7161 lines
336 KiB
C
7161 lines
336 KiB
C
/*
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** 2001 September 15
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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** This header file defines the interface that the SQLite library
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** presents to client programs. If a C-function, structure, datatype,
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** or constant definition does not appear in this file, then it is
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** not a published API of SQLite, is subject to change without
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** notice, and should not be referenced by programs that use SQLite.
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**
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** Some of the definitions that are in this file are marked as
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** "experimental". Experimental interfaces are normally new
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** features recently added to SQLite. We do not anticipate changes
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** to experimental interfaces but reserve the right to make minor changes
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** if experience from use "in the wild" suggest such changes are prudent.
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**
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** The official C-language API documentation for SQLite is derived
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** from comments in this file. This file is the authoritative source
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** on how SQLite interfaces are suppose to operate.
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**
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** The name of this file under configuration management is "sqlite.h.in".
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** The makefile makes some minor changes to this file (such as inserting
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** the version number) and changes its name to "sqlite3.h" as
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** part of the build process.
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*/
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#ifndef _SQLITE3_H_
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#define _SQLITE3_H_
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#include <stdarg.h> /* Needed for the definition of va_list */
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/*
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** Make sure we can call this stuff from C++.
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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/*
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** Add the ability to override 'extern'
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*/
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#ifndef SQLITE_EXTERN
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# define SQLITE_EXTERN extern
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#endif
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#ifndef SQLITE_API
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# define SQLITE_API
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#endif
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/*
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** These no-op macros are used in front of interfaces to mark those
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** interfaces as either deprecated or experimental. New applications
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** should not use deprecated interfaces - they are support for backwards
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** compatibility only. Application writers should be aware that
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** experimental interfaces are subject to change in point releases.
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**
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** These macros used to resolve to various kinds of compiler magic that
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** would generate warning messages when they were used. But that
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** compiler magic ended up generating such a flurry of bug reports
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** that we have taken it all out and gone back to using simple
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** noop macros.
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*/
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#define SQLITE_DEPRECATED
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#define SQLITE_EXPERIMENTAL
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/*
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** Ensure these symbols were not defined by some previous header file.
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*/
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#ifdef SQLITE_VERSION
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# undef SQLITE_VERSION
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#endif
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#ifdef SQLITE_VERSION_NUMBER
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# undef SQLITE_VERSION_NUMBER
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#endif
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/*
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** CAPI3REF: Compile-Time Library Version Numbers
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**
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** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
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** evaluates to a string literal that is the SQLite version in the
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** format "X.Y.Z" where X is the major version number (always 3 for
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** SQLite3) and Y is the minor version number and Z is the release number.)^
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** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
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** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
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** numbers used in [SQLITE_VERSION].)^
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** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
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** be larger than the release from which it is derived. Either Y will
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** be held constant and Z will be incremented or else Y will be incremented
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** and Z will be reset to zero.
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**
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** Since version 3.6.18, SQLite source code has been stored in the
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** <a href="http://www.fossil-scm.org/">Fossil configuration management
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** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
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** a string which identifies a particular check-in of SQLite
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** within its configuration management system. ^The SQLITE_SOURCE_ID
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** string contains the date and time of the check-in (UTC) and an SHA1
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** hash of the entire source tree.
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**
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** See also: [sqlite3_libversion()],
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** [sqlite3_libversion_number()], [sqlite3_sourceid()],
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** [sqlite_version()] and [sqlite_source_id()].
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*/
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#define SQLITE_VERSION "3.7.15"
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#define SQLITE_VERSION_NUMBER 3007015
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#define SQLITE_SOURCE_ID "2012-12-12 13:36:53 cd0b37c52658bfdf992b1e3dc467bae1835a94ae"
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/*
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** CAPI3REF: Run-Time Library Version Numbers
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** KEYWORDS: sqlite3_version, sqlite3_sourceid
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**
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** These interfaces provide the same information as the [SQLITE_VERSION],
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** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
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** but are associated with the library instead of the header file. ^(Cautious
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** programmers might include assert() statements in their application to
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** verify that values returned by these interfaces match the macros in
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** the header, and thus insure that the application is
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** compiled with matching library and header files.
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**
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** <blockquote><pre>
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** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
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** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
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** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
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** </pre></blockquote>)^
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**
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** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
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** macro. ^The sqlite3_libversion() function returns a pointer to the
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** to the sqlite3_version[] string constant. The sqlite3_libversion()
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** function is provided for use in DLLs since DLL users usually do not have
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** direct access to string constants within the DLL. ^The
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** sqlite3_libversion_number() function returns an integer equal to
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** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
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** a pointer to a string constant whose value is the same as the
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** [SQLITE_SOURCE_ID] C preprocessor macro.
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**
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** See also: [sqlite_version()] and [sqlite_source_id()].
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*/
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SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
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SQLITE_API const char *sqlite3_libversion(void);
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SQLITE_API const char *sqlite3_sourceid(void);
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SQLITE_API int sqlite3_libversion_number(void);
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/*
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** CAPI3REF: Run-Time Library Compilation Options Diagnostics
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**
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** ^The sqlite3_compileoption_used() function returns 0 or 1
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** indicating whether the specified option was defined at
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** compile time. ^The SQLITE_ prefix may be omitted from the
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** option name passed to sqlite3_compileoption_used().
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**
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** ^The sqlite3_compileoption_get() function allows iterating
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** over the list of options that were defined at compile time by
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** returning the N-th compile time option string. ^If N is out of range,
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** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
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** prefix is omitted from any strings returned by
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** sqlite3_compileoption_get().
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**
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** ^Support for the diagnostic functions sqlite3_compileoption_used()
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** and sqlite3_compileoption_get() may be omitted by specifying the
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** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
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**
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** See also: SQL functions [sqlite_compileoption_used()] and
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** [sqlite_compileoption_get()] and the [compile_options pragma].
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*/
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#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
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SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
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SQLITE_API const char *sqlite3_compileoption_get(int N);
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#endif
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/*
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** CAPI3REF: Test To See If The Library Is Threadsafe
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**
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** ^The sqlite3_threadsafe() function returns zero if and only if
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** SQLite was compiled with mutexing code omitted due to the
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** [SQLITE_THREADSAFE] compile-time option being set to 0.
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**
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** SQLite can be compiled with or without mutexes. When
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** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
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** are enabled and SQLite is threadsafe. When the
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** [SQLITE_THREADSAFE] macro is 0,
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** the mutexes are omitted. Without the mutexes, it is not safe
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** to use SQLite concurrently from more than one thread.
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**
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** Enabling mutexes incurs a measurable performance penalty.
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** So if speed is of utmost importance, it makes sense to disable
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** the mutexes. But for maximum safety, mutexes should be enabled.
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** ^The default behavior is for mutexes to be enabled.
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**
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** This interface can be used by an application to make sure that the
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** version of SQLite that it is linking against was compiled with
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** the desired setting of the [SQLITE_THREADSAFE] macro.
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**
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** This interface only reports on the compile-time mutex setting
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** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
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** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
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** can be fully or partially disabled using a call to [sqlite3_config()]
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** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
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** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
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** sqlite3_threadsafe() function shows only the compile-time setting of
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** thread safety, not any run-time changes to that setting made by
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** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
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** is unchanged by calls to sqlite3_config().)^
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**
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** See the [threading mode] documentation for additional information.
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*/
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SQLITE_API int sqlite3_threadsafe(void);
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/*
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** CAPI3REF: Database Connection Handle
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** KEYWORDS: {database connection} {database connections}
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**
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** Each open SQLite database is represented by a pointer to an instance of
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** the opaque structure named "sqlite3". It is useful to think of an sqlite3
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** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
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** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
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** and [sqlite3_close_v2()] are its destructors. There are many other
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** interfaces (such as
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** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
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** [sqlite3_busy_timeout()] to name but three) that are methods on an
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** sqlite3 object.
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*/
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typedef struct sqlite3 sqlite3;
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/*
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** CAPI3REF: 64-Bit Integer Types
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** KEYWORDS: sqlite_int64 sqlite_uint64
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**
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** Because there is no cross-platform way to specify 64-bit integer types
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** SQLite includes typedefs for 64-bit signed and unsigned integers.
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**
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** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
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** The sqlite_int64 and sqlite_uint64 types are supported for backwards
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** compatibility only.
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**
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** ^The sqlite3_int64 and sqlite_int64 types can store integer values
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** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
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** sqlite3_uint64 and sqlite_uint64 types can store integer values
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** between 0 and +18446744073709551615 inclusive.
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*/
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#ifdef SQLITE_INT64_TYPE
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typedef SQLITE_INT64_TYPE sqlite_int64;
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typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
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#elif defined(_MSC_VER) || defined(__BORLANDC__)
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typedef __int64 sqlite_int64;
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typedef unsigned __int64 sqlite_uint64;
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#else
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typedef long long int sqlite_int64;
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typedef unsigned long long int sqlite_uint64;
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#endif
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typedef sqlite_int64 sqlite3_int64;
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typedef sqlite_uint64 sqlite3_uint64;
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/*
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** If compiling for a processor that lacks floating point support,
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** substitute integer for floating-point.
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*/
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#ifdef SQLITE_OMIT_FLOATING_POINT
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# define double sqlite3_int64
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#endif
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/*
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** CAPI3REF: Closing A Database Connection
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**
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** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
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** for the [sqlite3] object.
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** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
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** the [sqlite3] object is successfully destroyed and all associated
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** resources are deallocated.
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**
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** ^If the database connection is associated with unfinalized prepared
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** statements or unfinished sqlite3_backup objects then sqlite3_close()
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** will leave the database connection open and return [SQLITE_BUSY].
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** ^If sqlite3_close_v2() is called with unfinalized prepared statements
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** and unfinished sqlite3_backups, then the database connection becomes
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** an unusable "zombie" which will automatically be deallocated when the
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** last prepared statement is finalized or the last sqlite3_backup is
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** finished. The sqlite3_close_v2() interface is intended for use with
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** host languages that are garbage collected, and where the order in which
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** destructors are called is arbitrary.
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**
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** Applications should [sqlite3_finalize | finalize] all [prepared statements],
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** [sqlite3_blob_close | close] all [BLOB handles], and
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** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
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** with the [sqlite3] object prior to attempting to close the object. ^If
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** sqlite3_close() is called on a [database connection] that still has
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** outstanding [prepared statements], [BLOB handles], and/or
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** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
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** of resources is deferred until all [prepared statements], [BLOB handles],
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** and [sqlite3_backup] objects are also destroyed.
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**
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** ^If an [sqlite3] object is destroyed while a transaction is open,
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** the transaction is automatically rolled back.
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**
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** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
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** must be either a NULL
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** pointer or an [sqlite3] object pointer obtained
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** from [sqlite3_open()], [sqlite3_open16()], or
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** [sqlite3_open_v2()], and not previously closed.
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** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
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** argument is a harmless no-op.
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*/
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SQLITE_API int sqlite3_close(sqlite3*);
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SQLITE_API int sqlite3_close_v2(sqlite3*);
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/*
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** The type for a callback function.
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** This is legacy and deprecated. It is included for historical
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** compatibility and is not documented.
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*/
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typedef int (*sqlite3_callback)(void*,int,char**, char**);
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/*
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** CAPI3REF: One-Step Query Execution Interface
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**
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** The sqlite3_exec() interface is a convenience wrapper around
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** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
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** that allows an application to run multiple statements of SQL
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** without having to use a lot of C code.
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**
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** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
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** semicolon-separate SQL statements passed into its 2nd argument,
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** in the context of the [database connection] passed in as its 1st
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** argument. ^If the callback function of the 3rd argument to
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** sqlite3_exec() is not NULL, then it is invoked for each result row
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** coming out of the evaluated SQL statements. ^The 4th argument to
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** sqlite3_exec() is relayed through to the 1st argument of each
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** callback invocation. ^If the callback pointer to sqlite3_exec()
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** is NULL, then no callback is ever invoked and result rows are
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** ignored.
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**
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** ^If an error occurs while evaluating the SQL statements passed into
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** sqlite3_exec(), then execution of the current statement stops and
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** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
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** is not NULL then any error message is written into memory obtained
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** from [sqlite3_malloc()] and passed back through the 5th parameter.
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** To avoid memory leaks, the application should invoke [sqlite3_free()]
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** on error message strings returned through the 5th parameter of
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** of sqlite3_exec() after the error message string is no longer needed.
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** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
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** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
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** NULL before returning.
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**
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** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
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** routine returns SQLITE_ABORT without invoking the callback again and
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** without running any subsequent SQL statements.
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**
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** ^The 2nd argument to the sqlite3_exec() callback function is the
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** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
|
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** callback is an array of pointers to strings obtained as if from
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** [sqlite3_column_text()], one for each column. ^If an element of a
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** result row is NULL then the corresponding string pointer for the
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** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
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** sqlite3_exec() callback is an array of pointers to strings where each
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** entry represents the name of corresponding result column as obtained
|
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** from [sqlite3_column_name()].
|
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**
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** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
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** to an empty string, or a pointer that contains only whitespace and/or
|
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** SQL comments, then no SQL statements are evaluated and the database
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** is not changed.
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**
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** Restrictions:
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**
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** <ul>
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** <li> The application must insure that the 1st parameter to sqlite3_exec()
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** is a valid and open [database connection].
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** <li> The application must not close [database connection] specified by
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** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
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** <li> The application must not modify the SQL statement text passed into
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** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
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** </ul>
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*/
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SQLITE_API int sqlite3_exec(
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sqlite3*, /* An open database */
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const char *sql, /* SQL to be evaluated */
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int (*callback)(void*,int,char**,char**), /* Callback function */
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void *, /* 1st argument to callback */
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char **errmsg /* Error msg written here */
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);
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/*
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** CAPI3REF: Result Codes
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|
** KEYWORDS: SQLITE_OK {error code} {error codes}
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|
** KEYWORDS: {result code} {result codes}
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|
**
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|
** Many SQLite functions return an integer result code from the set shown
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** here in order to indicate success or failure.
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|
**
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** New error codes may be added in future versions of SQLite.
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|
**
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** See also: [SQLITE_IOERR_READ | extended result codes],
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** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
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*/
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#define SQLITE_OK 0 /* Successful result */
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/* beginning-of-error-codes */
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#define SQLITE_ERROR 1 /* SQL error or missing database */
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#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
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#define SQLITE_PERM 3 /* Access permission denied */
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#define SQLITE_ABORT 4 /* Callback routine requested an abort */
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#define SQLITE_BUSY 5 /* The database file is locked */
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#define SQLITE_LOCKED 6 /* A table in the database is locked */
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#define SQLITE_NOMEM 7 /* A malloc() failed */
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#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
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#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
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#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
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#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
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#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
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#define SQLITE_FULL 13 /* Insertion failed because database is full */
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#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
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#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
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#define SQLITE_EMPTY 16 /* Database is empty */
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#define SQLITE_SCHEMA 17 /* The database schema changed */
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#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
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#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
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#define SQLITE_MISMATCH 20 /* Data type mismatch */
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#define SQLITE_MISUSE 21 /* Library used incorrectly */
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#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
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#define SQLITE_AUTH 23 /* Authorization denied */
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#define SQLITE_FORMAT 24 /* Auxiliary database format error */
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#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
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|
#define SQLITE_NOTADB 26 /* File opened that is not a database file */
|
|
#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
|
|
#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
|
|
/* end-of-error-codes */
|
|
|
|
/*
|
|
** CAPI3REF: Extended Result Codes
|
|
** KEYWORDS: {extended error code} {extended error codes}
|
|
** KEYWORDS: {extended result code} {extended result codes}
|
|
**
|
|
** In its default configuration, SQLite API routines return one of 26 integer
|
|
** [SQLITE_OK | result codes]. However, experience has shown that many of
|
|
** these result codes are too coarse-grained. They do not provide as
|
|
** much information about problems as programmers might like. In an effort to
|
|
** address this, newer versions of SQLite (version 3.3.8 and later) include
|
|
** support for additional result codes that provide more detailed information
|
|
** about errors. The extended result codes are enabled or disabled
|
|
** on a per database connection basis using the
|
|
** [sqlite3_extended_result_codes()] API.
|
|
**
|
|
** Some of the available extended result codes are listed here.
|
|
** One may expect the number of extended result codes will be expand
|
|
** over time. Software that uses extended result codes should expect
|
|
** to see new result codes in future releases of SQLite.
|
|
**
|
|
** The SQLITE_OK result code will never be extended. It will always
|
|
** be exactly zero.
|
|
*/
|
|
#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
|
|
#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
|
|
#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
|
|
#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
|
|
#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
|
|
#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
|
|
#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
|
|
#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
|
|
#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
|
|
#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
|
|
#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
|
|
#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
|
|
#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
|
|
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
|
|
#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
|
|
#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
|
|
#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
|
|
#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
|
|
#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
|
|
#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
|
|
#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
|
|
#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
|
|
#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
|
|
#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
|
|
#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
|
|
#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
|
|
#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
|
|
#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
|
|
#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
|
|
#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
|
|
#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
|
|
#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
|
|
|
|
/*
|
|
** CAPI3REF: Flags For File Open Operations
|
|
**
|
|
** These bit values are intended for use in the
|
|
** 3rd parameter to the [sqlite3_open_v2()] interface and
|
|
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
|
|
*/
|
|
#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
|
|
#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
|
|
#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
|
|
#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
|
|
#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
|
|
#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
|
|
#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
|
|
#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
|
|
#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
|
|
#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
|
|
#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
|
|
#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
|
|
|
|
/* Reserved: 0x00F00000 */
|
|
|
|
/*
|
|
** CAPI3REF: Device Characteristics
|
|
**
|
|
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
|
|
** object returns an integer which is a vector of these
|
|
** bit values expressing I/O characteristics of the mass storage
|
|
** device that holds the file that the [sqlite3_io_methods]
|
|
** refers to.
|
|
**
|
|
** The SQLITE_IOCAP_ATOMIC property means that all writes of
|
|
** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
|
|
** mean that writes of blocks that are nnn bytes in size and
|
|
** are aligned to an address which is an integer multiple of
|
|
** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
|
|
** that when data is appended to a file, the data is appended
|
|
** first then the size of the file is extended, never the other
|
|
** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
|
|
** information is written to disk in the same order as calls
|
|
** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
|
|
** after reboot following a crash or power loss, the only bytes in a
|
|
** file that were written at the application level might have changed
|
|
** and that adjacent bytes, even bytes within the same sector are
|
|
** guaranteed to be unchanged.
|
|
*/
|
|
#define SQLITE_IOCAP_ATOMIC 0x00000001
|
|
#define SQLITE_IOCAP_ATOMIC512 0x00000002
|
|
#define SQLITE_IOCAP_ATOMIC1K 0x00000004
|
|
#define SQLITE_IOCAP_ATOMIC2K 0x00000008
|
|
#define SQLITE_IOCAP_ATOMIC4K 0x00000010
|
|
#define SQLITE_IOCAP_ATOMIC8K 0x00000020
|
|
#define SQLITE_IOCAP_ATOMIC16K 0x00000040
|
|
#define SQLITE_IOCAP_ATOMIC32K 0x00000080
|
|
#define SQLITE_IOCAP_ATOMIC64K 0x00000100
|
|
#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
|
|
#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
|
|
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
|
|
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
|
|
|
|
/*
|
|
** CAPI3REF: File Locking Levels
|
|
**
|
|
** SQLite uses one of these integer values as the second
|
|
** argument to calls it makes to the xLock() and xUnlock() methods
|
|
** of an [sqlite3_io_methods] object.
|
|
*/
|
|
#define SQLITE_LOCK_NONE 0
|
|
#define SQLITE_LOCK_SHARED 1
|
|
#define SQLITE_LOCK_RESERVED 2
|
|
#define SQLITE_LOCK_PENDING 3
|
|
#define SQLITE_LOCK_EXCLUSIVE 4
|
|
|
|
/*
|
|
** CAPI3REF: Synchronization Type Flags
|
|
**
|
|
** When SQLite invokes the xSync() method of an
|
|
** [sqlite3_io_methods] object it uses a combination of
|
|
** these integer values as the second argument.
|
|
**
|
|
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
|
|
** sync operation only needs to flush data to mass storage. Inode
|
|
** information need not be flushed. If the lower four bits of the flag
|
|
** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
|
|
** If the lower four bits equal SQLITE_SYNC_FULL, that means
|
|
** to use Mac OS X style fullsync instead of fsync().
|
|
**
|
|
** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
|
|
** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
|
|
** settings. The [synchronous pragma] determines when calls to the
|
|
** xSync VFS method occur and applies uniformly across all platforms.
|
|
** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
|
|
** energetic or rigorous or forceful the sync operations are and
|
|
** only make a difference on Mac OSX for the default SQLite code.
|
|
** (Third-party VFS implementations might also make the distinction
|
|
** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
|
|
** operating systems natively supported by SQLite, only Mac OSX
|
|
** cares about the difference.)
|
|
*/
|
|
#define SQLITE_SYNC_NORMAL 0x00002
|
|
#define SQLITE_SYNC_FULL 0x00003
|
|
#define SQLITE_SYNC_DATAONLY 0x00010
|
|
|
|
/*
|
|
** CAPI3REF: OS Interface Open File Handle
|
|
**
|
|
** An [sqlite3_file] object represents an open file in the
|
|
** [sqlite3_vfs | OS interface layer]. Individual OS interface
|
|
** implementations will
|
|
** want to subclass this object by appending additional fields
|
|
** for their own use. The pMethods entry is a pointer to an
|
|
** [sqlite3_io_methods] object that defines methods for performing
|
|
** I/O operations on the open file.
|
|
*/
|
|
typedef struct sqlite3_file sqlite3_file;
|
|
struct sqlite3_file {
|
|
const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: OS Interface File Virtual Methods Object
|
|
**
|
|
** Every file opened by the [sqlite3_vfs.xOpen] method populates an
|
|
** [sqlite3_file] object (or, more commonly, a subclass of the
|
|
** [sqlite3_file] object) with a pointer to an instance of this object.
|
|
** This object defines the methods used to perform various operations
|
|
** against the open file represented by the [sqlite3_file] object.
|
|
**
|
|
** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
|
|
** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
|
|
** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
|
|
** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
|
|
** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
|
|
** to NULL.
|
|
**
|
|
** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
|
|
** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
|
|
** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
|
|
** flag may be ORed in to indicate that only the data of the file
|
|
** and not its inode needs to be synced.
|
|
**
|
|
** The integer values to xLock() and xUnlock() are one of
|
|
** <ul>
|
|
** <li> [SQLITE_LOCK_NONE],
|
|
** <li> [SQLITE_LOCK_SHARED],
|
|
** <li> [SQLITE_LOCK_RESERVED],
|
|
** <li> [SQLITE_LOCK_PENDING], or
|
|
** <li> [SQLITE_LOCK_EXCLUSIVE].
|
|
** </ul>
|
|
** xLock() increases the lock. xUnlock() decreases the lock.
|
|
** The xCheckReservedLock() method checks whether any database connection,
|
|
** either in this process or in some other process, is holding a RESERVED,
|
|
** PENDING, or EXCLUSIVE lock on the file. It returns true
|
|
** if such a lock exists and false otherwise.
|
|
**
|
|
** The xFileControl() method is a generic interface that allows custom
|
|
** VFS implementations to directly control an open file using the
|
|
** [sqlite3_file_control()] interface. The second "op" argument is an
|
|
** integer opcode. The third argument is a generic pointer intended to
|
|
** point to a structure that may contain arguments or space in which to
|
|
** write return values. Potential uses for xFileControl() might be
|
|
** functions to enable blocking locks with timeouts, to change the
|
|
** locking strategy (for example to use dot-file locks), to inquire
|
|
** about the status of a lock, or to break stale locks. The SQLite
|
|
** core reserves all opcodes less than 100 for its own use.
|
|
** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
|
|
** Applications that define a custom xFileControl method should use opcodes
|
|
** greater than 100 to avoid conflicts. VFS implementations should
|
|
** return [SQLITE_NOTFOUND] for file control opcodes that they do not
|
|
** recognize.
|
|
**
|
|
** The xSectorSize() method returns the sector size of the
|
|
** device that underlies the file. The sector size is the
|
|
** minimum write that can be performed without disturbing
|
|
** other bytes in the file. The xDeviceCharacteristics()
|
|
** method returns a bit vector describing behaviors of the
|
|
** underlying device:
|
|
**
|
|
** <ul>
|
|
** <li> [SQLITE_IOCAP_ATOMIC]
|
|
** <li> [SQLITE_IOCAP_ATOMIC512]
|
|
** <li> [SQLITE_IOCAP_ATOMIC1K]
|
|
** <li> [SQLITE_IOCAP_ATOMIC2K]
|
|
** <li> [SQLITE_IOCAP_ATOMIC4K]
|
|
** <li> [SQLITE_IOCAP_ATOMIC8K]
|
|
** <li> [SQLITE_IOCAP_ATOMIC16K]
|
|
** <li> [SQLITE_IOCAP_ATOMIC32K]
|
|
** <li> [SQLITE_IOCAP_ATOMIC64K]
|
|
** <li> [SQLITE_IOCAP_SAFE_APPEND]
|
|
** <li> [SQLITE_IOCAP_SEQUENTIAL]
|
|
** </ul>
|
|
**
|
|
** The SQLITE_IOCAP_ATOMIC property means that all writes of
|
|
** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
|
|
** mean that writes of blocks that are nnn bytes in size and
|
|
** are aligned to an address which is an integer multiple of
|
|
** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
|
|
** that when data is appended to a file, the data is appended
|
|
** first then the size of the file is extended, never the other
|
|
** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
|
|
** information is written to disk in the same order as calls
|
|
** to xWrite().
|
|
**
|
|
** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
|
|
** in the unread portions of the buffer with zeros. A VFS that
|
|
** fails to zero-fill short reads might seem to work. However,
|
|
** failure to zero-fill short reads will eventually lead to
|
|
** database corruption.
|
|
*/
|
|
typedef struct sqlite3_io_methods sqlite3_io_methods;
|
|
struct sqlite3_io_methods {
|
|
int iVersion;
|
|
int (*xClose)(sqlite3_file*);
|
|
int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
|
|
int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
|
|
int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
|
|
int (*xSync)(sqlite3_file*, int flags);
|
|
int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
|
|
int (*xLock)(sqlite3_file*, int);
|
|
int (*xUnlock)(sqlite3_file*, int);
|
|
int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
|
|
int (*xFileControl)(sqlite3_file*, int op, void *pArg);
|
|
int (*xSectorSize)(sqlite3_file*);
|
|
int (*xDeviceCharacteristics)(sqlite3_file*);
|
|
/* Methods above are valid for version 1 */
|
|
int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
|
|
int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
|
|
void (*xShmBarrier)(sqlite3_file*);
|
|
int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
|
|
/* Methods above are valid for version 2 */
|
|
/* Additional methods may be added in future releases */
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Standard File Control Opcodes
