same algorithm used by the database engine to michael@0: ** resolve unqualified table references. michael@0: ** michael@0: ** ^The third and fourth parameters to this function are the table and column michael@0: ** name of the desired column, respectively. Neither of these parameters michael@0: ** may be NULL. michael@0: ** michael@0: ** ^Metadata is returned by writing to the memory locations passed as the 5th michael@0: ** and subsequent parameters to this function. ^Any of these arguments may be michael@0: ** NULL, in which case the corresponding element of metadata is omitted. michael@0: ** michael@0: ** ^(
michael@0: ** michael@0: **
Parameter Output
Type 		Description michael@0: ** michael@0: **
5th const char* Data type michael@0: **
6th const char* Name of default collation sequence michael@0: **
7th int True if column has a NOT NULL constraint michael@0: **
8th int True if column is part of the PRIMARY KEY michael@0: **
9th int True if column is [AUTOINCREMENT] michael@0: **
michael@0: **
)^ michael@0: ** michael@0: ** ^The memory pointed to by the character pointers returned for the michael@0: ** declaration type and collation sequence is valid only until the next michael@0: ** call to any SQLite API function. michael@0: ** michael@0: ** ^If the specified table is actually a view, an [error code] is returned. michael@0: ** michael@0: ** ^If the specified column is "rowid", "oid" or "_rowid_" and an michael@0: ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output michael@0: ** parameters are set for the explicitly declared column. ^(If there is no michael@0: ** explicitly declared [INTEGER PRIMARY KEY] column, then the output michael@0: ** parameters are set as follows: michael@0: ** michael@0: ** 
michael@0: **     data type: "INTEGER"
michael@0: **     collation sequence: "BINARY"
michael@0: **     not null: 0
michael@0: **     primary key: 1
michael@0: **     auto increment: 0
michael@0: **
)^ michael@0: ** michael@0: ** ^(This function may load one or more schemas from database files. If an michael@0: ** error occurs during this process, or if the requested table or column michael@0: ** cannot be found, an [error code] is returned and an error message left michael@0: ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ michael@0: ** michael@0: ** ^This API is only available if the library was compiled with the michael@0: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. michael@0: */ michael@0: SQLITE_API int sqlite3_table_column_metadata( michael@0: sqlite3 *db, /* Connection handle */ michael@0: const char *zDbName, /* Database name or NULL */ michael@0: const char *zTableName, /* Table name */ michael@0: const char *zColumnName, /* Column name */ michael@0: char const **pzDataType, /* OUTPUT: Declared data type */ michael@0: char const **pzCollSeq, /* OUTPUT: Collation sequence name */ michael@0: int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ michael@0: int *pPrimaryKey, /* OUTPUT: True if column part of PK */ michael@0: int *pAutoinc /* OUTPUT: True if column is auto-increment */ michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Load An Extension michael@0: ** michael@0: ** ^This interface loads an SQLite extension library from the named file. michael@0: ** michael@0: ** ^The sqlite3_load_extension() interface attempts to load an michael@0: ** SQLite extension library contained in the file zFile. michael@0: ** michael@0: ** ^The entry point is zProc. michael@0: ** ^zProc may be 0, in which case the name of the entry point michael@0: ** defaults to "sqlite3_extension_init". michael@0: ** ^The sqlite3_load_extension() interface returns michael@0: ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. michael@0: ** ^If an error occurs and pzErrMsg is not 0, then the michael@0: ** [sqlite3_load_extension()] interface shall attempt to michael@0: ** fill *pzErrMsg with error message text stored in memory michael@0: ** obtained from [sqlite3_malloc()]. The calling function michael@0: ** should free this memory by calling [sqlite3_free()]. michael@0: ** michael@0: ** ^Extension loading must be enabled using michael@0: ** [sqlite3_enable_load_extension()] prior to calling this API, michael@0: ** otherwise an error will be returned. michael@0: ** michael@0: ** See also the [load_extension() SQL function]. michael@0: */ michael@0: SQLITE_API int sqlite3_load_extension( michael@0: sqlite3 *db, /* Load the extension into this database connection */ michael@0: const char *zFile, /* Name of the shared library containing extension */ michael@0: const char *zProc, /* Entry point. Derived from zFile if 0 */ michael@0: char **pzErrMsg /* Put error message here if not 0 */ michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Enable Or Disable Extension Loading michael@0: ** michael@0: ** ^So as not to open security holes in older applications that are michael@0: ** unprepared to deal with extension loading, and as a means of disabling michael@0: ** extension loading while evaluating user-entered SQL, the following API michael@0: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. michael@0: ** michael@0: ** ^Extension loading is off by default. See ticket #1863. michael@0: ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 michael@0: ** to turn extension loading on and call it with onoff==0 to turn michael@0: ** it back off again. michael@0: */ michael@0: SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); michael@0: michael@0: /* michael@0: ** CAPI3REF: Automatically Load Statically Linked Extensions michael@0: ** michael@0: ** ^This interface causes the xEntryPoint() function to be invoked for michael@0: ** each new [database connection] that is created. The idea here is that michael@0: ** xEntryPoint() is the entry point for a statically linked SQLite extension michael@0: ** that is to be automatically loaded into all new database connections. michael@0: ** michael@0: ** ^(Even though the function prototype shows that xEntryPoint() takes michael@0: ** no arguments and returns void, SQLite invokes xEntryPoint() with three michael@0: ** arguments and expects and integer result as if the signature of the michael@0: ** entry point where as follows: michael@0: ** michael@0: ** 
michael@0: **    int xEntryPoint(
michael@0: **      sqlite3 *db,
michael@0: **      const char **pzErrMsg,
michael@0: **      const struct sqlite3_api_routines *pThunk
michael@0: **    );
michael@0: **
)^ michael@0: ** michael@0: ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg michael@0: ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) michael@0: ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg michael@0: ** is NULL before calling the xEntryPoint(). ^SQLite will invoke michael@0: ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any michael@0: ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], michael@0: ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. michael@0: ** michael@0: ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already michael@0: ** on the list of automatic extensions is a harmless no-op. ^No entry point michael@0: ** will be called more than once for each database connection that is opened. michael@0: ** michael@0: ** See also: [sqlite3_reset_auto_extension()]. michael@0: */ michael@0: SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); michael@0: michael@0: /* michael@0: ** CAPI3REF: Reset Automatic Extension Loading michael@0: ** michael@0: ** ^This interface disables all automatic extensions previously michael@0: ** registered using [sqlite3_auto_extension()]. michael@0: */ michael@0: SQLITE_API void sqlite3_reset_auto_extension(void); michael@0: michael@0: /* michael@0: ** The interface to the virtual-table mechanism is currently considered michael@0: ** to be experimental. The interface might change in incompatible ways. michael@0: ** If this is a problem for you, do not use the interface at this time. michael@0: ** michael@0: ** When the virtual-table mechanism stabilizes, we will declare the michael@0: ** interface fixed, support it indefinitely, and remove this comment. michael@0: */ michael@0: michael@0: /* michael@0: ** Structures used by the virtual table interface michael@0: */ michael@0: typedef struct sqlite3_vtab sqlite3_vtab; michael@0: typedef struct sqlite3_index_info sqlite3_index_info; michael@0: typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; michael@0: typedef struct sqlite3_module sqlite3_module; michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual Table Object michael@0: ** KEYWORDS: sqlite3_module {virtual table module} michael@0: ** michael@0: ** This structure, sometimes called a "virtual table module", michael@0: ** defines the implementation of a [virtual tables]. michael@0: ** This structure consists mostly of methods for the module. michael@0: ** michael@0: ** ^A virtual table module is created by filling in a persistent michael@0: ** instance of this structure and passing a pointer to that instance michael@0: ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. michael@0: ** ^The registration remains valid until it is replaced by a different michael@0: ** module or until the [database connection] closes. The content michael@0: ** of this structure must not change while it is registered with michael@0: ** any database connection. michael@0: */ michael@0: struct sqlite3_module { michael@0: int iVersion; michael@0: int (*xCreate)(sqlite3*, void *pAux, michael@0: int argc, const char *const*argv, michael@0: sqlite3_vtab **ppVTab, char**); michael@0: int (*xConnect)(sqlite3*, void *pAux, michael@0: int argc, const char *const*argv, michael@0: sqlite3_vtab **ppVTab, char**); michael@0: int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); michael@0: int (*xDisconnect)(sqlite3_vtab *pVTab); michael@0: int (*xDestroy)(sqlite3_vtab *pVTab); michael@0: int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); michael@0: int (*xClose)(sqlite3_vtab_cursor*); michael@0: int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, michael@0: int argc, sqlite3_value **argv); michael@0: int (*xNext)(sqlite3_vtab_cursor*); michael@0: int (*xEof)(sqlite3_vtab_cursor*); michael@0: int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); michael@0: int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); michael@0: int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); michael@0: int (*xBegin)(sqlite3_vtab *pVTab); michael@0: int (*xSync)(sqlite3_vtab *pVTab); michael@0: int (*xCommit)(sqlite3_vtab *pVTab); michael@0: int (*xRollback)(sqlite3_vtab *pVTab); michael@0: int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, michael@0: void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), michael@0: void **ppArg); michael@0: int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); michael@0: /* The methods above are in version 1 of the sqlite_module object. Those michael@0: ** below are for version 2 and greater. */ michael@0: int (*xSavepoint)(sqlite3_vtab *pVTab, int); michael@0: int (*xRelease)(sqlite3_vtab *pVTab, int); michael@0: int (*xRollbackTo)(sqlite3_vtab *pVTab, int); michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual Table Indexing Information michael@0: ** KEYWORDS: sqlite3_index_info michael@0: ** michael@0: ** The sqlite3_index_info structure and its substructures is used as part michael@0: ** of the [virtual table] interface to michael@0: ** pass information into and receive the reply from the [xBestIndex] michael@0: ** method of a [virtual table module]. The fields under **Inputs** are the michael@0: ** inputs to xBestIndex and are read-only. xBestIndex inserts its michael@0: ** results into the **Outputs** fields. michael@0: ** michael@0: ** ^(The aConstraint[] array records WHERE clause constraints of the form: michael@0: ** michael@0: **
column OP expr
michael@0: ** michael@0: ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is michael@0: ** stored in aConstraint[].op using one of the michael@0: ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ michael@0: ** ^(The index of the column is stored in michael@0: ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the michael@0: ** expr on the right-hand side can be evaluated (and thus the constraint michael@0: ** is usable) and false if it cannot.)^ michael@0: ** michael@0: ** ^The optimizer automatically inverts terms of the form "expr OP column" michael@0: ** and makes other simplifications to the WHERE clause in an attempt to michael@0: ** get as many WHERE clause terms into the form shown above as possible. michael@0: ** ^The aConstraint[] array only reports WHERE clause terms that are michael@0: ** relevant to the particular virtual table being queried. michael@0: ** michael@0: ** ^Information about the ORDER BY clause is stored in aOrderBy[]. michael@0: ** ^Each term of aOrderBy records a column of the ORDER BY clause. michael@0: ** michael@0: ** The [xBestIndex] method must fill aConstraintUsage[] with information michael@0: ** about what parameters to pass to xFilter. ^If argvIndex>0 then michael@0: ** the right-hand side of the corresponding aConstraint[] is evaluated michael@0: ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit michael@0: ** is true, then the constraint is assumed to be fully handled by the michael@0: ** virtual table and is not checked again by SQLite.)