|
|
**
|
|
** These integer constants are opcodes for the xFileControl method
|
|
** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
|
|
** interface.
|
|
**
|
|
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
|
|
** opcode causes the xFileControl method to write the current state of
|
|
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
|
|
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
|
|
** into an integer that the pArg argument points to. This capability
|
|
** is used during testing and only needs to be supported when SQLITE_TEST
|
|
** is defined.
|
|
** <ul>
|
|
** <li>[[SQLITE_FCNTL_SIZE_HINT]]
|
|
** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
|
|
** layer a hint of how large the database file will grow to be during the
|
|
** current transaction. This hint is not guaranteed to be accurate but it
|
|
** is often close. The underlying VFS might choose to preallocate database
|
|
** file space based on this hint in order to help writes to the database
|
|
** file run faster.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
|
|
** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
|
|
** extends and truncates the database file in chunks of a size specified
|
|
** by the user. The fourth argument to [sqlite3_file_control()] should
|
|
** point to an integer (type int) containing the new chunk-size to use
|
|
** for the nominated database. Allocating database file space in large
|
|
** chunks (say 1MB at a time), may reduce file-system fragmentation and
|
|
** improve performance on some systems.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_FILE_POINTER]]
|
|
** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
|
|
** to the [sqlite3_file] object associated with a particular database
|
|
** connection. See the [sqlite3_file_control()] documentation for
|
|
** additional information.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
|
|
** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
|
|
** SQLite and sent to all VFSes in place of a call to the xSync method
|
|
** when the database connection has [PRAGMA synchronous] set to OFF.)^
|
|
** Some specialized VFSes need this signal in order to operate correctly
|
|
** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most
|
|
** VFSes do not need this signal and should silently ignore this opcode.
|
|
** Applications should not call [sqlite3_file_control()] with this
|
|
** opcode as doing so may disrupt the operation of the specialized VFSes
|
|
** that do require it.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
|
|
** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
|
|
** retry counts and intervals for certain disk I/O operations for the
|
|
** windows [VFS] in order to provide robustness in the presence of
|
|
** anti-virus programs. By default, the windows VFS will retry file read,
|
|
** file write, and file delete operations up to 10 times, with a delay
|
|
** of 25 milliseconds before the first retry and with the delay increasing
|
|
** by an additional 25 milliseconds with each subsequent retry. This
|
|
** opcode allows these two values (10 retries and 25 milliseconds of delay)
|
|
** to be adjusted. The values are changed for all database connections
|
|
** within the same process. The argument is a pointer to an array of two
|
|
** integers where the first integer i the new retry count and the second
|
|
** integer is the delay. If either integer is negative, then the setting
|
|
** is not changed but instead the prior value of that setting is written
|
|
** into the array entry, allowing the current retry settings to be
|
|
** interrogated. The zDbName parameter is ignored.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
|
|
** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
|
|
** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
|
|
** write ahead log and shared memory files used for transaction control
|
|
** are automatically deleted when the latest connection to the database
|
|
** closes. Setting persistent WAL mode causes those files to persist after
|
|
** close. Persisting the files is useful when other processes that do not
|
|
** have write permission on the directory containing the database file want
|
|
** to read the database file, as the WAL and shared memory files must exist
|
|
** in order for the database to be readable. The fourth parameter to
|
|
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
|
|
** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
|
|
** WAL mode. If the integer is -1, then it is overwritten with the current
|
|
** WAL persistence setting.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
|
|
** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
|
|
** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
|
|
** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
|
|
** xDeviceCharacteristics methods. The fourth parameter to
|
|
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
|
|
** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
|
|
** mode. If the integer is -1, then it is overwritten with the current
|
|
** zero-damage mode setting.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_OVERWRITE]]
|
|
** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
|
|
** a write transaction to indicate that, unless it is rolled back for some
|
|
** reason, the entire database file will be overwritten by the current
|
|
** transaction. This is used by VACUUM operations.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_VFSNAME]]
|
|
** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
|
|
** all [VFSes] in the VFS stack. The names are of all VFS shims and the
|
|
** final bottom-level VFS are written into memory obtained from
|
|
** [sqlite3_malloc()] and the result is stored in the char* variable
|
|
** that the fourth parameter of [sqlite3_file_control()] points to.
|
|
** The caller is responsible for freeing the memory when done. As with
|
|
** all file-control actions, there is no guarantee that this will actually
|
|
** do anything. Callers should initialize the char* variable to a NULL
|
|
** pointer in case this file-control is not implemented. This file-control
|
|
** is intended for diagnostic use only.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_PRAGMA]]
|
|
** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
|
|
** file control is sent to the open [sqlite3_file] object corresponding
|
|
** to the database file to which the pragma statement refers. ^The argument
|
|
** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
|
|
** pointers to strings (char**) in which the second element of the array
|
|
** is the name of the pragma and the third element is the argument to the
|
|
** pragma or NULL if the pragma has no argument. ^The handler for an
|
|
** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
|
|
** of the char** argument point to a string obtained from [sqlite3_mprintf()]
|
|
** or the equivalent and that string will become the result of the pragma or
|
|
** the error message if the pragma fails. ^If the
|
|
** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
|
|
** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
|
|
** file control returns [SQLITE_OK], then the parser assumes that the
|
|
** VFS has handled the PRAGMA itself and the parser generates a no-op
|
|
** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns
|
|
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
|
|
** that the VFS encountered an error while handling the [PRAGMA] and the
|
|
** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
|
|
** file control occurs at the beginning of pragma statement analysis and so
|
|
** it is able to override built-in [PRAGMA] statements.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
|
|
** ^This file-control may be invoked by SQLite on the database file handle
|
|
** shortly after it is opened in order to provide a custom VFS with access
|
|
** to the connections busy-handler callback. The argument is of type (void **)
|
|
** - an array of two (void *) values. The first (void *) actually points
|
|
** to a function of type (int (*)(void *)). In order to invoke the connections
|
|
** busy-handler, this function should be invoked with the second (void *) in
|
|
** the array as the only argument. If it returns non-zero, then the operation
|
|
** should be retried. If it returns zero, the custom VFS should abandon the
|
|
** current operation.
|
|
**
|
|
** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
|
|
** ^Application can invoke this file-control to have SQLite generate a
|
|
** temporary filename using the same algorithm that is followed to generate
|
|
** temporary filenames for TEMP tables and other internal uses. The
|
|
** argument should be a char** which will be filled with the filename
|
|
** written into memory obtained from [sqlite3_malloc()]. The caller should
|
|
** invoke [sqlite3_free()] on the result to avoid a memory leak.
|
|
**
|
|
** </ul>
|
|
*/
|
|
#define SQLITE_FCNTL_LOCKSTATE 1
|
|
#define SQLITE_GET_LOCKPROXYFILE 2
|
|
#define SQLITE_SET_LOCKPROXYFILE 3
|
|
#define SQLITE_LAST_ERRNO 4
|
|
#define SQLITE_FCNTL_SIZE_HINT 5
|
|
#define SQLITE_FCNTL_CHUNK_SIZE 6
|
|
#define SQLITE_FCNTL_FILE_POINTER 7
|
|
#define SQLITE_FCNTL_SYNC_OMITTED 8
|
|
#define SQLITE_FCNTL_WIN32_AV_RETRY 9
|
|
#define SQLITE_FCNTL_PERSIST_WAL 10
|
|
#define SQLITE_FCNTL_OVERWRITE 11
|
|
#define SQLITE_FCNTL_VFSNAME 12
|
|
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
|
|
#define SQLITE_FCNTL_PRAGMA 14
|
|
#define SQLITE_FCNTL_BUSYHANDLER 15
|
|
#define SQLITE_FCNTL_TEMPFILENAME 16
|
|
|
|
/*
|
|
** CAPI3REF: Mutex Handle
|
|
**
|
|
** The mutex module within SQLite defines [sqlite3_mutex] to be an
|
|
** abstract type for a mutex object. The SQLite core never looks
|
|
** at the internal representation of an [sqlite3_mutex]. It only
|
|
** deals with pointers to the [sqlite3_mutex] object.
|
|
**
|
|
** Mutexes are created using [sqlite3_mutex_alloc()].
|
|
*/
|
|
typedef struct sqlite3_mutex sqlite3_mutex;
|
|
|
|
/*
|
|
** CAPI3REF: OS Interface Object
|
|
**
|
|
** An instance of the sqlite3_vfs object defines the interface between
|
|
** the SQLite core and the underlying operating system. The "vfs"
|
|
** in the name of the object stands for "virtual file system". See
|
|
** the [VFS | VFS documentation] for further information.
|
|
**
|
|
** The value of the iVersion field is initially 1 but may be larger in
|
|
** future versions of SQLite. Additional fields may be appended to this
|
|
** object when the iVersion value is increased. Note that the structure
|
|
** of the sqlite3_vfs object changes in the transaction between
|
|
** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
|
|
** modified.
|
|
**
|
|
** The szOsFile field is the size of the subclassed [sqlite3_file]
|
|
** structure used by this VFS. mxPathname is the maximum length of
|
|
** a pathname in this VFS.
|
|
**
|
|
** Registered sqlite3_vfs objects are kept on a linked list formed by
|
|
** the pNext pointer. The [sqlite3_vfs_register()]
|
|
** and [sqlite3_vfs_unregister()] interfaces manage this list
|
|
** in a thread-safe way. The [sqlite3_vfs_find()] interface
|
|
** searches the list. Neither the application code nor the VFS
|
|
** implementation should use the pNext pointer.
|
|
**
|
|
** The pNext field is the only field in the sqlite3_vfs
|
|
** structure that SQLite will ever modify. SQLite will only access
|
|
** or modify this field while holding a particular static mutex.
|
|
** The application should never modify anything within the sqlite3_vfs
|
|
** object once the object has been registered.
|
|
**
|
|
** The zName field holds the name of the VFS module. The name must
|
|
** be unique across all VFS modules.
|
|
**
|
|
** [[sqlite3_vfs.xOpen]]
|
|
** ^SQLite guarantees that the zFilename parameter to xOpen
|
|
** is either a NULL pointer or string obtained
|
|
** from xFullPathname() with an optional suffix added.
|
|
** ^If a suffix is added to the zFilename parameter, it will
|
|
** consist of a single "-" character followed by no more than
|
|
** 11 alphanumeric and/or "-" characters.
|
|
** ^SQLite further guarantees that
|
|
** the string will be valid and unchanged until xClose() is
|
|
** called. Because of the previous sentence,
|
|
** the [sqlite3_file] can safely store a pointer to the
|
|
** filename if it needs to remember the filename for some reason.
|
|
** If the zFilename parameter to xOpen is a NULL pointer then xOpen
|
|
** must invent its own temporary name for the file. ^Whenever the
|
|
** xFilename parameter is NULL it will also be the case that the
|
|
** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
|
|
**
|
|
** The flags argument to xOpen() includes all bits set in
|
|
** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
|
|
** or [sqlite3_open16()] is used, then flags includes at least
|
|
** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
|
|
** If xOpen() opens a file read-only then it sets *pOutFlags to
|
|
** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
|
|
**
|
|
** ^(SQLite will also add one of the following flags to the xOpen()
|
|
** call, depending on the object being opened:
|
|
**
|
|
** <ul>
|
|
** <li> [SQLITE_OPEN_MAIN_DB]
|
|
** <li> [SQLITE_OPEN_MAIN_JOURNAL]
|
|
** <li> [SQLITE_OPEN_TEMP_DB]
|
|
** <li> [SQLITE_OPEN_TEMP_JOURNAL]
|
|
** <li> [SQLITE_OPEN_TRANSIENT_DB]
|
|
** <li> [SQLITE_OPEN_SUBJOURNAL]
|
|
** <li> [SQLITE_OPEN_MASTER_JOURNAL]
|
|
** <li> [SQLITE_OPEN_WAL]
|
|
** </ul>)^
|
|
**
|
|
** The file I/O implementation can use the object type flags to
|
|
** change the way it deals with files. For example, an application
|
|
** that does not care about crash recovery or rollback might make
|
|
** the open of a journal file a no-op. Writes to this journal would
|
|
** also be no-ops, and any attempt to read the journal would return
|
|
** SQLITE_IOERR. Or the implementation might recognize that a database
|
|
** file will be doing page-aligned sector reads and writes in a random
|
|
** order and set up its I/O subsystem accordingly.
|
|
**
|
|
** SQLite might also add one of the following flags to the xOpen method:
|
|
**
|
|
** <ul>
|
|
** <li> [SQLITE_OPEN_DELETEONCLOSE]
|
|
** <li> [SQLITE_OPEN_EXCLUSIVE]
|
|
** </ul>
|
|
**
|
|
** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
|
|
** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
|
|
** will be set for TEMP databases and their journals, transient
|
|
** databases, and subjournals.
|
|
**
|
|
** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
|
|
** with the [SQLITE_OPEN_CREATE] flag, which are both directly
|
|
** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
|
|
** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
|
|
** SQLITE_OPEN_CREATE, is used to indicate that file should always
|
|
** be created, and that it is an error if it already exists.
|
|
** It is <i>not</i> used to indicate the file should be opened
|
|
** for exclusive access.
|
|
**
|
|
** ^At least szOsFile bytes of memory are allocated by SQLite
|
|
** to hold the [sqlite3_file] structure passed as the third
|
|
** argument to xOpen. The xOpen method does not have to
|
|
** allocate the structure; it should just fill it in. Note that
|
|
** the xOpen method must set the sqlite3_file.pMethods to either
|
|
** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
|
|
** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
|
|
** element will be valid after xOpen returns regardless of the success
|
|
** or failure of the xOpen call.
|
|
**
|
|
** [[sqlite3_vfs.xAccess]]
|
|
** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
|
|
** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
|
|
** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
|
|
** to test whether a file is at least readable. The file can be a
|
|
** directory.
|
|
**
|
|
** ^SQLite will always allocate at least mxPathname+1 bytes for the
|
|
** output buffer xFullPathname. The exact size of the output buffer
|
|
** is also passed as a parameter to both methods. If the output buffer
|
|
** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
|
|
** handled as a fatal error by SQLite, vfs implementations should endeavor
|
|
** to prevent this by setting mxPathname to a sufficiently large value.
|
|
**
|
|
** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
|
|
** interfaces are not strictly a part of the filesystem, but they are
|
|
** included in the VFS structure for completeness.
|
|
** The xRandomness() function attempts to return nBytes bytes
|
|
** of good-quality randomness into zOut. The return value is
|
|
** the actual number of bytes of randomness obtained.
|
|
** The xSleep() method causes the calling thread to sleep for at
|
|
** least the number of microseconds given. ^The xCurrentTime()
|
|
** method returns a Julian Day Number for the current date and time as
|
|
** a floating point value.
|
|
** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
|
|
** Day Number multiplied by 86400000 (the number of milliseconds in
|
|
** a 24-hour day).
|
|
** ^SQLite will use the xCurrentTimeInt64() method to get the current
|
|
** date and time if that method is available (if iVersion is 2 or
|
|
** greater and the function pointer is not NULL) and will fall back
|
|
** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
|
|
**
|
|
** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
|
|
** are not used by the SQLite core. These optional interfaces are provided
|
|
** by some VFSes to facilitate testing of the VFS code. By overriding
|
|
** system calls with functions under its control, a test program can
|
|
** simulate faults and error conditions that would otherwise be difficult
|
|
** or impossible to induce. The set of system calls that can be overridden
|
|
** varies from one VFS to another, and from one version of the same VFS to the
|
|
** next. Applications that use these interfaces must be prepared for any
|
|
** or all of these interfaces to be NULL or for their behavior to change
|
|
** from one release to the next. Applications must not attempt to access
|
|
** any of these methods if the iVersion of the VFS is less than 3.
|
|
*/
|
|
typedef struct sqlite3_vfs sqlite3_vfs;
|
|
typedef void (*sqlite3_syscall_ptr)(void);
|
|
struct sqlite3_vfs {
|
|
int iVersion; /* Structure version number (currently 3) */
|
|
int szOsFile; /* Size of subclassed sqlite3_file */
|
|
int mxPathname; /* Maximum file pathname length */
|
|
sqlite3_vfs *pNext; /* Next registered VFS */
|
|
const char *zName; /* Name of this virtual file system */
|
|
void *pAppData; /* Pointer to application-specific data */
|
|
int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
|
|
int flags, int *pOutFlags);
|
|
int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
|
|
int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
|
|
int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
|
|
void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
|
|
void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
|
|
void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
|
|
void (*xDlClose)(sqlite3_vfs*, void*);
|
|
int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
|
|
int (*xSleep)(sqlite3_vfs*, int microseconds);
|
|
int (*xCurrentTime)(sqlite3_vfs*, double*);
|
|
int (*xGetLastError)(sqlite3_vfs*, int, char *);
|
|
/*
|
|
** The methods above are in version 1 of the sqlite_vfs object
|
|
** definition. Those that follow are added in version 2 or later
|
|
*/
|
|
int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
|
|
/*
|
|
** The methods above are in versions 1 and 2 of the sqlite_vfs object.
|
|
** Those below are for version 3 and greater.
|
|
*/
|
|
int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
|
|
sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
|
|
const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
|
|
/*
|
|
** The methods above are in versions 1 through 3 of the sqlite_vfs object.
|
|
** New fields may be appended in figure versions. The iVersion
|
|
** value will increment whenever this happens.
|
|
*/
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Flags for the xAccess VFS method
|
|
**
|
|
** These integer constants can be used as the third parameter to
|
|
** the xAccess method of an [sqlite3_vfs] object. They determine
|
|
** what kind of permissions the xAccess method is looking for.
|
|
** With SQLITE_ACCESS_EXISTS, the xAccess method
|
|
** simply checks whether the file exists.
|
|
** With SQLITE_ACCESS_READWRITE, the xAccess method
|
|
** checks whether the named directory is both readable and writable
|
|
** (in other words, if files can be added, removed, and renamed within
|
|
** the directory).
|
|
** The SQLITE_ACCESS_READWRITE constant is currently used only by the
|
|
** [temp_store_directory pragma], though this could change in a future
|
|
** release of SQLite.
|
|
** With SQLITE_ACCESS_READ, the xAccess method
|
|
** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
|
|
** currently unused, though it might be used in a future release of
|
|
** SQLite.
|
|
*/
|
|
#define SQLITE_ACCESS_EXISTS 0
|
|
#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
|
|
#define SQLITE_ACCESS_READ 2 /* Unused */
|
|
|
|
/*
|
|
** CAPI3REF: Flags for the xShmLock VFS method
|
|
**
|
|
** These integer constants define the various locking operations
|
|
** allowed by the xShmLock method of [sqlite3_io_methods]. The
|
|
** following are the only legal combinations of flags to the
|
|
** xShmLock method:
|
|
**
|
|
** <ul>
|
|
** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
|
|
** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
|
|
** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
|
|
** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
|
|
** </ul>
|
|
**
|
|
** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
|
|
** was given no the corresponding lock.
|
|
**
|
|
** The xShmLock method can transition between unlocked and SHARED or
|
|
** between unlocked and EXCLUSIVE. It cannot transition between SHARED
|
|
** and EXCLUSIVE.
|
|
*/
|
|
#define SQLITE_SHM_UNLOCK 1
|
|
#define SQLITE_SHM_LOCK 2
|
|
#define SQLITE_SHM_SHARED 4
|
|
#define SQLITE_SHM_EXCLUSIVE 8
|
|
|
|
/*
|
|
** CAPI3REF: Maximum xShmLock index
|
|
**
|
|
** The xShmLock method on [sqlite3_io_methods] may use values
|
|
** between 0 and this upper bound as its "offset" argument.
|
|
** The SQLite core will never attempt to acquire or release a
|
|
** lock outside of this range
|
|
*/
|
|
#define SQLITE_SHM_NLOCK 8
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Initialize The SQLite Library
|
|
**
|
|
** ^The sqlite3_initialize() routine initializes the
|
|
** SQLite library. ^The sqlite3_shutdown() routine
|
|
** deallocates any resources that were allocated by sqlite3_initialize().
|
|
** These routines are designed to aid in process initialization and
|
|
** shutdown on embedded systems. Workstation applications using
|
|
** SQLite normally do not need to invoke either of these routines.
|
|
**
|
|
** A call to sqlite3_initialize() is an "effective" call if it is
|
|
** the first time sqlite3_initialize() is invoked during the lifetime of
|
|
** the process, or if it is the first time sqlite3_initialize() is invoked
|
|
** following a call to sqlite3_shutdown(). ^(Only an effective call
|
|
** of sqlite3_initialize() does any initialization. All other calls
|
|
** are harmless no-ops.)^
|
|
**
|
|
** A call to sqlite3_shutdown() is an "effective" call if it is the first
|
|
** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
|
|
** an effective call to sqlite3_shutdown() does any deinitialization.
|
|
** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
|
|
**
|
|
** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
|
|
** is not. The sqlite3_shutdown() interface must only be called from a
|
|
** single thread. All open [database connections] must be closed and all
|
|
** other SQLite resources must be deallocated prior to invoking
|
|
** sqlite3_shutdown().
|
|
**
|
|
** Among other things, ^sqlite3_initialize() will invoke
|
|
** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
|
|
** will invoke sqlite3_os_end().
|
|
**
|
|
** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
|
|
** ^If for some reason, sqlite3_initialize() is unable to initialize
|
|
** the library (perhaps it is unable to allocate a needed resource such
|
|
** as a mutex) it returns an [error code] other than [SQLITE_OK].
|
|
**
|
|
** ^The sqlite3_initialize() routine is called internally by many other
|
|
** SQLite interfaces so that an application usually does not need to
|
|
** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
|
|
** calls sqlite3_initialize() so the SQLite library will be automatically
|
|
** initialized when [sqlite3_open()] is called if it has not be initialized
|
|
** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
|
|
** compile-time option, then the automatic calls to sqlite3_initialize()
|
|
** are omitted and the application must call sqlite3_initialize() directly
|
|
** prior to using any other SQLite interface. For maximum portability,
|
|
** it is recommended that applications always invoke sqlite3_initialize()
|
|
** directly prior to using any other SQLite interface. Future releases
|
|
** of SQLite may require this. In other words, the behavior exhibited
|
|
** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
|
|
** default behavior in some future release of SQLite.
|
|
**
|
|
** The sqlite3_os_init() routine does operating-system specific
|
|
** initialization of the SQLite library. The sqlite3_os_end()
|
|
** routine undoes the effect of sqlite3_os_init(). Typical tasks
|
|
** performed by these routines include allocation or deallocation
|
|
** of static resources, initialization of global variables,
|
|
** setting up a default [sqlite3_vfs] module, or setting up
|
|
** a default configuration using [sqlite3_config()].
|
|
**
|
|
** The application should never invoke either sqlite3_os_init()
|
|
** or sqlite3_os_end() directly. The application should only invoke
|
|
** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
|
|
** interface is called automatically by sqlite3_initialize() and
|
|
** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
|
|
** implementations for sqlite3_os_init() and sqlite3_os_end()
|
|
** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
|
|
** When [custom builds | built for other platforms]
|
|
** (using the [SQLITE_OS_OTHER=1] compile-time
|
|
** option) the application must supply a suitable implementation for
|
|
** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
|
|
** implementation of sqlite3_os_init() or sqlite3_os_end()
|
|
** must return [SQLITE_OK] on success and some other [error code] upon
|
|
** failure.
|
|
*/
|
|
SQLITE_API int sqlite3_initialize(void);
|
|
SQLITE_API int sqlite3_shutdown(void);
|
|
SQLITE_API int sqlite3_os_init(void);
|
|
SQLITE_API int sqlite3_os_end(void);
|
|
|
|
/*
|
|
** CAPI3REF: Configuring The SQLite Library
|
|
**
|
|
** The sqlite3_config() interface is used to make global configuration
|
|
** changes to SQLite in order to tune SQLite to the specific needs of
|
|
** the application. The default configuration is recommended for most
|
|
** applications and so this routine is usually not necessary. It is
|
|
** provided to support rare applications with unusual needs.
|
|
**
|
|
** The sqlite3_config() interface is not threadsafe. The application
|
|
** must insure that no other SQLite interfaces are invoked by other
|
|
** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
|
|
** may only be invoked prior to library initialization using
|
|
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
|
|
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
|
|
** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
|
|
** Note, however, that ^sqlite3_config() can be called as part of the
|
|
** implementation of an application-defined [sqlite3_os_init()].
|
|
**
|
|
** The first argument to sqlite3_config() is an integer
|
|
** [configuration option] that determines
|
|
** what property of SQLite is to be configured. Subsequent arguments
|
|
** vary depending on the [configuration option]
|
|
** in the first argument.
|
|
**
|
|
** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
|
|
** ^If the option is unknown or SQLite is unable to set the option
|
|
** then this routine returns a non-zero [error code].
|
|
*/
|
|
SQLITE_API int sqlite3_config(int, ...);
|
|
|
|
/*
|
|
** CAPI3REF: Configure database connections
|
|
**
|
|
** The sqlite3_db_config() interface is used to make configuration
|
|
** changes to a [database connection]. The interface is similar to
|
|
** [sqlite3_config()] except that the changes apply to a single
|
|
** [database connection] (specified in the first argument).
|
|
**
|
|
** The second argument to sqlite3_db_config(D,V,...) is the
|
|
** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
|
|
** that indicates what aspect of the [database connection] is being configured.
|
|
** Subsequent arguments vary depending on the configuration verb.
|
|
**
|
|
** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
|
|
** the call is considered successful.
|
|
*/
|
|
SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
|
|
|
|
/*
|
|
** CAPI3REF: Memory Allocation Routines
|
|
**
|
|
** An instance of this object defines the interface between SQLite
|
|
** and low-level memory allocation routines.
|
|
**
|
|
** This object is used in only one place in the SQLite interface.
|
|
** A pointer to an instance of this object is the argument to
|
|
** [sqlite3_config()] when the configuration option is
|
|
** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
|
|
** By creating an instance of this object
|
|
** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
|
|
** during configuration, an application can specify an alternative
|
|
** memory allocation subsystem for SQLite to use for all of its
|
|
** dynamic memory needs.
|
|
**
|
|
** Note that SQLite comes with several [built-in memory allocators]
|
|
** that are perfectly adequate for the overwhelming majority of applications
|
|
** and that this object is only useful to a tiny minority of applications
|
|
** with specialized memory allocation requirements. This object is
|
|
** also used during testing of SQLite in order to specify an alternative
|
|
** memory allocator that simulates memory out-of-memory conditions in
|
|
** order to verify that SQLite recovers gracefully from such
|
|
** conditions.
|
|
**
|
|
** The xMalloc, xRealloc, and xFree methods must work like the
|
|
** malloc(), realloc() and free() functions from the standard C library.
|
|
** ^SQLite guarantees that the second argument to
|
|
** xRealloc is always a value returned by a prior call to xRoundup.
|
|
**
|
|
** xSize should return the allocated size of a memory allocation
|
|
** previously obtained from xMalloc or xRealloc. The allocated size
|
|
** is always at least as big as the requested size but may be larger.
|
|
**
|
|
** The xRoundup method returns what would be the allocated size of
|
|
** a memory allocation given a particular requested size. Most memory
|
|
** allocators round up memory allocations at least to the next multiple
|
|
** of 8. Some allocators round up to a larger multiple or to a power of 2.
|
|
** Every memory allocation request coming in through [sqlite3_malloc()]
|
|
** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
|
|
** that causes the corresponding memory allocation to fail.
|
|
**
|
|
** The xInit method initializes the memory allocator. (For example,
|
|
** it might allocate any require mutexes or initialize internal data
|
|
** structures. The xShutdown method is invoked (indirectly) by
|
|
** [sqlite3_shutdown()] and should deallocate any resources acquired
|
|
** by xInit. The pAppData pointer is used as the only parameter to
|
|
** xInit and xShutdown.
|
|
**
|
|
** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
|
|
** the xInit method, so the xInit method need not be threadsafe. The
|
|
** xShutdown method is only called from [sqlite3_shutdown()] so it does
|
|
** not need to be threadsafe either. For all other methods, SQLite
|
|
** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
|
|
** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
|
|
** it is by default) and so the methods are automatically serialized.
|
|
** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
|
|
** methods must be threadsafe or else make their own arrangements for
|
|
** serialization.
|
|
**
|
|
** SQLite will never invoke xInit() more than once without an intervening
|
|
** call to xShutdown().
|
|
*/
|
|
typedef struct sqlite3_mem_methods sqlite3_mem_methods;