^ michael@0: ** michael@0: ** ^The idxNum and idxPtr values are recorded and passed into the michael@0: ** [xFilter] method. michael@0: ** ^[sqlite3_free()] is used to free idxPtr if and only if michael@0: ** needToFreeIdxPtr is true. michael@0: ** michael@0: ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in michael@0: ** the correct order to satisfy the ORDER BY clause so that no separate michael@0: ** sorting step is required. michael@0: ** michael@0: ** ^The estimatedCost value is an estimate of the cost of doing the michael@0: ** particular lookup. A full scan of a table with N entries should have michael@0: ** a cost of N. A binary search of a table of N entries should have a michael@0: ** cost of approximately log(N). michael@0: */ michael@0: struct sqlite3_index_info { michael@0: /* Inputs */ michael@0: int nConstraint; /* Number of entries in aConstraint */ michael@0: struct sqlite3_index_constraint { michael@0: int iColumn; /* Column on left-hand side of constraint */ michael@0: unsigned char op; /* Constraint operator */ michael@0: unsigned char usable; /* True if this constraint is usable */ michael@0: int iTermOffset; /* Used internally - xBestIndex should ignore */ michael@0: } *aConstraint; /* Table of WHERE clause constraints */ michael@0: int nOrderBy; /* Number of terms in the ORDER BY clause */ michael@0: struct sqlite3_index_orderby { michael@0: int iColumn; /* Column number */ michael@0: unsigned char desc; /* True for DESC. False for ASC. */ michael@0: } *aOrderBy; /* The ORDER BY clause */ michael@0: /* Outputs */ michael@0: struct sqlite3_index_constraint_usage { michael@0: int argvIndex; /* if >0, constraint is part of argv to xFilter */ michael@0: unsigned char omit; /* Do not code a test for this constraint */ michael@0: } *aConstraintUsage; michael@0: int idxNum; /* Number used to identify the index */ michael@0: char *idxStr; /* String, possibly obtained from sqlite3_malloc */ michael@0: int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ michael@0: int orderByConsumed; /* True if output is already ordered */ michael@0: double estimatedCost; /* Estimated cost of using this index */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual Table Constraint Operator Codes michael@0: ** michael@0: ** These macros defined the allowed values for the michael@0: ** [sqlite3_index_info].aConstraint[].op field. Each value represents michael@0: ** an operator that is part of a constraint term in the wHERE clause of michael@0: ** a query that uses a [virtual table]. michael@0: */ michael@0: #define SQLITE_INDEX_CONSTRAINT_EQ 2 michael@0: #define SQLITE_INDEX_CONSTRAINT_GT 4 michael@0: #define SQLITE_INDEX_CONSTRAINT_LE 8 michael@0: #define SQLITE_INDEX_CONSTRAINT_LT 16 michael@0: #define SQLITE_INDEX_CONSTRAINT_GE 32 michael@0: #define SQLITE_INDEX_CONSTRAINT_MATCH 64 michael@0: michael@0: /* michael@0: ** CAPI3REF: Register A Virtual Table Implementation michael@0: ** michael@0: ** ^These routines are used to register a new [virtual table module] name. michael@0: ** ^Module names must be registered before michael@0: ** creating a new [virtual table] using the module and before using a michael@0: ** preexisting [virtual table] for the module. michael@0: ** michael@0: ** ^The module name is registered on the [database connection] specified michael@0: ** by the first parameter. ^The name of the module is given by the michael@0: ** second parameter. ^The third parameter is a pointer to michael@0: ** the implementation of the [virtual table module]. ^The fourth michael@0: ** parameter is an arbitrary client data pointer that is passed through michael@0: ** into the [xCreate] and [xConnect] methods of the virtual table module michael@0: ** when a new virtual table is be being created or reinitialized. michael@0: ** michael@0: ** ^The sqlite3_create_module_v2() interface has a fifth parameter which michael@0: ** is a pointer to a destructor for the pClientData. ^SQLite will michael@0: ** invoke the destructor function (if it is not NULL) when SQLite michael@0: ** no longer needs the pClientData pointer. ^The destructor will also michael@0: ** be invoked if the call to sqlite3_create_module_v2() fails. michael@0: ** ^The sqlite3_create_module() michael@0: ** interface is equivalent to sqlite3_create_module_v2() with a NULL michael@0: ** destructor. michael@0: */ michael@0: SQLITE_API int sqlite3_create_module( michael@0: sqlite3 *db, /* SQLite connection to register module with */ michael@0: const char *zName, /* Name of the module */ michael@0: const sqlite3_module *p, /* Methods for the module */ michael@0: void *pClientData /* Client data for xCreate/xConnect */ michael@0: ); michael@0: SQLITE_API int sqlite3_create_module_v2( michael@0: sqlite3 *db, /* SQLite connection to register module with */ michael@0: const char *zName, /* Name of the module */ michael@0: const sqlite3_module *p, /* Methods for the module */ michael@0: void *pClientData, /* Client data for xCreate/xConnect */ michael@0: void(*xDestroy)(void*) /* Module destructor function */ michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual Table Instance Object michael@0: ** KEYWORDS: sqlite3_vtab michael@0: ** michael@0: ** Every [virtual table module] implementation uses a subclass michael@0: ** of this object to describe a particular instance michael@0: ** of the [virtual table]. Each subclass will michael@0: ** be tailored to the specific needs of the module implementation. michael@0: ** The purpose of this superclass is to define certain fields that are michael@0: ** common to all module implementations. michael@0: ** michael@0: ** ^Virtual tables methods can set an error message by assigning a michael@0: ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should michael@0: ** take care that any prior string is freed by a call to [sqlite3_free()] michael@0: ** prior to assigning a new string to zErrMsg. ^After the error message michael@0: ** is delivered up to the client application, the string will be automatically michael@0: ** freed by sqlite3_free() and the zErrMsg field will be zeroed. michael@0: */ michael@0: struct sqlite3_vtab { michael@0: const sqlite3_module *pModule; /* The module for this virtual table */ michael@0: int nRef; /* NO LONGER USED */ michael@0: char *zErrMsg; /* Error message from sqlite3_mprintf() */ michael@0: /* Virtual table implementations will typically add additional fields */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual Table Cursor Object michael@0: ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} michael@0: ** michael@0: ** Every [virtual table module] implementation uses a subclass of the michael@0: ** following structure to describe cursors that point into the michael@0: ** [virtual table] and are used michael@0: ** to loop through the virtual table. Cursors are created using the michael@0: ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed michael@0: ** by the [sqlite3_module.xClose | xClose] method. Cursors are used michael@0: ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods michael@0: ** of the module. Each module implementation will define michael@0: ** the content of a cursor structure to suit its own needs. michael@0: ** michael@0: ** This superclass exists in order to define fields of the cursor that michael@0: ** are common to all implementations. michael@0: */ michael@0: struct sqlite3_vtab_cursor { michael@0: sqlite3_vtab *pVtab; /* Virtual table of this cursor */ michael@0: /* Virtual table implementations will typically add additional fields */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Declare The Schema Of A Virtual Table michael@0: ** michael@0: ** ^The [xCreate] and [xConnect] methods of a michael@0: ** [virtual table module] call this interface michael@0: ** to declare the format (the names and datatypes of the columns) of michael@0: ** the virtual tables they implement. michael@0: */ michael@0: SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); michael@0: michael@0: /* michael@0: ** CAPI3REF: Overload A Function For A Virtual Table michael@0: ** michael@0: ** ^(Virtual tables can provide alternative implementations of functions michael@0: ** using the [xFindFunction] method of the [virtual table module]. michael@0: ** But global versions of those functions michael@0: ** must exist in order to be overloaded.)^ michael@0: ** michael@0: ** ^(This API makes sure a global version of a function with a particular michael@0: ** name and number of parameters exists. If no such function exists michael@0: ** before this API is called, a new function is created.)^ ^The implementation michael@0: ** of the new function always causes an exception to be thrown. So michael@0: ** the new function is not good for anything by itself. Its only michael@0: ** purpose is to be a placeholder function that can be overloaded michael@0: ** by a [virtual table]. michael@0: */ michael@0: SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); michael@0: michael@0: /* michael@0: ** The interface to the virtual-table mechanism defined above (back up michael@0: ** to a comment remarkably similar to this one) is currently considered michael@0: ** to be experimental. The interface might change in incompatible ways. michael@0: ** If this is a problem for you, do not use the interface at this time. michael@0: ** michael@0: ** When the virtual-table mechanism stabilizes, we will declare the michael@0: ** interface fixed, support it indefinitely, and remove this comment. michael@0: */ michael@0: michael@0: /* michael@0: ** CAPI3REF: A Handle To An Open BLOB michael@0: ** KEYWORDS: {BLOB handle} {BLOB handles} michael@0: ** michael@0: ** An instance of this object represents an open BLOB on which michael@0: ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. michael@0: ** ^Objects of this type are created by [sqlite3_blob_open()] michael@0: ** and destroyed by [sqlite3_blob_close()]. michael@0: ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces michael@0: ** can be used to read or write small subsections of the BLOB. michael@0: ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. michael@0: */ michael@0: typedef struct sqlite3_blob sqlite3_blob; michael@0: michael@0: /* michael@0: ** CAPI3REF: Open A BLOB For Incremental I/O michael@0: ** michael@0: ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located michael@0: ** in row iRow, column zColumn, table zTable in database zDb; michael@0: ** in other words, the same BLOB that would be selected by: michael@0: ** michael@0: ** 
michael@0: **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
michael@0: **
)^ michael@0: ** michael@0: ** ^If the flags parameter is non-zero, then the BLOB is opened for read michael@0: ** and write access. ^If it is zero, the BLOB is opened for read access. michael@0: ** ^It is not possible to open a column that is part of an index or primary michael@0: ** key for writing. ^If [foreign key constraints] are enabled, it is michael@0: ** not possible to open a column that is part of a [child key] for writing. michael@0: ** michael@0: ** ^Note that the database name is not the filename that contains michael@0: ** the database but rather the symbolic name of the database that michael@0: ** appears after the AS keyword when the database is connected using [ATTACH]. michael@0: ** ^For the main database file, the database name is "main". michael@0: ** ^For TEMP tables, the database name is "temp". michael@0: ** michael@0: ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written michael@0: ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set michael@0: ** to be a null pointer.)^ michael@0: ** ^This function sets the [database connection] error code and message michael@0: ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related michael@0: ** functions. ^Note that the *ppBlob variable is always initialized in a michael@0: ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob michael@0: ** regardless of the success or failure of this routine. michael@0: ** michael@0: ** ^(If the row that a BLOB handle points to is modified by an michael@0: ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects michael@0: ** then the BLOB handle is marked as "expired". michael@0: ** This is true if any column of the row is changed, even a column michael@0: ** other than the one the BLOB handle is open on.)^ michael@0: ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for michael@0: ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. michael@0: ** ^(Changes written into a BLOB prior to the BLOB expiring are not michael@0: ** rolled back by the expiration of the BLOB. Such changes will eventually michael@0: ** commit if the transaction continues to completion.)^ michael@0: ** michael@0: ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of michael@0: ** the opened blob. ^The size of a blob may not be changed by this michael@0: ** interface. Use the [UPDATE] SQL command to change the size of a michael@0: ** blob. michael@0: ** michael@0: ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces michael@0: ** and the built-in [zeroblob] SQL function can be used, if desired, michael@0: ** to create an empty, zero-filled blob in which to read or write using michael@0: ** this interface. michael@0: ** michael@0: ** To avoid a resource leak, every open [BLOB handle] should eventually michael@0: ** be released by a call to [sqlite3_blob_close()]. michael@0: */ michael@0: SQLITE_API int sqlite3_blob_open( michael@0: sqlite3*, michael@0: const char *zDb, michael@0: const char *zTable, michael@0: const char *zColumn, michael@0: sqlite3_int64 iRow, michael@0: int flags, michael@0: sqlite3_blob **ppBlob michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Move a BLOB Handle to a New Row michael@0: ** michael@0: ** ^This function is used to move an existing blob handle so that it points michael@0: ** to a different row of the same database table. ^The new row is identified michael@0: ** by the rowid value passed as the second argument. Only the row can be michael@0: ** changed. ^The database, table and column on which the blob handle is open michael@0: ** remain the same. Moving an existing blob handle to a new row can be michael@0: ** faster than closing the existing handle and opening a new one. michael@0: ** michael@0: ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - michael@0: ** it must exist and there must be either a blob or text value stored in michael@0: ** the nominated column.)^ ^If the new row is not present in the table, or if michael@0: ** it does not contain a blob or text value, or if another error occurs, an michael@0: ** SQLite error code is returned and the blob handle is considered aborted. michael@0: ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or michael@0: ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return michael@0: ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle michael@0: ** always returns zero. michael@0: ** michael@0: ** ^This function sets the database handle error code and message. michael@0: */ michael@0: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); michael@0: michael@0: /* michael@0: ** CAPI3REF: Close A BLOB Handle michael@0: ** michael@0: ** ^Closes an open [BLOB handle]. michael@0: ** michael@0: ** ^Closing a BLOB shall cause the current transaction to commit michael@0: ** if there are no other BLOBs, no pending prepared statements, and the michael@0: ** database connection is in [autocommit mode]. michael@0: ** ^If any writes were made to the BLOB, they might be held in cache michael@0: ** until the close operation if they will fit. michael@0: ** michael@0: ** ^(Closing the BLOB often forces the changes michael@0: ** out to disk and so if any I/O errors occur, they will likely occur michael@0: ** at the time when the BLOB is closed. Any errors that occur during michael@0: ** closing are reported as a non-zero return value.)^ michael@0: ** michael@0: ** ^(The BLOB is closed unconditionally. Even if this routine returns michael@0: ** an error code, the BLOB is still closed.)