|
|
struct sqlite3_mem_methods {
|
|
void *(*xMalloc)(int); /* Memory allocation function */
|
|
void (*xFree)(void*); /* Free a prior allocation */
|
|
void *(*xRealloc)(void*,int); /* Resize an allocation */
|
|
int (*xSize)(void*); /* Return the size of an allocation */
|
|
int (*xRoundup)(int); /* Round up request size to allocation size */
|
|
int (*xInit)(void*); /* Initialize the memory allocator */
|
|
void (*xShutdown)(void*); /* Deinitialize the memory allocator */
|
|
void *pAppData; /* Argument to xInit() and xShutdown() */
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Configuration Options
|
|
** KEYWORDS: {configuration option}
|
|
**
|
|
** These constants are the available integer configuration options that
|
|
** can be passed as the first argument to the [sqlite3_config()] interface.
|
|
**
|
|
** New configuration options may be added in future releases of SQLite.
|
|
** Existing configuration options might be discontinued. Applications
|
|
** should check the return code from [sqlite3_config()] to make sure that
|
|
** the call worked. The [sqlite3_config()] interface will return a
|
|
** non-zero [error code] if a discontinued or unsupported configuration option
|
|
** is invoked.
|
|
**
|
|
** <dl>
|
|
** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
|
|
** <dd>There are no arguments to this option. ^This option sets the
|
|
** [threading mode] to Single-thread. In other words, it disables
|
|
** all mutexing and puts SQLite into a mode where it can only be used
|
|
** by a single thread. ^If SQLite is compiled with
|
|
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
|
** it is not possible to change the [threading mode] from its default
|
|
** value of Single-thread and so [sqlite3_config()] will return
|
|
** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
|
|
** configuration option.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
|
|
** <dd>There are no arguments to this option. ^This option sets the
|
|
** [threading mode] to Multi-thread. In other words, it disables
|
|
** mutexing on [database connection] and [prepared statement] objects.
|
|
** The application is responsible for serializing access to
|
|
** [database connections] and [prepared statements]. But other mutexes
|
|
** are enabled so that SQLite will be safe to use in a multi-threaded
|
|
** environment as long as no two threads attempt to use the same
|
|
** [database connection] at the same time. ^If SQLite is compiled with
|
|
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
|
** it is not possible to set the Multi-thread [threading mode] and
|
|
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
|
|
** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
|
|
** <dd>There are no arguments to this option. ^This option sets the
|
|
** [threading mode] to Serialized. In other words, this option enables
|
|
** all mutexes including the recursive
|
|
** mutexes on [database connection] and [prepared statement] objects.
|
|
** In this mode (which is the default when SQLite is compiled with
|
|
** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
|
|
** to [database connections] and [prepared statements] so that the
|
|
** application is free to use the same [database connection] or the
|
|
** same [prepared statement] in different threads at the same time.
|
|
** ^If SQLite is compiled with
|
|
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
|
** it is not possible to set the Serialized [threading mode] and
|
|
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
|
|
** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
|
|
** <dd> ^(This option takes a single argument which is a pointer to an
|
|
** instance of the [sqlite3_mem_methods] structure. The argument specifies
|
|
** alternative low-level memory allocation routines to be used in place of
|
|
** the memory allocation routines built into SQLite.)^ ^SQLite makes
|
|
** its own private copy of the content of the [sqlite3_mem_methods] structure
|
|
** before the [sqlite3_config()] call returns.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
|
|
** <dd> ^(This option takes a single argument which is a pointer to an
|
|
** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
|
|
** structure is filled with the currently defined memory allocation routines.)^
|
|
** This option can be used to overload the default memory allocation
|
|
** routines with a wrapper that simulations memory allocation failure or
|
|
** tracks memory usage, for example. </dd>
|
|
**
|
|
** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
|
|
** <dd> ^This option takes single argument of type int, interpreted as a
|
|
** boolean, which enables or disables the collection of memory allocation
|
|
** statistics. ^(When memory allocation statistics are disabled, the
|
|
** following SQLite interfaces become non-operational:
|
|
** <ul>
|
|
** <li> [sqlite3_memory_used()]
|
|
** <li> [sqlite3_memory_highwater()]
|
|
** <li> [sqlite3_soft_heap_limit64()]
|
|
** <li> [sqlite3_status()]
|
|
** </ul>)^
|
|
** ^Memory allocation statistics are enabled by default unless SQLite is
|
|
** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
|
|
** allocation statistics are disabled by default.
|
|
** </dd>
|
|
**
|
|
** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
|
|
** <dd> ^This option specifies a static memory buffer that SQLite can use for
|
|
** scratch memory. There are three arguments: A pointer an 8-byte
|
|
** aligned memory buffer from which the scratch allocations will be
|
|
** drawn, the size of each scratch allocation (sz),
|
|
** and the maximum number of scratch allocations (N). The sz
|
|
** argument must be a multiple of 16.
|
|
** The first argument must be a pointer to an 8-byte aligned buffer
|
|
** of at least sz*N bytes of memory.
|
|
** ^SQLite will use no more than two scratch buffers per thread. So
|
|
** N should be set to twice the expected maximum number of threads.
|
|
** ^SQLite will never require a scratch buffer that is more than 6
|
|
** times the database page size. ^If SQLite needs needs additional
|
|
** scratch memory beyond what is provided by this configuration option, then
|
|
** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
|
|
** <dd> ^This option specifies a static memory buffer that SQLite can use for
|
|
** the database page cache with the default page cache implementation.
|
|
** This configuration should not be used if an application-define page
|
|
** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
|
|
** There are three arguments to this option: A pointer to 8-byte aligned
|
|
** memory, the size of each page buffer (sz), and the number of pages (N).
|
|
** The sz argument should be the size of the largest database page
|
|
** (a power of two between 512 and 32768) plus a little extra for each
|
|
** page header. ^The page header size is 20 to 40 bytes depending on
|
|
** the host architecture. ^It is harmless, apart from the wasted memory,
|
|
** to make sz a little too large. The first
|
|
** argument should point to an allocation of at least sz*N bytes of memory.
|
|
** ^SQLite will use the memory provided by the first argument to satisfy its
|
|
** memory needs for the first N pages that it adds to cache. ^If additional
|
|
** page cache memory is needed beyond what is provided by this option, then
|
|
** SQLite goes to [sqlite3_malloc()] for the additional storage space.
|
|
** The pointer in the first argument must
|
|
** be aligned to an 8-byte boundary or subsequent behavior of SQLite
|
|
** will be undefined.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
|
|
** <dd> ^This option specifies a static memory buffer that SQLite will use
|
|
** for all of its dynamic memory allocation needs beyond those provided
|
|
** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
|
|
** There are three arguments: An 8-byte aligned pointer to the memory,
|
|
** the number of bytes in the memory buffer, and the minimum allocation size.
|
|
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
|
|
** to using its default memory allocator (the system malloc() implementation),
|
|
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
|
|
** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
|
|
** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
|
|
** allocator is engaged to handle all of SQLites memory allocation needs.
|
|
** The first pointer (the memory pointer) must be aligned to an 8-byte
|
|
** boundary or subsequent behavior of SQLite will be undefined.
|
|
** The minimum allocation size is capped at 2**12. Reasonable values
|
|
** for the minimum allocation size are 2**5 through 2**8.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
|
|
** <dd> ^(This option takes a single argument which is a pointer to an
|
|
** instance of the [sqlite3_mutex_methods] structure. The argument specifies
|
|
** alternative low-level mutex routines to be used in place
|
|
** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
|
|
** content of the [sqlite3_mutex_methods] structure before the call to
|
|
** [sqlite3_config()] returns. ^If SQLite is compiled with
|
|
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
|
** the entire mutexing subsystem is omitted from the build and hence calls to
|
|
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
|
|
** return [SQLITE_ERROR].</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
|
|
** <dd> ^(This option takes a single argument which is a pointer to an
|
|
** instance of the [sqlite3_mutex_methods] structure. The
|
|
** [sqlite3_mutex_methods]
|
|
** structure is filled with the currently defined mutex routines.)^
|
|
** This option can be used to overload the default mutex allocation
|
|
** routines with a wrapper used to track mutex usage for performance
|
|
** profiling or testing, for example. ^If SQLite is compiled with
|
|
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
|
|
** the entire mutexing subsystem is omitted from the build and hence calls to
|
|
** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
|
|
** return [SQLITE_ERROR].</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
|
|
** <dd> ^(This option takes two arguments that determine the default
|
|
** memory allocation for the lookaside memory allocator on each
|
|
** [database connection]. The first argument is the
|
|
** size of each lookaside buffer slot and the second is the number of
|
|
** slots allocated to each database connection.)^ ^(This option sets the
|
|
** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
|
|
** verb to [sqlite3_db_config()] can be used to change the lookaside
|
|
** configuration on individual connections.)^ </dd>
|
|
**
|
|
** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
|
|
** <dd> ^(This option takes a single argument which is a pointer to
|
|
** an [sqlite3_pcache_methods2] object. This object specifies the interface
|
|
** to a custom page cache implementation.)^ ^SQLite makes a copy of the
|
|
** object and uses it for page cache memory allocations.</dd>
|
|
**
|
|
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
|
|
** <dd> ^(This option takes a single argument which is a pointer to an
|
|
** [sqlite3_pcache_methods2] object. SQLite copies of the current
|
|
** page cache implementation into that object.)^ </dd>
|
|
**
|
|
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
|
|
** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
|
|
** function with a call signature of void(*)(void*,int,const char*),
|
|
** and a pointer to void. ^If the function pointer is not NULL, it is
|
|
** invoked by [sqlite3_log()] to process each logging event. ^If the
|
|
** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
|
|
** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
|
|
** passed through as the first parameter to the application-defined logger
|
|
** function whenever that function is invoked. ^The second parameter to
|
|
** the logger function is a copy of the first parameter to the corresponding
|
|
** [sqlite3_log()] call and is intended to be a [result code] or an
|
|
** [extended result code]. ^The third parameter passed to the logger is
|
|
** log message after formatting via [sqlite3_snprintf()].
|
|
** The SQLite logging interface is not reentrant; the logger function
|
|
** supplied by the application must not invoke any SQLite interface.
|
|
** In a multi-threaded application, the application-defined logger
|
|
** function must be threadsafe. </dd>
|
|
**
|
|
** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
|
|
** <dd> This option takes a single argument of type int. If non-zero, then
|
|
** URI handling is globally enabled. If the parameter is zero, then URI handling
|
|
** is globally disabled. If URI handling is globally enabled, all filenames
|
|
** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
|
|
** specified as part of [ATTACH] commands are interpreted as URIs, regardless
|
|
** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
|
|
** connection is opened. If it is globally disabled, filenames are
|
|
** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
|
|
** database connection is opened. By default, URI handling is globally
|
|
** disabled. The default value may be changed by compiling with the
|
|
** [SQLITE_USE_URI] symbol defined.
|
|
**
|
|
** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
|
|
** <dd> This option takes a single integer argument which is interpreted as
|
|
** a boolean in order to enable or disable the use of covering indices for
|
|
** full table scans in the query optimizer. The default setting is determined
|
|
** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
|
|
** if that compile-time option is omitted.
|
|
** The ability to disable the use of covering indices for full table scans
|
|
** is because some incorrectly coded legacy applications might malfunction
|
|
** malfunction when the optimization is enabled. Providing the ability to
|
|
** disable the optimization allows the older, buggy application code to work
|
|
** without change even with newer versions of SQLite.
|
|
**
|
|
** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
|
|
** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
|
|
** <dd> These options are obsolete and should not be used by new code.
|
|
** They are retained for backwards compatibility but are now no-ops.
|
|
** </dl>
|
|
**
|
|
** [[SQLITE_CONFIG_SQLLOG]]
|
|
** <dt>SQLITE_CONFIG_SQLLOG
|
|
** <dd>This option is only available if sqlite is compiled with the
|
|
** SQLITE_ENABLE_SQLLOG pre-processor macro defined. The first argument should
|
|
** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
|
|
** The second should be of type (void*). The callback is invoked by the library
|
|
** in three separate circumstances, identified by the value passed as the
|
|
** fourth parameter. If the fourth parameter is 0, then the database connection
|
|
** passed as the second argument has just been opened. The third argument
|
|
** points to a buffer containing the name of the main database file. If the
|
|
** fourth parameter is 1, then the SQL statement that the third parameter
|
|
** points to has just been executed. Or, if the fourth parameter is 2, then
|
|
** the connection being passed as the second parameter is being closed. The
|
|
** third parameter is passed NULL In this case.
|
|
** </dl>
|
|
*/
|
|
#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
|
|
#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
|
|
#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
|
|
#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
|
|
#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
|
|
#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
|
|
#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
|
|
#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
|
|
#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
|
|
#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
|
|
#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
|
|
/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
|
|
#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
|
|
#define SQLITE_CONFIG_PCACHE 14 /* no-op */
|
|
#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
|
|
#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
|
|
#define SQLITE_CONFIG_URI 17 /* int */
|
|
#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
|
|
#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
|
|
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
|
|
#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
|
|
|
|
/*
|
|
** CAPI3REF: Database Connection Configuration Options
|
|
**
|
|
** These constants are the available integer configuration options that
|
|
** can be passed as the second argument to the [sqlite3_db_config()] interface.
|
|
**
|
|
** New configuration options may be added in future releases of SQLite.
|
|
** Existing configuration options might be discontinued. Applications
|
|
** should check the return code from [sqlite3_db_config()] to make sure that
|
|
** the call worked. ^The [sqlite3_db_config()] interface will return a
|
|
** non-zero [error code] if a discontinued or unsupported configuration option
|
|
** is invoked.
|
|
**
|
|
** <dl>
|
|
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
|
|
** <dd> ^This option takes three additional arguments that determine the
|
|
** [lookaside memory allocator] configuration for the [database connection].
|
|
** ^The first argument (the third parameter to [sqlite3_db_config()] is a
|
|
** pointer to a memory buffer to use for lookaside memory.
|
|
** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
|
|
** may be NULL in which case SQLite will allocate the
|
|
** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
|
|
** size of each lookaside buffer slot. ^The third argument is the number of
|
|
** slots. The size of the buffer in the first argument must be greater than
|
|
** or equal to the product of the second and third arguments. The buffer
|
|
** must be aligned to an 8-byte boundary. ^If the second argument to
|
|
** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
|
|
** rounded down to the next smaller multiple of 8. ^(The lookaside memory
|
|
** configuration for a database connection can only be changed when that
|
|
** connection is not currently using lookaside memory, or in other words
|
|
** when the "current value" returned by
|
|
** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
|
|
** Any attempt to change the lookaside memory configuration when lookaside
|
|
** memory is in use leaves the configuration unchanged and returns
|
|
** [SQLITE_BUSY].)^</dd>
|
|
**
|
|
** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
|
|
** <dd> ^This option is used to enable or disable the enforcement of
|
|
** [foreign key constraints]. There should be two additional arguments.
|
|
** The first argument is an integer which is 0 to disable FK enforcement,
|
|
** positive to enable FK enforcement or negative to leave FK enforcement
|
|
** unchanged. The second parameter is a pointer to an integer into which
|
|
** is written 0 or 1 to indicate whether FK enforcement is off or on
|
|
** following this call. The second parameter may be a NULL pointer, in
|
|
** which case the FK enforcement setting is not reported back. </dd>
|
|
**
|
|
** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
|
|
** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
|
|
** There should be two additional arguments.
|
|
** The first argument is an integer which is 0 to disable triggers,
|
|
** positive to enable triggers or negative to leave the setting unchanged.
|
|
** The second parameter is a pointer to an integer into which
|
|
** is written 0 or 1 to indicate whether triggers are disabled or enabled
|
|
** following this call. The second parameter may be a NULL pointer, in
|
|
** which case the trigger setting is not reported back. </dd>
|
|
**
|
|
** </dl>
|
|
*/
|
|
#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
|
|
#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
|
|
#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Enable Or Disable Extended Result Codes
|
|
**
|
|
** ^The sqlite3_extended_result_codes() routine enables or disables the
|
|
** [extended result codes] feature of SQLite. ^The extended result
|
|
** codes are disabled by default for historical compatibility.
|
|
*/
|
|
SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
|
|
|
|
/*
|
|
** CAPI3REF: Last Insert Rowid
|
|
**
|
|
** ^Each entry in an SQLite table has a unique 64-bit signed
|
|
** integer key called the [ROWID | "rowid"]. ^The rowid is always available
|
|
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
|
|
** names are not also used by explicitly declared columns. ^If
|
|
** the table has a column of type [INTEGER PRIMARY KEY] then that column
|
|
** is another alias for the rowid.
|
|
**
|
|
** ^This routine returns the [rowid] of the most recent
|
|
** successful [INSERT] into the database from the [database connection]
|
|
** in the first argument. ^As of SQLite version 3.7.7, this routines
|
|
** records the last insert rowid of both ordinary tables and [virtual tables].
|
|
** ^If no successful [INSERT]s
|
|
** have ever occurred on that database connection, zero is returned.
|
|
**
|
|
** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
|
|
** method, then this routine will return the [rowid] of the inserted
|
|
** row as long as the trigger or virtual table method is running.
|
|
** But once the trigger or virtual table method ends, the value returned
|
|
** by this routine reverts to what it was before the trigger or virtual
|
|
** table method began.)^
|
|
**
|
|
** ^An [INSERT] that fails due to a constraint violation is not a
|
|
** successful [INSERT] and does not change the value returned by this
|
|
** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
|
|
** and INSERT OR ABORT make no changes to the return value of this
|
|
** routine when their insertion fails. ^(When INSERT OR REPLACE
|
|
** encounters a constraint violation, it does not fail. The
|
|
** INSERT continues to completion after deleting rows that caused
|
|
** the constraint problem so INSERT OR REPLACE will always change
|
|
** the return value of this interface.)^
|
|
**
|
|
** ^For the purposes of this routine, an [INSERT] is considered to
|
|
** be successful even if it is subsequently rolled back.
|
|
**
|
|
** This function is accessible to SQL statements via the
|
|
** [last_insert_rowid() SQL function].
|
|
**
|
|
** If a separate thread performs a new [INSERT] on the same
|
|
** database connection while the [sqlite3_last_insert_rowid()]
|
|
** function is running and thus changes the last insert [rowid],
|
|
** then the value returned by [sqlite3_last_insert_rowid()] is
|
|
** unpredictable and might not equal either the old or the new
|
|
** last insert [rowid].
|
|
*/
|
|
SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
|
|
|
|
/*
|
|
** CAPI3REF: Count The Number Of Rows Modified
|
|
**
|
|
** ^This function returns the number of database rows that were changed
|
|
** or inserted or deleted by the most recently completed SQL statement
|
|
** on the [database connection] specified by the first parameter.
|
|
** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
|
|
** or [DELETE] statement are counted. Auxiliary changes caused by
|
|
** triggers or [foreign key actions] are not counted.)^ Use the
|
|
** [sqlite3_total_changes()] function to find the total number of changes
|
|
** including changes caused by triggers and foreign key actions.
|
|
**
|
|
** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
|
|
** are not counted. Only real table changes are counted.
|
|
**
|
|
** ^(A "row change" is a change to a single row of a single table
|
|
** caused by an INSERT, DELETE, or UPDATE statement. Rows that
|
|
** are changed as side effects of [REPLACE] constraint resolution,
|
|
** rollback, ABORT processing, [DROP TABLE], or by any other
|
|
** mechanisms do not count as direct row changes.)^
|
|
**
|
|
** A "trigger context" is a scope of execution that begins and
|
|
** ends with the script of a [CREATE TRIGGER | trigger].
|
|
** Most SQL statements are
|
|
** evaluated outside of any trigger. This is the "top level"
|
|
** trigger context. If a trigger fires from the top level, a
|
|
** new trigger context is entered for the duration of that one
|
|
** trigger. Subtriggers create subcontexts for their duration.
|
|
**
|
|
** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
|
|
** not create a new trigger context.
|
|
**
|
|
** ^This function returns the number of direct row changes in the
|
|
** most recent INSERT, UPDATE, or DELETE statement within the same
|
|
** trigger context.
|
|
**
|
|
** ^Thus, when called from the top level, this function returns the
|
|
** number of changes in the most recent INSERT, UPDATE, or DELETE
|
|
** that also occurred at the top level. ^(Within the body of a trigger,
|
|
** the sqlite3_changes() interface can be called to find the number of
|
|
** changes in the most recently completed INSERT, UPDATE, or DELETE
|
|
** statement within the body of the same trigger.
|
|
** However, the number returned does not include changes
|
|
** caused by subtriggers since those have their own context.)^
|
|
**
|
|
** See also the [sqlite3_total_changes()] interface, the
|
|
** [count_changes pragma], and the [changes() SQL function].
|
|
**
|
|
** If a separate thread makes changes on the same database connection
|
|
** while [sqlite3_changes()] is running then the value returned
|
|
** is unpredictable and not meaningful.
|
|
*/
|
|
SQLITE_API int sqlite3_changes(sqlite3*);
|
|
|
|
/*
|
|
** CAPI3REF: Total Number Of Rows Modified
|
|
**
|
|
** ^This function returns the number of row changes caused by [INSERT],
|
|
** [UPDATE] or [DELETE] statements since the [database connection] was opened.
|
|
** ^(The count returned by sqlite3_total_changes() includes all changes
|
|
** from all [CREATE TRIGGER | trigger] contexts and changes made by
|
|
** [foreign key actions]. However,
|
|
** the count does not include changes used to implement [REPLACE] constraints,
|
|
** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
|
|
** count does not include rows of views that fire an [INSTEAD OF trigger],
|
|
** though if the INSTEAD OF trigger makes changes of its own, those changes
|
|
** are counted.)^
|
|
** ^The sqlite3_total_changes() function counts the changes as soon as
|
|
** the statement that makes them is completed (when the statement handle
|
|
** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
|
|
**
|
|
** See also the [sqlite3_changes()] interface, the
|
|
** [count_changes pragma], and the [total_changes() SQL function].
|
|
**
|
|
** If a separate thread makes changes on the same database connection
|
|
** while [sqlite3_total_changes()] is running then the value
|
|
** returned is unpredictable and not meaningful.
|
|
*/
|
|
SQLITE_API int sqlite3_total_changes(sqlite3*);
|
|
|
|
/*
|
|
** CAPI3REF: Interrupt A Long-Running Query
|
|
**
|
|
** ^This function causes any pending database operation to abort and
|
|
** return at its earliest opportunity. This routine is typically
|
|
** called in response to a user action such as pressing "Cancel"
|
|
** or Ctrl-C where the user wants a long query operation to halt
|
|
** immediately.
|
|
**
|
|
** ^It is safe to call this routine from a thread different from the
|
|
** thread that is currently running the database operation. But it
|
|
** is not safe to call this routine with a [database connection] that
|
|
** is closed or might close before sqlite3_interrupt() returns.
|
|
**
|
|
** ^If an SQL operation is very nearly finished at the time when
|
|
** sqlite3_interrupt() is called, then it might not have an opportunity
|
|
** to be interrupted and might continue to completion.
|
|
**
|
|
** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
|
|
** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
|
|
** that is inside an explicit transaction, then the entire transaction
|
|
** will be rolled back automatically.
|
|
**
|
|
** ^The sqlite3_interrupt(D) call is in effect until all currently running
|
|
** SQL statements on [database connection] D complete. ^Any new SQL statements
|
|
** that are started after the sqlite3_interrupt() call and before the
|
|
** running statements reaches zero are interrupted as if they had been
|
|
** running prior to the sqlite3_interrupt() call. ^New SQL statements
|
|
** that are started after the running statement count reaches zero are
|
|
** not effected by the sqlite3_interrupt().
|
|
** ^A call to sqlite3_interrupt(D) that occurs when there are no running
|
|
** SQL statements is a no-op and has no effect on SQL statements
|
|
** that are started after the sqlite3_interrupt() call returns.
|
|
**
|
|
** If the database connection closes while [sqlite3_interrupt()]
|
|
** is running then bad things will likely happen.
|
|
*/
|
|
SQLITE_API void sqlite3_interrupt(sqlite3*);
|
|
|
|
/*
|
|
** CAPI3REF: Determine If An SQL Statement Is Complete
|
|
**
|
|
** These routines are useful during command-line input to determine if the
|
|
** currently entered text seems to form a complete SQL statement or
|
|
** if additional input is needed before sending the text into
|
|
** SQLite for parsing. ^These routines return 1 if the input string
|
|
** appears to be a complete SQL statement. ^A statement is judged to be
|
|
** complete if it ends with a semicolon token and is not a prefix of a
|
|
** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
|
|
** string literals or quoted identifier names or comments are not
|
|
** independent tokens (they are part of the token in which they are
|
|
** embedded) and thus do not count as a statement terminator. ^Whitespace
|
|
** and comments that follow the final semicolon are ignored.
|
|
**
|
|
** ^These routines return 0 if the statement is incomplete. ^If a
|
|
** memory allocation fails, then SQLITE_NOMEM is returned.
|
|
**
|
|
** ^These routines do not parse the SQL statements thus
|
|
** will not detect syntactically incorrect SQL.
|
|
**
|
|
** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
|
|
** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
|
|
** automatically by sqlite3_complete16(). If that initialization fails,
|
|
** then the return value from sqlite3_complete16() will be non-zero
|
|
** regardless of whether or not the input SQL is complete.)^
|
|
**
|
|
** The input to [sqlite3_complete()] must be a zero-terminated
|
|
** UTF-8 string.
|
|
**
|
|
** The input to [sqlite3_complete16()] must be a zero-terminated
|
|
** UTF-16 string in native byte order.
|
|
*/
|
|
SQLITE_API int sqlite3_complete(const char *sql);
|
|
SQLITE_API int sqlite3_complete16(const void *sql);
|
|
|
|
/*
|
|
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
|
|
**
|
|
** ^This routine sets a callback function that might be invoked whenever
|
|
** an attempt is made to open a database table that another thread
|
|
** or process has locked.
|
|
**
|
|
** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
|
|
** is returned immediately upon encountering the lock. ^If the busy callback
|
|
** is not NULL, then the callback might be invoked with two arguments.
|
|
**
|
|
** ^The first argument to the busy handler is a copy of the void* pointer which
|
|
** is the third argument to sqlite3_busy_handler(). ^The second argument to
|
|
** the busy handler callback is the number of times that the busy handler has
|
|
** been invoked for this locking event. ^If the
|
|
** busy callback returns 0, then no additional attempts are made to
|
|
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
|
|
** ^If the callback returns non-zero, then another attempt
|
|
** is made to open the database for reading and the cycle repeats.
|
|
**
|
|
** The presence of a busy handler does not guarantee that it will be invoked
|
|
** when there is lock contention. ^If SQLite determines that invoking the busy
|
|
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
|
|
** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
|
|
** Consider a scenario where one process is holding a read lock that
|
|
** it is trying to promote to a reserved lock and
|
|
** a second process is holding a reserved lock that it is trying
|
|
** to promote to an exclusive lock. The first process cannot proceed
|
|
** because it is blocked by the second and the second process cannot
|
|
** proceed because it is blocked by the first. If both processes
|
|
** invoke the busy handlers, neither will make any progress. Therefore,
|
|
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
|
|
** will induce the first process to release its read lock and allow
|
|
** the second process to proceed.
|
|
**
|
|
** ^The default busy callback is NULL.
|
|
**
|
|
** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
|
|
** when SQLite is in the middle of a large transaction where all the
|
|
** changes will not fit into the in-memory cache. SQLite will
|
|
** already hold a RESERVED lock on the database file, but it needs
|
|
** to promote this lock to EXCLUSIVE so that it can spill cache
|
|
** pages into the database file without harm to concurrent
|
|
** readers. ^If it is unable to promote the lock, then the in-memory
|
|
** cache will be left in an inconsistent state and so the error
|
|
** code is promoted from the relatively benign [SQLITE_BUSY] to
|
|
** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
|
|
** forces an automatic rollback of the changes. See the
|
|
** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
|
|
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
|
|
** this is important.
|
|
**
|
|
** ^(There can only be a single busy handler defined for each
|
|
** [database connection]. Setting a new busy handler clears any
|
|
** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
|
|
** will also set or clear the busy handler.
|
|
**
|
|
** The busy callback should not take any actions which modify the
|
|
** database connection that invoked the busy handler. Any such actions
|
|
** result in undefined behavior.
|
|
**
|
|
** A busy handler must not close the database connection
|
|
** or [prepared statement] that invoked the busy handler.
|
|
*/
|
|
SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
|
|
|
|
/*
|
|
** CAPI3REF: Set A Busy Timeout
|
|
**
|
|
** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
|
|
** for a specified amount of time when a table is locked. ^The handler
|
|
** will sleep multiple times until at least "ms" milliseconds of sleeping
|
|
** have accumulated. ^After at least "ms" milliseconds of sleeping,
|
|
** the handler returns 0 which causes [sqlite3_step()] to return
|
|
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
|
|
**
|
|
** ^Calling this routine with an argument less than or equal to zero
|
|
** turns off all busy handlers.
|
|
**
|
|
** ^(There can only be a single busy handler for a particular
|
|
** [database connection] any any given moment. If another busy handler
|
|
** was defined (using [sqlite3_busy_handler()]) prior to calling
|
|
** this routine, that other busy handler is cleared.)^
|
|
*/
|
|
SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
|
|
|
|
/*
|
|
** CAPI3REF: Convenience Routines For Running Queries
|
|
**
|
|
** This is a legacy interface that is preserved for backwards compatibility.
|
|
** Use of this interface is not recommended.
|
|
**
|
|
** Definition: A <b>result table</b> is memory data structure created by the
|
|
** [sqlite3_get_table()] interface. A result table records the
|
|
** complete query results from one or more queries.
|
|
**
|
|
** The table conceptually has a number of rows and columns. But
|
|
** these numbers are not part of the result table itself. These
|
|
** numbers are obtained separately. Let N be the number of rows
|
|
** and M be the number of columns.
|
|
**
|
|
** A result table is an array of pointers to zero-terminated UTF-8 strings.
|
|
** There are (N+1)*M elements in the array. The first M pointers point
|
|
** to zero-terminated strings that contain the names of the columns.
|
|
** The remaining entries all point to query results. NULL values result
|
|
** in NULL pointers. All other values are in their UTF-8 zero-terminated
|
|
** string representation as returned by [sqlite3_column_text()].
|
|
**
|
|
** A result table might consist of one or more memory allocations.
|
|
** It is not safe to pass a result table directly to [sqlite3_free()].
|
|
** A result table should be deallocated using [sqlite3_free_table()].
|
|
**
|
|
** ^(As an example of the result table format, suppose a query result
|
|
** is as follows:
|
|
**
|
|
** <blockquote><pre>
|
|
** Name | Age
|
|
** -----------------------
|
|
** Alice | 43
|
|
** Bob | 28
|
|
** Cindy | 21
|
|
** </pre></blockquote>
|
|
**
|
|
** There are two column (M==2) and three rows (N==3). Thus the
|
|
** result table has 8 entries. Suppose the result table is stored
|
|
** in an array names azResult. Then azResult holds this content:
|
|
**
|
|
** <blockquote><pre>
|
|
** azResult[0] = "Name";
|
|
** azResult[1] = "Age";
|
|
** azResult[2] = "Alice";
|
|
** azResult[3] = "43";
|
|
** azResult[4] = "Bob";
|
|
** azResult[5] = "28";
|
|
** azResult[6] = "Cindy";
|
|
** azResult[7] = "21";
|
|
** </pre></blockquote>)^
|
|
**
|
|
** ^The sqlite3_get_table() function evaluates one or more
|
|
** semicolon-separated SQL statements in the zero-terminated UTF-8
|
|
** string of its 2nd parameter and returns a result table to the
|
|
** pointer given in its 3rd parameter.
|
|
**
|
|
** After the application has finished with the result from sqlite3_get_table(),
|
|
** it must pass the result table pointer to sqlite3_free_table() in order to
|
|
** release the memory that was malloced. Because of the way the
|
|
** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
|
|
** function must not try to call [sqlite3_free()] directly. Only
|
|
** [sqlite3_free_table()] is able to release the memory properly and safely.
|
|
**
|
|
** The sqlite3_get_table() interface is implemented as a wrapper around
|
|
** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
|
|
** to any internal data structures of SQLite. It uses only the public
|
|
** interface defined here. As a consequence, errors that occur in the
|
|
** wrapper layer outside of the internal [sqlite3_exec()] call are not
|
|
** reflected in subsequent calls to [sqlite3_errcode()] or
|
|
** [sqlite3_errmsg()].
|
|
*/
|
|
SQLITE_API int sqlite3_get_table(
|
|
sqlite3 *db, /* An open database */
|
|
const char *zSql, /* SQL to be evaluated */
|
|
char ***pazResult, /* Results of the query */
|
|
int *pnRow, /* Number of result rows written here */
|
|
int *pnColumn, /* Number of result columns written here */
|
|
char **pzErrmsg /* Error msg written here */
|
|
);
|
|
SQLITE_API void sqlite3_free_table(char **result);
|
|
|
|
/*
|
|
** CAPI3REF: Formatted String Printing Functions
|
|
**
|
|
** These routines are work-alikes of the "printf()" family of functions
|
|
** from the standard C library.
|
|
**
|
|
** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
|
|
** results into memory obtained from [sqlite3_malloc()].
|
|
** The strings returned by these two routines should be
|
|
** released by [sqlite3_free()]. ^Both routines return a
|
|
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
|
|
** memory to hold the resulting string.
|
|
**
|
|
** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
|
|
** the standard C library. The result is written into the
|
|
** buffer supplied as the second parameter whose size is given by
|
|
** the first parameter. Note that the order of the
|
|
** first two parameters is reversed from snprintf().)^ This is an
|
|
** historical accident that cannot be fixed without breaking
|
|
** backwards compatibility. ^(Note also that sqlite3_snprintf()
|
|
** returns a pointer to its buffer instead of the number of
|
|
** characters actually written into the buffer.)^ We admit that
|
|
** the number of characters written would be a more useful return
|
|
** value but we cannot change the implementation of sqlite3_snprintf()
|
|
** now without breaking compatibility.
|
|
**
|
|
** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
|
|
** guarantees that the buffer is always zero-terminated. ^The first
|
|
** parameter "n" is the total size of the buffer, including space for
|
|
** the zero terminator. So the longest string that can be completely
|
|
** written will be n-1 characters.
|
|
**
|
|
** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
|
|
**
|
|
** These routines all implement some additional formatting
|
|
** options that are useful for constructing SQL statements.
|
|
** All of the usual printf() formatting options apply. In addition, there
|
|
** is are "%q", "%Q", and "%z" options.
|
|
**
|
|
** ^(The %q option works like %s in that it substitutes a nul-terminated
|
|
** string from the argument list. But %q also doubles every '\'' character.
|
|
** %q is designed for use inside a string literal.)^ By doubling each '\''
|
|
** character it escapes that character and allows it to be inserted into
|
|
** the string.
|
|
**
|
|
** For example, assume the string variable zText contains text as follows:
|
|
**
|
|
** <blockquote><pre>
|
|
** char *zText = "It's a happy day!";
|
|
** </pre></blockquote>
|
|
**
|
|
** One can use this text in an SQL statement as follows:
|
|
**
|
|
** <blockquote><pre>
|
|
** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
|
|
** sqlite3_exec(db, zSQL, 0, 0, 0);
|
|
** sqlite3_free(zSQL);
|
|
** </pre></blockquote>
|
|
**
|
|
** Because the %q format string is used, the '\'' character in zText
|
|
** is escaped and the SQL generated is as follows:
|
|
**
|
|
** <blockquote><pre>
|
|
** INSERT INTO table1 VALUES('It''s a happy day!')
|
|
** </pre></blockquote>
|
|
**
|
|
** This is correct. Had we used %s instead of %q, the generated SQL
|
|
** would have looked like this:
|
|
**
|
|
** <blockquote><pre>
|
|
** INSERT INTO table1 VALUES('It's a happy day!');
|
|
** </pre></blockquote>
|
|
**
|
|
** This second example is an SQL syntax error. As a general rule you should
|
|
** always use %q instead of %s when inserting text into a string literal.
|
|
**
|
|
** ^(The %Q option works like %q except it also adds single quotes around
|
|
** the outside of the total string. Additionally, if the parameter in the
|
|
** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
|
|
** single quotes).)^ So, for example, one could say:
|
|
**
|
|
** <blockquote><pre>
|
|
** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
|
|
** sqlite3_exec(db, zSQL, 0, 0, 0);
|
|
** sqlite3_free(zSQL);
|
|
** </pre></blockquote>
|
|
**
|
|
** The code above will render a correct SQL statement in the zSQL
|
|
** variable even if the zText variable is a NULL pointer.
|
|
**
|
|
** ^(The "%z" formatting option works like "%s" but with the
|
|
** addition that after the string has been read and copied into
|
|
** the result, [sqlite3_free()] is called on the input string.)^
|
|
*/
|
|
SQLITE_API char *sqlite3_mprintf(const char*,...);
|
|
SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
|
|
SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
|
|
SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
|
|
|
|
/*
|
|
** CAPI3REF: Memory Allocation Subsystem
|
|
**
|
|
** The SQLite core uses these three routines for all of its own
|
|
** internal memory allocation needs. "Core" in the previous sentence
|
|
** does not include operating-system specific VFS implementation. The
|
|
** Windows VFS uses native malloc() and free() for some operations.
|
|
**
|
|
** ^The sqlite3_malloc() routine returns a pointer to a block
|
|
** of memory at least N bytes in length, where N is the parameter.
|
|
** ^If sqlite3_malloc() is unable to obtain sufficient free
|
|
** memory, it returns a NULL pointer. ^If the parameter N to
|
|
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
|
|
** a NULL pointer.
|
|
**
|
|
** ^Calling sqlite3_free() with a pointer previously returned
|
|
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
|
|
** that it might be reused. ^The sqlite3_free() routine is
|
|
** a no-op if is called with a NULL pointer. Passing a NULL pointer
|
|
** to sqlite3_free() is harmless. After being freed, memory
|
|
** should neither be read nor written. Even reading previously freed
|
|
** memory might result in a segmentation fault or other severe error.
|
|
** Memory corruption, a segmentation fault, or other severe error
|
|
** might result if sqlite3_free() is called with a non-NULL pointer that
|
|
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
|
|
**
|
|
** ^(The sqlite3_realloc() interface attempts to resize a
|
|
** prior memory allocation to be at least N bytes, where N is the
|
|
** second parameter. The memory allocation to be resized is the first
|
|
** parameter.)^ ^ If the first parameter to sqlite3_realloc()
|
|
** is a NULL pointer then its behavior is identical to calling
|
|
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
|
|
** ^If the second parameter to sqlite3_realloc() is zero or
|
|
** negative then the behavior is exactly the same as calling
|
|
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
|
|
** ^sqlite3_realloc() returns a pointer to a memory allocation
|
|
** of at least N bytes in size or NULL if sufficient memory is unavailable.
|
|
** ^If M is the size of the prior allocation, then min(N,M) bytes
|
|
** of the prior allocation are copied into the beginning of buffer returned
|
|
** by sqlite3_realloc() and the prior allocation is freed.
|
|
** ^If sqlite3_realloc() returns NULL, then the prior allocation
|
|
** is not freed.
|
|
**
|
|
** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
|
|
** is always aligned to at least an 8 byte boundary, or to a
|
|
** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
|
|
** option is used.
|
|
**
|
|
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
|
|
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
|
|
** implementation of these routines to be omitted. That capability
|
|
** is no longer provided. Only built-in memory allocators can be used.
|
|
**
|
|
** Prior to SQLite version 3.7.10, the Windows OS interface layer called
|
|
** the system malloc() and free() directly when converting
|
|
** filenames between the UTF-8 encoding used by SQLite
|
|
** and whatever filename encoding is used by the particular Windows
|
|
** installation. Memory allocation errors were detected, but
|
|
** they were reported back as [SQLITE_CANTOPEN] or
|
|
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
|
|
**
|
|
** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
|
|
** must be either NULL or else pointers obtained from a prior
|
|
** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
|
|
** not yet been released.
|
|
**
|
|
** The application must not read or write any part of
|
|
** a block of memory after it has been released using
|
|
** [sqlite3_free()] or [sqlite3_realloc()].
|
|
*/
|
|
SQLITE_API void *sqlite3_malloc(int);
|
|
SQLITE_API void *sqlite3_realloc(void*, int);
|
|
SQLITE_API void sqlite3_free(void*);
|
|
|
|
/*
|
|
** CAPI3REF: Memory Allocator Statistics
|
|
**
|
|
** SQLite provides these two interfaces for reporting on the status
|
|
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
|
|
** routines, which form the built-in memory allocation subsystem.
|
|
**
|
|
** ^The [sqlite3_memory_used()] routine returns the number of bytes
|
|
** of memory currently outstanding (malloced but not freed).
|
|
** ^The [sqlite3_memory_highwater()] routine returns the maximum
|
|
** value of [sqlite3_memory_used()] since the high-water mark
|
|
** was last reset. ^The values returned by [sqlite3_memory_used()] and
|
|
** [sqlite3_memory_highwater()] include any overhead
|
|
** added by SQLite in its implementation of [sqlite3_malloc()],
|
|
** but not overhead added by the any underlying system library
|
|
** routines that [sqlite3_malloc()] may call.
|
|
**
|
|
** ^The memory high-water mark is reset to the current value of
|
|
** [sqlite3_memory_used()] if and only if the parameter to
|
|
** [sqlite3_memory_highwater()] is true. ^The value returned
|
|
** by [sqlite3_memory_highwater(1)] is the high-water mark
|
|
** prior to the reset.
|
|
*/
|
|
SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
|
|
SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
|
|
|
|
/*
|
|
** CAPI3REF: Pseudo-Random Number Generator
|
|
**
|
|
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
|
|
** select random [ROWID | ROWIDs] when inserting new records into a table that
|
|
** already uses the largest possible [ROWID]. The PRNG is also used for
|
|
** the build-in random() and randomblob() SQL functions. This interface allows
|
|
** applications to access the same PRNG for other purposes.
|
|
**
|
|
** ^A call to this routine stores N bytes of randomness into buffer P.
|
|
**
|
|
** ^The first time this routine is invoked (either internally or by
|
|
** the application) the PRNG is seeded using randomness obtained
|
|
** from the xRandomness method of the default [sqlite3_vfs] object.
|
|
** ^On all subsequent invocations, the pseudo-randomness is generated
|
|
** internally and without recourse to the [sqlite3_vfs] xRandomness
|
|
** method.
|
|
*/
|
|
SQLITE_API void sqlite3_randomness(int N, void *P);
|
|
|
|
/*
|
|
** CAPI3REF: Compile-Time Authorization Callbacks
|
|
**
|
|
** ^This routine registers an authorizer callback with a particular
|
|
** [database connection], supplied in the first argument.
|
|
** ^The authorizer callback is invoked as SQL statements are being compiled
|
|
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
|
|
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
|
|
** points during the compilation process, as logic is being created
|
|
** to perform various actions, the authorizer callback is invoked to
|
|
** see if those actions are allowed. ^The authorizer callback should
|
|
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
|
|
** specific action but allow the SQL statement to continue to be
|
|
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
|
|
** rejected with an error. ^If the authorizer callback returns
|
|
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
|
|
** then the [sqlite3_prepare_v2()] or equivalent call that triggered
|
|
** the authorizer will fail with an error message.
|
|
**
|
|
** When the callback returns [SQLITE_OK], that means the operation
|
|
** requested is ok. ^When the callback returns [SQLITE_DENY], the
|
|
** [sqlite3_prepare_v2()] or equivalent call that triggered the
|
|
** authorizer will fail with an error message explaining that
|
|
** access is denied.
|
|
**
|
|
** ^The first parameter to the authorizer callback is a copy of the third
|
|
** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
|
|
** to the callback is an integer [SQLITE_COPY | action code] that specifies
|
|
** the particular action to be authorized. ^The third through sixth parameters
|
|
** to the callback are zero-terminated strings that contain additional
|
|
** details about the action to be authorized.
|
|
**
|
|
** ^If the action code is [SQLITE_READ]
|
|
** and the callback returns [SQLITE_IGNORE] then the
|
|
** [prepared statement] statement is constructed to substitute
|
|
** a NULL value in place of the table column that would have
|
|
** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
|
|
** return can be used to deny an untrusted user access to individual
|
|
** columns of a table.
|
|
** ^If the action code is [SQLITE_DELETE] and the callback returns
|
|
** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
|
|
** [truncate optimization] is disabled and all rows are deleted individually.
|
|
**
|
|
** An authorizer is used when [sqlite3_prepare | preparing]
|
|
** SQL statements from an untrusted source, to ensure that the SQL statements
|
|
** do not try to access data they are not allowed to see, or that they do not
|
|
** try to execute malicious statements that damage the database. For
|
|
** example, an application may allow a user to enter arbitrary
|
|
** SQL queries for evaluation by a database. But the application does
|
|
** not want the user to be able to make arbitrary changes to the
|
|
** database. An authorizer could then be put in place while the
|
|
** user-entered SQL is being [sqlite3_prepare | prepared] that
|
|
** disallows everything except [SELECT] statements.
|
|
**
|
|
** Applications that need to process SQL from untrusted sources
|
|
** might also consider lowering resource limits using [sqlite3_limit()]
|
|
** and limiting database size using the [max_page_count] [PRAGMA]
|
|
** in addition to using an authorizer.
|
|
**
|
|
** ^(Only a single authorizer can be in place on a database connection
|
|
** at a time. Each call to sqlite3_set_authorizer overrides the
|
|
** previous call.)^ ^Disable the authorizer by installing a NULL callback.
|
|
** The authorizer is disabled by default.
|
|
**
|
|
** The authorizer callback must not do anything that will modify
|
|
** the database connection that invoked the authorizer callback.
|
|
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
|
** database connections for the meaning of "modify" in this paragraph.
|
|
**
|
|
** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
|
|
** statement might be re-prepared during [sqlite3_step()] due to a
|
|
** schema change. Hence, the application should ensure that the
|
|
** correct authorizer callback remains in place during the [sqlite3_step()].
|
|
**
|
|
** ^Note that the authorizer callback is invoked only during
|
|
** [sqlite3_prepare()] or its variants. Authorization is not
|
|
** performed during statement evaluation in [sqlite3_step()], unless
|
|
** as stated in the previous paragraph, sqlite3_step() invokes
|
|
** sqlite3_prepare_v2() to reprepare a statement after a schema change.
|
|
*/
|
|
SQLITE_API int sqlite3_set_authorizer(
|
|
sqlite3*,
|
|
int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
|
|
void *pUserData
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Authorizer Return Codes
|
|
**
|
|
** The [sqlite3_set_authorizer | authorizer callback function] must
|
|
** return either [SQLITE_OK] or one of these two constants in order
|
|
** to signal SQLite whether or not the action is permitted. See the
|
|
** [sqlite3_set_authorizer | authorizer documentation] for additional
|
|
** information.
|
|
**
|
|
** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
|
|
** from the [sqlite3_vtab_on_conflict()] interface.
|
|
*/
|
|
#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
|
|
#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
|
|
|
|
/*
|
|
** CAPI3REF: Authorizer Action Codes
|
|
**
|
|
** The [sqlite3_set_authorizer()] interface registers a callback function
|
|
** that is invoked to authorize certain SQL statement actions. The
|
|
** second parameter to the callback is an integer code that specifies
|
|
** what action is being authorized. These are the integer action codes that
|
|
** the authorizer callback may be passed.
|
|
**
|
|
** These action code values signify what kind of operation is to be
|
|
** authorized. The 3rd and 4th parameters to the authorization
|
|
** callback function will be parameters or NULL depending on which of these
|
|
** codes is used as the second parameter. ^(The 5th parameter to the
|
|
** authorizer callback is the name of the database ("main", "temp",
|
|
** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
|
|
** is the name of the inner-most trigger or view that is responsible for
|
|
** the access attempt or NULL if this access attempt is directly from
|
|
** top-level SQL code.
|
|
*/
|
|
/******************************************* 3rd ************ 4th ***********/
|
|
#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
|
|
#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
|
|
#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
|
|
#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
|
|
#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
|
|
#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
|
|
#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
|
|
#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
|
|
#define SQLITE_DELETE 9 /* Table Name NULL */
|
|
#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
|
|
#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
|
|
#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
|
|
#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
|
|
#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
|
|
#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
|
|
#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
|
|
#define SQLITE_DROP_VIEW 17 /* View Name NULL */
|
|
#define SQLITE_INSERT 18 /* Table Name NULL */
|
|
#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
|
|
#define SQLITE_READ 20 /* Table Name Column Name */
|
|
#define SQLITE_SELECT 21 /* NULL NULL */
|
|
#define SQLITE_TRANSACTION 22 /* Operation NULL */
|
|
#define SQLITE_UPDATE 23 /* Table Name Column Name */
|
|
#define SQLITE_ATTACH 24 /* Filename NULL */
|
|
#define SQLITE_DETACH 25 /* Database Name NULL */
|
|
#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
|
|
#define SQLITE_REINDEX 27 /* Index Name NULL */
|
|
#define SQLITE_ANALYZE 28 /* Table Name NULL */
|
|
#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
|
|
#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
|
|
#define SQLITE_FUNCTION 31 /* NULL Function Name */
|
|
#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
|
|
#define SQLITE_COPY 0 /* No longer used */
|
|
|
|
/*
|
|
** CAPI3REF: Tracing And Profiling Functions
|
|
**
|
|
** These routines register callback functions that can be used for
|
|
** tracing and profiling the execution of SQL statements.
|
|
**
|
|
** ^The callback function registered by sqlite3_trace() is invoked at
|
|
** various times when an SQL statement is being run by [sqlite3_step()].
|
|
** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
|
|
** SQL statement text as the statement first begins executing.
|
|
** ^(Additional sqlite3_trace() callbacks might occur
|
|
** as each triggered subprogram is entered. The callbacks for triggers
|
|
** contain a UTF-8 SQL comment that identifies the trigger.)^
|
|
**
|
|
** ^The callback function registered by sqlite3_profile() is invoked
|
|
** as each SQL statement finishes. ^The profile callback contains
|
|
** the original statement text and an estimate of wall-clock time
|
|
** of how long that statement took to run. ^The profile callback
|
|
** time is in units of nanoseconds, however the current implementation
|
|
** is only capable of millisecond resolution so the six least significant
|
|
** digits in the time are meaningless. Future versions of SQLite
|
|
** might provide greater resolution on the profiler callback. The
|
|
** sqlite3_profile() function is considered experimental and is
|
|
** subject to change in future versions of SQLite.
|
|
*/
|
|
SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
|
|
SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
|
|
void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
|
|
|
|
/*
|
|
** CAPI3REF: Query Progress Callbacks
|
|
**
|
|
** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
|
|
** function X to be invoked periodically during long running calls to
|
|
** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
|
|
** database connection D. An example use for this
|
|
** interface is to keep a GUI updated during a large query.
|
|
**
|
|
** ^The parameter P is passed through as the only parameter to the
|
|
** callback function X. ^The parameter N is the number of
|
|
** [virtual machine instructions] that are evaluated between successive
|
|
** invocations of the callback X.
|
|
**
|
|
** ^Only a single progress handler may be defined at one time per
|
|
** [database connection]; setting a new progress handler cancels the
|
|
** old one. ^Setting parameter X to NULL disables the progress handler.
|
|
** ^The progress handler is also disabled by setting N to a value less
|
|
** than 1.
|
|
**
|
|
** ^If the progress callback returns non-zero, the operation is
|
|
** interrupted. This feature can be used to implement a
|
|
** "Cancel" button on a GUI progress dialog box.
|
|
**
|
|
** The progress handler callback must not do anything that will modify
|
|
** the database connection that invoked the progress handler.
|
|
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
|
** database connections for the meaning of "modify" in this paragraph.
|
|
**
|
|
*/
|
|
SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
|
|
|
|
/*
|
|
** CAPI3REF: Opening A New Database Connection
|
|
**
|
|
** ^These routines open an SQLite database file as specified by the
|
|
** filename argument. ^The filename argument is interpreted as UTF-8 for
|
|
** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
|
|
** order for sqlite3_open16(). ^(A [database connection] handle is usually
|
|
** returned in *ppDb, even if an error occurs. The only exception is that
|
|
** if SQLite is unable to allocate memory to hold the [sqlite3] object,
|
|
** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
|
|
** object.)^ ^(If the database is opened (and/or created) successfully, then
|
|
** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
|
|
** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
|
|
** an English language description of the error following a failure of any
|
|
** of the sqlite3_open() routines.
|
|
**
|
|
** ^The default encoding for the database will be UTF-8 if
|
|
** sqlite3_open() or sqlite3_open_v2() is called and
|
|
** UTF-16 in the native byte order if sqlite3_open16() is used.
|
|
**
|
|
** Whether or not an error occurs when it is opened, resources
|
|
** associated with the [database connection] handle should be released by
|
|
** passing it to [sqlite3_close()] when it is no longer required.
|
|
**
|
|
** The sqlite3_open_v2() interface works like sqlite3_open()
|
|
** except that it accepts two additional parameters for additional control
|
|
** over the new database connection. ^(The flags parameter to
|
|
** sqlite3_open_v2() can take one of
|
|
** the following three values, optionally combined with the
|
|
** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
|
|
** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
|
|
**
|
|
** <dl>
|
|
** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
|
|
** <dd>The database is opened in read-only mode. If the database does not
|
|
** already exist, an error is returned.</dd>)^
|
|
**
|
|
** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
|
|
** <dd>The database is opened for reading and writing if possible, or reading
|
|
** only if the file is write protected by the operating system. In either
|
|
** case the database must already exist, otherwise an error is returned.</dd>)^
|
|
**
|
|
** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
|
|
** <dd>The database is opened for reading and writing, and is created if
|
|
** it does not already exist. This is the behavior that is always used for
|
|
** sqlite3_open() and sqlite3_open16().</dd>)^
|
|
** </dl>
|
|
**
|
|
** If the 3rd parameter to sqlite3_open_v2() is not one of the
|
|
** combinations shown above optionally combined with other
|
|
** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
|
|
** then the behavior is undefined.
|
|
**
|
|
** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
|
|
** opens in the multi-thread [threading mode] as long as the single-thread
|
|
** mode has not been set at compile-time or start-time. ^If the
|
|
** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
|
|
** in the serialized [threading mode] unless single-thread was
|
|
** previously selected at compile-time or start-time.
|
|
** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
|
|
** eligible to use [shared cache mode], regardless of whether or not shared
|
|
** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
|
|
** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
|
|
** participate in [shared cache mode] even if it is enabled.
|
|
**
|
|
** ^The fourth parameter to sqlite3_open_v2() is the name of the
|
|
** [sqlite3_vfs] object that defines the operating system interface that
|
|
** the new database connection should use. ^If the fourth parameter is
|
|
** a NULL pointer then the default [sqlite3_vfs] object is used.
|
|
**
|
|
** ^If the filename is ":memory:", then a private, temporary in-memory database
|
|
** is created for the connection. ^This in-memory database will vanish when
|
|
** the database connection is closed. Future versions of SQLite might
|
|
** make use of additional special filenames that begin with the ":" character.
|
|
** It is recommended that when a database filename actually does begin with
|
|
** a ":" character you should prefix the filename with a pathname such as
|
|
** "./" to avoid ambiguity.
|
|
**
|
|
** ^If the filename is an empty string, then a private, temporary
|
|
** on-disk database will be created. ^This private database will be
|
|
** automatically deleted as soon as the database connection is closed.
|
|
**
|
|
** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
|
|
**
|
|
** ^If [URI filename] interpretation is enabled, and the filename argument
|
|
** begins with "file:", then the filename is interpreted as a URI. ^URI
|
|
** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
|
|
** set in the fourth argument to sqlite3_open_v2(), or if it has
|
|
** been enabled globally using the [SQLITE_CONFIG_URI] option with the
|
|
** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
|
|
** As of SQLite version 3.7.7, URI filename interpretation is turned off
|
|
** by default, but future releases of SQLite might enable URI filename
|
|
** interpretation by default. See "[URI filenames]" for additional
|
|
** information.
|
|
**
|
|
** URI filenames are parsed according to RFC 3986. ^If the URI contains an
|
|
** authority, then it must be either an empty string or the string
|
|
** "localhost". ^If the authority is not an empty string or "localhost", an
|
|
** error is returned to the caller. ^The fragment component of a URI, if
|
|
** present, is ignored.
|
|
**
|
|
** ^SQLite uses the path component of the URI as the name of the disk file
|
|
** which contains the database. ^If the path begins with a '/' character,
|
|
** then it is interpreted as an absolute path. ^If the path does not begin
|
|
** with a '/' (meaning that the authority section is omitted from the URI)
|
|
** then the path is interpreted as a relative path.
|
|
** ^On windows, the first component of an absolute path
|
|
** is a drive specification (e.g. "C:").
|
|
**
|
|
** [[core URI query parameters]]
|
|
** The query component of a URI may contain parameters that are interpreted
|
|
** either by SQLite itself, or by a [VFS | custom VFS implementation].
|
|
** SQLite interprets the following three query parameters:
|
|
**
|
|
** <ul>
|
|
** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
|
|
** a VFS object that provides the operating system interface that should
|
|
** be used to access the database file on disk. ^If this option is set to
|
|
** an empty string the default VFS object is used. ^Specifying an unknown
|
|
** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
|
|
** present, then the VFS specified by the option takes precedence over
|
|
** the value passed as the fourth parameter to sqlite3_open_v2().
|
|
**
|
|
** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
|
|
** "rwc", or "memory". Attempting to set it to any other value is
|
|
** an error)^.
|
|
** ^If "ro" is specified, then the database is opened for read-only
|
|
** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
|
|
** third argument to sqlite3_open_v2(). ^If the mode option is set to
|
|
** "rw", then the database is opened for read-write (but not create)
|
|
** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
|
|
** been set. ^Value "rwc" is equivalent to setting both
|
|
** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
|
|
** set to "memory" then a pure [in-memory database] that never reads
|
|
** or writes from disk is used. ^It is an error to specify a value for
|
|
** the mode parameter that is less restrictive than that specified by
|
|
** the flags passed in the third parameter to sqlite3_open_v2().
|
|
**
|
|
** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
|
|
** "private". ^Setting it to "shared" is equivalent to setting the
|
|
** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
|
|
** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
|
|
** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
|
|
** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
|
|
** a URI filename, its value overrides any behaviour requested by setting
|
|
** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
|
|
** </ul>
|
|
**
|
|
** ^Specifying an unknown parameter in the query component of a URI is not an
|
|
** error. Future versions of SQLite might understand additional query
|
|
** parameters. See "[query parameters with special meaning to SQLite]" for
|
|
** additional information.
|
|
**
|
|
** [[URI filename examples]] <h3>URI filename examples</h3>
|
|
**
|
|
** <table border="1" align=center cellpadding=5>
|
|
** <tr><th> URI filenames <th> Results
|
|
** <tr><td> file:data.db <td>
|
|
** Open the file "data.db" in the current directory.
|
|
** <tr><td> file:/home/fred/data.db<br>
|
|
** file:///home/fred/data.db <br>
|
|
** file://localhost/home/fred/data.db <br> <td>
|
|
** Open the database file "/home/fred/data.db".
|
|
** <tr><td> file://darkstar/home/fred/data.db <td>
|
|
** An error. "darkstar" is not a recognized authority.
|
|
** <tr><td style="white-space:nowrap">
|
|
** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
|
|
** <td> Windows only: Open the file "data.db" on fred's desktop on drive
|
|
** C:. Note that the %20 escaping in this example is not strictly
|
|
** necessary - space characters can be used literally
|
|
** in URI filenames.
|
|
** <tr><td> file:data.db?mode=ro&cache=private <td>
|
|
** Open file "data.db" in the current directory for read-only access.
|
|
** Regardless of whether or not shared-cache mode is enabled by
|
|
** default, use a private cache.
|
|
** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
|
|
** Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
|
|
** <tr><td> file:data.db?mode=readonly <td>
|
|
** An error. "readonly" is not a valid option for the "mode" parameter.
|
|
** </table>
|
|
**
|
|
** ^URI hexadecimal escape sequences (%HH) are supported within the path and
|
|
** query components of a URI. A hexadecimal escape sequence consists of a
|
|
** percent sign - "%" - followed by exactly two hexadecimal digits
|
|
** specifying an octet value. ^Before the path or query components of a
|
|
** URI filename are interpreted, they are encoded using UTF-8 and all
|
|
** hexadecimal escape sequences replaced by a single byte containing the
|
|
** corresponding octet. If this process generates an invalid UTF-8 encoding,
|
|
** the results are undefined.
|
|
**
|
|
** <b>Note to Windows users:</b> The encoding used for the filename argument
|
|
** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
|
|
** codepage is currently defined. Filenames containing international
|
|
** characters must be converted to UTF-8 prior to passing them into
|
|
** sqlite3_open() or sqlite3_open_v2().
|
|
**
|
|
** <b>Note to Windows Runtime users:</b> The temporary directory must be set
|
|
** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
|
|
** features that require the use of temporary files may fail.
|
|
**
|
|
** See also: [sqlite3_temp_directory]
|
|
*/
|
|
SQLITE_API int sqlite3_open(
|
|
const char *filename, /* Database filename (UTF-8) */
|
|
sqlite3 **ppDb /* OUT: SQLite db handle */
|
|
);
|
|
SQLITE_API int sqlite3_open16(
|
|
const void *filename, /* Database filename (UTF-16) */
|
|
sqlite3 **ppDb /* OUT: SQLite db handle */
|
|
);
|
|
SQLITE_API int sqlite3_open_v2(
|
|
const char *filename, /* Database filename (UTF-8) */
|
|
sqlite3 **ppDb, /* OUT: SQLite db handle */
|
|
int flags, /* Flags */
|
|
const char *zVfs /* Name of VFS module to use */
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Obtain Values For URI Parameters