^ michael@0: ** michael@0: ** ^Calling this routine with a null pointer (such as would be returned michael@0: ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. michael@0: */ michael@0: SQLITE_API int sqlite3_blob_close(sqlite3_blob *); michael@0: michael@0: /* michael@0: ** CAPI3REF: Return The Size Of An Open BLOB michael@0: ** michael@0: ** ^Returns the size in bytes of the BLOB accessible via the michael@0: ** successfully opened [BLOB handle] in its only argument. ^The michael@0: ** incremental blob I/O routines can only read or overwriting existing michael@0: ** blob content; they cannot change the size of a blob. michael@0: ** michael@0: ** This routine only works on a [BLOB handle] which has been created michael@0: ** by a prior successful call to [sqlite3_blob_open()] and which has not michael@0: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in michael@0: ** to this routine results in undefined and probably undesirable behavior. michael@0: */ michael@0: SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); michael@0: michael@0: /* michael@0: ** CAPI3REF: Read Data From A BLOB Incrementally michael@0: ** michael@0: ** ^(This function is used to read data from an open [BLOB handle] into a michael@0: ** caller-supplied buffer. N bytes of data are copied into buffer Z michael@0: ** from the open BLOB, starting at offset iOffset.)^ michael@0: ** michael@0: ** ^If offset iOffset is less than N bytes from the end of the BLOB, michael@0: ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is michael@0: ** less than zero, [SQLITE_ERROR] is returned and no data is read. michael@0: ** ^The size of the blob (and hence the maximum value of N+iOffset) michael@0: ** can be determined using the [sqlite3_blob_bytes()] interface. michael@0: ** michael@0: ** ^An attempt to read from an expired [BLOB handle] fails with an michael@0: ** error code of [SQLITE_ABORT]. michael@0: ** michael@0: ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. michael@0: ** Otherwise, an [error code] or an [extended error code] is returned.)^ michael@0: ** michael@0: ** This routine only works on a [BLOB handle] which has been created michael@0: ** by a prior successful call to [sqlite3_blob_open()] and which has not michael@0: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in michael@0: ** to this routine results in undefined and probably undesirable behavior. michael@0: ** michael@0: ** See also: [sqlite3_blob_write()]. michael@0: */ michael@0: SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); michael@0: michael@0: /* michael@0: ** CAPI3REF: Write Data Into A BLOB Incrementally michael@0: ** michael@0: ** ^This function is used to write data into an open [BLOB handle] from a michael@0: ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z michael@0: ** into the open BLOB, starting at offset iOffset. michael@0: ** michael@0: ** ^If the [BLOB handle] passed as the first argument was not opened for michael@0: ** writing (the flags parameter to [sqlite3_blob_open()] was zero), michael@0: ** this function returns [SQLITE_READONLY]. michael@0: ** michael@0: ** ^This function may only modify the contents of the BLOB; it is michael@0: ** not possible to increase the size of a BLOB using this API. michael@0: ** ^If offset iOffset is less than N bytes from the end of the BLOB, michael@0: ** [SQLITE_ERROR] is returned and no data is written. ^If N is michael@0: ** less than zero [SQLITE_ERROR] is returned and no data is written. michael@0: ** The size of the BLOB (and hence the maximum value of N+iOffset) michael@0: ** can be determined using the [sqlite3_blob_bytes()] interface. michael@0: ** michael@0: ** ^An attempt to write to an expired [BLOB handle] fails with an michael@0: ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred michael@0: ** before the [BLOB handle] expired are not rolled back by the michael@0: ** expiration of the handle, though of course those changes might michael@0: ** have been overwritten by the statement that expired the BLOB handle michael@0: ** or by other independent statements. michael@0: ** michael@0: ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. michael@0: ** Otherwise, an [error code] or an [extended error code] is returned.)^ michael@0: ** michael@0: ** This routine only works on a [BLOB handle] which has been created michael@0: ** by a prior successful call to [sqlite3_blob_open()] and which has not michael@0: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in michael@0: ** to this routine results in undefined and probably undesirable behavior. michael@0: ** michael@0: ** See also: [sqlite3_blob_read()]. michael@0: */ michael@0: SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual File System Objects michael@0: ** michael@0: ** A virtual filesystem (VFS) is an [sqlite3_vfs] object michael@0: ** that SQLite uses to interact michael@0: ** with the underlying operating system. Most SQLite builds come with a michael@0: ** single default VFS that is appropriate for the host computer. michael@0: ** New VFSes can be registered and existing VFSes can be unregistered. michael@0: ** The following interfaces are provided. michael@0: ** michael@0: ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. michael@0: ** ^Names are case sensitive. michael@0: ** ^Names are zero-terminated UTF-8 strings. michael@0: ** ^If there is no match, a NULL pointer is returned. michael@0: ** ^If zVfsName is NULL then the default VFS is returned. michael@0: ** michael@0: ** ^New VFSes are registered with sqlite3_vfs_register(). michael@0: ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. michael@0: ** ^The same VFS can be registered multiple times without injury. michael@0: ** ^To make an existing VFS into the default VFS, register it again michael@0: ** with the makeDflt flag set. If two different VFSes with the michael@0: ** same name are registered, the behavior is undefined. If a michael@0: ** VFS is registered with a name that is NULL or an empty string, michael@0: ** then the behavior is undefined. michael@0: ** michael@0: ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. michael@0: ** ^(If the default VFS is unregistered, another VFS is chosen as michael@0: ** the default. The choice for the new VFS is arbitrary.)^ michael@0: */ michael@0: SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); michael@0: SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); michael@0: SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Mutexes michael@0: ** michael@0: ** The SQLite core uses these routines for thread michael@0: ** synchronization. Though they are intended for internal michael@0: ** use by SQLite, code that links against SQLite is michael@0: ** permitted to use any of these routines. michael@0: ** michael@0: ** The SQLite source code contains multiple implementations michael@0: ** of these mutex routines. An appropriate implementation michael@0: ** is selected automatically at compile-time. ^(The following michael@0: ** implementations are available in the SQLite core: michael@0: ** michael@0: ** )^ michael@0: ** michael@0: ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines michael@0: ** that does no real locking and is appropriate for use in michael@0: ** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and michael@0: ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix michael@0: ** and Windows. michael@0: ** michael@0: ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor michael@0: ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex michael@0: ** implementation is included with the library. In this case the michael@0: ** application must supply a custom mutex implementation using the michael@0: ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function michael@0: ** before calling sqlite3_initialize() or any other public sqlite3_ michael@0: ** function that calls sqlite3_initialize().)^ michael@0: ** michael@0: ** ^The sqlite3_mutex_alloc() routine allocates a new michael@0: ** mutex and returns a pointer to it. ^If it returns NULL michael@0: ** that means that a mutex could not be allocated. ^SQLite michael@0: ** will unwind its stack and return an error. ^(The argument michael@0: ** to sqlite3_mutex_alloc() is one of these integer constants: michael@0: ** michael@0: ** )^ michael@0: ** michael@0: ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) michael@0: ** cause sqlite3_mutex_alloc() to create michael@0: ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE michael@0: ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. michael@0: ** The mutex implementation does not need to make a distinction michael@0: ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does michael@0: ** not want to. ^SQLite will only request a recursive mutex in michael@0: ** cases where it really needs one. ^If a faster non-recursive mutex michael@0: ** implementation is available on the host platform, the mutex subsystem michael@0: ** might return such a mutex in response to SQLITE_MUTEX_FAST. michael@0: ** michael@0: ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other michael@0: ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return michael@0: ** a pointer to a static preexisting mutex. ^Six static mutexes are michael@0: ** used by the current version of SQLite. Future versions of SQLite michael@0: ** may add additional static mutexes. Static mutexes are for internal michael@0: ** use by SQLite only. Applications that use SQLite mutexes should michael@0: ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or michael@0: ** SQLITE_MUTEX_RECURSIVE. michael@0: ** michael@0: ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST michael@0: ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() michael@0: ** returns a different mutex on every call. ^But for the static michael@0: ** mutex types, the same mutex is returned on every call that has michael@0: ** the same type number. michael@0: ** michael@0: ** ^The sqlite3_mutex_free() routine deallocates a previously michael@0: ** allocated dynamic mutex. ^SQLite is careful to deallocate every michael@0: ** dynamic mutex that it allocates. The dynamic mutexes must not be in michael@0: ** use when they are deallocated. Attempting to deallocate a static michael@0: ** mutex results in undefined behavior. ^SQLite never deallocates michael@0: ** a static mutex. michael@0: ** michael@0: ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt michael@0: ** to enter a mutex. ^If another thread is already within the mutex, michael@0: ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return michael@0: ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] michael@0: ** upon successful entry. ^(Mutexes created using michael@0: ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. michael@0: ** In such cases the, michael@0: ** mutex must be exited an equal number of times before another thread michael@0: ** can enter.)^ ^(If the same thread tries to enter any other michael@0: ** kind of mutex more than once, the behavior is undefined. michael@0: ** SQLite will never exhibit michael@0: ** such behavior in its own use of mutexes.)^ michael@0: ** michael@0: ** ^(Some systems (for example, Windows 95) do not support the operation michael@0: ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() michael@0: ** will always return SQLITE_BUSY. The SQLite core only ever uses michael@0: ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ michael@0: ** michael@0: ** ^The sqlite3_mutex_leave() routine exits a mutex that was michael@0: ** previously entered by the same thread. ^(The behavior michael@0: ** is undefined if the mutex is not currently entered by the michael@0: ** calling thread or is not currently allocated. SQLite will michael@0: ** never do either.)^ michael@0: ** michael@0: ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or michael@0: ** sqlite3_mutex_leave() is a NULL pointer, then all three routines michael@0: ** behave as no-ops. michael@0: ** michael@0: ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. michael@0: */ michael@0: SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); michael@0: SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); michael@0: SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); michael@0: SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); michael@0: SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Mutex Methods Object michael@0: ** michael@0: ** An instance of this structure defines the low-level routines michael@0: ** used to allocate and use mutexes. michael@0: ** michael@0: ** Usually, the default mutex implementations provided by SQLite are michael@0: ** sufficient, however the user has the option of substituting a custom michael@0: ** implementation for specialized deployments or systems for which SQLite michael@0: ** does not provide a suitable implementation. In this case, the user michael@0: ** creates and populates an instance of this structure to pass michael@0: ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. michael@0: ** Additionally, an instance of this structure can be used as an michael@0: ** output variable when querying the system for the current mutex michael@0: ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. michael@0: ** michael@0: ** ^The xMutexInit method defined by this structure is invoked as michael@0: ** part of system initialization by the sqlite3_initialize() function. michael@0: ** ^The xMutexInit routine is called by SQLite exactly once for each michael@0: ** effective call to [sqlite3_initialize()]. michael@0: ** michael@0: ** ^The xMutexEnd method defined by this structure is invoked as michael@0: ** part of system shutdown by the sqlite3_shutdown() function. The michael@0: ** implementation of this method is expected to release all outstanding michael@0: ** resources obtained by the mutex methods implementation, especially michael@0: ** those obtained by the xMutexInit method. ^The xMutexEnd() michael@0: ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. michael@0: ** michael@0: ** ^(The remaining seven methods defined by this structure (xMutexAlloc, michael@0: ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and michael@0: ** xMutexNotheld) implement the following interfaces (respectively): michael@0: ** michael@0: ** )^ michael@0: ** michael@0: ** The only difference is that the public sqlite3_XXX functions enumerated michael@0: ** above silently ignore any invocations that pass a NULL pointer instead michael@0: ** of a valid mutex handle. The implementations of the methods defined michael@0: ** by this structure are not required to handle this case, the results michael@0: ** of passing a NULL pointer instead of a valid mutex handle are undefined michael@0: ** (i.e. it is acceptable to provide an implementation that segfaults if michael@0: ** it is passed a NULL pointer). michael@0: ** michael@0: ** The xMutexInit() method must be threadsafe. ^It must be harmless to michael@0: ** invoke xMutexInit() multiple times within the same process and without michael@0: ** intervening calls to xMutexEnd(). Second and subsequent calls to michael@0: ** xMutexInit() must be no-ops. michael@0: ** michael@0: ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] michael@0: ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory michael@0: ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite michael@0: ** memory allocation for a fast or recursive mutex. michael@0: ** michael@0: ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is michael@0: ** called, but only if the prior call to xMutexInit returned SQLITE_OK. michael@0: ** If xMutexInit fails in any way, it is expected to clean up after itself michael@0: ** prior to returning. michael@0: */ michael@0: typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; michael@0: struct sqlite3_mutex_methods { michael@0: int (*xMutexInit)(void); michael@0: int (*xMutexEnd)(void); michael@0: sqlite3_mutex *(*xMutexAlloc)(int); michael@0: void (*xMutexFree)(sqlite3_mutex *); michael@0: void (*xMutexEnter)(sqlite3_mutex *); michael@0: int (*xMutexTry)(sqlite3_mutex *); michael@0: void (*xMutexLeave)(sqlite3_mutex *); michael@0: int (*xMutexHeld)(sqlite3_mutex *); michael@0: int (*xMutexNotheld)(sqlite3_mutex *); michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Mutex Verification Routines michael@0: ** michael@0: ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines michael@0: ** are intended for use inside assert() statements. ^The SQLite core michael@0: ** never uses these routines except inside an assert() and applications michael@0: ** are advised to follow the lead of the core. ^The SQLite core only michael@0: ** provides implementations for these routines when it is compiled michael@0: ** with the SQLITE_DEBUG flag. ^External mutex implementations michael@0: ** are only required to provide these routines if SQLITE_DEBUG is michael@0: ** defined and if NDEBUG is not defined. michael@0: ** michael@0: ** ^These routines should return true if the mutex in their argument michael@0: ** is held or not held, respectively, by the calling thread. michael@0: ** michael@0: ** ^The implementation is not required to provide versions of these michael@0: ** routines that actually work. If the implementation does not provide working michael@0: ** versions of these routines, it should at least provide stubs that always michael@0: ** return true so that one does not get spurious assertion failures. michael@0: ** michael@0: ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then michael@0: ** the routine should return 1. This seems counter-intuitive since michael@0: ** clearly the mutex cannot be held if it does not exist. But michael@0: ** the reason the mutex does not exist is because the build is not michael@0: ** using mutexes. And we do not want the assert() containing the michael@0: ** call to sqlite3_mutex_held() to fail, so a non-zero return is michael@0: ** the appropriate thing to do. ^The sqlite3_mutex_notheld() michael@0: ** interface should also return 1 when given a NULL pointer. michael@0: */ michael@0: #ifndef NDEBUG michael@0: SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); michael@0: SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); michael@0: #endif michael@0: michael@0: /* michael@0: ** CAPI3REF: Mutex Types michael@0: ** michael@0: ** The [sqlite3_mutex_alloc()] interface takes a single argument michael@0: ** which is one of these integer constants. michael@0: ** michael@0: ** The set of static mutexes may change from one SQLite release to the michael@0: ** next. Applications that override the built-in mutex logic must be michael@0: ** prepared to accommodate additional static mutexes. michael@0: */ michael@0: #define SQLITE_MUTEX_FAST 0 michael@0: #define SQLITE_MUTEX_RECURSIVE 1 michael@0: #define SQLITE_MUTEX_STATIC_MASTER 2 michael@0: #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ michael@0: #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ michael@0: #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ michael@0: #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ michael@0: #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ michael@0: #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ michael@0: #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ michael@0: michael@0: /* michael@0: ** CAPI3REF: Retrieve the mutex for a database connection michael@0: ** michael@0: ** ^This interface returns a pointer the [sqlite3_mutex] object that michael@0: ** serializes access to the [database connection] given in the argument michael@0: ** when the [threading mode] is Serialized. michael@0: ** ^If the [threading mode] is Single-thread or Multi-thread then this michael@0: ** routine returns a NULL pointer. michael@0: */ michael@0: SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Low-Level Control Of Database Files michael@0: ** michael@0: ** ^The [sqlite3_file_control()] interface makes a direct call to the michael@0: ** xFileControl method for the [sqlite3_io_methods] object associated michael@0: ** with a particular database identified by the second argument. ^The michael@0: ** name of the database is "main" for the main database or "temp" for the michael@0: ** TEMP database, or the name that appears after the AS keyword for michael@0: ** databases that are added using the [ATTACH] SQL command. michael@0: ** ^A NULL pointer can be used in place of "main" to refer to the michael@0: ** main database file. michael@0: ** ^The third and fourth parameters to this routine michael@0: ** are passed directly through to the second and third parameters of michael@0: ** the xFileControl method. ^The return value of the xFileControl michael@0: ** method becomes the return value of this routine. michael@0: ** michael@0: ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes michael@0: ** a pointer to the underlying [sqlite3_file] object to be written into michael@0: ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER michael@0: ** case is a short-circuit path which does not actually invoke the michael@0: ** underlying sqlite3_io_methods.xFileControl method. michael@0: ** michael@0: ** ^If the second parameter (zDbName) does not match the name of any michael@0: ** open database file, then SQLITE_ERROR is returned. ^This error michael@0: ** code is not remembered and will not be recalled by [sqlite3_errcode()] michael@0: ** or [sqlite3_errmsg()]. The underlying xFileControl method might michael@0: ** also return SQLITE_ERROR. There is no way to distinguish between michael@0: ** an incorrect zDbName and an SQLITE_ERROR return from the underlying michael@0: ** xFileControl method. michael@0: ** michael@0: ** See also: [SQLITE_FCNTL_LOCKSTATE] michael@0: */ michael@0: SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); michael@0: michael@0: /* michael@0: ** CAPI3REF: Testing Interface michael@0: ** michael@0: ** ^The sqlite3_test_control() interface is used to read out internal michael@0: ** state of SQLite and to inject faults into SQLite for testing michael@0: ** purposes. ^The first parameter is an operation code that determines michael@0: ** the number, meaning, and operation of all subsequent parameters. michael@0: ** michael@0: ** This interface is not for use by applications. It exists solely michael@0: ** for verifying the correct operation of the SQLite library. Depending michael@0: ** on how the SQLite library is compiled, this interface might not exist. michael@0: ** michael@0: ** The details of the operation codes, their meanings, the parameters michael@0: ** they take, and what they do are all subject to change without notice. michael@0: ** Unlike most of the SQLite API, this function is not guaranteed to michael@0: ** operate consistently from one release to the next. michael@0: */ michael@0: SQLITE_API int sqlite3_test_control(int op, ...); michael@0: michael@0: /* michael@0: ** CAPI3REF: Testing Interface Operation Codes michael@0: ** michael@0: ** These constants are the valid operation code parameters used michael@0: ** as the first argument to [sqlite3_test_control()]. michael@0: ** michael@0: ** These parameters and their meanings are subject to change michael@0: ** without notice. These values are for testing purposes only. michael@0: ** Applications should not use any of these parameters or the michael@0: ** [sqlite3_test_control()] interface. michael@0: */ michael@0: #define SQLITE_TESTCTRL_FIRST 5 michael@0: #define SQLITE_TESTCTRL_PRNG_SAVE 5 michael@0: #define SQLITE_TESTCTRL_PRNG_RESTORE 6 michael@0: #define SQLITE_TESTCTRL_PRNG_RESET 7 michael@0: #define SQLITE_TESTCTRL_BITVEC_TEST 8 michael@0: #define SQLITE_TESTCTRL_FAULT_INSTALL 9 michael@0: #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 michael@0: #define SQLITE_TESTCTRL_PENDING_BYTE 11 michael@0: #define SQLITE_TESTCTRL_ASSERT 12 michael@0: #define SQLITE_TESTCTRL_ALWAYS 13 michael@0: #define SQLITE_TESTCTRL_RESERVE 14 michael@0: #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 michael@0: #define SQLITE_TESTCTRL_ISKEYWORD 16 michael@0: #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 michael@0: #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 michael@0: #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 michael@0: #define SQLITE_TESTCTRL_LAST 19 michael@0: michael@0: /* michael@0: ** CAPI3REF: SQLite Runtime Status michael@0: ** michael@0: ** ^This interface is used to retrieve runtime status information michael@0: ** about the performance of SQLite, and optionally to reset various michael@0: ** highwater marks. ^The first argument is an integer code for michael@0: ** the specific parameter to measure. ^(Recognized integer codes michael@0: ** are of the form [status parameters | SQLITE_STATUS_...].)^ michael@0: ** ^The current value of the parameter is returned into *pCurrent. michael@0: ** ^The highest recorded value is returned in *pHighwater. ^If the michael@0: ** resetFlag is true, then the highest record value is reset after michael@0: ** *pHighwater is written. ^(Some parameters do not record the highest michael@0: ** value. For those parameters michael@0: ** nothing is written into *pHighwater and the resetFlag is ignored.)^ michael@0: ** ^(Other parameters record only the highwater mark and not the current michael@0: ** value. For these latter parameters nothing is written into *pCurrent.)^ michael@0: ** michael@0: ** ^The sqlite3_status() routine returns SQLITE_OK on success and a michael@0: ** non-zero [error code] on failure. michael@0: ** michael@0: ** This routine is threadsafe but is not atomic. This routine can be michael@0: ** called while other threads are running the same or different SQLite michael@0: ** interfaces. However the values returned in *pCurrent and michael@0: ** *pHighwater reflect the status of SQLite at different points in time michael@0: ** and it is possible that another thread might change the parameter michael@0: ** in between the times when *pCurrent and *pHighwater are written. michael@0: ** michael@0: ** See also: [sqlite3_db_status()] michael@0: */ michael@0: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Status Parameters michael@0: ** KEYWORDS: {status parameters} michael@0: ** michael@0: ** These integer constants designate various run-time status parameters michael@0: ** that can be returned by [sqlite3_status()]. michael@0: ** michael@0: **
michael@0: ** [[SQLITE_STATUS_MEMORY_USED]] ^(
SQLITE_STATUS_MEMORY_USED
michael@0: **
This parameter is the current amount of memory checked out michael@0: ** using [sqlite3_malloc()], either directly or indirectly. The michael@0: ** figure includes calls made to [sqlite3_malloc()] by the application michael@0: ** and internal memory usage by the SQLite library. Scratch memory michael@0: ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache michael@0: ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in michael@0: ** this parameter. The amount returned is the sum of the allocation michael@0: ** sizes as reported by the xSize method in [sqlite3_mem_methods].
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(
SQLITE_STATUS_MALLOC_SIZE
michael@0: **
This parameter records the largest memory allocation request michael@0: ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their michael@0: ** internal equivalents). Only the value returned in the michael@0: ** *pHighwater parameter to [sqlite3_status()] is of interest. michael@0: ** The value written into the *pCurrent parameter is undefined.
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(
SQLITE_STATUS_MALLOC_COUNT
michael@0: **
This parameter records the number of separate memory allocations michael@0: ** currently checked out.
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(
SQLITE_STATUS_PAGECACHE_USED
michael@0: **
This parameter returns the number of pages used out of the michael@0: ** [pagecache memory allocator] that was configured using michael@0: ** [SQLITE_CONFIG_PAGECACHE]. The michael@0: ** value returned is in pages, not in bytes.
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] michael@0: ** ^(
SQLITE_STATUS_PAGECACHE_OVERFLOW
michael@0: **
This parameter returns the number of bytes of page cache michael@0: ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] michael@0: ** buffer and where forced to overflow to [sqlite3_malloc()]. The michael@0: ** returned value includes allocations that overflowed because they michael@0: ** where too large (they were larger than the "sz" parameter to michael@0: ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because michael@0: ** no space was left in the page cache.
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(
SQLITE_STATUS_PAGECACHE_SIZE
michael@0: **
This parameter records the largest memory allocation request michael@0: ** handed to [pagecache memory allocator]. Only the value returned in the michael@0: ** *pHighwater parameter to [sqlite3_status()] is of interest. michael@0: ** The value written into the *pCurrent parameter is undefined.
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_SCRATCH_USED]] ^(
SQLITE_STATUS_SCRATCH_USED
michael@0: **
This parameter returns the number of allocations used out of the michael@0: ** [scratch memory allocator] configured using michael@0: ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not michael@0: ** in bytes. Since a single thread may only have one scratch allocation michael@0: ** outstanding at time, this parameter also reports the number of threads michael@0: ** using scratch memory at the same time.
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(
SQLITE_STATUS_SCRATCH_OVERFLOW
michael@0: **
This parameter returns the number of bytes of scratch memory michael@0: ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] michael@0: ** buffer and where forced to overflow to [sqlite3_malloc()]. The values michael@0: ** returned include overflows because the requested allocation was too michael@0: ** larger (that is, because the requested allocation was larger than the michael@0: ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer michael@0: ** slots were available. michael@0: **
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(
SQLITE_STATUS_SCRATCH_SIZE
michael@0: **
This parameter records the largest memory allocation request michael@0: ** handed to [scratch memory allocator]. Only the value returned in the michael@0: ** *pHighwater parameter to [sqlite3_status()] is of interest. michael@0: ** The value written into the *pCurrent parameter is undefined.
)^ michael@0: ** michael@0: ** [[SQLITE_STATUS_PARSER_STACK]] ^(
SQLITE_STATUS_PARSER_STACK
michael@0: **
This parameter records the deepest parser stack. It is only michael@0: ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].