|
|
**
|
|
** These are utility routines, useful to VFS implementations, that check
|
|
** to see if a database file was a URI that contained a specific query
|
|
** parameter, and if so obtains the value of that query parameter.
|
|
**
|
|
** If F is the database filename pointer passed into the xOpen() method of
|
|
** a VFS implementation when the flags parameter to xOpen() has one or
|
|
** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
|
|
** P is the name of the query parameter, then
|
|
** sqlite3_uri_parameter(F,P) returns the value of the P
|
|
** parameter if it exists or a NULL pointer if P does not appear as a
|
|
** query parameter on F. If P is a query parameter of F
|
|
** has no explicit value, then sqlite3_uri_parameter(F,P) returns
|
|
** a pointer to an empty string.
|
|
**
|
|
** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
|
|
** parameter and returns true (1) or false (0) according to the value
|
|
** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
|
|
** value of query parameter P is one of "yes", "true", or "on" in any
|
|
** case or if the value begins with a non-zero number. The
|
|
** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
|
|
** query parameter P is one of "no", "false", or "off" in any case or
|
|
** if the value begins with a numeric zero. If P is not a query
|
|
** parameter on F or if the value of P is does not match any of the
|
|
** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
|
|
**
|
|
** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
|
|
** 64-bit signed integer and returns that integer, or D if P does not
|
|
** exist. If the value of P is something other than an integer, then
|
|
** zero is returned.
|
|
**
|
|
** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
|
|
** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
|
|
** is not a database file pathname pointer that SQLite passed into the xOpen
|
|
** VFS method, then the behavior of this routine is undefined and probably
|
|
** undesirable.
|
|
*/
|
|
SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
|
|
SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
|
|
SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Error Codes And Messages
|
|
**
|
|
** ^The sqlite3_errcode() interface returns the numeric [result code] or
|
|
** [extended result code] for the most recent failed sqlite3_* API call
|
|
** associated with a [database connection]. If a prior API call failed
|
|
** but the most recent API call succeeded, the return value from
|
|
** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
|
|
** interface is the same except that it always returns the
|
|
** [extended result code] even when extended result codes are
|
|
** disabled.
|
|
**
|
|
** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
|
|
** text that describes the error, as either UTF-8 or UTF-16 respectively.
|
|
** ^(Memory to hold the error message string is managed internally.
|
|
** The application does not need to worry about freeing the result.
|
|
** However, the error string might be overwritten or deallocated by
|
|
** subsequent calls to other SQLite interface functions.)^
|
|
**
|
|
** ^The sqlite3_errstr() interface returns the English-language text
|
|
** that describes the [result code], as UTF-8.
|
|
** ^(Memory to hold the error message string is managed internally
|
|
** and must not be freed by the application)^.
|
|
**
|
|
** When the serialized [threading mode] is in use, it might be the
|
|
** case that a second error occurs on a separate thread in between
|
|
** the time of the first error and the call to these interfaces.
|
|
** When that happens, the second error will be reported since these
|
|
** interfaces always report the most recent result. To avoid
|
|
** this, each thread can obtain exclusive use of the [database connection] D
|
|
** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
|
|
** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
|
|
** all calls to the interfaces listed here are completed.
|
|
**
|
|
** If an interface fails with SQLITE_MISUSE, that means the interface
|
|
** was invoked incorrectly by the application. In that case, the
|
|
** error code and message may or may not be set.
|
|
*/
|
|
SQLITE_API int sqlite3_errcode(sqlite3 *db);
|
|
SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
|
|
SQLITE_API const char *sqlite3_errmsg(sqlite3*);
|
|
SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
|
|
SQLITE_API const char *sqlite3_errstr(int);
|
|
|
|
/*
|
|
** CAPI3REF: SQL Statement Object
|
|
** KEYWORDS: {prepared statement} {prepared statements}
|
|
**
|
|
** An instance of this object represents a single SQL statement.
|
|
** This object is variously known as a "prepared statement" or a
|
|
** "compiled SQL statement" or simply as a "statement".
|
|
**
|
|
** The life of a statement object goes something like this:
|
|
**
|
|
** <ol>
|
|
** <li> Create the object using [sqlite3_prepare_v2()] or a related
|
|
** function.
|
|
** <li> Bind values to [host parameters] using the sqlite3_bind_*()
|
|
** interfaces.
|
|
** <li> Run the SQL by calling [sqlite3_step()] one or more times.
|
|
** <li> Reset the statement using [sqlite3_reset()] then go back
|
|
** to step 2. Do this zero or more times.
|
|
** <li> Destroy the object using [sqlite3_finalize()].
|
|
** </ol>
|
|
**
|
|
** Refer to documentation on individual methods above for additional
|
|
** information.
|
|
*/
|
|
typedef struct sqlite3_stmt sqlite3_stmt;
|
|
|
|
/*
|
|
** CAPI3REF: Run-time Limits
|
|
**
|
|
** ^(This interface allows the size of various constructs to be limited
|
|
** on a connection by connection basis. The first parameter is the
|
|
** [database connection] whose limit is to be set or queried. The
|
|
** second parameter is one of the [limit categories] that define a
|
|
** class of constructs to be size limited. The third parameter is the
|
|
** new limit for that construct.)^
|
|
**
|
|
** ^If the new limit is a negative number, the limit is unchanged.
|
|
** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
|
|
** [limits | hard upper bound]
|
|
** set at compile-time by a C preprocessor macro called
|
|
** [limits | SQLITE_MAX_<i>NAME</i>].
|
|
** (The "_LIMIT_" in the name is changed to "_MAX_".))^
|
|
** ^Attempts to increase a limit above its hard upper bound are
|
|
** silently truncated to the hard upper bound.
|
|
**
|
|
** ^Regardless of whether or not the limit was changed, the
|
|
** [sqlite3_limit()] interface returns the prior value of the limit.
|
|
** ^Hence, to find the current value of a limit without changing it,
|
|
** simply invoke this interface with the third parameter set to -1.
|
|
**
|
|
** Run-time limits are intended for use in applications that manage
|
|
** both their own internal database and also databases that are controlled
|
|
** by untrusted external sources. An example application might be a
|
|
** web browser that has its own databases for storing history and
|
|
** separate databases controlled by JavaScript applications downloaded
|
|
** off the Internet. The internal databases can be given the
|
|
** large, default limits. Databases managed by external sources can
|
|
** be given much smaller limits designed to prevent a denial of service
|
|
** attack. Developers might also want to use the [sqlite3_set_authorizer()]
|
|
** interface to further control untrusted SQL. The size of the database
|
|
** created by an untrusted script can be contained using the
|
|
** [max_page_count] [PRAGMA].
|
|
**
|
|
** New run-time limit categories may be added in future releases.
|
|
*/
|
|
SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
|
|
|
|
/*
|
|
** CAPI3REF: Run-Time Limit Categories
|
|
** KEYWORDS: {limit category} {*limit categories}
|
|
**
|
|
** These constants define various performance limits
|
|
** that can be lowered at run-time using [sqlite3_limit()].
|
|
** The synopsis of the meanings of the various limits is shown below.
|
|
** Additional information is available at [limits | Limits in SQLite].
|
|
**
|
|
** <dl>
|
|
** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
|
|
** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
|
|
** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
|
|
** <dd>The maximum number of columns in a table definition or in the
|
|
** result set of a [SELECT] or the maximum number of columns in an index
|
|
** or in an ORDER BY or GROUP BY clause.</dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
|
|
** <dd>The maximum depth of the parse tree on any expression.</dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
|
|
** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
|
|
** <dd>The maximum number of instructions in a virtual machine program
|
|
** used to implement an SQL statement. This limit is not currently
|
|
** enforced, though that might be added in some future release of
|
|
** SQLite.</dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
|
|
** <dd>The maximum number of arguments on a function.</dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
|
|
** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
|
|
**
|
|
** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
|
|
** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
|
|
** <dd>The maximum length of the pattern argument to the [LIKE] or
|
|
** [GLOB] operators.</dd>)^
|
|
**
|
|
** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
|
|
** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
|
|
** <dd>The maximum index number of any [parameter] in an SQL statement.)^
|
|
**
|
|
** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
|
|
** <dd>The maximum depth of recursion for triggers.</dd>)^
|
|
** </dl>
|
|
*/
|
|
#define SQLITE_LIMIT_LENGTH 0
|
|
#define SQLITE_LIMIT_SQL_LENGTH 1
|
|
#define SQLITE_LIMIT_COLUMN 2
|
|
#define SQLITE_LIMIT_EXPR_DEPTH 3
|
|
#define SQLITE_LIMIT_COMPOUND_SELECT 4
|
|
#define SQLITE_LIMIT_VDBE_OP 5
|
|
#define SQLITE_LIMIT_FUNCTION_ARG 6
|
|
#define SQLITE_LIMIT_ATTACHED 7
|
|
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
|
|
#define SQLITE_LIMIT_VARIABLE_NUMBER 9
|
|
#define SQLITE_LIMIT_TRIGGER_DEPTH 10
|
|
|
|
/*
|
|
** CAPI3REF: Compiling An SQL Statement
|
|
** KEYWORDS: {SQL statement compiler}
|
|
**
|
|
** To execute an SQL query, it must first be compiled into a byte-code
|
|
** program using one of these routines.
|
|
**
|
|
** The first argument, "db", is a [database connection] obtained from a
|
|
** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
|
|
** [sqlite3_open16()]. The database connection must not have been closed.
|
|
**
|
|
** The second argument, "zSql", is the statement to be compiled, encoded
|
|
** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
|
|
** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
|
|
** use UTF-16.
|
|
**
|
|
** ^If the nByte argument is less than zero, then zSql is read up to the
|
|
** first zero terminator. ^If nByte is non-negative, then it is the maximum
|
|
** number of bytes read from zSql. ^When nByte is non-negative, the
|
|
** zSql string ends at either the first '\000' or '\u0000' character or
|
|
** the nByte-th byte, whichever comes first. If the caller knows
|
|
** that the supplied string is nul-terminated, then there is a small
|
|
** performance advantage to be gained by passing an nByte parameter that
|
|
** is equal to the number of bytes in the input string <i>including</i>
|
|
** the nul-terminator bytes as this saves SQLite from having to
|
|
** make a copy of the input string.
|
|
**
|
|
** ^If pzTail is not NULL then *pzTail is made to point to the first byte
|
|
** past the end of the first SQL statement in zSql. These routines only
|
|
** compile the first statement in zSql, so *pzTail is left pointing to
|
|
** what remains uncompiled.
|
|
**
|
|
** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
|
|
** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
|
|
** to NULL. ^If the input text contains no SQL (if the input is an empty
|
|
** string or a comment) then *ppStmt is set to NULL.
|
|
** The calling procedure is responsible for deleting the compiled
|
|
** SQL statement using [sqlite3_finalize()] after it has finished with it.
|
|
** ppStmt may not be NULL.
|
|
**
|
|
** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
|
|
** otherwise an [error code] is returned.
|
|
**
|
|
** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
|
|
** recommended for all new programs. The two older interfaces are retained
|
|
** for backwards compatibility, but their use is discouraged.
|
|
** ^In the "v2" interfaces, the prepared statement
|
|
** that is returned (the [sqlite3_stmt] object) contains a copy of the
|
|
** original SQL text. This causes the [sqlite3_step()] interface to
|
|
** behave differently in three ways:
|
|
**
|
|
** <ol>
|
|
** <li>
|
|
** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
|
|
** always used to do, [sqlite3_step()] will automatically recompile the SQL
|
|
** statement and try to run it again.
|
|
** </li>
|
|
**
|
|
** <li>
|
|
** ^When an error occurs, [sqlite3_step()] will return one of the detailed
|
|
** [error codes] or [extended error codes]. ^The legacy behavior was that
|
|
** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
|
|
** and the application would have to make a second call to [sqlite3_reset()]
|
|
** in order to find the underlying cause of the problem. With the "v2" prepare
|
|
** interfaces, the underlying reason for the error is returned immediately.
|
|
** </li>
|
|
**
|
|
** <li>
|
|
** ^If the specific value bound to [parameter | host parameter] in the
|
|
** WHERE clause might influence the choice of query plan for a statement,
|
|
** then the statement will be automatically recompiled, as if there had been
|
|
** a schema change, on the first [sqlite3_step()] call following any change
|
|
** to the [sqlite3_bind_text | bindings] of that [parameter].
|
|
** ^The specific value of WHERE-clause [parameter] might influence the
|
|
** choice of query plan if the parameter is the left-hand side of a [LIKE]
|
|
** or [GLOB] operator or if the parameter is compared to an indexed column
|
|
** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
|
|
** the
|
|
** </li>
|
|
** </ol>
|
|
*/
|
|
SQLITE_API int sqlite3_prepare(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zSql, /* SQL statement, UTF-8 encoded */
|
|
int nByte, /* Maximum length of zSql in bytes. */
|
|
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
|
const char **pzTail /* OUT: Pointer to unused portion of zSql */
|
|
);
|
|
SQLITE_API int sqlite3_prepare_v2(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zSql, /* SQL statement, UTF-8 encoded */
|
|
int nByte, /* Maximum length of zSql in bytes. */
|
|
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
|
const char **pzTail /* OUT: Pointer to unused portion of zSql */
|
|
);
|
|
SQLITE_API int sqlite3_prepare16(
|
|
sqlite3 *db, /* Database handle */
|
|
const void *zSql, /* SQL statement, UTF-16 encoded */
|
|
int nByte, /* Maximum length of zSql in bytes. */
|
|
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
|
const void **pzTail /* OUT: Pointer to unused portion of zSql */
|
|
);
|
|
SQLITE_API int sqlite3_prepare16_v2(
|
|
sqlite3 *db, /* Database handle */
|
|
const void *zSql, /* SQL statement, UTF-16 encoded */
|
|
int nByte, /* Maximum length of zSql in bytes. */
|
|
sqlite3_stmt **ppStmt, /* OUT: Statement handle */
|
|
const void **pzTail /* OUT: Pointer to unused portion of zSql */
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Retrieving Statement SQL
|
|
**
|
|
** ^This interface can be used to retrieve a saved copy of the original
|
|
** SQL text used to create a [prepared statement] if that statement was
|
|
** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
|
|
*/
|
|
SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
|
|
|
|
/*
|
|
** CAPI3REF: Determine If An SQL Statement Writes The Database
|
|
**
|
|
** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
|
|
** and only if the [prepared statement] X makes no direct changes to
|
|
** the content of the database file.
|
|
**
|
|
** Note that [application-defined SQL functions] or
|
|
** [virtual tables] might change the database indirectly as a side effect.
|
|
** ^(For example, if an application defines a function "eval()" that
|
|
** calls [sqlite3_exec()], then the following SQL statement would
|
|
** change the database file through side-effects:
|
|
**
|
|
** <blockquote><pre>
|
|
** SELECT eval('DELETE FROM t1') FROM t2;
|
|
** </pre></blockquote>
|
|
**
|
|
** But because the [SELECT] statement does not change the database file
|
|
** directly, sqlite3_stmt_readonly() would still return true.)^
|
|
**
|
|
** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
|
|
** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
|
|
** since the statements themselves do not actually modify the database but
|
|
** rather they control the timing of when other statements modify the
|
|
** database. ^The [ATTACH] and [DETACH] statements also cause
|
|
** sqlite3_stmt_readonly() to return true since, while those statements
|
|
** change the configuration of a database connection, they do not make
|
|
** changes to the content of the database files on disk.
|
|
*/
|
|
SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
|
|
|
|
/*
|
|
** CAPI3REF: Determine If A Prepared Statement Has Been Reset
|
|
**
|
|
** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
|
|
** [prepared statement] S has been stepped at least once using
|
|
** [sqlite3_step(S)] but has not run to completion and/or has not
|
|
** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
|
|
** interface returns false if S is a NULL pointer. If S is not a
|
|
** NULL pointer and is not a pointer to a valid [prepared statement]
|
|
** object, then the behavior is undefined and probably undesirable.
|
|
**
|
|
** This interface can be used in combination [sqlite3_next_stmt()]
|
|
** to locate all prepared statements associated with a database
|
|
** connection that are in need of being reset. This can be used,
|
|
** for example, in diagnostic routines to search for prepared
|
|
** statements that are holding a transaction open.
|
|
*/
|
|
SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
|
|
|
|
/*
|
|
** CAPI3REF: Dynamically Typed Value Object
|
|
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
|
|
**
|
|
** SQLite uses the sqlite3_value object to represent all values
|
|
** that can be stored in a database table. SQLite uses dynamic typing
|
|
** for the values it stores. ^Values stored in sqlite3_value objects
|
|
** can be integers, floating point values, strings, BLOBs, or NULL.
|
|
**
|
|
** An sqlite3_value object may be either "protected" or "unprotected".
|
|
** Some interfaces require a protected sqlite3_value. Other interfaces
|
|
** will accept either a protected or an unprotected sqlite3_value.
|
|
** Every interface that accepts sqlite3_value arguments specifies
|
|
** whether or not it requires a protected sqlite3_value.
|
|
**
|
|
** The terms "protected" and "unprotected" refer to whether or not
|
|
** a mutex is held. An internal mutex is held for a protected
|
|
** sqlite3_value object but no mutex is held for an unprotected
|
|
** sqlite3_value object. If SQLite is compiled to be single-threaded
|
|
** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
|
|
** or if SQLite is run in one of reduced mutex modes
|
|
** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
|
|
** then there is no distinction between protected and unprotected
|
|
** sqlite3_value objects and they can be used interchangeably. However,
|
|
** for maximum code portability it is recommended that applications
|
|
** still make the distinction between protected and unprotected
|
|
** sqlite3_value objects even when not strictly required.
|
|
**
|
|
** ^The sqlite3_value objects that are passed as parameters into the
|
|
** implementation of [application-defined SQL functions] are protected.
|
|
** ^The sqlite3_value object returned by
|
|
** [sqlite3_column_value()] is unprotected.
|
|
** Unprotected sqlite3_value objects may only be used with
|
|
** [sqlite3_result_value()] and [sqlite3_bind_value()].
|
|
** The [sqlite3_value_blob | sqlite3_value_type()] family of
|
|
** interfaces require protected sqlite3_value objects.
|
|
*/
|
|
typedef struct Mem sqlite3_value;
|
|
|
|
/*
|
|
** CAPI3REF: SQL Function Context Object
|
|
**
|
|
** The context in which an SQL function executes is stored in an
|
|
** sqlite3_context object. ^A pointer to an sqlite3_context object
|
|
** is always first parameter to [application-defined SQL functions].
|
|
** The application-defined SQL function implementation will pass this
|
|
** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
|
|
** [sqlite3_aggregate_context()], [sqlite3_user_data()],
|
|
** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
|
|
** and/or [sqlite3_set_auxdata()].
|
|
*/
|
|
typedef struct sqlite3_context sqlite3_context;