)^ michael@0: **
michael@0: ** michael@0: ** New status parameters may be added from time to time. michael@0: */ michael@0: #define SQLITE_STATUS_MEMORY_USED 0 michael@0: #define SQLITE_STATUS_PAGECACHE_USED 1 michael@0: #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 michael@0: #define SQLITE_STATUS_SCRATCH_USED 3 michael@0: #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 michael@0: #define SQLITE_STATUS_MALLOC_SIZE 5 michael@0: #define SQLITE_STATUS_PARSER_STACK 6 michael@0: #define SQLITE_STATUS_PAGECACHE_SIZE 7 michael@0: #define SQLITE_STATUS_SCRATCH_SIZE 8 michael@0: #define SQLITE_STATUS_MALLOC_COUNT 9 michael@0: michael@0: /* michael@0: ** CAPI3REF: Database Connection Status michael@0: ** michael@0: ** ^This interface is used to retrieve runtime status information michael@0: ** about a single [database connection]. ^The first argument is the michael@0: ** database connection object to be interrogated. ^The second argument michael@0: ** is an integer constant, taken from the set of michael@0: ** [SQLITE_DBSTATUS options], that michael@0: ** determines the parameter to interrogate. The set of michael@0: ** [SQLITE_DBSTATUS options] is likely michael@0: ** to grow in future releases of SQLite. michael@0: ** michael@0: ** ^The current value of the requested parameter is written into *pCur michael@0: ** and the highest instantaneous value is written into *pHiwtr. ^If michael@0: ** the resetFlg is true, then the highest instantaneous value is michael@0: ** reset back down to the current value. michael@0: ** michael@0: ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a michael@0: ** non-zero [error code] on failure. michael@0: ** michael@0: ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. michael@0: */ michael@0: SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); michael@0: michael@0: /* michael@0: ** CAPI3REF: Status Parameters for database connections michael@0: ** KEYWORDS: {SQLITE_DBSTATUS options} michael@0: ** michael@0: ** These constants are the available integer "verbs" that can be passed as michael@0: ** the second argument to the [sqlite3_db_status()] interface. michael@0: ** michael@0: ** New verbs may be added in future releases of SQLite. Existing verbs michael@0: ** might be discontinued. Applications should check the return code from michael@0: ** [sqlite3_db_status()] to make sure that the call worked. michael@0: ** The [sqlite3_db_status()] interface will return a non-zero error code michael@0: ** if a discontinued or unsupported verb is invoked. michael@0: ** michael@0: **
michael@0: ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(
SQLITE_DBSTATUS_LOOKASIDE_USED
michael@0: **
This parameter returns the number of lookaside memory slots currently michael@0: ** checked out.
)^ michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(
SQLITE_DBSTATUS_LOOKASIDE_HIT
michael@0: **
This parameter returns the number malloc attempts that were michael@0: ** satisfied using lookaside memory. Only the high-water value is meaningful; michael@0: ** the current value is always zero.)^ michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] michael@0: ** ^(
SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE
michael@0: **
This parameter returns the number malloc attempts that might have michael@0: ** been satisfied using lookaside memory but failed due to the amount of michael@0: ** memory requested being larger than the lookaside slot size. michael@0: ** Only the high-water value is meaningful; michael@0: ** the current value is always zero.)^ michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] michael@0: ** ^(
SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL
michael@0: **
This parameter returns the number malloc attempts that might have michael@0: ** been satisfied using lookaside memory but failed due to all lookaside michael@0: ** memory already being in use. michael@0: ** Only the high-water value is meaningful; michael@0: ** the current value is always zero.)^ michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(
SQLITE_DBSTATUS_CACHE_USED
michael@0: **
This parameter returns the approximate number of of bytes of heap michael@0: ** memory used by all pager caches associated with the database connection.)^ michael@0: ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(
SQLITE_DBSTATUS_SCHEMA_USED
michael@0: **
This parameter returns the approximate number of of bytes of heap michael@0: ** memory used to store the schema for all databases associated michael@0: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ michael@0: ** ^The full amount of memory used by the schemas is reported, even if the michael@0: ** schema memory is shared with other database connections due to michael@0: ** [shared cache mode] being enabled. michael@0: ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_STMT_USED]] ^(
SQLITE_DBSTATUS_STMT_USED
michael@0: **
This parameter returns the approximate number of of bytes of heap michael@0: ** and lookaside memory used by all prepared statements associated with michael@0: ** the database connection.)^ michael@0: ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. michael@0: **
michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(
SQLITE_DBSTATUS_CACHE_HIT
michael@0: **
This parameter returns the number of pager cache hits that have michael@0: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT michael@0: ** is always 0. michael@0: **
michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(
SQLITE_DBSTATUS_CACHE_MISS
michael@0: **
This parameter returns the number of pager cache misses that have michael@0: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS michael@0: ** is always 0. michael@0: **
michael@0: ** michael@0: ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(
SQLITE_DBSTATUS_CACHE_WRITE
michael@0: **
This parameter returns the number of dirty cache entries that have michael@0: ** been written to disk. Specifically, the number of pages written to the michael@0: ** wal file in wal mode databases, or the number of pages written to the michael@0: ** database file in rollback mode databases. Any pages written as part of michael@0: ** transaction rollback or database recovery operations are not included. michael@0: ** If an IO or other error occurs while writing a page to disk, the effect michael@0: ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The michael@0: ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. michael@0: **
michael@0: **
michael@0: */ michael@0: #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 michael@0: #define SQLITE_DBSTATUS_CACHE_USED 1 michael@0: #define SQLITE_DBSTATUS_SCHEMA_USED 2 michael@0: #define SQLITE_DBSTATUS_STMT_USED 3 michael@0: #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 michael@0: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 michael@0: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 michael@0: #define SQLITE_DBSTATUS_CACHE_HIT 7 michael@0: #define SQLITE_DBSTATUS_CACHE_MISS 8 michael@0: #define SQLITE_DBSTATUS_CACHE_WRITE 9 michael@0: #define SQLITE_DBSTATUS_MAX 9 /* Largest defined DBSTATUS */ michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Prepared Statement Status michael@0: ** michael@0: ** ^(Each prepared statement maintains various michael@0: ** [SQLITE_STMTSTATUS counters] that measure the number michael@0: ** of times it has performed specific operations.)^ These counters can michael@0: ** be used to monitor the performance characteristics of the prepared michael@0: ** statements. For example, if the number of table steps greatly exceeds michael@0: ** the number of table searches or result rows, that would tend to indicate michael@0: ** that the prepared statement is using a full table scan rather than michael@0: ** an index. michael@0: ** michael@0: ** ^(This interface is used to retrieve and reset counter values from michael@0: ** a [prepared statement]. The first argument is the prepared statement michael@0: ** object to be interrogated. The second argument michael@0: ** is an integer code for a specific [SQLITE_STMTSTATUS counter] michael@0: ** to be interrogated.)^ michael@0: ** ^The current value of the requested counter is returned. michael@0: ** ^If the resetFlg is true, then the counter is reset to zero after this michael@0: ** interface call returns. michael@0: ** michael@0: ** See also: [sqlite3_status()] and [sqlite3_db_status()]. michael@0: */ michael@0: SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); michael@0: michael@0: /* michael@0: ** CAPI3REF: Status Parameters for prepared statements michael@0: ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} michael@0: ** michael@0: ** These preprocessor macros define integer codes that name counter michael@0: ** values associated with the [sqlite3_stmt_status()] interface. michael@0: ** The meanings of the various counters are as follows: michael@0: ** michael@0: **
michael@0: ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]]
SQLITE_STMTSTATUS_FULLSCAN_STEP
michael@0: **
^This is the number of times that SQLite has stepped forward in michael@0: ** a table as part of a full table scan. Large numbers for this counter michael@0: ** may indicate opportunities for performance improvement through michael@0: ** careful use of indices.
michael@0: ** michael@0: ** [[SQLITE_STMTSTATUS_SORT]]
SQLITE_STMTSTATUS_SORT
michael@0: **
^This is the number of sort operations that have occurred. michael@0: ** A non-zero value in this counter may indicate an opportunity to michael@0: ** improvement performance through careful use of indices.
michael@0: ** michael@0: ** [[SQLITE_STMTSTATUS_AUTOINDEX]]
SQLITE_STMTSTATUS_AUTOINDEX
michael@0: **
^This is the number of rows inserted into transient indices that michael@0: ** were created automatically in order to help joins run faster. michael@0: ** A non-zero value in this counter may indicate an opportunity to michael@0: ** improvement performance by adding permanent indices that do not michael@0: ** need to be reinitialized each time the statement is run.
michael@0: **
michael@0: */ michael@0: #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 michael@0: #define SQLITE_STMTSTATUS_SORT 2 michael@0: #define SQLITE_STMTSTATUS_AUTOINDEX 3 michael@0: michael@0: /* michael@0: ** CAPI3REF: Custom Page Cache Object michael@0: ** michael@0: ** The sqlite3_pcache type is opaque. It is implemented by michael@0: ** the pluggable module. The SQLite core has no knowledge of michael@0: ** its size or internal structure and never deals with the michael@0: ** sqlite3_pcache object except by holding and passing pointers michael@0: ** to the object. michael@0: ** michael@0: ** See [sqlite3_pcache_methods2] for additional information. michael@0: */ michael@0: typedef struct sqlite3_pcache sqlite3_pcache; michael@0: michael@0: /* michael@0: ** CAPI3REF: Custom Page Cache Object michael@0: ** michael@0: ** The sqlite3_pcache_page object represents a single page in the michael@0: ** page cache. The page cache will allocate instances of this michael@0: ** object. Various methods of the page cache use pointers to instances michael@0: ** of this object as parameters or as their return value. michael@0: ** michael@0: ** See [sqlite3_pcache_methods2] for additional information. michael@0: */ michael@0: typedef struct sqlite3_pcache_page sqlite3_pcache_page; michael@0: struct sqlite3_pcache_page { michael@0: void *pBuf; /* The content of the page */ michael@0: void *pExtra; /* Extra information associated with the page */ michael@0: }; michael@0: michael@0: /* michael@0: ** CAPI3REF: Application Defined Page Cache. michael@0: ** KEYWORDS: {page cache} michael@0: ** michael@0: ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can michael@0: ** register an alternative page cache implementation by passing in an michael@0: ** instance of the sqlite3_pcache_methods2 structure.)^ michael@0: ** In many applications, most of the heap memory allocated by michael@0: ** SQLite is used for the page cache. michael@0: ** By implementing a michael@0: ** custom page cache using this API, an application can better control michael@0: ** the amount of memory consumed by SQLite, the way in which michael@0: ** that memory is allocated and released, and the policies used to michael@0: ** determine exactly which parts of a database file are cached and for michael@0: ** how long. michael@0: ** michael@0: ** The alternative page cache mechanism is an michael@0: ** extreme measure that is only needed by the most demanding applications. michael@0: ** The built-in page cache is recommended for most uses. michael@0: ** michael@0: ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an michael@0: ** internal buffer by SQLite within the call to [sqlite3_config]. Hence michael@0: ** the application may discard the parameter after the call to michael@0: ** [sqlite3_config()] returns.)^ michael@0: ** michael@0: ** [[the xInit() page cache method]] michael@0: ** ^(The xInit() method is called once for each effective michael@0: ** call to [sqlite3_initialize()])^ michael@0: ** (usually only once during the lifetime of the process). ^(The xInit() michael@0: ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ michael@0: ** The intent of the xInit() method is to set up global data structures michael@0: ** required by the custom page cache implementation. michael@0: ** ^(If the xInit() method is NULL, then the michael@0: ** built-in default page cache is used instead of the application defined michael@0: ** page cache.)^ michael@0: ** michael@0: ** [[the xShutdown() page cache method]] michael@0: ** ^The xShutdown() method is called by [sqlite3_shutdown()]. michael@0: ** It can be used to clean up michael@0: ** any outstanding resources before process shutdown, if required. michael@0: ** ^The xShutdown() method may be NULL. michael@0: ** michael@0: ** ^SQLite automatically serializes calls to the xInit method, michael@0: ** so the xInit method need not be threadsafe. ^The michael@0: ** xShutdown method is only called from [sqlite3_shutdown()] so it does michael@0: ** not need to be threadsafe either. All other methods must be threadsafe michael@0: ** in multithreaded applications. michael@0: ** michael@0: ** ^SQLite will never invoke xInit() more than once without an intervening michael@0: ** call to xShutdown(). michael@0: ** michael@0: ** [[the xCreate() page cache methods]] michael@0: ** ^SQLite invokes the xCreate() method to construct a new cache instance. michael@0: ** SQLite will typically create one cache instance for each open database file, michael@0: ** though this is not guaranteed. ^The michael@0: ** first parameter, szPage, is the size in bytes of the pages that must michael@0: ** be allocated by the cache. ^szPage will always a power of two. ^The michael@0: ** second parameter szExtra is a number of bytes of extra storage michael@0: ** associated with each page cache entry. ^The szExtra parameter will michael@0: ** a number less than 250. SQLite will use the michael@0: ** extra szExtra bytes on each page to store metadata about the underlying michael@0: ** database page on disk. The value passed into szExtra depends michael@0: ** on the SQLite version, the target platform, and how SQLite was compiled. michael@0: ** ^The third argument to xCreate(), bPurgeable, is true if the cache being michael@0: ** created will be used to cache database pages of a file stored on disk, or michael@0: ** false if it is used for an in-memory database. The cache implementation michael@0: ** does not have to do anything special based with the value of bPurgeable; michael@0: ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will michael@0: ** never invoke xUnpin() except to deliberately delete a page. michael@0: ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to michael@0: ** false will always have the "discard" flag set to true. michael@0: ** ^Hence, a cache created with bPurgeable false will michael@0: ** never contain any unpinned pages. michael@0: ** michael@0: ** [[the xCachesize() page cache method]] michael@0: ** ^(The xCachesize() method may be called at any time by SQLite to set the michael@0: ** suggested maximum cache-size (number of pages stored by) the cache michael@0: ** instance passed as the first argument. This is the value configured using michael@0: ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable michael@0: ** parameter, the implementation is not required to do anything with this michael@0: ** value; it is advisory only. michael@0: ** michael@0: ** [[the xPagecount() page cache methods]] michael@0: ** The xPagecount() method must return the number of pages currently michael@0: ** stored in the cache, both pinned and unpinned. michael@0: ** michael@0: ** [[the xFetch() page cache methods]] michael@0: ** The xFetch() method locates a page in the cache and returns a pointer to michael@0: ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. michael@0: ** The pBuf element of the returned sqlite3_pcache_page object will be a michael@0: ** pointer to a buffer of szPage bytes used to store the content of a michael@0: ** single database page. The pExtra element of sqlite3_pcache_page will be michael@0: ** a pointer to the szExtra bytes of extra storage that SQLite has requested michael@0: ** for each entry in the page cache. michael@0: ** michael@0: ** The page to be fetched is determined by the key. ^The minimum key value michael@0: ** is 1. After it has been retrieved using xFetch, the page is considered michael@0: ** to be "pinned". michael@0: ** michael@0: ** If the requested page is already in the page cache, then the page cache michael@0: ** implementation must return a pointer to the page buffer with its content michael@0: ** intact. If the requested page is not already in the cache, then the michael@0: ** cache implementation should use the value of the createFlag michael@0: ** parameter to help it determined what action to take: michael@0: ** michael@0: ** michael@0: **
createFlag Behaviour when page is not already in cache michael@0: **
0 Do not allocate a new page. Return NULL. michael@0: **
1 Allocate a new page if it easy and convenient to do so. michael@0: ** Otherwise return NULL. michael@0: **
2 Make every effort to allocate a new page. Only return michael@0: ** NULL if allocating a new page is effectively impossible. michael@0: **
michael@0: ** michael@0: ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite michael@0: ** will only use a createFlag of 2 after a prior call with a createFlag of 1 michael@0: ** failed.)^ In between the to xFetch() calls, SQLite may michael@0: ** attempt to unpin one or more cache pages by spilling the content of michael@0: ** pinned pages to disk and synching the operating system disk cache. michael@0: ** michael@0: ** [[the xUnpin() page cache method]] michael@0: ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page michael@0: ** as its second argument. If the third parameter, discard, is non-zero, michael@0: ** then the page must be evicted from the cache. michael@0: ** ^If the discard parameter is michael@0: ** zero, then the page may be discarded or retained at the discretion of michael@0: ** page cache implementation. ^The page cache implementation michael@0: ** may choose to evict unpinned pages at any time. michael@0: ** michael@0: ** The cache must not perform any reference counting. A single michael@0: ** call to xUnpin() unpins the page regardless of the number of prior calls michael@0: ** to xFetch(). michael@0: ** michael@0: ** [[the xRekey() page cache methods]] michael@0: ** The xRekey() method is used to change the key value associated with the michael@0: ** page passed as the second argument. If the cache michael@0: ** previously contains an entry associated with newKey, it must be michael@0: ** discarded. ^Any prior cache entry associated with newKey is guaranteed not michael@0: ** to be pinned. michael@0: ** michael@0: ** When SQLite calls the xTruncate() method, the cache must discard all michael@0: ** existing cache entries with page numbers (keys) greater than or equal michael@0: ** to the value of the iLimit parameter passed to xTruncate(). If any michael@0: ** of these pages are pinned, they are implicitly unpinned, meaning that michael@0: ** they can be safely discarded. michael@0: ** michael@0: ** [[the xDestroy() page cache method]] michael@0: ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). michael@0: ** All resources associated with the specified cache should be freed. ^After michael@0: ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] michael@0: ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 michael@0: ** functions. michael@0: ** michael@0: ** [[the xShrink() page cache method]] michael@0: ** ^SQLite invokes the xShrink() method when it wants the page cache to michael@0: ** free up as much of heap memory as possible. The page cache implementation michael@0: ** is not obligated to free any memory, but well-behaved implementations should michael@0: ** do their best. michael@0: */ michael@0: typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; michael@0: struct sqlite3_pcache_methods2 { michael@0: int iVersion; michael@0: void *pArg; michael@0: int (*xInit)(void*); michael@0: void (*xShutdown)(void*); michael@0: sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); michael@0: void (*xCachesize)(sqlite3_pcache*, int nCachesize); michael@0: int (*xPagecount)(sqlite3_pcache*); michael@0: sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); michael@0: void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); michael@0: void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, michael@0: unsigned oldKey, unsigned newKey); michael@0: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); michael@0: void (*xDestroy)(sqlite3_pcache*); michael@0: void (*xShrink)(sqlite3_pcache*); michael@0: }; michael@0: michael@0: /* michael@0: ** This is the obsolete pcache_methods object that has now been replaced michael@0: ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is michael@0: ** retained in the header file for backwards compatibility only. michael@0: */ michael@0: typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; michael@0: struct sqlite3_pcache_methods { michael@0: void *pArg; michael@0: int (*xInit)(void*); michael@0: void (*xShutdown)(void*); michael@0: sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); michael@0: void (*xCachesize)(sqlite3_pcache*, int nCachesize); michael@0: int (*xPagecount)(sqlite3_pcache*); michael@0: void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); michael@0: void (*xUnpin)(sqlite3_pcache*, void*, int discard); michael@0: void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); michael@0: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); michael@0: void (*xDestroy)(sqlite3_pcache*); michael@0: }; michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: Online Backup Object michael@0: ** michael@0: ** The sqlite3_backup object records state information about an ongoing michael@0: ** online backup operation. ^The sqlite3_backup object is created by michael@0: ** a call to [sqlite3_backup_init()] and is destroyed by a call to michael@0: ** [sqlite3_backup_finish()]. michael@0: ** michael@0: ** See Also: [Using the SQLite Online Backup API] michael@0: */ michael@0: typedef struct sqlite3_backup sqlite3_backup; michael@0: michael@0: /* michael@0: ** CAPI3REF: Online Backup API. michael@0: ** michael@0: ** The backup API copies the content of one database into another. michael@0: ** It is useful either for creating backups of databases or michael@0: ** for copying in-memory databases to or from persistent files. michael@0: ** michael@0: ** See Also: [Using the SQLite Online Backup API] michael@0: ** michael@0: ** ^SQLite holds a write transaction open on the destination database file michael@0: ** for the duration of the backup operation. michael@0: ** ^The source database is read-locked only while it is being read; michael@0: ** it is not locked continuously for the entire backup operation. michael@0: ** ^Thus, the backup may be performed on a live source database without michael@0: ** preventing other database connections from michael@0: ** reading or writing to the source database while the backup is underway. michael@0: ** michael@0: ** ^(To perform a backup operation: michael@0: **
    michael@0: **
  1. sqlite3_backup_init() is called once to initialize the michael@0: ** backup, michael@0: **
  2. sqlite3_backup_step() is called one or more times to transfer michael@0: ** the data between the two databases, and finally michael@0: **
  3. sqlite3_backup_finish() is called to release all resources michael@0: ** associated with the backup operation. michael@0: **
)^ michael@0: ** There should be exactly one call to sqlite3_backup_finish() for each michael@0: ** successful call to sqlite3_backup_init(). michael@0: ** michael@0: ** [[sqlite3_backup_init()]] sqlite3_backup_init() michael@0: ** michael@0: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the michael@0: ** [database connection] associated with the destination database michael@0: ** and the database name, respectively. michael@0: ** ^The database name is "main" for the main database, "temp" for the michael@0: ** temporary database, or the name specified after the AS keyword in michael@0: ** an [ATTACH] statement for an attached database. michael@0: ** ^The S and M arguments passed to michael@0: ** sqlite3_backup_init(D,N,S,M) identify the [database connection] michael@0: ** and database name of the source database, respectively. michael@0: ** ^The source and destination [database connections] (parameters S and D) michael@0: ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with michael@0: ** an error. michael@0: ** michael@0: ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is michael@0: ** returned and an error code and error message are stored in the michael@0: ** destination [database connection] D. michael@0: ** ^The error code and message for the failed call to sqlite3_backup_init() michael@0: ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or michael@0: ** [sqlite3_errmsg16()] functions. michael@0: ** ^A successful call to sqlite3_backup_init() returns a pointer to an michael@0: ** [sqlite3_backup] object. michael@0: ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and michael@0: ** sqlite3_backup_finish() functions to perform the specified backup michael@0: ** operation. michael@0: ** michael@0: ** [[sqlite3_backup_step()]] sqlite3_backup_step() michael@0: ** michael@0: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between michael@0: ** the source and destination databases specified by [sqlite3_backup] object B. michael@0: ** ^If N is negative, all remaining source pages are copied. michael@0: ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there michael@0: ** are still more pages to be copied, then the function returns [SQLITE_OK]. michael@0: ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages michael@0: ** from source to destination, then it returns [SQLITE_DONE]. michael@0: ** ^If an error occurs while running sqlite3_backup_step(B,N), michael@0: ** then an [error code] is returned. ^As well as [SQLITE_OK] and michael@0: ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], michael@0: ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an michael@0: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. michael@0: ** michael@0: ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if michael@0: **
    michael@0: **
  1. the destination database was opened read-only, or michael@0: **
  2. the destination database is using write-ahead-log journaling michael@0: ** and the destination and source page sizes differ, or michael@0: **
  3. the destination database is an in-memory database and the michael@0: ** destination and source page sizes differ. michael@0: **
)^ michael@0: ** michael@0: ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then michael@0: ** the [sqlite3_busy_handler | busy-handler function] michael@0: ** is invoked (if one is specified). ^If the michael@0: ** busy-handler returns non-zero before the lock is available, then michael@0: ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to michael@0: ** sqlite3_backup_step() can be retried later. ^If the source michael@0: ** [database connection] michael@0: ** is being used to write to the source database when sqlite3_backup_step() michael@0: ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this michael@0: ** case the call to sqlite3_backup_step() can be retried later on. ^(If michael@0: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or michael@0: ** [SQLITE_READONLY] is returned, then michael@0: ** there is no point in retrying the call to sqlite3_backup_step(). These michael@0: ** errors are considered fatal.)