|
|
|
|
/*
|
|
** CAPI3REF: Binding Values To Prepared Statements
|
|
** KEYWORDS: {host parameter} {host parameters} {host parameter name}
|
|
** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
|
|
**
|
|
** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
|
|
** literals may be replaced by a [parameter] that matches one of following
|
|
** templates:
|
|
**
|
|
** <ul>
|
|
** <li> ?
|
|
** <li> ?NNN
|
|
** <li> :VVV
|
|
** <li> @VVV
|
|
** <li> $VVV
|
|
** </ul>
|
|
**
|
|
** In the templates above, NNN represents an integer literal,
|
|
** and VVV represents an alphanumeric identifier.)^ ^The values of these
|
|
** parameters (also called "host parameter names" or "SQL parameters")
|
|
** can be set using the sqlite3_bind_*() routines defined here.
|
|
**
|
|
** ^The first argument to the sqlite3_bind_*() routines is always
|
|
** a pointer to the [sqlite3_stmt] object returned from
|
|
** [sqlite3_prepare_v2()] or its variants.
|
|
**
|
|
** ^The second argument is the index of the SQL parameter to be set.
|
|
** ^The leftmost SQL parameter has an index of 1. ^When the same named
|
|
** SQL parameter is used more than once, second and subsequent
|
|
** occurrences have the same index as the first occurrence.
|
|
** ^The index for named parameters can be looked up using the
|
|
** [sqlite3_bind_parameter_index()] API if desired. ^The index
|
|
** for "?NNN" parameters is the value of NNN.
|
|
** ^The NNN value must be between 1 and the [sqlite3_limit()]
|
|
** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
|
|
**
|
|
** ^The third argument is the value to bind to the parameter.
|
|
**
|
|
** ^(In those routines that have a fourth argument, its value is the
|
|
** number of bytes in the parameter. To be clear: the value is the
|
|
** number of <u>bytes</u> in the value, not the number of characters.)^
|
|
** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
|
|
** is negative, then the length of the string is
|
|
** the number of bytes up to the first zero terminator.
|
|
** If the fourth parameter to sqlite3_bind_blob() is negative, then
|
|
** the behavior is undefined.
|
|
** If a non-negative fourth parameter is provided to sqlite3_bind_text()
|
|
** or sqlite3_bind_text16() then that parameter must be the byte offset
|
|
** where the NUL terminator would occur assuming the string were NUL
|
|
** terminated. If any NUL characters occur at byte offsets less than
|
|
** the value of the fourth parameter then the resulting string value will
|
|
** contain embedded NULs. The result of expressions involving strings
|
|
** with embedded NULs is undefined.
|
|
**
|
|
** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
|
|
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
|
|
** string after SQLite has finished with it. ^The destructor is called
|
|
** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
|
|
** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
|
|
** ^If the fifth argument is
|
|
** the special value [SQLITE_STATIC], then SQLite assumes that the
|
|
** information is in static, unmanaged space and does not need to be freed.
|
|
** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
|
|
** SQLite makes its own private copy of the data immediately, before
|
|
** the sqlite3_bind_*() routine returns.
|
|
**
|
|
** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
|
|
** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
|
|
** (just an integer to hold its size) while it is being processed.
|
|
** Zeroblobs are intended to serve as placeholders for BLOBs whose
|
|
** content is later written using
|
|
** [sqlite3_blob_open | incremental BLOB I/O] routines.
|
|
** ^A negative value for the zeroblob results in a zero-length BLOB.
|
|
**
|
|
** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
|
|
** for the [prepared statement] or with a prepared statement for which
|
|
** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
|
|
** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
|
|
** routine is passed a [prepared statement] that has been finalized, the
|
|
** result is undefined and probably harmful.
|
|
**
|
|
** ^Bindings are not cleared by the [sqlite3_reset()] routine.
|
|
** ^Unbound parameters are interpreted as NULL.
|
|
**
|
|
** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
|
|
** [error code] if anything goes wrong.
|
|
** ^[SQLITE_RANGE] is returned if the parameter
|
|
** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
|
|
**
|
|
** See also: [sqlite3_bind_parameter_count()],
|
|
** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
|
|
*/
|
|
SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
|
|
SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
|
|
SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
|
|
SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
|
|
SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
|
|
SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
|
|
SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
|
|
SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
|
|
SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
|
|
|
|
/*
|
|
** CAPI3REF: Number Of SQL Parameters
|
|
**
|
|
** ^This routine can be used to find the number of [SQL parameters]
|
|
** in a [prepared statement]. SQL parameters are tokens of the
|
|
** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
|
|
** placeholders for values that are [sqlite3_bind_blob | bound]
|
|
** to the parameters at a later time.
|
|
**
|
|
** ^(This routine actually returns the index of the largest (rightmost)
|
|
** parameter. For all forms except ?NNN, this will correspond to the
|
|
** number of unique parameters. If parameters of the ?NNN form are used,
|
|
** there may be gaps in the list.)^
|
|
**
|
|
** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
|
** [sqlite3_bind_parameter_name()], and
|
|
** [sqlite3_bind_parameter_index()].
|
|
*/
|
|
SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
|
|
|
|
/*
|
|
** CAPI3REF: Name Of A Host Parameter
|
|
**
|
|
** ^The sqlite3_bind_parameter_name(P,N) interface returns
|
|
** the name of the N-th [SQL parameter] in the [prepared statement] P.
|
|
** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
|
|
** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
|
|
** respectively.
|
|
** In other words, the initial ":" or "$" or "@" or "?"
|
|
** is included as part of the name.)^
|
|
** ^Parameters of the form "?" without a following integer have no name
|
|
** and are referred to as "nameless" or "anonymous parameters".
|
|
**
|
|
** ^The first host parameter has an index of 1, not 0.
|
|
**
|
|
** ^If the value N is out of range or if the N-th parameter is
|
|
** nameless, then NULL is returned. ^The returned string is
|
|
** always in UTF-8 encoding even if the named parameter was
|
|
** originally specified as UTF-16 in [sqlite3_prepare16()] or
|
|
** [sqlite3_prepare16_v2()].
|
|
**
|
|
** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
|
** [sqlite3_bind_parameter_count()], and
|
|
** [sqlite3_bind_parameter_index()].
|
|
*/
|
|
SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
|
|
|
|
/*
|
|
** CAPI3REF: Index Of A Parameter With A Given Name
|
|
**
|
|
** ^Return the index of an SQL parameter given its name. ^The
|
|
** index value returned is suitable for use as the second
|
|
** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
|
|
** is returned if no matching parameter is found. ^The parameter
|
|
** name must be given in UTF-8 even if the original statement
|
|
** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
|
|
**
|
|
** See also: [sqlite3_bind_blob|sqlite3_bind()],
|
|
** [sqlite3_bind_parameter_count()], and
|
|
** [sqlite3_bind_parameter_index()].
|
|
*/
|
|
SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
|
|
|
|
/*
|
|
** CAPI3REF: Reset All Bindings On A Prepared Statement
|
|
**
|
|
** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
|
|
** the [sqlite3_bind_blob | bindings] on a [prepared statement].
|
|
** ^Use this routine to reset all host parameters to NULL.
|
|
*/
|
|
SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
|
|
|
|
/*
|
|
** CAPI3REF: Number Of Columns In A Result Set
|
|
**
|
|
** ^Return the number of columns in the result set returned by the
|
|
** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
|
|
** statement that does not return data (for example an [UPDATE]).
|
|
**
|
|
** See also: [sqlite3_data_count()]
|
|
*/
|
|
SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
|
|
|
|
/*
|
|
** CAPI3REF: Column Names In A Result Set
|
|
**
|
|
** ^These routines return the name assigned to a particular column
|
|
** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
|
|
** interface returns a pointer to a zero-terminated UTF-8 string
|
|
** and sqlite3_column_name16() returns a pointer to a zero-terminated
|
|
** UTF-16 string. ^The first parameter is the [prepared statement]
|
|
** that implements the [SELECT] statement. ^The second parameter is the
|
|
** column number. ^The leftmost column is number 0.
|
|
**
|
|
** ^The returned string pointer is valid until either the [prepared statement]
|
|
** is destroyed by [sqlite3_finalize()] or until the statement is automatically
|
|
** reprepared by the first call to [sqlite3_step()] for a particular run
|
|
** or until the next call to
|
|
** sqlite3_column_name() or sqlite3_column_name16() on the same column.
|
|
**
|
|
** ^If sqlite3_malloc() fails during the processing of either routine
|
|
** (for example during a conversion from UTF-8 to UTF-16) then a
|
|
** NULL pointer is returned.
|
|
**
|
|
** ^The name of a result column is the value of the "AS" clause for
|
|
** that column, if there is an AS clause. If there is no AS clause
|
|
** then the name of the column is unspecified and may change from
|
|
** one release of SQLite to the next.
|
|
*/
|
|
SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
|
|
SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
|
|
|
|
/*
|
|
** CAPI3REF: Source Of Data In A Query Result
|
|
**
|
|
** ^These routines provide a means to determine the database, table, and
|
|
** table column that is the origin of a particular result column in
|
|
** [SELECT] statement.
|
|
** ^The name of the database or table or column can be returned as
|
|
** either a UTF-8 or UTF-16 string. ^The _database_ routines return
|
|
** the database name, the _table_ routines return the table name, and
|
|
** the origin_ routines return the column name.
|
|
** ^The returned string is valid until the [prepared statement] is destroyed
|
|
** using [sqlite3_finalize()] or until the statement is automatically
|
|
** reprepared by the first call to [sqlite3_step()] for a particular run
|
|
** or until the same information is requested
|
|
** again in a different encoding.
|
|
**
|
|
** ^The names returned are the original un-aliased names of the
|
|
** database, table, and column.
|
|
**
|
|
** ^The first argument to these interfaces is a [prepared statement].
|
|
** ^These functions return information about the Nth result column returned by
|
|
** the statement, where N is the second function argument.
|
|
** ^The left-most column is column 0 for these routines.
|
|
**
|
|
** ^If the Nth column returned by the statement is an expression or
|
|
** subquery and is not a column value, then all of these functions return
|
|
** NULL. ^These routine might also return NULL if a memory allocation error
|
|
** occurs. ^Otherwise, they return the name of the attached database, table,
|
|
** or column that query result column was extracted from.
|
|
**
|
|
** ^As with all other SQLite APIs, those whose names end with "16" return
|
|
** UTF-16 encoded strings and the other functions return UTF-8.
|
|
**
|
|
** ^These APIs are only available if the library was compiled with the
|
|
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
|
|
**
|
|
** If two or more threads call one or more of these routines against the same
|
|
** prepared statement and column at the same time then the results are
|
|
** undefined.
|
|
**
|
|
** If two or more threads call one or more
|
|
** [sqlite3_column_database_name | column metadata interfaces]
|
|
** for the same [prepared statement] and result column
|
|
** at the same time then the results are undefined.
|
|
*/
|
|
SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
|
|
SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
|
|
SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
|
|
SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
|
|
SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
|
|
SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
|
|
|
|
/*
|
|
** CAPI3REF: Declared Datatype Of A Query Result
|
|
**
|
|
** ^(The first parameter is a [prepared statement].
|
|
** If this statement is a [SELECT] statement and the Nth column of the
|
|
** returned result set of that [SELECT] is a table column (not an
|
|
** expression or subquery) then the declared type of the table
|
|
** column is returned.)^ ^If the Nth column of the result set is an
|
|
** expression or subquery, then a NULL pointer is returned.
|
|
** ^The returned string is always UTF-8 encoded.
|
|
**
|
|
** ^(For example, given the database schema:
|
|
**
|
|
** CREATE TABLE t1(c1 VARIANT);
|
|
**
|
|
** and the following statement to be compiled:
|
|
**
|
|
** SELECT c1 + 1, c1 FROM t1;
|
|
**
|
|
** this routine would return the string "VARIANT" for the second result
|
|
** column (i==1), and a NULL pointer for the first result column (i==0).)^
|
|
**
|
|
** ^SQLite uses dynamic run-time typing. ^So just because a column
|
|
** is declared to contain a particular type does not mean that the
|
|
** data stored in that column is of the declared type. SQLite is
|
|
** strongly typed, but the typing is dynamic not static. ^Type
|
|
** is associated with individual values, not with the containers
|
|
** used to hold those values.
|
|
*/
|
|
SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
|
|
SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
|
|
|
|
/*
|
|
** CAPI3REF: Evaluate An SQL Statement
|
|
**
|
|
** After a [prepared statement] has been prepared using either
|
|
** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
|
|
** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
|
|
** must be called one or more times to evaluate the statement.
|
|
**
|
|
** The details of the behavior of the sqlite3_step() interface depend
|
|
** on whether the statement was prepared using the newer "v2" interface
|
|
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
|
|
** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
|
|
** new "v2" interface is recommended for new applications but the legacy
|
|
** interface will continue to be supported.
|
|
**
|
|
** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
|
|
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
|
|
** ^With the "v2" interface, any of the other [result codes] or
|
|
** [extended result codes] might be returned as well.
|
|
**
|
|
** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
|
|
** database locks it needs to do its job. ^If the statement is a [COMMIT]
|
|
** or occurs outside of an explicit transaction, then you can retry the
|
|
** statement. If the statement is not a [COMMIT] and occurs within an
|
|
** explicit transaction then you should rollback the transaction before
|
|
** continuing.
|
|
**
|
|
** ^[SQLITE_DONE] means that the statement has finished executing
|
|
** successfully. sqlite3_step() should not be called again on this virtual
|
|
** machine without first calling [sqlite3_reset()] to reset the virtual
|
|
** machine back to its initial state.
|
|
**
|
|
** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
|
|
** is returned each time a new row of data is ready for processing by the
|
|
** caller. The values may be accessed using the [column access functions].
|
|
** sqlite3_step() is called again to retrieve the next row of data.
|
|
**
|
|
** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
|
|
** violation) has occurred. sqlite3_step() should not be called again on
|
|
** the VM. More information may be found by calling [sqlite3_errmsg()].
|
|
** ^With the legacy interface, a more specific error code (for example,
|
|
** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
|
|
** can be obtained by calling [sqlite3_reset()] on the
|
|
** [prepared statement]. ^In the "v2" interface,
|
|
** the more specific error code is returned directly by sqlite3_step().
|
|
**
|
|
** [SQLITE_MISUSE] means that the this routine was called inappropriately.
|
|
** Perhaps it was called on a [prepared statement] that has
|
|
** already been [sqlite3_finalize | finalized] or on one that had
|
|
** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
|
|
** be the case that the same database connection is being used by two or
|
|
** more threads at the same moment in time.
|
|
**
|
|
** For all versions of SQLite up to and including 3.6.23.1, a call to
|
|
** [sqlite3_reset()] was required after sqlite3_step() returned anything
|
|
** other than [SQLITE_ROW] before any subsequent invocation of
|
|
** sqlite3_step(). Failure to reset the prepared statement using
|
|
** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
|
|
** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
|
|
** calling [sqlite3_reset()] automatically in this circumstance rather
|
|
** than returning [SQLITE_MISUSE]. This is not considered a compatibility
|
|
** break because any application that ever receives an SQLITE_MISUSE error
|
|
** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
|
|
** can be used to restore the legacy behavior.
|
|
**
|
|
** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
|
|
** API always returns a generic error code, [SQLITE_ERROR], following any
|
|
** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
|
|
** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
|
|
** specific [error codes] that better describes the error.
|
|
** We admit that this is a goofy design. The problem has been fixed
|
|
** with the "v2" interface. If you prepare all of your SQL statements
|
|
** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
|
|
** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
|
|
** then the more specific [error codes] are returned directly
|
|
** by sqlite3_step(). The use of the "v2" interface is recommended.
|
|
*/
|
|
SQLITE_API int sqlite3_step(sqlite3_stmt*);
|
|
|
|
/*
|
|
** CAPI3REF: Number of columns in a result set
|
|
**
|
|
** ^The sqlite3_data_count(P) interface returns the number of columns in the
|
|
** current row of the result set of [prepared statement] P.
|
|
** ^If prepared statement P does not have results ready to return
|
|
** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
|
|
** interfaces) then sqlite3_data_count(P) returns 0.
|
|
** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
|
|
** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
|
|
** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
|
|
** will return non-zero if previous call to [sqlite3_step](P) returned
|
|
** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
|
|
** where it always returns zero since each step of that multi-step
|
|
** pragma returns 0 columns of data.
|
|
**
|
|
** See also: [sqlite3_column_count()]
|
|
*/
|
|
SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
|
|
|
|
/*
|
|
** CAPI3REF: Fundamental Datatypes
|
|
** KEYWORDS: SQLITE_TEXT
|
|
**
|
|
** ^(Every value in SQLite has one of five fundamental datatypes:
|
|
**
|
|
** <ul>
|
|
** <li> 64-bit signed integer
|
|
** <li> 64-bit IEEE floating point number
|
|
** <li> string
|
|
** <li> BLOB
|
|
** <li> NULL
|
|
** </ul>)^
|
|
**
|
|
** These constants are codes for each of those types.
|
|
**
|
|
** Note that the SQLITE_TEXT constant was also used in SQLite version 2
|
|
** for a completely different meaning. Software that links against both
|
|
** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
|
|
** SQLITE_TEXT.
|
|
*/
|
|
#define SQLITE_INTEGER 1
|
|
#define SQLITE_FLOAT 2
|
|
#define SQLITE_BLOB 4
|
|
#define SQLITE_NULL 5
|
|
#ifdef SQLITE_TEXT
|
|
# undef SQLITE_TEXT
|
|
#else
|
|
# define SQLITE_TEXT 3
|
|
#endif
|
|
#define SQLITE3_TEXT 3
|
|
|
|
/*
|
|
** CAPI3REF: Result Values From A Query
|
|
** KEYWORDS: {column access functions}
|
|
**
|
|
** These routines form the "result set" interface.
|
|
**
|
|
** ^These routines return information about a single column of the current
|
|
** result row of a query. ^In every case the first argument is a pointer
|
|
** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
|
|
** that was returned from [sqlite3_prepare_v2()] or one of its variants)
|
|
** and the second argument is the index of the column for which information
|
|
** should be returned. ^The leftmost column of the result set has the index 0.
|
|
** ^The number of columns in the result can be determined using
|
|
** [sqlite3_column_count()].
|
|
**
|
|
** If the SQL statement does not currently point to a valid row, or if the
|
|
** column index is out of range, the result is undefined.
|
|
** These routines may only be called when the most recent call to
|
|
** [sqlite3_step()] has returned [SQLITE_ROW] and neither
|
|
** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
|
|
** If any of these routines are called after [sqlite3_reset()] or
|
|
** [sqlite3_finalize()] or after [sqlite3_step()] has returned
|
|
** something other than [SQLITE_ROW], the results are undefined.
|
|
** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
|
|
** are called from a different thread while any of these routines
|
|
** are pending, then the results are undefined.
|
|
**
|
|
** ^The sqlite3_column_type() routine returns the
|
|
** [SQLITE_INTEGER | datatype code] for the initial data type
|
|
** of the result column. ^The returned value is one of [SQLITE_INTEGER],
|
|
** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
|
|
** returned by sqlite3_column_type() is only meaningful if no type
|
|
** conversions have occurred as described below. After a type conversion,
|
|
** the value returned by sqlite3_column_type() is undefined. Future
|
|
** versions of SQLite may change the behavior of sqlite3_column_type()
|
|
** following a type conversion.
|
|
**
|
|
** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
|
|
** routine returns the number of bytes in that BLOB or string.
|
|
** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
|
|
** the string to UTF-8 and then returns the number of bytes.
|
|
** ^If the result is a numeric value then sqlite3_column_bytes() uses
|
|
** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
|
|
** the number of bytes in that string.
|
|
** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
|
|
**
|
|
** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
|
|
** routine returns the number of bytes in that BLOB or string.
|
|
** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
|
|
** the string to UTF-16 and then returns the number of bytes.
|
|
** ^If the result is a numeric value then sqlite3_column_bytes16() uses
|
|
** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
|
|
** the number of bytes in that string.
|
|
** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
|
|
**
|
|
** ^The values returned by [sqlite3_column_bytes()] and
|
|
** [sqlite3_column_bytes16()] do not include the zero terminators at the end
|
|
** of the string. ^For clarity: the values returned by
|
|
** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
|
|
** bytes in the string, not the number of characters.
|
|
**
|
|
** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
|
|
** even empty strings, are always zero-terminated. ^The return
|
|
** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
|
|
**
|
|
** ^The object returned by [sqlite3_column_value()] is an
|
|
** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
|
|
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
|
|
** If the [unprotected sqlite3_value] object returned by
|
|
** [sqlite3_column_value()] is used in any other way, including calls
|
|
** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
|
|
** or [sqlite3_value_bytes()], then the behavior is undefined.
|
|
**
|
|
** These routines attempt to convert the value where appropriate. ^For
|
|
** example, if the internal representation is FLOAT and a text result
|
|
** is requested, [sqlite3_snprintf()] is used internally to perform the
|
|
** conversion automatically. ^(The following table details the conversions
|
|
** that are applied:
|
|
**
|
|
** <blockquote>
|
|
** <table border="1">
|
|
** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
|
|
**
|
|
** <tr><td> NULL <td> INTEGER <td> Result is 0
|
|
** <tr><td> NULL <td> FLOAT <td> Result is 0.0
|
|
** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
|
|
** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
|
|
** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
|
|
** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
|
|
** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
|
|
** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
|
|
** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
|
|
** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
|
|
** <tr><td> TEXT <td> INTEGER <td> Use atoi()
|
|
** <tr><td> TEXT <td> FLOAT <td> Use atof()
|
|
** <tr><td> TEXT <td> BLOB <td> No change
|
|
** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
|
|
** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
|
|
** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
|
|
** </table>
|
|
** </blockquote>)^
|
|
**
|
|
** The table above makes reference to standard C library functions atoi()
|
|
** and atof(). SQLite does not really use these functions. It has its
|
|
** own equivalent internal routines. The atoi() and atof() names are
|
|
** used in the table for brevity and because they are familiar to most
|
|
** C programmers.
|
|
**
|
|
** Note that when type conversions occur, pointers returned by prior
|
|
** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
|
|
** sqlite3_column_text16() may be invalidated.
|
|
** Type conversions and pointer invalidations might occur
|
|
** in the following cases:
|
|
**
|
|
** <ul>
|
|
** <li> The initial content is a BLOB and sqlite3_column_text() or
|
|
** sqlite3_column_text16() is called. A zero-terminator might
|
|
** need to be added to the string.</li>
|
|
** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
|
|
** sqlite3_column_text16() is called. The content must be converted
|
|
** to UTF-16.</li>
|
|
** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
|
|
** sqlite3_column_text() is called. The content must be converted
|
|
** to UTF-8.</li>
|
|
** </ul>
|
|
**
|
|
** ^Conversions between UTF-16be and UTF-16le are always done in place and do
|
|
** not invalidate a prior pointer, though of course the content of the buffer
|
|
** that the prior pointer references will have been modified. Other kinds
|
|
** of conversion are done in place when it is possible, but sometimes they
|
|
** are not possible and in those cases prior pointers are invalidated.
|
|
**
|
|
** The safest and easiest to remember policy is to invoke these routines
|
|
** in one of the following ways:
|
|
**
|
|
** <ul>
|
|
** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
|
|
** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
|
|
** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
|
|
** </ul>
|
|
**
|
|
** In other words, you should call sqlite3_column_text(),
|
|
** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
|
|
** into the desired format, then invoke sqlite3_column_bytes() or
|
|
** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
|
|
** to sqlite3_column_text() or sqlite3_column_blob() with calls to
|
|
** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
|
|
** with calls to sqlite3_column_bytes().
|
|
**
|
|
** ^The pointers returned are valid until a type conversion occurs as
|
|
** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
|
|
** [sqlite3_finalize()] is called. ^The memory space used to hold strings
|
|
** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
|
|
** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
|
|
** [sqlite3_free()].
|
|
**
|
|
** ^(If a memory allocation error occurs during the evaluation of any
|
|
** of these routines, a default value is returned. The default value
|
|
** is either the integer 0, the floating point number 0.0, or a NULL
|
|
** pointer. Subsequent calls to [sqlite3_errcode()] will return
|
|
** [SQLITE_NOMEM].)^
|
|
*/
|
|
SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
|
|
SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
|
|
SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
|
|
SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
|
|
SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
|
|
SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
|
|
SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
|
|
SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
|
|
SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
|
|
SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
|
|
|
|
/*
|
|
** CAPI3REF: Destroy A Prepared Statement Object
|
|
**
|
|
** ^The sqlite3_finalize() function is called to delete a [prepared statement].
|
|
** ^If the most recent evaluation of the statement encountered no errors
|
|
** or if the statement is never been evaluated, then sqlite3_finalize() returns
|
|
** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
|
|
** sqlite3_finalize(S) returns the appropriate [error code] or
|
|
** [extended error code].
|
|
**
|
|
** ^The sqlite3_finalize(S) routine can be called at any point during
|
|
** the life cycle of [prepared statement] S:
|
|
** before statement S is ever evaluated, after
|
|
** one or more calls to [sqlite3_reset()], or after any call
|
|
** to [sqlite3_step()] regardless of whether or not the statement has
|
|
** completed execution.
|
|
**
|
|
** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
|
|
**
|
|
** The application must finalize every [prepared statement] in order to avoid
|
|
** resource leaks. It is a grievous error for the application to try to use
|
|
** a prepared statement after it has been finalized. Any use of a prepared
|
|
** statement after it has been finalized can result in undefined and
|
|
** undesirable behavior such as segfaults and heap corruption.
|
|
*/
|
|
SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
|
|
|
|
/*
|
|
** CAPI3REF: Reset A Prepared Statement Object
|
|
**
|
|
** The sqlite3_reset() function is called to reset a [prepared statement]
|
|
** object back to its initial state, ready to be re-executed.
|
|
** ^Any SQL statement variables that had values bound to them using
|
|
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
|
|
** Use [sqlite3_clear_bindings()] to reset the bindings.
|
|
**
|
|
** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
|
|
** back to the beginning of its program.
|
|
**
|
|
** ^If the most recent call to [sqlite3_step(S)] for the
|
|
** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
|
|
** or if [sqlite3_step(S)] has never before been called on S,
|
|
** then [sqlite3_reset(S)] returns [SQLITE_OK].
|
|
**
|
|
** ^If the most recent call to [sqlite3_step(S)] for the
|
|
** [prepared statement] S indicated an error, then
|
|
** [sqlite3_reset(S)] returns an appropriate [error code].
|
|
**
|
|
** ^The [sqlite3_reset(S)] interface does not change the values
|
|
** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
|
|
*/
|
|
SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
|
|
|
|
/*
|
|
** CAPI3REF: Create Or Redefine SQL Functions
|
|
** KEYWORDS: {function creation routines}
|
|
** KEYWORDS: {application-defined SQL function}
|
|
** KEYWORDS: {application-defined SQL functions}
|
|
**
|
|
** ^These functions (collectively known as "function creation routines")
|
|
** are used to add SQL functions or aggregates or to redefine the behavior
|
|
** of existing SQL functions or aggregates. The only differences between
|
|
** these routines are the text encoding expected for
|
|
** the second parameter (the name of the function being created)
|
|
** and the presence or absence of a destructor callback for
|
|
** the application data pointer.
|
|
**
|
|
** ^The first parameter is the [database connection] to which the SQL
|
|
** function is to be added. ^If an application uses more than one database
|
|
** connection then application-defined SQL functions must be added
|
|
** to each database connection separately.
|
|
**
|
|
** ^The second parameter is the name of the SQL function to be created or
|
|
** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
|
|
** representation, exclusive of the zero-terminator. ^Note that the name
|
|
** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
|
|
** ^Any attempt to create a function with a longer name
|
|
** will result in [SQLITE_MISUSE] being returned.
|
|
**
|
|
** ^The third parameter (nArg)
|
|
** is the number of arguments that the SQL function or
|
|
** aggregate takes. ^If this parameter is -1, then the SQL function or
|
|
** aggregate may take any number of arguments between 0 and the limit
|
|
** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
|
|
** parameter is less than -1 or greater than 127 then the behavior is
|
|
** undefined.
|
|
**
|
|
** ^The fourth parameter, eTextRep, specifies what
|
|
** [SQLITE_UTF8 | text encoding] this SQL function prefers for
|
|
** its parameters. Every SQL function implementation must be able to work
|
|
** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
|
|
** more efficient with one encoding than another. ^An application may
|
|
** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
|
|
** times with the same function but with different values of eTextRep.
|
|
** ^When multiple implementations of the same function are available, SQLite
|
|
** will pick the one that involves the least amount of data conversion.
|
|
** If there is only a single implementation which does not care what text
|
|
** encoding is used, then the fourth argument should be [SQLITE_ANY].
|
|
**
|
|
** ^(The fifth parameter is an arbitrary pointer. The implementation of the
|
|
** function can gain access to this pointer using [sqlite3_user_data()].)^
|
|
**
|
|
** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
|
|
** pointers to C-language functions that implement the SQL function or
|
|
** aggregate. ^A scalar SQL function requires an implementation of the xFunc
|
|
** callback only; NULL pointers must be passed as the xStep and xFinal
|
|
** parameters. ^An aggregate SQL function requires an implementation of xStep
|
|
** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
|
|
** SQL function or aggregate, pass NULL pointers for all three function
|
|
** callbacks.
|
|
**
|
|
** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
|
|
** then it is destructor for the application data pointer.
|
|
** The destructor is invoked when the function is deleted, either by being
|
|
** overloaded or when the database connection closes.)^
|
|
** ^The destructor is also invoked if the call to
|
|
** sqlite3_create_function_v2() fails.
|
|
** ^When the destructor callback of the tenth parameter is invoked, it
|
|
** is passed a single argument which is a copy of the application data
|
|
** pointer which was the fifth parameter to sqlite3_create_function_v2().
|
|
**
|
|
** ^It is permitted to register multiple implementations of the same
|
|
** functions with the same name but with either differing numbers of
|
|
** arguments or differing preferred text encodings. ^SQLite will use
|
|
** the implementation that most closely matches the way in which the
|
|
** SQL function is used. ^A function implementation with a non-negative
|
|
** nArg parameter is a better match than a function implementation with
|
|
** a negative nArg. ^A function where the preferred text encoding
|
|
** matches the database encoding is a better
|
|
** match than a function where the encoding is different.
|
|
** ^A function where the encoding difference is between UTF16le and UTF16be
|
|
** is a closer match than a function where the encoding difference is
|
|
** between UTF8 and UTF16.
|
|
**
|
|
** ^Built-in functions may be overloaded by new application-defined functions.
|
|
**
|
|
** ^An application-defined function is permitted to call other
|
|
** SQLite interfaces. However, such calls must not
|
|
** close the database connection nor finalize or reset the prepared
|
|
** statement in which the function is running.
|
|
*/
|
|
SQLITE_API int sqlite3_create_function(
|
|
sqlite3 *db,
|
|
const char *zFunctionName,
|
|
int nArg,
|
|
int eTextRep,
|
|
void *pApp,
|
|
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
|
|
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
|
|
void (*xFinal)(sqlite3_context*)
|
|
);
|
|
SQLITE_API int sqlite3_create_function16(
|
|
sqlite3 *db,
|
|
const void *zFunctionName,
|
|
int nArg,
|
|
int eTextRep,
|
|
void *pApp,
|
|
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
|
|
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
|
|
void (*xFinal)(sqlite3_context*)
|
|
);
|
|
SQLITE_API int sqlite3_create_function_v2(
|
|
sqlite3 *db,
|
|
const char *zFunctionName,
|
|
int nArg,
|
|
int eTextRep,
|
|
void *pApp,
|
|
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
|
|
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
|
|
void (*xFinal)(sqlite3_context*),
|
|
void(*xDestroy)(void*)
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Text Encodings
|
|
**
|
|
** These constant define integer codes that represent the various
|
|
** text encodings supported by SQLite.
|
|
*/
|
|
#define SQLITE_UTF8 1
|
|
#define SQLITE_UTF16LE 2
|
|
#define SQLITE_UTF16BE 3
|
|
#define SQLITE_UTF16 4 /* Use native byte order */
|
|
#define SQLITE_ANY 5 /* sqlite3_create_function only */
|
|
#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
|
|
|
|
/*
|
|
** CAPI3REF: Deprecated Functions
|
|
** DEPRECATED
|
|
**
|
|
** These functions are [deprecated]. In order to maintain
|
|
** backwards compatibility with older code, these functions continue
|
|
** to be supported. However, new applications should avoid
|
|
** the use of these functions. To help encourage people to avoid
|
|
** using these functions, we are not going to tell you what they do.
|
|
*/
|
|
#ifndef SQLITE_OMIT_DEPRECATED
|
|
SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
|
|
SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
|
|
SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
|
|
SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
|
|
SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
|
|
SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
|
|
#endif
|
|
|
|
/*
|
|
** CAPI3REF: Obtaining SQL Function Parameter Values
|
|
**
|
|
** The C-language implementation of SQL functions and aggregates uses
|
|
** this set of interface routines to access the parameter values on
|
|
** the function or aggregate.
|
|
**
|
|
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
|
|
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
|
|
** define callbacks that implement the SQL functions and aggregates.
|
|
** The 3rd parameter to these callbacks is an array of pointers to
|
|
** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
|
|
** each parameter to the SQL function. These routines are used to
|
|
** extract values from the [sqlite3_value] objects.
|
|
**
|
|
** These routines work only with [protected sqlite3_value] objects.
|
|
** Any attempt to use these routines on an [unprotected sqlite3_value]
|
|
** object results in undefined behavior.
|
|
**
|
|
** ^These routines work just like the corresponding [column access functions]
|
|
** except that these routines take a single [protected sqlite3_value] object
|
|
** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
|
|
**
|
|
** ^The sqlite3_value_text16() interface extracts a UTF-16 string
|
|
** in the native byte-order of the host machine. ^The
|
|
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
|
|
** extract UTF-16 strings as big-endian and little-endian respectively.
|
|
**
|
|
** ^(The sqlite3_value_numeric_type() interface attempts to apply
|
|
** numeric affinity to the value. This means that an attempt is
|
|
** made to convert the value to an integer or floating point. If
|
|
** such a conversion is possible without loss of information (in other
|
|
** words, if the value is a string that looks like a number)
|
|
** then the conversion is performed. Otherwise no conversion occurs.
|
|
** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
|
|
**
|
|
** Please pay particular attention to the fact that the pointer returned
|
|
** from [sqlite3_value_blob()], [sqlite3_value_text()], or
|
|
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
|
|
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
|
|
** or [sqlite3_value_text16()].
|
|
**
|
|
** These routines must be called from the same thread as
|
|
** the SQL function that supplied the [sqlite3_value*] parameters.
|
|
*/
|
|
SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
|
|
SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
|
|
SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
|
|
SQLITE_API double sqlite3_value_double(sqlite3_value*);
|
|
SQLITE_API int sqlite3_value_int(sqlite3_value*);
|
|
SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
|
|
SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
|
|
SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
|
|
SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
|
|
SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
|
|
SQLITE_API int sqlite3_value_type(sqlite3_value*);
|
|
SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
|
|
|
|
/*
|
|
** CAPI3REF: Obtain Aggregate Function Context
|
|
**
|
|
** Implementations of aggregate SQL functions use this
|
|
** routine to allocate memory for storing their state.
|
|
**
|
|
** ^The first time the sqlite3_aggregate_context(C,N) routine is called
|
|
** for a particular aggregate function, SQLite
|
|
** allocates N of memory, zeroes out that memory, and returns a pointer
|
|
** to the new memory. ^On second and subsequent calls to
|
|
** sqlite3_aggregate_context() for the same aggregate function instance,
|
|
** the same buffer is returned. Sqlite3_aggregate_context() is normally
|
|
** called once for each invocation of the xStep callback and then one
|
|
** last time when the xFinal callback is invoked. ^(When no rows match
|
|
** an aggregate query, the xStep() callback of the aggregate function
|
|
** implementation is never called and xFinal() is called exactly once.
|
|
** In those cases, sqlite3_aggregate_context() might be called for the
|
|
** first time from within xFinal().)^
|
|
**
|
|
** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
|
|
** less than or equal to zero or if a memory allocate error occurs.
|
|
**
|
|
** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
|
|
** determined by the N parameter on first successful call. Changing the
|
|
** value of N in subsequent call to sqlite3_aggregate_context() within
|
|
** the same aggregate function instance will not resize the memory
|
|
** allocation.)^
|
|
**
|
|
** ^SQLite automatically frees the memory allocated by
|
|
** sqlite3_aggregate_context() when the aggregate query concludes.
|
|
**
|
|
** The first parameter must be a copy of the
|
|
** [sqlite3_context | SQL function context] that is the first parameter
|
|
** to the xStep or xFinal callback routine that implements the aggregate
|
|
** function.
|
|
**
|
|
** This routine must be called from the same thread in which
|
|
** the aggregate SQL function is running.
|
|
*/
|
|
SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
|
|
|
|
/*
|
|
** CAPI3REF: User Data For Functions
|
|
**
|
|
** ^The sqlite3_user_data() interface returns a copy of
|
|
** the pointer that was the pUserData parameter (the 5th parameter)
|
|
** of the [sqlite3_create_function()]
|
|
** and [sqlite3_create_function16()] routines that originally
|
|
** registered the application defined function.
|
|
**
|
|
** This routine must be called from the same thread in which
|
|
** the application-defined function is running.
|
|
*/
|
|
SQLITE_API void *sqlite3_user_data(sqlite3_context*);
|
|
|
|
/*
|
|
** CAPI3REF: Database Connection For Functions
|
|
**
|
|
** ^The sqlite3_context_db_handle() interface returns a copy of
|
|
** the pointer to the [database connection] (the 1st parameter)
|
|
** of the [sqlite3_create_function()]
|
|
** and [sqlite3_create_function16()] routines that originally
|
|
** registered the application defined function.
|
|
*/
|
|
SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
|
|
|
|
/*
|
|
** CAPI3REF: Function Auxiliary Data
|
|
**
|
|
** The following two functions may be used by scalar SQL functions to
|
|
** associate metadata with argument values. If the same value is passed to
|
|
** multiple invocations of the same SQL function during query execution, under
|
|
** some circumstances the associated metadata may be preserved. This may
|
|
** be used, for example, to add a regular-expression matching scalar
|
|
** function. The compiled version of the regular expression is stored as
|
|
** metadata associated with the SQL value passed as the regular expression
|
|
** pattern. The compiled regular expression can be reused on multiple
|
|
** invocations of the same function so that the original pattern string
|
|
** does not need to be recompiled on each invocation.
|
|
**
|
|
** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
|
|
** associated by the sqlite3_set_auxdata() function with the Nth argument
|
|
** value to the application-defined function. ^If no metadata has been ever
|
|
** been set for the Nth argument of the function, or if the corresponding
|
|
** function parameter has changed since the meta-data was set,
|
|
** then sqlite3_get_auxdata() returns a NULL pointer.
|
|
**
|
|
** ^The sqlite3_set_auxdata() interface saves the metadata
|
|
** pointed to by its 3rd parameter as the metadata for the N-th
|
|
** argument of the application-defined function. Subsequent
|
|
** calls to sqlite3_get_auxdata() might return this data, if it has
|
|
** not been destroyed.
|
|
** ^If it is not NULL, SQLite will invoke the destructor
|
|
** function given by the 4th parameter to sqlite3_set_auxdata() on
|
|
** the metadata when the corresponding function parameter changes
|
|
** or when the SQL statement completes, whichever comes first.
|
|
**
|
|
** SQLite is free to call the destructor and drop metadata on any
|
|
** parameter of any function at any time. ^The only guarantee is that
|
|
** the destructor will be called before the metadata is dropped.
|
|
**
|
|
** ^(In practice, metadata is preserved between function calls for
|
|
** expressions that are constant at compile time. This includes literal
|
|
** values and [parameters].)^
|
|
**
|
|
** These routines must be called from the same thread in which
|
|
** the SQL function is running.
|
|
*/
|
|
SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
|
|
SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Constants Defining Special Destructor Behavior
|
|
**
|
|
** These are special values for the destructor that is passed in as the
|
|
** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
|
|
** argument is SQLITE_STATIC, it means that the content pointer is constant
|
|
** and will never change. It does not need to be destroyed. ^The
|
|
** SQLITE_TRANSIENT value means that the content will likely change in
|
|
** the near future and that SQLite should make its own private copy of
|
|
** the content before returning.
|
|
**
|
|
** The typedef is necessary to work around problems in certain
|
|
** C++ compilers. See ticket #2191.
|
|
*/
|
|
typedef void (*sqlite3_destructor_type)(void*);
|
|
#define SQLITE_STATIC ((sqlite3_destructor_type)0)
|
|
#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
|
|
|
|
/*
|
|
** CAPI3REF: Setting The Result Of An SQL Function
|
|
**
|
|
** These routines are used by the xFunc or xFinal callbacks that
|
|
** implement SQL functions and aggregates. See
|
|
** [sqlite3_create_function()] and [sqlite3_create_function16()]
|
|
** for additional information.
|
|
**
|
|
** These functions work very much like the [parameter binding] family of
|
|
** functions used to bind values to host parameters in prepared statements.
|
|
** Refer to the [SQL parameter] documentation for additional information.
|
|
**
|
|
** ^The sqlite3_result_blob() interface sets the result from
|
|
** an application-defined function to be the BLOB whose content is pointed
|
|
** to by the second parameter and which is N bytes long where N is the
|
|
** third parameter.
|
|
**
|
|
** ^The sqlite3_result_zeroblob() interfaces set the result of
|
|
** the application-defined function to be a BLOB containing all zero
|
|
** bytes and N bytes in size, where N is the value of the 2nd parameter.
|
|
**
|
|
** ^The sqlite3_result_double() interface sets the result from
|
|
** an application-defined function to be a floating point value specified
|
|
** by its 2nd argument.
|
|
**
|
|
** ^The sqlite3_result_error() and sqlite3_result_error16() functions
|
|
** cause the implemented SQL function to throw an exception.
|
|
** ^SQLite uses the string pointed to by the
|
|
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
|
|
** as the text of an error message. ^SQLite interprets the error
|
|
** message string from sqlite3_result_error() as UTF-8. ^SQLite
|
|
** interprets the string from sqlite3_result_error16() as UTF-16 in native
|
|
** byte order. ^If the third parameter to sqlite3_result_error()
|
|
** or sqlite3_result_error16() is negative then SQLite takes as the error
|
|
** message all text up through the first zero character.
|
|
** ^If the third parameter to sqlite3_result_error() or
|
|
** sqlite3_result_error16() is non-negative then SQLite takes that many
|
|
** bytes (not characters) from the 2nd parameter as the error message.
|
|
** ^The sqlite3_result_error() and sqlite3_result_error16()
|
|
** routines make a private copy of the error message text before
|
|
** they return. Hence, the calling function can deallocate or
|
|
** modify the text after they return without harm.
|
|
** ^The sqlite3_result_error_code() function changes the error code
|
|
** returned by SQLite as a result of an error in a function. ^By default,
|
|
** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
|
|
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
|
|
**
|
|
** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
|
|
** error indicating that a string or BLOB is too long to represent.
|
|
**
|
|
** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
|
|
** error indicating that a memory allocation failed.
|
|
**
|
|
** ^The sqlite3_result_int() interface sets the return value
|
|
** of the application-defined function to be the 32-bit signed integer
|
|
** value given in the 2nd argument.
|
|
** ^The sqlite3_result_int64() interface sets the return value
|
|
** of the application-defined function to be the 64-bit signed integer
|
|
** value given in the 2nd argument.
|
|
**
|
|
** ^The sqlite3_result_null() interface sets the return value
|
|
** of the application-defined function to be NULL.
|
|
**
|
|
** ^The sqlite3_result_text(), sqlite3_result_text16(),
|
|
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
|
|
** set the return value of the application-defined function to be
|
|
** a text string which is represented as UTF-8, UTF-16 native byte order,
|
|
** UTF-16 little endian, or UTF-16 big endian, respectively.
|
|
** ^SQLite takes the text result from the application from
|
|
** the 2nd parameter of the sqlite3_result_text* interfaces.
|
|
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
|
|
** is negative, then SQLite takes result text from the 2nd parameter
|
|
** through the first zero character.
|
|
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
|
|
** is non-negative, then as many bytes (not characters) of the text
|
|
** pointed to by the 2nd parameter are taken as the application-defined
|
|
** function result. If the 3rd parameter is non-negative, then it
|
|
** must be the byte offset into the string where the NUL terminator would
|
|
** appear if the string where NUL terminated. If any NUL characters occur
|
|
** in the string at a byte offset that is less than the value of the 3rd
|
|
** parameter, then the resulting string will contain embedded NULs and the
|
|
** result of expressions operating on strings with embedded NULs is undefined.
|
|
** ^If the 4th parameter to the sqlite3_result_text* interfaces
|
|
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
|
|
** function as the destructor on the text or BLOB result when it has
|
|
** finished using that result.
|
|
** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
|
|
** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
|
|
** assumes that the text or BLOB result is in constant space and does not
|
|
** copy the content of the parameter nor call a destructor on the content
|
|
** when it has finished using that result.
|
|
** ^If the 4th parameter to the sqlite3_result_text* interfaces
|
|
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
|
|
** then SQLite makes a copy of the result into space obtained from
|
|
** from [sqlite3_malloc()] before it returns.
|
|
**
|
|
** ^The sqlite3_result_value() interface sets the result of
|
|
** the application-defined function to be a copy the
|
|
** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
|
|
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
|
|
** so that the [sqlite3_value] specified in the parameter may change or
|
|
** be deallocated after sqlite3_result_value() returns without harm.
|
|
** ^A [protected sqlite3_value] object may always be used where an
|
|
** [unprotected sqlite3_value] object is required, so either
|
|
** kind of [sqlite3_value] object can be used with this interface.
|
|
**
|
|
** If these routines are called from within the different thread
|
|
** than the one containing the application-defined function that received
|
|
** the [sqlite3_context] pointer, the results are undefined.
|
|
*/
|
|
SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
|
|
SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
|
|
SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
|
|
SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
|
|
SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
|
|
SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
|
|
SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
|
|
SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
|
|
SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
|
|
SQLITE_API void sqlite3_result_null(sqlite3_context*);
|
|
SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
|
|
SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
|
|
SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
|
|
SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
|
|
SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
|
|
SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
|
|
|
|
/*
|
|
** CAPI3REF: Define New Collating Sequences
|
|
**
|
|
** ^These functions add, remove, or modify a [collation] associated
|
|
** with the [database connection] specified as the first argument.
|
|
**
|
|
** ^The name of the collation is a UTF-8 string
|
|
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
|
|
** and a UTF-16 string in native byte order for sqlite3_create_collation16().
|
|
** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
|
|
** considered to be the same name.
|
|
**
|
|
** ^(The third argument (eTextRep) must be one of the constants:
|
|
** <ul>
|
|
** <li> [SQLITE_UTF8],
|
|
** <li> [SQLITE_UTF16LE],
|
|
** <li> [SQLITE_UTF16BE],
|
|
** <li> [SQLITE_UTF16], or
|
|
** <li> [SQLITE_UTF16_ALIGNED].
|
|
** </ul>)^
|
|
** ^The eTextRep argument determines the encoding of strings passed
|
|
** to the collating function callback, xCallback.
|
|
** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
|
|
** force strings to be UTF16 with native byte order.
|
|
** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
|
|
** on an even byte address.
|
|
**
|
|
** ^The fourth argument, pArg, is an application data pointer that is passed
|
|
** through as the first argument to the collating function callback.
|
|
**
|
|
** ^The fifth argument, xCallback, is a pointer to the collating function.
|
|
** ^Multiple collating functions can be registered using the same name but
|
|
** with different eTextRep parameters and SQLite will use whichever
|
|
** function requires the least amount of data transformation.
|
|
** ^If the xCallback argument is NULL then the collating function is
|
|
** deleted. ^When all collating functions having the same name are deleted,
|
|
** that collation is no longer usable.
|
|
**
|
|
** ^The collating function callback is invoked with a copy of the pArg
|
|
** application data pointer and with two strings in the encoding specified
|
|
** by the eTextRep argument. The collating function must return an
|
|
** integer that is negative, zero, or positive
|
|
** if the first string is less than, equal to, or greater than the second,
|
|
** respectively. A collating function must always return the same answer
|
|
** given the same inputs. If two or more collating functions are registered
|
|
** to the same collation name (using different eTextRep values) then all
|
|
** must give an equivalent answer when invoked with equivalent strings.
|
|
** The collating function must obey the following properties for all
|
|
** strings A, B, and C:
|
|
**
|
|
** <ol>
|
|
** <li> If A==B then B==A.
|
|
** <li> If A==B and B==C then A==C.
|
|
** <li> If A<B THEN B>A.
|
|
** <li> If A<B and B<C then A<C.
|
|
** </ol>
|
|
**
|
|
** If a collating function fails any of the above constraints and that
|
|
** collating function is registered and used, then the behavior of SQLite
|
|
** is undefined.
|
|
**
|
|
** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
|
|
** with the addition that the xDestroy callback is invoked on pArg when
|
|
** the collating function is deleted.
|
|
** ^Collating functions are deleted when they are overridden by later
|
|
** calls to the collation creation functions or when the
|
|
** [database connection] is closed using [sqlite3_close()].
|
|
**
|
|
** ^The xDestroy callback is <u>not</u> called if the
|
|
** sqlite3_create_collation_v2() function fails. Applications that invoke
|
|
** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
|
|
** check the return code and dispose of the application data pointer
|
|
** themselves rather than expecting SQLite to deal with it for them.
|
|
** This is different from every other SQLite interface. The inconsistency
|
|
** is unfortunate but cannot be changed without breaking backwards
|
|
** compatibility.
|
|
**
|
|
** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
|
|
*/
|
|
SQLITE_API int sqlite3_create_collation(
|
|
sqlite3*,
|
|
const char *zName,
|
|
int eTextRep,
|
|
void *pArg,
|
|
int(*xCompare)(void*,int,const void*,int,const void*)
|
|
);
|
|
SQLITE_API int sqlite3_create_collation_v2(
|
|
sqlite3*,
|
|
const char *zName,
|
|
int eTextRep,
|
|
void *pArg,
|
|
int(*xCompare)(void*,int,const void*,int,const void*),
|
|
void(*xDestroy)(void*)
|
|
);
|
|
SQLITE_API int sqlite3_create_collation16(
|
|
sqlite3*,
|
|
const void *zName,
|
|
int eTextRep,
|
|
void *pArg,
|
|
int(*xCompare)(void*,int,const void*,int,const void*)
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Collation Needed Callbacks
|
|
**
|
|
** ^To avoid having to register all collation sequences before a database
|
|
** can be used, a single callback function may be registered with the
|
|
** [database connection] to be invoked whenever an undefined collation
|
|
** sequence is required.
|
|
**
|
|
** ^If the function is registered using the sqlite3_collation_needed() API,
|
|
** then it is passed the names of undefined collation sequences as strings
|
|
** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
|
|
** the names are passed as UTF-16 in machine native byte order.
|
|
** ^A call to either function replaces the existing collation-needed callback.
|
|
**
|
|
** ^(When the callback is invoked, the first argument passed is a copy
|
|
** of the second argument to sqlite3_collation_needed() or
|
|
** sqlite3_collation_needed16(). The second argument is the database
|
|
** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
|
|
** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
|
|
** sequence function required. The fourth parameter is the name of the
|
|
** required collation sequence.)^
|
|
**
|
|
** The callback function should register the desired collation using
|
|
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
|
|
** [sqlite3_create_collation_v2()].
|
|
*/
|
|
SQLITE_API int sqlite3_collation_needed(
|
|
sqlite3*,
|
|
void*,
|
|
void(*)(void*,sqlite3*,int eTextRep,const char*)
|
|
);
|
|
SQLITE_API int sqlite3_collation_needed16(
|
|
sqlite3*,
|
|
void*,
|
|
void(*)(void*,sqlite3*,int eTextRep,const void*)
|
|
);
|
|
|
|
#ifdef SQLITE_HAS_CODEC
|
|
/*
|
|
** Specify the key for an encrypted database. This routine should be
|
|
** called right after sqlite3_open().
|
|
**
|
|
** The code to implement this API is not available in the public release
|
|
** of SQLite.
|
|
*/
|
|
SQLITE_API int sqlite3_key(
|
|
sqlite3 *db, /* Database to be rekeyed */
|
|
const void *pKey, int nKey /* The key */
|
|
);
|
|
|
|
/*
|
|
** Change the key on an open database. If the current database is not
|
|
** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
|
|
** database is decrypted.
|
|
**
|
|
** The code to implement this API is not available in the public release
|
|
** of SQLite.
|
|
*/
|
|
SQLITE_API int sqlite3_rekey(
|
|
sqlite3 *db, /* Database to be rekeyed */
|
|
const void *pKey, int nKey /* The new key */
|
|
);
|
|
|
|
/*
|
|
** Specify the activation key for a SEE database. Unless
|
|
** activated, none of the SEE routines will work.
|
|
*/
|
|
SQLITE_API void sqlite3_activate_see(
|
|
const char *zPassPhrase /* Activation phrase */
|
|
);
|
|
#endif
|
|
|
|
#ifdef SQLITE_ENABLE_CEROD
|
|
/*
|
|
** Specify the activation key for a CEROD database. Unless
|
|
** activated, none of the CEROD routines will work.
|
|
*/
|
|
SQLITE_API void sqlite3_activate_cerod(
|
|
const char *zPassPhrase /* Activation phrase */
|
|
);
|
|
#endif
|
|
|
|
/*
|
|
** CAPI3REF: Suspend Execution For A Short Time
|
|
**
|
|
** The sqlite3_sleep() function causes the current thread to suspend execution
|
|
** for at least a number of milliseconds specified in its parameter.
|
|
**
|
|
** If the operating system does not support sleep requests with
|
|
** millisecond time resolution, then the time will be rounded up to
|
|
** the nearest second. The number of milliseconds of sleep actually
|
|
** requested from the operating system is returned.
|
|
**
|
|
** ^SQLite implements this interface by calling the xSleep()
|
|
** method of the default [sqlite3_vfs] object. If the xSleep() method
|
|
** of the default VFS is not implemented correctly, or not implemented at
|
|
** all, then the behavior of sqlite3_sleep() may deviate from the description
|
|
** in the previous paragraphs.
|
|
*/
|
|
SQLITE_API int sqlite3_sleep(int);
|
|
|
|
/*
|
|
** CAPI3REF: Name Of The Folder Holding Temporary Files
|
|
**
|
|
** ^(If this global variable is made to point to a string which is
|
|
** the name of a folder (a.k.a. directory), then all temporary files
|
|
** created by SQLite when using a built-in [sqlite3_vfs | VFS]
|
|
** will be placed in that directory.)^ ^If this variable
|
|
** is a NULL pointer, then SQLite performs a search for an appropriate
|
|
** temporary file directory.
|
|
**
|
|
** It is not safe to read or modify this variable in more than one
|
|
** thread at a time. It is not safe to read or modify this variable
|
|
** if a [database connection] is being used at the same time in a separate
|
|
** thread.
|
|
** It is intended that this variable be set once
|
|
** as part of process initialization and before any SQLite interface
|
|
** routines have been called and that this variable remain unchanged
|
|
** thereafter.
|
|
**
|
|
** ^The [temp_store_directory pragma] may modify this variable and cause
|
|
** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
|
|
** the [temp_store_directory pragma] always assumes that any string
|
|
** that this variable points to is held in memory obtained from
|
|
** [sqlite3_malloc] and the pragma may attempt to free that memory
|
|
** using [sqlite3_free].
|
|
** Hence, if this variable is modified directly, either it should be
|
|
** made NULL or made to point to memory obtained from [sqlite3_malloc]
|
|
** or else the use of the [temp_store_directory pragma] should be avoided.
|
|
**
|
|
** <b>Note to Windows Runtime users:</b> The temporary directory must be set
|
|
** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
|
|
** features that require the use of temporary files may fail. Here is an
|
|
** example of how to do this using C++ with the Windows Runtime:
|
|
**
|
|
** <blockquote><pre>
|
|
** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
|
|
** TemporaryFolder->Path->Data();
|
|
** char zPathBuf[MAX_PATH + 1];
|
|
** memset(zPathBuf, 0, sizeof(zPathBuf));
|
|
** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
|
|
** NULL, NULL);
|
|
** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
|
|
** </pre></blockquote>
|
|
*/
|
|
SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
|
|
|
|
/*
|
|
** CAPI3REF: Name Of The Folder Holding Database Files
|
|
**
|
|
** ^(If this global variable is made to point to a string which is
|
|
** the name of a folder (a.k.a. directory), then all database files
|
|
** specified with a relative pathname and created or accessed by
|
|
** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
|
|
** to be relative to that directory.)^ ^If this variable is a NULL
|
|
** pointer, then SQLite assumes that all database files specified
|
|
** with a relative pathname are relative to the current directory
|
|
** for the process. Only the windows VFS makes use of this global
|
|
** variable; it is ignored by the unix VFS.
|
|
**
|
|
** Changing the value of this variable while a database connection is
|
|
** open can result in a corrupt database.
|
|
**
|
|
** It is not safe to read or modify this variable in more than one
|
|
** thread at a time. It is not safe to read or modify this variable
|
|
** if a [database connection] is being used at the same time in a separate
|
|
** thread.
|
|
** It is intended that this variable be set once
|
|
** as part of process initialization and before any SQLite interface
|
|
** routines have been called and that this variable remain unchanged
|
|
** thereafter.
|
|
**
|
|
** ^The [data_store_directory pragma] may modify this variable and cause
|
|
** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
|
|
** the [data_store_directory pragma] always assumes that any string
|
|
** that this variable points to is held in memory obtained from
|
|
** [sqlite3_malloc] and the pragma may attempt to free that memory
|
|
** using [sqlite3_free].
|
|
** Hence, if this variable is modified directly, either it should be
|
|
** made NULL or made to point to memory obtained from [sqlite3_malloc]
|
|
** or else the use of the [data_store_directory pragma] should be avoided.
|
|
*/
|
|
SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
|
|
|
|
/*
|
|
** CAPI3REF: Test For Auto-Commit Mode
|
|
** KEYWORDS: {autocommit mode}
|
|
**
|
|
** ^The sqlite3_get_autocommit() interface returns non-zero or
|
|
** zero if the given database connection is or is not in autocommit mode,
|
|
** respectively. ^Autocommit mode is on by default.
|
|
** ^Autocommit mode is disabled by a [BEGIN] statement.
|
|
** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
|
|
**
|
|
** If certain kinds of errors occur on a statement within a multi-statement
|
|
** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
|
|
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
|
|
** transaction might be rolled back automatically. The only way to
|
|
** find out whether SQLite automatically rolled back the transaction after
|
|
** an error is to use this function.
|
|
**
|
|
** If another thread changes the autocommit status of the database
|
|
** connection while this routine is running, then the return value
|
|
** is undefined.
|
|
*/
|
|
SQLITE_API int sqlite3_get_autocommit(sqlite3*);
|
|
|
|
/*
|
|
** CAPI3REF: Find The Database Handle Of A Prepared Statement
|
|
**
|
|
** ^The sqlite3_db_handle interface returns the [database connection] handle
|
|
** to which a [prepared statement] belongs. ^The [database connection]
|
|
** returned by sqlite3_db_handle is the same [database connection]
|
|
** that was the first argument
|
|
** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
|
|
** create the statement in the first place.
|
|
*/
|
|
SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
|
|
|
|
/*
|
|
** CAPI3REF: Return The Filename For A Database Connection
|
|
**
|
|
** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
|
|
** associated with database N of connection D. ^The main database file
|
|
** has the name "main". If there is no attached database N on the database
|
|
** connection D, or if database N is a temporary or in-memory database, then
|
|
** a NULL pointer is returned.
|
|
**
|
|
** ^The filename returned by this function is the output of the
|
|
** xFullPathname method of the [VFS]. ^In other words, the filename
|
|
** will be an absolute pathname, even if the filename used
|
|
** to open the database originally was a URI or relative pathname.
|
|
*/
|
|
SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
|
|
|
|
/*
|
|
** CAPI3REF: Determine if a database is read-only
|
|
**
|
|
** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
|
|
** of connection D is read-only, 0 if it is read/write, or -1 if N is not
|
|
** the name of a database on connection D.
|
|
*/
|
|
SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
|
|
|
|
/*
|
|
** CAPI3REF: Find the next prepared statement
|
|
**
|
|
** ^This interface returns a pointer to the next [prepared statement] after
|
|
** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
|
|
** then this interface returns a pointer to the first prepared statement
|
|
** associated with the database connection pDb. ^If no prepared statement
|
|
** satisfies the conditions of this routine, it returns NULL.
|
|
**
|
|
** The [database connection] pointer D in a call to
|
|
** [sqlite3_next_stmt(D,S)] must refer to an open database
|
|
** connection and in particular must not be a NULL pointer.
|
|
*/
|
|
SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
|
|
|
|
/*
|
|
** CAPI3REF: Commit And Rollback Notification Callbacks
|
|
**
|
|
** ^The sqlite3_commit_hook() interface registers a callback
|
|
** function to be invoked whenever a transaction is [COMMIT | committed].
|
|
** ^Any callback set by a previous call to sqlite3_commit_hook()
|
|
** for the same database connection is overridden.
|
|
** ^The sqlite3_rollback_hook() interface registers a callback
|
|
** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
|
|
** ^Any callback set by a previous call to sqlite3_rollback_hook()
|
|
** for the same database connection is overridden.
|
|
** ^The pArg argument is passed through to the callback.
|
|
** ^If the callback on a commit hook function returns non-zero,
|
|
** then the commit is converted into a rollback.
|
|
**
|
|
** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
|
|
** return the P argument from the previous call of the same function
|
|
** on the same [database connection] D, or NULL for
|
|
** the first call for each function on D.
|
|
**
|
|
** The commit and rollback hook callbacks are not reentrant.
|
|
** The callback implementation must not do anything that will modify
|
|
** the database connection that invoked the callback. Any actions
|
|
** to modify the database connection must be deferred until after the
|
|
** completion of the [sqlite3_step()] call that triggered the commit
|
|
** or rollback hook in the first place.
|
|
** Note that running any other SQL statements, including SELECT statements,
|
|
** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
|
|
** the database connections for the meaning of "modify" in this paragraph.
|
|
**
|
|
** ^Registering a NULL function disables the callback.
|
|
**
|
|
** ^When the commit hook callback routine returns zero, the [COMMIT]
|
|
** operation is allowed to continue normally. ^If the commit hook
|
|
** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
|
|
** ^The rollback hook is invoked on a rollback that results from a commit
|
|
** hook returning non-zero, just as it would be with any other rollback.
|
|
**
|
|
** ^For the purposes of this API, a transaction is said to have been
|
|
** rolled back if an explicit "ROLLBACK" statement is executed, or
|
|
** an error or constraint causes an implicit rollback to occur.
|
|
** ^The rollback callback is not invoked if a transaction is
|
|
** automatically rolled back because the database connection is closed.
|
|
**
|
|
** See also the [sqlite3_update_hook()] interface.
|
|
*/
|
|
SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
|
|
SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
|
|
|
|
/*
|
|
** CAPI3REF: Data Change Notification Callbacks
|
|
**
|
|
** ^The sqlite3_update_hook() interface registers a callback function
|
|
** with the [database connection] identified by the first argument
|
|
** to be invoked whenever a row is updated, inserted or deleted.
|
|
** ^Any callback set by a previous call to this function
|
|
** for the same database connection is overridden.
|
|
**
|
|
** ^The second argument is a pointer to the function to invoke when a
|
|
** row is updated, inserted or deleted.
|
|
** ^The first argument to the callback is a copy of the third argument
|
|
** to sqlite3_update_hook().
|
|
** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
|
|
** or [SQLITE_UPDATE], depending on the operation that caused the callback
|
|
** to be invoked.
|
|
** ^The third and fourth arguments to the callback contain pointers to the
|
|
** database and table name containing the affected row.
|
|
** ^The final callback parameter is the [rowid] of the row.
|
|
** ^In the case of an update, this is the [rowid] after the update takes place.
|
|
**
|
|
** ^(The update hook is not invoked when internal system tables are
|
|
** modified (i.e. sqlite_master and sqlite_sequence).)^
|
|
**
|
|
** ^In the current implementation, the update hook
|
|
** is not invoked when duplication rows are deleted because of an
|
|
** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
|
|
** invoked when rows are deleted using the [truncate optimization].
|
|
** The exceptions defined in this paragraph might change in a future
|
|
** release of SQLite.
|
|
**
|
|
** The update hook implementation must not do anything that will modify
|
|
** the database connection that invoked the update hook. Any actions
|
|
** to modify the database connection must be deferred until after the
|
|
** completion of the [sqlite3_step()] call that triggered the update hook.
|
|
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
|
|
** database connections for the meaning of "modify" in this paragraph.
|
|
**
|
|
** ^The sqlite3_update_hook(D,C,P) function
|
|
** returns the P argument from the previous call
|
|
** on the same [database connection] D, or NULL for
|
|
** the first call on D.
|
|
**
|
|
** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
|
|
** interfaces.
|
|
*/
|
|
SQLITE_API void *sqlite3_update_hook(
|
|
sqlite3*,
|
|
void(*)(void *,int ,char const *,char const *,sqlite3_int64),
|
|
void*
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Enable Or Disable Shared Pager Cache
|
|
**
|
|
** ^(This routine enables or disables the sharing of the database cache
|
|
** and schema data structures between [database connection | connections]
|
|
** to the same database. Sharing is enabled if the argument is true
|
|
** and disabled if the argument is false.)^
|
|
**
|
|
** ^Cache sharing is enabled and disabled for an entire process.
|
|
** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
|
|
** sharing was enabled or disabled for each thread separately.
|
|
**
|
|
** ^(The cache sharing mode set by this interface effects all subsequent
|
|
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
|
|
** Existing database connections continue use the sharing mode
|
|
** that was in effect at the time they were opened.)^
|
|
**
|
|
** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
|
|
** successfully. An [error code] is returned otherwise.)^
|
|
**
|
|
** ^Shared cache is disabled by default. But this might change in
|
|
** future releases of SQLite. Applications that care about shared
|
|
** cache setting should set it explicitly.
|
|
**
|
|
** This interface is threadsafe on processors where writing a
|
|
** 32-bit integer is atomic.
|
|
**
|
|
** See Also: [SQLite Shared-Cache Mode]
|
|
*/
|
|
SQLITE_API int sqlite3_enable_shared_cache(int);
|
|
|
|
/*
|
|
** CAPI3REF: Attempt To Free Heap Memory
|
|
**
|
|
** ^The sqlite3_release_memory() interface attempts to free N bytes
|
|
** of heap memory by deallocating non-essential memory allocations
|
|
** held by the database library. Memory used to cache database
|
|
** pages to improve performance is an example of non-essential memory.
|
|
** ^sqlite3_release_memory() returns the number of bytes actually freed,
|
|
** which might be more or less than the amount requested.
|
|
** ^The sqlite3_release_memory() routine is a no-op returning zero
|
|
** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
|
|
**
|
|
** See also: [sqlite3_db_release_memory()]
|
|
*/
|
|
SQLITE_API int sqlite3_release_memory(int);
|
|
|
|
/*
|
|
** CAPI3REF: Free Memory Used By A Database Connection
|
|
**
|
|
** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
|
|
** memory as possible from database connection D. Unlike the
|
|
** [sqlite3_release_memory()] interface, this interface is effect even
|
|
** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
|
|
** omitted.
|
|
**
|
|
** See also: [sqlite3_release_memory()]
|
|
*/
|
|
SQLITE_API int sqlite3_db_release_memory(sqlite3*);
|
|
|
|
/*
|
|
** CAPI3REF: Impose A Limit On Heap Size
|
|
**
|
|
** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
|
|
** soft limit on the amount of heap memory that may be allocated by SQLite.
|
|
** ^SQLite strives to keep heap memory utilization below the soft heap
|
|
** limit by reducing the number of pages held in the page cache
|
|
** as heap memory usages approaches the limit.
|
|
** ^The soft heap limit is "soft" because even though SQLite strives to stay
|
|
** below the limit, it will exceed the limit rather than generate
|
|
** an [SQLITE_NOMEM] error. In other words, the soft heap limit
|
|
** is advisory only.
|
|
**
|
|
** ^The return value from sqlite3_soft_heap_limit64() is the size of
|
|
** the soft heap limit prior to the call, or negative in the case of an
|
|
** error. ^If the argument N is negative
|
|
** then no change is made to the soft heap limit. Hence, the current
|
|
** size of the soft heap limit can be determined by invoking
|
|
** sqlite3_soft_heap_limit64() with a negative argument.
|
|
**
|
|
** ^If the argument N is zero then the soft heap limit is disabled.
|
|
**
|
|
** ^(The soft heap limit is not enforced in the current implementation
|
|
** if one or more of following conditions are true:
|
|
**
|
|
** <ul>
|
|
** <li> The soft heap limit is set to zero.
|
|
** <li> Memory accounting is disabled using a combination of the
|
|
** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
|
|
** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
|
|
** <li> An alternative page cache implementation is specified using
|
|
** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
|
|
** <li> The page cache allocates from its own memory pool supplied
|
|
** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
|
|
** from the heap.
|
|
** </ul>)^
|
|
**
|
|
** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
|
|
** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
|
|
** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
|
|
** the soft heap limit is enforced on every memory allocation. Without
|
|
** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
|
|
** when memory is allocated by the page cache. Testing suggests that because
|
|
** the page cache is the predominate memory user in SQLite, most
|
|
** applications will achieve adequate soft heap limit enforcement without
|
|
** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
|
|
**
|
|
** The circumstances under which SQLite will enforce the soft heap limit may
|
|
** changes in future releases of SQLite.
|
|
*/
|
|
SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
|
|
|
|
/*
|
|
** CAPI3REF: Deprecated Soft Heap Limit Interface
|
|
** DEPRECATED
|
|
**
|
|
** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
|
|
** interface. This routine is provided for historical compatibility
|
|
** only. All new applications should use the
|
|
** [sqlite3_soft_heap_limit64()] interface rather than this one.
|
|
*/
|
|
SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Extract Metadata About A Column Of A Table
|
|
**
|
|
** ^This routine returns metadata about a specific column of a specific
|
|
** database table accessible using the [database connection] handle
|
|
** passed as the first function argument.
|
|
**
|
|
** ^The column is identified by the second, third and fourth parameters to
|
|
** this function. ^The second parameter is either the name of the database
|
|
** (i.e. "main", "temp", or an attached database) containing the specified
|
|
** table or NULL. ^If it is NULL, then all attached databases are searched
|
|
** for the table using the same algorithm used by the database engine to
|
|
** resolve unqualified table references.
|
|
**
|
|
** ^The third and fourth parameters to this function are the table and column
|
|
** name of the desired column, respectively. Neither of these parameters
|
|
** may be NULL.
|
|
**
|
|
** ^Metadata is returned by writing to the memory locations passed as the 5th
|
|
** and subsequent parameters to this function. ^Any of these arguments may be
|
|
** NULL, in which case the corresponding element of metadata is omitted.
|
|
**
|
|
** ^(<blockquote>
|
|
** <table border="1">
|
|
** <tr><th> Parameter <th> Output<br>Type <th> Description
|
|
**
|
|
** <tr><td> 5th <td> const char* <td> Data type
|
|
** <tr><td> 6th <td> const char* <td> Name of default collation sequence
|
|
** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
|
|
** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
|
|
** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
|
|
** </table>
|
|
** </blockquote>)^
|
|
**
|
|
** ^The memory pointed to by the character pointers returned for the
|
|
** declaration type and collation sequence is valid only until the next
|
|
** call to any SQLite API function.
|
|
**
|
|
** ^If the specified table is actually a view, an [error code] is returned.
|
|
**
|
|
** ^If the specified column is "rowid", "oid" or "_rowid_" and an
|
|
** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
|
|
** parameters are set for the explicitly declared column. ^(If there is no
|
|
** explicitly declared [INTEGER PRIMARY KEY] column, then the output
|
|
** parameters are set as follows:
|
|
**
|
|
** <pre>
|
|
** data type: "INTEGER"
|
|
** collation sequence: "BINARY"
|
|
** not null: 0
|
|
** primary key: 1
|
|
** auto increment: 0
|
|
** </pre>)^
|
|
**
|
|
** ^(This function may load one or more schemas from database files. If an
|
|
** error occurs during this process, or if the requested table or column
|
|
** cannot be found, an [error code] is returned and an error message left
|
|
** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
|
|
**
|
|
** ^This API is only available if the library was compiled with the
|
|
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
|
|
*/
|
|
SQLITE_API int sqlite3_table_column_metadata(
|
|
sqlite3 *db, /* Connection handle */
|
|
const char *zDbName, /* Database name or NULL */
|
|
const char *zTableName, /* Table name */
|
|
const char *zColumnName, /* Column name */
|
|
char const **pzDataType, /* OUTPUT: Declared data type */
|
|
char const **pzCollSeq, /* OUTPUT: Collation sequence name */
|
|
int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
|
|
int *pPrimaryKey, /* OUTPUT: True if column part of PK */
|
|
int *pAutoinc /* OUTPUT: True if column is auto-increment */
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Load An Extension
|
|
**
|
|
** ^This interface loads an SQLite extension library from the named file.
|
|
**
|
|
** ^The sqlite3_load_extension() interface attempts to load an
|
|
** SQLite extension library contained in the file zFile.
|
|
**
|
|
** ^The entry point is zProc.
|
|
** ^zProc may be 0, in which case the name of the entry point
|
|
** defaults to "sqlite3_extension_init".
|
|
** ^The sqlite3_load_extension() interface returns
|
|
** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
|
|
** ^If an error occurs and pzErrMsg is not 0, then the
|
|
** [sqlite3_load_extension()] interface shall attempt to
|
|
** fill *pzErrMsg with error message text stored in memory
|
|
** obtained from [sqlite3_malloc()]. The calling function
|
|
** should free this memory by calling [sqlite3_free()].
|
|
**
|
|
** ^Extension loading must be enabled using
|
|
** [sqlite3_enable_load_extension()] prior to calling this API,
|
|
** otherwise an error will be returned.
|
|
**
|
|
** See also the [load_extension() SQL function].
|
|
*/
|
|
SQLITE_API int sqlite3_load_extension(
|
|
sqlite3 *db, /* Load the extension into this database connection */
|
|
const char *zFile, /* Name of the shared library containing extension */
|
|
const char *zProc, /* Entry point. Derived from zFile if 0 */
|
|
char **pzErrMsg /* Put error message here if not 0 */
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Enable Or Disable Extension Loading
|
|
**
|
|
** ^So as not to open security holes in older applications that are
|
|
** unprepared to deal with extension loading, and as a means of disabling
|
|
** extension loading while evaluating user-entered SQL, the following API
|
|
** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
|
|
**
|
|
** ^Extension loading is off by default. See ticket #1863.
|
|
** ^Call the sqlite3_enable_load_extension() routine with onoff==1
|
|
** to turn extension loading on and call it with onoff==0 to turn
|
|
** it back off again.
|
|
*/
|
|
SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
|
|
|
|
/*
|
|
** CAPI3REF: Automatically Load Statically Linked Extensions
|
|
**
|
|
** ^This interface causes the xEntryPoint() function to be invoked for
|
|
** each new [database connection] that is created. The idea here is that
|
|
** xEntryPoint() is the entry point for a statically linked SQLite extension
|
|
** that is to be automatically loaded into all new database connections.
|
|
**
|
|
** ^(Even though the function prototype shows that xEntryPoint() takes
|
|
** no arguments and returns void, SQLite invokes xEntryPoint() with three
|
|
** arguments and expects and integer result as if the signature of the
|
|
** entry point where as follows:
|
|
**
|
|
** <blockquote><pre>
|
|
** int xEntryPoint(
|
|
** sqlite3 *db,
|
|
** const char **pzErrMsg,
|
|
** const struct sqlite3_api_routines *pThunk
|
|
** );
|
|
** </pre></blockquote>)^
|
|
**
|
|
** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
|
|
** point to an appropriate error message (obtained from [sqlite3_mprintf()])
|
|
** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
|
|
** is NULL before calling the xEntryPoint(). ^SQLite will invoke
|
|
** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
|
|
** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
|
|
** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
|
|
**
|
|
** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
|
|
** on the list of automatic extensions is a harmless no-op. ^No entry point
|
|
** will be called more than once for each database connection that is opened.
|
|
**
|
|
** See also: [sqlite3_reset_auto_extension()].
|
|
*/
|
|
SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
|
|
|
|
/*
|
|
** CAPI3REF: Reset Automatic Extension Loading
|
|
**
|
|
** ^This interface disables all automatic extensions previously
|
|
** registered using [sqlite3_auto_extension()].
|
|
*/
|
|
SQLITE_API void sqlite3_reset_auto_extension(void);
|
|
|
|
/*
|
|
** The interface to the virtual-table mechanism is currently considered
|
|
** to be experimental. The interface might change in incompatible ways.
|
|
** If this is a problem for you, do not use the interface at this time.
|
|
**
|
|
** When the virtual-table mechanism stabilizes, we will declare the
|
|
** interface fixed, support it indefinitely, and remove this comment.
|
|
*/
|
|
|
|
/*
|
|
** Structures used by the virtual table interface
|
|
*/
|
|
typedef struct sqlite3_vtab sqlite3_vtab;
|
|
typedef struct sqlite3_index_info sqlite3_index_info;
|
|
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
|
|
typedef struct sqlite3_module sqlite3_module;
|
|
|
|
/*
|
|
** CAPI3REF: Virtual Table Object
|
|
** KEYWORDS: sqlite3_module {virtual table module}
|
|
**
|
|
** This structure, sometimes called a "virtual table module",
|
|
** defines the implementation of a [virtual tables].
|
|
** This structure consists mostly of methods for the module.
|
|
**
|
|
** ^A virtual table module is created by filling in a persistent
|
|
** instance of this structure and passing a pointer to that instance
|
|
** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
|
|
** ^The registration remains valid until it is replaced by a different
|
|
** module or until the [database connection] closes. The content
|
|
** of this structure must not change while it is registered with
|
|
** any database connection.
|
|
*/
|
|
struct sqlite3_module {
|
|
int iVersion;
|
|
int (*xCreate)(sqlite3*, void *pAux,
|
|
int argc, const char *const*argv,
|
|
sqlite3_vtab **ppVTab, char**);
|
|
int (*xConnect)(sqlite3*, void *pAux,
|
|
int argc, const char *const*argv,
|
|
sqlite3_vtab **ppVTab, char**);
|
|
int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
|
|
int (*xDisconnect)(sqlite3_vtab *pVTab);
|
|
int (*xDestroy)(sqlite3_vtab *pVTab);
|
|
int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
|
|
int (*xClose)(sqlite3_vtab_cursor*);
|
|
int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
|
|
int argc, sqlite3_value **argv);
|
|
int (*xNext)(sqlite3_vtab_cursor*);
|
|
int (*xEof)(sqlite3_vtab_cursor*);
|
|
int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
|
|
int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
|
|
int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
|
|
int (*xBegin)(sqlite3_vtab *pVTab);
|
|
int (*xSync)(sqlite3_vtab *pVTab);
|
|
int (*xCommit)(sqlite3_vtab *pVTab);
|
|
int (*xRollback)(sqlite3_vtab *pVTab);
|
|
int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
|
|
void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
|
|
void **ppArg);
|
|
int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
|
|
/* The methods above are in version 1 of the sqlite_module object. Those
|
|
** below are for version 2 and greater. */
|
|
int (*xSavepoint)(sqlite3_vtab *pVTab, int);
|
|
int (*xRelease)(sqlite3_vtab *pVTab, int);
|
|
int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Virtual Table Indexing Information
|
|
** KEYWORDS: sqlite3_index_info
|
|
**
|
|
** The sqlite3_index_info structure and its substructures is used as part
|
|
** of the [virtual table] interface to
|
|
** pass information into and receive the reply from the [xBestIndex]
|
|
** method of a [virtual table module]. The fields under **Inputs** are the
|
|
** inputs to xBestIndex and are read-only. xBestIndex inserts its
|
|
** results into the **Outputs** fields.
|
|
**
|
|
** ^(The aConstraint[] array records WHERE clause constraints of the form:
|
|
**
|
|
** <blockquote>column OP expr</blockquote>
|
|
**
|
|
** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
|
|
** stored in aConstraint[].op using one of the
|
|
** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
|
|
** ^(The index of the column is stored in
|
|
** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
|
|
** expr on the right-hand side can be evaluated (and thus the constraint
|
|
** is usable) and false if it cannot.)^
|
|
**
|
|
** ^The optimizer automatically inverts terms of the form "expr OP column"
|
|
** and makes other simplifications to the WHERE clause in an attempt to
|
|
** get as many WHERE clause terms into the form shown above as possible.
|
|
** ^The aConstraint[] array only reports WHERE clause terms that are
|
|
** relevant to the particular virtual table being queried.
|
|
**
|
|
** ^Information about the ORDER BY clause is stored in aOrderBy[].
|
|
** ^Each term of aOrderBy records a column of the ORDER BY clause.
|
|
**
|
|
** The [xBestIndex] method must fill aConstraintUsage[] with information
|
|
** about what parameters to pass to xFilter. ^If argvIndex>0 then
|
|
** the right-hand side of the corresponding aConstraint[] is evaluated
|
|
** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
|
|
** is true, then the constraint is assumed to be fully handled by the
|
|
** virtual table and is not checked again by SQLite.)^
|
|
**
|
|
** ^The idxNum and idxPtr values are recorded and passed into the
|
|
** [xFilter] method.
|
|
** ^[sqlite3_free()] is used to free idxPtr if and only if
|
|
** needToFreeIdxPtr is true.
|
|
**
|
|
** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
|
|
** the correct order to satisfy the ORDER BY clause so that no separate
|
|
** sorting step is required.
|
|
**
|
|
** ^The estimatedCost value is an estimate of the cost of doing the
|
|
** particular lookup. A full scan of a table with N entries should have
|
|
** a cost of N. A binary search of a table of N entries should have a
|
|
** cost of approximately log(N).
|
|
*/
|
|
struct sqlite3_index_info {
|
|
/* Inputs */
|
|
int nConstraint; /* Number of entries in aConstraint */
|
|
struct sqlite3_index_constraint {
|
|
int iColumn; /* Column on left-hand side of constraint */
|
|
unsigned char op; /* Constraint operator */
|
|
unsigned char usable; /* True if this constraint is usable */
|
|
int iTermOffset; /* Used internally - xBestIndex should ignore */
|
|
} *aConstraint; /* Table of WHERE clause constraints */
|
|
int nOrderBy; /* Number of terms in the ORDER BY clause */
|
|
struct sqlite3_index_orderby {
|
|
int iColumn; /* Column number */
|
|
unsigned char desc; /* True for DESC. False for ASC. */
|
|
} *aOrderBy; /* The ORDER BY clause */
|
|
/* Outputs */
|
|
struct sqlite3_index_constraint_usage {
|
|
int argvIndex; /* if >0, constraint is part of argv to xFilter */
|
|
unsigned char omit; /* Do not code a test for this constraint */
|
|
} *aConstraintUsage;
|
|
int idxNum; /* Number used to identify the index */
|
|
char *idxStr; /* String, possibly obtained from sqlite3_malloc */
|
|
int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
|
|
int orderByConsumed; /* True if output is already ordered */
|
|
double estimatedCost; /* Estimated cost of using this index */
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Virtual Table Constraint Operator Codes
|
|
**
|
|
** These macros defined the allowed values for the
|
|
** [sqlite3_index_info].aConstraint[].op field. Each value represents
|
|
** an operator that is part of a constraint term in the wHERE clause of
|
|
** a query that uses a [virtual table].
|
|
*/
|
|
#define SQLITE_INDEX_CONSTRAINT_EQ 2
|
|
#define SQLITE_INDEX_CONSTRAINT_GT 4
|
|
#define SQLITE_INDEX_CONSTRAINT_LE 8
|
|
#define SQLITE_INDEX_CONSTRAINT_LT 16
|
|
#define SQLITE_INDEX_CONSTRAINT_GE 32
|
|
#define SQLITE_INDEX_CONSTRAINT_MATCH 64
|
|
|
|
/*
|
|
** CAPI3REF: Register A Virtual Table Implementation
|
|
**
|
|
** ^These routines are used to register a new [virtual table module] name.
|
|
** ^Module names must be registered before
|
|
** creating a new [virtual table] using the module and before using a
|
|
** preexisting [virtual table] for the module.
|
|
**
|
|
** ^The module name is registered on the [database connection] specified
|
|
** by the first parameter. ^The name of the module is given by the
|
|
** second parameter. ^The third parameter is a pointer to
|
|
** the implementation of the [virtual table module]. ^The fourth
|
|
** parameter is an arbitrary client data pointer that is passed through
|
|
** into the [xCreate] and [xConnect] methods of the virtual table module
|
|
** when a new virtual table is be being created or reinitialized.
|
|
**
|
|
** ^The sqlite3_create_module_v2() interface has a fifth parameter which
|
|
** is a pointer to a destructor for the pClientData. ^SQLite will
|
|
** invoke the destructor function (if it is not NULL) when SQLite
|
|
** no longer needs the pClientData pointer. ^The destructor will also
|
|
** be invoked if the call to sqlite3_create_module_v2() fails.
|
|
** ^The sqlite3_create_module()
|
|
** interface is equivalent to sqlite3_create_module_v2() with a NULL
|
|
** destructor.
|
|
*/
|
|
SQLITE_API int sqlite3_create_module(
|
|
sqlite3 *db, /* SQLite connection to register module with */
|
|
const char *zName, /* Name of the module */
|
|
const sqlite3_module *p, /* Methods for the module */
|
|
void *pClientData /* Client data for xCreate/xConnect */
|
|
);
|
|
SQLITE_API int sqlite3_create_module_v2(
|
|
sqlite3 *db, /* SQLite connection to register module with */
|
|
const char *zName, /* Name of the module */
|
|
const sqlite3_module *p, /* Methods for the module */
|
|
void *pClientData, /* Client data for xCreate/xConnect */
|
|
void(*xDestroy)(void*) /* Module destructor function */
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Virtual Table Instance Object
|
|
** KEYWORDS: sqlite3_vtab
|
|
**
|
|
** Every [virtual table module] implementation uses a subclass
|
|
** of this object to describe a particular instance
|
|
** of the [virtual table]. Each subclass will
|
|
** be tailored to the specific needs of the module implementation.
|
|
** The purpose of this superclass is to define certain fields that are
|
|
** common to all module implementations.
|
|
**
|
|
** ^Virtual tables methods can set an error message by assigning a
|
|
** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
|
|
** take care that any prior string is freed by a call to [sqlite3_free()]
|
|
** prior to assigning a new string to zErrMsg. ^After the error message
|
|
** is delivered up to the client application, the string will be automatically
|
|
** freed by sqlite3_free() and the zErrMsg field will be zeroed.
|
|
*/
|
|
struct sqlite3_vtab {
|
|
const sqlite3_module *pModule; /* The module for this virtual table */
|
|
int nRef; /* NO LONGER USED */
|
|
char *zErrMsg; /* Error message from sqlite3_mprintf() */
|
|
/* Virtual table implementations will typically add additional fields */
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Virtual Table Cursor Object
|
|
** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
|
|
**
|
|
** Every [virtual table module] implementation uses a subclass of the
|
|
** following structure to describe cursors that point into the
|
|
** [virtual table] and are used
|
|
** to loop through the virtual table. Cursors are created using the
|
|
** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
|
|
** by the [sqlite3_module.xClose | xClose] method. Cursors are used
|
|
** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
|
|
** of the module. Each module implementation will define
|
|
** the content of a cursor structure to suit its own needs.
|
|
**
|
|
** This superclass exists in order to define fields of the cursor that
|
|
** are common to all implementations.
|
|
*/
|
|
struct sqlite3_vtab_cursor {
|
|
sqlite3_vtab *pVtab; /* Virtual table of this cursor */
|
|
/* Virtual table implementations will typically add additional fields */
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Declare The Schema Of A Virtual Table
|
|
**
|
|
** ^The [xCreate] and [xConnect] methods of a
|
|
** [virtual table module] call this interface
|
|
** to declare the format (the names and datatypes of the columns) of
|
|
** the virtual tables they implement.
|
|
*/
|
|
SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
|
|
|
|
/*
|
|
** CAPI3REF: Overload A Function For A Virtual Table
|
|
**
|
|
** ^(Virtual tables can provide alternative implementations of functions
|
|
** using the [xFindFunction] method of the [virtual table module].
|
|
** But global versions of those functions
|
|
** must exist in order to be overloaded.)^
|
|
**
|
|
** ^(This API makes sure a global version of a function with a particular
|
|
** name and number of parameters exists. If no such function exists
|
|
** before this API is called, a new function is created.)^ ^The implementation
|
|
** of the new function always causes an exception to be thrown. So
|
|
** the new function is not good for anything by itself. Its only
|
|
** purpose is to be a placeholder function that can be overloaded
|
|
** by a [virtual table].
|
|
*/
|
|
SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
|
|
|
|
/*
|
|
** The interface to the virtual-table mechanism defined above (back up
|
|
** to a comment remarkably similar to this one) is currently considered
|
|
** to be experimental. The interface might change in incompatible ways.
|
|
** If this is a problem for you, do not use the interface at this time.
|
|
**
|
|
** When the virtual-table mechanism stabilizes, we will declare the
|
|
** interface fixed, support it indefinitely, and remove this comment.
|
|
*/
|
|
|
|
/*
|
|
** CAPI3REF: A Handle To An Open BLOB
|
|
** KEYWORDS: {BLOB handle} {BLOB handles}
|
|
**
|
|
** An instance of this object represents an open BLOB on which
|
|
** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
|
|
** ^Objects of this type are created by [sqlite3_blob_open()]
|
|
** and destroyed by [sqlite3_blob_close()].
|
|
** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
|
|
** can be used to read or write small subsections of the BLOB.
|
|
** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
|
|
*/
|
|
typedef struct sqlite3_blob sqlite3_blob;
|
|
|
|
/*
|
|
** CAPI3REF: Open A BLOB For Incremental I/O
|
|
**
|
|
** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
|
|
** in row iRow, column zColumn, table zTable in database zDb;
|
|
** in other words, the same BLOB that would be selected by:
|
|
**
|
|
** <pre>
|
|
** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
|
|
** </pre>)^
|
|
**
|
|
** ^If the flags parameter is non-zero, then the BLOB is opened for read
|
|
** and write access. ^If it is zero, the BLOB is opened for read access.
|
|
** ^It is not possible to open a column that is part of an index or primary
|
|
** key for writing. ^If [foreign key constraints] are enabled, it is
|
|
** not possible to open a column that is part of a [child key] for writing.
|
|
**
|
|
** ^Note that the database name is not the filename that contains
|
|
** the database but rather the symbolic name of the database that
|
|
** appears after the AS keyword when the database is connected using [ATTACH].
|
|
** ^For the main database file, the database name is "main".
|
|
** ^For TEMP tables, the database name is "temp".
|
|
**
|
|
** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
|
|
** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
|
|
** to be a null pointer.)^
|
|
** ^This function sets the [database connection] error code and message
|
|
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
|
|
** functions. ^Note that the *ppBlob variable is always initialized in a
|
|
** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
|
|
** regardless of the success or failure of this routine.
|
|
**
|
|
** ^(If the row that a BLOB handle points to is modified by an
|
|
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
|
|
** then the BLOB handle is marked as "expired".
|
|
** This is true if any column of the row is changed, even a column
|
|
** other than the one the BLOB handle is open on.)^
|
|
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
|
|
** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
|
|
** ^(Changes written into a BLOB prior to the BLOB expiring are not
|
|
** rolled back by the expiration of the BLOB. Such changes will eventually
|
|
** commit if the transaction continues to completion.)^
|
|
**
|
|
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
|
|
** the opened blob. ^The size of a blob may not be changed by this
|
|
** interface. Use the [UPDATE] SQL command to change the size of a
|
|
** blob.
|
|
**
|
|
** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
|
|
** and the built-in [zeroblob] SQL function can be used, if desired,
|
|
** to create an empty, zero-filled blob in which to read or write using
|
|
** this interface.
|
|
**
|
|
** To avoid a resource leak, every open [BLOB handle] should eventually
|
|
** be released by a call to [sqlite3_blob_close()].
|
|
*/
|
|
SQLITE_API int sqlite3_blob_open(
|
|
sqlite3*,
|
|
const char *zDb,
|
|
const char *zTable,
|
|
const char *zColumn,
|
|
sqlite3_int64 iRow,
|
|
int flags,
|
|
sqlite3_blob **ppBlob
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Move a BLOB Handle to a New Row
|
|
**
|
|
** ^This function is used to move an existing blob handle so that it points
|
|
** to a different row of the same database table. ^The new row is identified
|
|
** by the rowid value passed as the second argument. Only the row can be
|
|
** changed. ^The database, table and column on which the blob handle is open
|
|
** remain the same. Moving an existing blob handle to a new row can be
|
|
** faster than closing the existing handle and opening a new one.
|
|
**
|
|
** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
|
|
** it must exist and there must be either a blob or text value stored in
|
|
** the nominated column.)^ ^If the new row is not present in the table, or if
|
|
** it does not contain a blob or text value, or if another error occurs, an
|
|
** SQLite error code is returned and the blob handle is considered aborted.
|
|
** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
|
|
** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
|
|
** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
|
|
** always returns zero.
|
|
**
|
|
** ^This function sets the database handle error code and message.
|
|
*/
|
|
SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
|
|
|
|
/*
|
|
** CAPI3REF: Close A BLOB Handle
|
|
**
|
|
** ^Closes an open [BLOB handle].
|
|
**
|
|
** ^Closing a BLOB shall cause the current transaction to commit
|
|
** if there are no other BLOBs, no pending prepared statements, and the
|
|
** database connection is in [autocommit mode].
|
|
** ^If any writes were made to the BLOB, they might be held in cache
|
|
** until the close operation if they will fit.
|
|
**
|
|
** ^(Closing the BLOB often forces the changes
|
|
** out to disk and so if any I/O errors occur, they will likely occur
|
|
** at the time when the BLOB is closed. Any errors that occur during
|
|
** closing are reported as a non-zero return value.)^
|
|
**
|
|
** ^(The BLOB is closed unconditionally. Even if this routine returns
|
|
** an error code, the BLOB is still closed.)^
|
|
**
|
|
** ^Calling this routine with a null pointer (such as would be returned
|
|
** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
|
|
*/
|
|
SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
|
|
|
|
/*
|
|
** CAPI3REF: Return The Size Of An Open BLOB
|
|
**
|
|
** ^Returns the size in bytes of the BLOB accessible via the
|
|
** successfully opened [BLOB handle] in its only argument. ^The
|
|
** incremental blob I/O routines can only read or overwriting existing
|
|
** blob content; they cannot change the size of a blob.
|
|
**
|
|
** This routine only works on a [BLOB handle] which has been created
|
|
** by a prior successful call to [sqlite3_blob_open()] and which has not
|
|
** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
|
** to this routine results in undefined and probably undesirable behavior.
|
|
*/
|
|
SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
|
|
|
|
/*
|
|
** CAPI3REF: Read Data From A BLOB Incrementally
|
|
**
|
|
** ^(This function is used to read data from an open [BLOB handle] into a
|
|
** caller-supplied buffer. N bytes of data are copied into buffer Z
|
|
** from the open BLOB, starting at offset iOffset.)^
|
|
**
|
|
** ^If offset iOffset is less than N bytes from the end of the BLOB,
|
|
** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
|
|
** less than zero, [SQLITE_ERROR] is returned and no data is read.
|
|
** ^The size of the blob (and hence the maximum value of N+iOffset)
|
|
** can be determined using the [sqlite3_blob_bytes()] interface.
|
|
**
|
|
** ^An attempt to read from an expired [BLOB handle] fails with an
|
|
** error code of [SQLITE_ABORT].
|
|
**
|
|
** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
|
|
** Otherwise, an [error code] or an [extended error code] is returned.)^
|
|
**
|
|
** This routine only works on a [BLOB handle] which has been created
|
|
** by a prior successful call to [sqlite3_blob_open()] and which has not
|
|
** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
|
** to this routine results in undefined and probably undesirable behavior.
|
|
**
|
|
** See also: [sqlite3_blob_write()].
|
|
*/
|
|
SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
|
|
|
|
/*
|
|
** CAPI3REF: Write Data Into A BLOB Incrementally
|
|
**
|
|
** ^This function is used to write data into an open [BLOB handle] from a
|
|
** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
|
|
** into the open BLOB, starting at offset iOffset.
|
|
**
|
|
** ^If the [BLOB handle] passed as the first argument was not opened for
|
|
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
|
|
** this function returns [SQLITE_READONLY].
|
|
**
|
|
** ^This function may only modify the contents of the BLOB; it is
|
|
** not possible to increase the size of a BLOB using this API.
|
|
** ^If offset iOffset is less than N bytes from the end of the BLOB,
|
|
** [SQLITE_ERROR] is returned and no data is written. ^If N is
|
|
** less than zero [SQLITE_ERROR] is returned and no data is written.
|
|
** The size of the BLOB (and hence the maximum value of N+iOffset)
|
|
** can be determined using the [sqlite3_blob_bytes()] interface.
|
|
**
|
|
** ^An attempt to write to an expired [BLOB handle] fails with an
|
|
** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
|
|
** before the [BLOB handle] expired are not rolled back by the
|
|
** expiration of the handle, though of course those changes might
|
|
** have been overwritten by the statement that expired the BLOB handle
|
|
** or by other independent statements.
|
|
**
|
|
** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
|
|
** Otherwise, an [error code] or an [extended error code] is returned.)^
|
|
**
|
|
** This routine only works on a [BLOB handle] which has been created
|
|
** by a prior successful call to [sqlite3_blob_open()] and which has not
|
|
** been closed by [sqlite3_blob_close()]. Passing any other pointer in
|
|
** to this routine results in undefined and probably undesirable behavior.
|
|
**
|
|
** See also: [sqlite3_blob_read()].
|
|
*/
|
|
SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
|
|
|
|
/*
|
|
** CAPI3REF: Virtual File System Objects
|
|
**
|
|
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
|
|
** that SQLite uses to interact
|
|
** with the underlying operating system. Most SQLite builds come with a
|
|
** single default VFS that is appropriate for the host computer.
|
|
** New VFSes can be registered and existing VFSes can be unregistered.
|
|
** The following interfaces are provided.
|
|
**
|
|
** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
|
|
** ^Names are case sensitive.
|
|
** ^Names are zero-terminated UTF-8 strings.
|
|
** ^If there is no match, a NULL pointer is returned.
|
|
** ^If zVfsName is NULL then the default VFS is returned.
|
|
**
|
|
** ^New VFSes are registered with sqlite3_vfs_register().
|
|
** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
|
|
** ^The same VFS can be registered multiple times without injury.
|
|
** ^To make an existing VFS into the default VFS, register it again
|
|
** with the makeDflt flag set. If two different VFSes with the
|
|
** same name are registered, the behavior is undefined. If a
|
|
** VFS is registered with a name that is NULL or an empty string,
|
|
** then the behavior is undefined.
|
|
**
|
|
** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
|
|
** ^(If the default VFS is unregistered, another VFS is chosen as
|
|
** the default. The choice for the new VFS is arbitrary.)^
|
|
*/
|
|
SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
|
|
SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
|
|
SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
|
|
|
|
/*
|
|
** CAPI3REF: Mutexes
|
|
**
|
|
** The SQLite core uses these routines for thread
|
|
** synchronization. Though they are intended for internal
|
|
** use by SQLite, code that links against SQLite is
|
|
** permitted to use any of these routines.
|
|
**
|
|
** The SQLite source code contains multiple implementations
|
|
** of these mutex routines. An appropriate implementation
|
|
** is selected automatically at compile-time. ^(The following
|
|
** implementations are available in the SQLite core:
|
|
**
|
|
** <ul>
|
|
** <li> SQLITE_MUTEX_PTHREADS
|
|
** <li> SQLITE_MUTEX_W32
|
|
** <li> SQLITE_MUTEX_NOOP
|
|
** </ul>)^
|
|
**
|
|
** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
|
|
** that does no real locking and is appropriate for use in
|
|
** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and
|
|
** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
|
|
** and Windows.
|
|
**
|
|
** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
|
|
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
|
|
** implementation is included with the library. In this case the
|
|
** application must supply a custom mutex implementation using the
|
|
** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
|
|
** before calling sqlite3_initialize() or any other public sqlite3_
|
|
** function that calls sqlite3_initialize().)^
|
|
**
|
|
** ^The sqlite3_mutex_alloc() routine allocates a new
|
|
** mutex and returns a pointer to it. ^If it returns NULL
|
|
** that means that a mutex could not be allocated. ^SQLite
|
|
** will unwind its stack and return an error. ^(The argument
|
|
** to sqlite3_mutex_alloc() is one of these integer constants:
|
|
**
|
|
** <ul>
|
|
** <li> SQLITE_MUTEX_FAST
|
|
** <li> SQLITE_MUTEX_RECURSIVE
|
|
** <li> SQLITE_MUTEX_STATIC_MASTER
|
|
** <li> SQLITE_MUTEX_STATIC_MEM
|
|
** <li> SQLITE_MUTEX_STATIC_MEM2
|
|
** <li> SQLITE_MUTEX_STATIC_PRNG
|
|
** <li> SQLITE_MUTEX_STATIC_LRU
|
|
** <li