^ The application must accept michael@0: ** that the backup operation has failed and pass the backup operation handle michael@0: ** to the sqlite3_backup_finish() to release associated resources. michael@0: ** michael@0: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock michael@0: ** on the destination file. ^The exclusive lock is not released until either michael@0: ** sqlite3_backup_finish() is called or the backup operation is complete michael@0: ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to michael@0: ** sqlite3_backup_step() obtains a [shared lock] on the source database that michael@0: ** lasts for the duration of the sqlite3_backup_step() call. michael@0: ** ^Because the source database is not locked between calls to michael@0: ** sqlite3_backup_step(), the source database may be modified mid-way michael@0: ** through the backup process. ^If the source database is modified by an michael@0: ** external process or via a database connection other than the one being michael@0: ** used by the backup operation, then the backup will be automatically michael@0: ** restarted by the next call to sqlite3_backup_step(). ^If the source michael@0: ** database is modified by the using the same database connection as is used michael@0: ** by the backup operation, then the backup database is automatically michael@0: ** updated at the same time. michael@0: ** michael@0: ** [[sqlite3_backup_finish()]] sqlite3_backup_finish() michael@0: ** michael@0: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the michael@0: ** application wishes to abandon the backup operation, the application michael@0: ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). michael@0: ** ^The sqlite3_backup_finish() interfaces releases all michael@0: ** resources associated with the [sqlite3_backup] object. michael@0: ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any michael@0: ** active write-transaction on the destination database is rolled back. michael@0: ** The [sqlite3_backup] object is invalid michael@0: ** and may not be used following a call to sqlite3_backup_finish(). michael@0: ** michael@0: ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no michael@0: ** sqlite3_backup_step() errors occurred, regardless or whether or not michael@0: ** sqlite3_backup_step() completed. michael@0: ** ^If an out-of-memory condition or IO error occurred during any prior michael@0: ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then michael@0: ** sqlite3_backup_finish() returns the corresponding [error code]. michael@0: ** michael@0: ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() michael@0: ** is not a permanent error and does not affect the return value of michael@0: ** sqlite3_backup_finish(). michael@0: ** michael@0: ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] michael@0: ** sqlite3_backup_remaining() and sqlite3_backup_pagecount() michael@0: ** michael@0: ** ^Each call to sqlite3_backup_step() sets two values inside michael@0: ** the [sqlite3_backup] object: the number of pages still to be backed michael@0: ** up and the total number of pages in the source database file. michael@0: ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces michael@0: ** retrieve these two values, respectively. michael@0: ** michael@0: ** ^The values returned by these functions are only updated by michael@0: ** sqlite3_backup_step(). ^If the source database is modified during a backup michael@0: ** operation, then the values are not updated to account for any extra michael@0: ** pages that need to be updated or the size of the source database file michael@0: ** changing. michael@0: ** michael@0: ** Concurrent Usage of Database Handles michael@0: ** michael@0: ** ^The source [database connection] may be used by the application for other michael@0: ** purposes while a backup operation is underway or being initialized. michael@0: ** ^If SQLite is compiled and configured to support threadsafe database michael@0: ** connections, then the source database connection may be used concurrently michael@0: ** from within other threads. michael@0: ** michael@0: ** However, the application must guarantee that the destination michael@0: ** [database connection] is not passed to any other API (by any thread) after michael@0: ** sqlite3_backup_init() is called and before the corresponding call to michael@0: ** sqlite3_backup_finish(). SQLite does not currently check to see michael@0: ** if the application incorrectly accesses the destination [database connection] michael@0: ** and so no error code is reported, but the operations may malfunction michael@0: ** nevertheless. Use of the destination database connection while a michael@0: ** backup is in progress might also also cause a mutex deadlock. michael@0: ** michael@0: ** If running in [shared cache mode], the application must michael@0: ** guarantee that the shared cache used by the destination database michael@0: ** is not accessed while the backup is running. In practice this means michael@0: ** that the application must guarantee that the disk file being michael@0: ** backed up to is not accessed by any connection within the process, michael@0: ** not just the specific connection that was passed to sqlite3_backup_init(). michael@0: ** michael@0: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple michael@0: ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). michael@0: ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() michael@0: ** APIs are not strictly speaking threadsafe. If they are invoked at the michael@0: ** same time as another thread is invoking sqlite3_backup_step() it is michael@0: ** possible that they return invalid values. michael@0: */ michael@0: SQLITE_API sqlite3_backup *sqlite3_backup_init( michael@0: sqlite3 *pDest, /* Destination database handle */ michael@0: const char *zDestName, /* Destination database name */ michael@0: sqlite3 *pSource, /* Source database handle */ michael@0: const char *zSourceName /* Source database name */ michael@0: ); michael@0: SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); michael@0: SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); michael@0: SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); michael@0: SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); michael@0: michael@0: /* michael@0: ** CAPI3REF: Unlock Notification michael@0: ** michael@0: ** ^When running in shared-cache mode, a database operation may fail with michael@0: ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or michael@0: ** individual tables within the shared-cache cannot be obtained. See michael@0: ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. michael@0: ** ^This API may be used to register a callback that SQLite will invoke michael@0: ** when the connection currently holding the required lock relinquishes it. michael@0: ** ^This API is only available if the library was compiled with the michael@0: ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. michael@0: ** michael@0: ** See Also: [Using the SQLite Unlock Notification Feature]. michael@0: ** michael@0: ** ^Shared-cache locks are released when a database connection concludes michael@0: ** its current transaction, either by committing it or rolling it back. michael@0: ** michael@0: ** ^When a connection (known as the blocked connection) fails to obtain a michael@0: ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the michael@0: ** identity of the database connection (the blocking connection) that michael@0: ** has locked the required resource is stored internally. ^After an michael@0: ** application receives an SQLITE_LOCKED error, it may call the michael@0: ** sqlite3_unlock_notify() method with the blocked connection handle as michael@0: ** the first argument to register for a callback that will be invoked michael@0: ** when the blocking connections current transaction is concluded. ^The michael@0: ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] michael@0: ** call that concludes the blocking connections transaction. michael@0: ** michael@0: ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, michael@0: ** there is a chance that the blocking connection will have already michael@0: ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. michael@0: ** If this happens, then the specified callback is invoked immediately, michael@0: ** from within the call to sqlite3_unlock_notify().)^ michael@0: ** michael@0: ** ^If the blocked connection is attempting to obtain a write-lock on a michael@0: ** shared-cache table, and more than one other connection currently holds michael@0: ** a read-lock on the same table, then SQLite arbitrarily selects one of michael@0: ** the other connections to use as the blocking connection. michael@0: ** michael@0: ** ^(There may be at most one unlock-notify callback registered by a michael@0: ** blocked connection. If sqlite3_unlock_notify() is called when the michael@0: ** blocked connection already has a registered unlock-notify callback, michael@0: ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is michael@0: ** called with a NULL pointer as its second argument, then any existing michael@0: ** unlock-notify callback is canceled. ^The blocked connections michael@0: ** unlock-notify callback may also be canceled by closing the blocked michael@0: ** connection using [sqlite3_close()]. michael@0: ** michael@0: ** The unlock-notify callback is not reentrant. If an application invokes michael@0: ** any sqlite3_xxx API functions from within an unlock-notify callback, a michael@0: ** crash or deadlock may be the result. michael@0: ** michael@0: ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always michael@0: ** returns SQLITE_OK. michael@0: ** michael@0: ** Callback Invocation Details michael@0: ** michael@0: ** When an unlock-notify callback is registered, the application provides a michael@0: ** single void* pointer that is passed to the callback when it is invoked. michael@0: ** However, the signature of the callback function allows SQLite to pass michael@0: ** it an array of void* context pointers. The first argument passed to michael@0: ** an unlock-notify callback is a pointer to an array of void* pointers, michael@0: ** and the second is the number of entries in the array. michael@0: ** michael@0: ** When a blocking connections transaction is concluded, there may be michael@0: ** more than one blocked connection that has registered for an unlock-notify michael@0: ** callback. ^If two or more such blocked connections have specified the michael@0: ** same callback function, then instead of invoking the callback function michael@0: ** multiple times, it is invoked once with the set of void* context pointers michael@0: ** specified by the blocked connections bundled together into an array. michael@0: ** This gives the application an opportunity to prioritize any actions michael@0: ** related to the set of unblocked database connections. michael@0: ** michael@0: ** Deadlock Detection michael@0: ** michael@0: ** Assuming that after registering for an unlock-notify callback a michael@0: ** database waits for the callback to be issued before taking any further michael@0: ** action (a reasonable assumption), then using this API may cause the michael@0: ** application to deadlock. For example, if connection X is waiting for michael@0: ** connection Y's transaction to be concluded, and similarly connection michael@0: ** Y is waiting on connection X's transaction, then neither connection michael@0: ** will proceed and the system may remain deadlocked indefinitely. michael@0: ** michael@0: ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock michael@0: ** detection. ^If a given call to sqlite3_unlock_notify() would put the michael@0: ** system in a deadlocked state, then SQLITE_LOCKED is returned and no michael@0: ** unlock-notify callback is registered. The system is said to be in michael@0: ** a deadlocked state if connection A has registered for an unlock-notify michael@0: ** callback on the conclusion of connection B's transaction, and connection michael@0: ** B has itself registered for an unlock-notify callback when connection michael@0: ** A's transaction is concluded. ^Indirect deadlock is also detected, so michael@0: ** the system is also considered to be deadlocked if connection B has michael@0: ** registered for an unlock-notify callback on the conclusion of connection michael@0: ** C's transaction, where connection C is waiting on connection A. ^Any michael@0: ** number of levels of indirection are allowed. michael@0: ** michael@0: ** The "DROP TABLE" Exception michael@0: ** michael@0: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost michael@0: ** always appropriate to call sqlite3_unlock_notify(). There is however, michael@0: ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, michael@0: ** SQLite checks if there are any currently executing SELECT statements michael@0: ** that belong to the same connection. If there are, SQLITE_LOCKED is michael@0: ** returned. In this case there is no "blocking connection", so invoking michael@0: ** sqlite3_unlock_notify() results in the unlock-notify callback being michael@0: ** invoked immediately. If the application then re-attempts the "DROP TABLE" michael@0: ** or "DROP INDEX" query, an infinite loop might be the result. michael@0: ** michael@0: ** One way around this problem is to check the extended error code returned michael@0: ** by an sqlite3_step() call. ^(If there is a blocking connection, then the michael@0: ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in michael@0: ** the special "DROP TABLE/INDEX" case, the extended error code is just michael@0: ** SQLITE_LOCKED.)^ michael@0: */ michael@0: SQLITE_API int sqlite3_unlock_notify( michael@0: sqlite3 *pBlocked, /* Waiting connection */ michael@0: void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ michael@0: void *pNotifyArg /* Argument to pass to xNotify */ michael@0: ); michael@0: michael@0: michael@0: /* michael@0: ** CAPI3REF: String Comparison michael@0: ** michael@0: ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications michael@0: ** and extensions to compare the contents of two buffers containing UTF-8 michael@0: ** strings in a case-independent fashion, using the same definition of "case michael@0: ** independence" that SQLite uses internally when comparing identifiers. michael@0: */ michael@0: SQLITE_API int sqlite3_stricmp(const char *, const char *); michael@0: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); michael@0: michael@0: /* michael@0: ** CAPI3REF: Error Logging Interface michael@0: ** michael@0: ** ^The [sqlite3_log()] interface writes a message into the error log michael@0: ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. michael@0: ** ^If logging is enabled, the zFormat string and subsequent arguments are michael@0: ** used with [sqlite3_snprintf()] to generate the final output string. michael@0: ** michael@0: ** The sqlite3_log() interface is intended for use by extensions such as michael@0: ** virtual tables, collating functions, and SQL functions. While there is michael@0: ** nothing to prevent an application from calling sqlite3_log(), doing so michael@0: ** is considered bad form. michael@0: ** michael@0: ** The zFormat string must not be NULL. michael@0: ** michael@0: ** To avoid deadlocks and other threading problems, the sqlite3_log() routine michael@0: ** will not use dynamically allocated memory. The log message is stored in michael@0: ** a fixed-length buffer on the stack. If the log message is longer than michael@0: ** a few hundred characters, it will be truncated to the length of the michael@0: ** buffer. michael@0: */ michael@0: SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); michael@0: michael@0: /* michael@0: ** CAPI3REF: Write-Ahead Log Commit Hook michael@0: ** michael@0: ** ^The [sqlite3_wal_hook()] function is used to register a callback that michael@0: ** will be invoked each time a database connection commits data to a michael@0: ** [write-ahead log] (i.e. whenever a transaction is committed in michael@0: ** [journal_mode | journal_mode=WAL mode]). michael@0: ** michael@0: ** ^The callback is invoked by SQLite after the commit has taken place and michael@0: ** the associated write-lock on the database released, so the implementation michael@0: ** may read, write or [checkpoint] the database as required. michael@0: ** michael@0: ** ^The first parameter passed to the callback function when it is invoked michael@0: ** is a copy of the third parameter passed to sqlite3_wal_hook() when michael@0: ** registering the callback. ^The second is a copy of the database handle. michael@0: ** ^The third parameter is the name of the database that was written to - michael@0: ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter michael@0: ** is the number of pages currently in the write-ahead log file, michael@0: ** including those that were just committed. michael@0: ** michael@0: ** The callback function should normally return [SQLITE_OK]. ^If an error michael@0: ** code is returned, that error will propagate back up through the michael@0: ** SQLite code base to cause the statement that provoked the callback michael@0: ** to report an error, though the commit will have still occurred. If the michael@0: ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value michael@0: ** that does not correspond to any valid SQLite error code, the results michael@0: ** are undefined. michael@0: ** michael@0: ** A single database handle may have at most a single write-ahead log callback michael@0: ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any michael@0: ** previously registered write-ahead log callback. ^Note that the michael@0: ** [sqlite3_wal_autocheckpoint()] interface and the michael@0: ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will michael@0: ** those overwrite any prior [sqlite3_wal_hook()] settings. michael@0: */ michael@0: SQLITE_API void *sqlite3_wal_hook( michael@0: sqlite3*, michael@0: int(*)(void *,sqlite3*,const char*,int), michael@0: void* michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Configure an auto-checkpoint michael@0: ** michael@0: ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around michael@0: ** [sqlite3_wal_hook()] that causes any database on [database connection] D michael@0: ** to automatically [checkpoint] michael@0: ** after committing a transaction if there are N or michael@0: ** more frames in the [write-ahead log] file. ^Passing zero or michael@0: ** a negative value as the nFrame parameter disables automatic michael@0: ** checkpoints entirely. michael@0: ** michael@0: ** ^The callback registered by this function replaces any existing callback michael@0: ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback michael@0: ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism michael@0: ** configured by this function. michael@0: ** michael@0: ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface michael@0: ** from SQL. michael@0: ** michael@0: ** ^Every new [database connection] defaults to having the auto-checkpoint michael@0: ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] michael@0: ** pages. The use of this interface michael@0: ** is only necessary if the default setting is found to be suboptimal michael@0: ** for a particular application. michael@0: */ michael@0: SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); michael@0: michael@0: /* michael@0: ** CAPI3REF: Checkpoint a database michael@0: ** michael@0: ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X michael@0: ** on [database connection] D to be [checkpointed]. ^If X is NULL or an michael@0: ** empty string, then a checkpoint is run on all databases of michael@0: ** connection D. ^If the database connection D is not in michael@0: ** [WAL | write-ahead log mode] then this interface is a harmless no-op. michael@0: ** michael@0: ** ^The [wal_checkpoint pragma] can be used to invoke this interface michael@0: ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the michael@0: ** [wal_autocheckpoint pragma] can be used to cause this interface to be michael@0: ** run whenever the WAL reaches a certain size threshold. michael@0: ** michael@0: ** See also: [sqlite3_wal_checkpoint_v2()] michael@0: */ michael@0: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); michael@0: michael@0: /* michael@0: ** CAPI3REF: Checkpoint a database michael@0: ** michael@0: ** Run a checkpoint operation on WAL database zDb attached to database michael@0: ** handle db. The specific operation is determined by the value of the michael@0: ** eMode parameter: michael@0: ** michael@0: **
michael@0: **
SQLITE_CHECKPOINT_PASSIVE
michael@0: ** Checkpoint as many frames as possible without waiting for any database michael@0: ** readers or writers to finish. Sync the db file if all frames in the log michael@0: ** are checkpointed. This mode is the same as calling michael@0: ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. michael@0: ** michael@0: **
SQLITE_CHECKPOINT_FULL
michael@0: ** This mode blocks (calls the busy-handler callback) until there is no michael@0: ** database writer and all readers are reading from the most recent database michael@0: ** snapshot. It then checkpoints all frames in the log file and syncs the michael@0: ** database file. This call blocks database writers while it is running, michael@0: ** but not database readers. michael@0: ** michael@0: **
SQLITE_CHECKPOINT_RESTART
michael@0: ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after michael@0: ** checkpointing the log file it blocks (calls the busy-handler callback) michael@0: ** until all readers are reading from the database file only. This ensures michael@0: ** that the next client to write to the database file restarts the log file michael@0: ** from the beginning. This call blocks database writers while it is running, michael@0: ** but not database readers. michael@0: **
michael@0: ** michael@0: ** If pnLog is not NULL, then *pnLog is set to the total number of frames in michael@0: ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to michael@0: ** the total number of checkpointed frames (including any that were already michael@0: ** checkpointed when this function is called). *pnLog and *pnCkpt may be michael@0: ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. michael@0: ** If no values are available because of an error, they are both set to -1 michael@0: ** before returning to communicate this to the caller. michael@0: ** michael@0: ** All calls obtain an exclusive "checkpoint" lock on the database file. If michael@0: ** any other process is running a checkpoint operation at the same time, the michael@0: ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a michael@0: ** busy-handler configured, it will not be invoked in this case. michael@0: ** michael@0: ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive michael@0: ** "writer" lock on the database file. If the writer lock cannot be obtained michael@0: ** immediately, and a busy-handler is configured, it is invoked and the writer michael@0: ** lock retried until either the busy-handler returns 0 or the lock is michael@0: ** successfully obtained. The busy-handler is also invoked while waiting for michael@0: ** database readers as described above. If the busy-handler returns 0 before michael@0: ** the writer lock is obtained or while waiting for database readers, the michael@0: ** checkpoint operation proceeds from that point in the same way as michael@0: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible michael@0: ** without blocking any further. SQLITE_BUSY is returned in this case. michael@0: ** michael@0: ** If parameter zDb is NULL or points to a zero length string, then the michael@0: ** specified operation is attempted on all WAL databases. In this case the michael@0: ** values written to output parameters *pnLog and *pnCkpt are undefined. If michael@0: ** an SQLITE_BUSY error is encountered when processing one or more of the michael@0: ** attached WAL databases, the operation is still attempted on any remaining michael@0: ** attached databases and SQLITE_BUSY is returned to the caller. If any other michael@0: ** error occurs while processing an attached database, processing is abandoned michael@0: ** and the error code returned to the caller immediately. If no error michael@0: ** (SQLITE_BUSY or otherwise) is encountered while processing the attached michael@0: ** databases, SQLITE_OK is returned. michael@0: ** michael@0: ** If database zDb is the name of an attached database that is not in WAL michael@0: ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If michael@0: ** zDb is not NULL (or a zero length string) and is not the name of any michael@0: ** attached database, SQLITE_ERROR is returned to the caller. michael@0: */ michael@0: SQLITE_API int sqlite3_wal_checkpoint_v2( michael@0: sqlite3 *db, /* Database handle */ michael@0: const char *zDb, /* Name of attached database (or NULL) */ michael@0: int eMode, /* SQLITE_CHECKPOINT_* value */ michael@0: int *pnLog, /* OUT: Size of WAL log in frames */ michael@0: int *pnCkpt /* OUT: Total number of frames checkpointed */ michael@0: ); michael@0: michael@0: /* michael@0: ** CAPI3REF: Checkpoint operation parameters michael@0: ** michael@0: ** These constants can be used as the 3rd parameter to michael@0: ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] michael@0: ** documentation for additional information about the meaning and use of michael@0: ** each of these values. michael@0: */ michael@0: #define SQLITE_CHECKPOINT_PASSIVE 0 michael@0: #define SQLITE_CHECKPOINT_FULL 1 michael@0: #define SQLITE_CHECKPOINT_RESTART 2 michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual Table Interface Configuration michael@0: ** michael@0: ** This function may be called by either the [xConnect] or [xCreate] method michael@0: ** of a [virtual table] implementation to configure michael@0: ** various facets of the virtual table interface. michael@0: ** michael@0: ** If this interface is invoked outside the context of an xConnect or michael@0: ** xCreate virtual table method then the behavior is undefined. michael@0: ** michael@0: ** At present, there is only one option that may be configured using michael@0: ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options michael@0: ** may be added in the future. michael@0: */ michael@0: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); michael@0: michael@0: /* michael@0: ** CAPI3REF: Virtual Table Configuration Options michael@0: ** michael@0: ** These macros define the various options to the michael@0: ** [sqlite3_vtab_config()] interface that [virtual table] implementations michael@0: ** can use to customize and optimize their behavior. michael@0: ** michael@0: **
michael@0: **
SQLITE_VTAB_CONSTRAINT_SUPPORT michael@0: **
Calls of the form michael@0: ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, michael@0: ** where X is an integer. If X is zero, then the [virtual table] whose michael@0: ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not michael@0: ** support constraints. In this configuration (which is the default) if michael@0: ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire michael@0: ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been michael@0: ** specified as part of the users SQL statement, regardless of the actual michael@0: ** ON CONFLICT mode specified. michael@0: ** michael@0: ** If X is non-zero, then the virtual table implementation guarantees michael@0: ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before michael@0: ** any modifications to internal or persistent data structures have been made. michael@0: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite michael@0: ** is able to roll back a statement or database transaction, and abandon michael@0: ** or continue processing the current SQL statement as appropriate. michael@0: ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns michael@0: ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode michael@0: ** had been ABORT. michael@0: ** michael@0: ** Virtual table implementations that are required to handle OR REPLACE michael@0: ** must do so within the [xUpdate] method. If a call to the michael@0: ** [sqlite3_vtab_on_conflict()] function indicates that the current ON michael@0: ** CONFLICT policy is REPLACE, the virtual table implementation should michael@0: ** silently replace the appropriate rows within the xUpdate callback and michael@0: ** return SQLITE_OK. Or, if this is not possible, it may return michael@0: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT michael@0: ** constraint handling. michael@0: **
michael@0: */ michael@0: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 michael@0: michael@0: /* michael@0: ** CAPI3REF: Determine The Virtual Table Conflict Policy michael@0: ** michael@0: ** This function may only be called from within a call to the [xUpdate] method michael@0: ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The michael@0: ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], michael@0: ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode michael@0: ** of the SQL statement that triggered the call to the [xUpdate] method of the michael@0: ** [virtual table]. michael@0: */ michael@0: SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); michael@0: michael@0: /* michael@0: ** CAPI3REF: Conflict resolution modes michael@0: ** michael@0: ** These constants are returned by [sqlite3_vtab_on_conflict()] to michael@0: ** inform a [virtual table] implementation what the [ON CONFLICT] mode michael@0: ** is for the SQL statement being evaluated. michael@0: ** michael@0: ** Note that the [SQLITE_IGNORE] constant is also used as a potential michael@0: ** return value from the [sqlite3_set_authorizer()] callback and that michael@0: ** [SQLITE_ABORT] is also a [result code]. michael@0: */ michael@0: #define SQLITE_ROLLBACK 1 michael@0: /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ michael@0: #define SQLITE_FAIL 3 michael@0: /* #define SQLITE_ABORT 4 // Also an error code */ michael@0: #define SQLITE_REPLACE 5 michael@0: michael@0: michael@0: michael@0: /* michael@0: ** Undo the hack that converts floating point types to integer for michael@0: ** builds on processors without floating point support. michael@0: */ michael@0: #ifdef SQLITE_OMIT_FLOATING_POINT michael@0: # undef double michael@0: #endif michael@0: michael@0: #ifdef __cplusplus michael@0: } /* End of the 'extern "C"' block */ michael@0: #endif michael@0: #endif michael@0: michael@0: /* michael@0: ** 2010 August 30 michael@0: ** michael@0: ** The author disclaims copyright to this source code. In place of michael@0: ** a legal notice, here is a blessing: michael@0: ** michael@0: ** May you do good and not evil. michael@0: ** May you find forgiveness for yourself and forgive others. michael@0: ** May you share freely, never taking more than you give. michael@0: ** michael@0: ************************************************************************* michael@0: */ michael@0: michael@0: #ifndef _SQLITE3RTREE_H_ michael@0: #define _SQLITE3RTREE_H_ michael@0: michael@0: michael@0: #ifdef __cplusplus michael@0: extern "C" { michael@0: #endif michael@0: michael@0: typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; michael@0: michael@0: /* michael@0: ** Register a geometry callback named zGeom that can be used as part of an michael@0: ** R-Tree geometry query as follows: michael@0: ** michael@0: ** SELECT ... FROM WHERE MATCH $zGeom(... params ...) michael@0: */ michael@0: SQLITE_API int sqlite3_rtree_geometry_callback( michael@0: sqlite3 *db, michael@0: const char *zGeom, michael@0: #ifdef SQLITE_RTREE_INT_ONLY michael@0: int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes), michael@0: #else michael@0: int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes), michael@0: #endif michael@0: void *pContext michael@0: ); michael@0: michael@0: michael@0: /* michael@0: ** A pointer to a structure of the following type is passed as the first michael@0: ** argument to callbacks registered using rtree_geometry_callback(). michael@0: */ michael@0: struct sqlite3_rtree_geometry { michael@0: void *pContext; /* Copy of pContext passed to s_r_g_c() */ michael@0: int nParam; /* Size of array aParam[] */ michael@0: double *aParam; /* Parameters passed to SQL geom function */ michael@0: void *pUser; /* Callback implementation user data */ michael@0: void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ michael@0: }; michael@0: michael@0: michael@0: #ifdef __cplusplus michael@0: } /* end of the 'extern "C"' block */ michael@0: #endif michael@0: michael@0: #endif /* ifndef _SQLITE3RTREE_H_ */ michael@0: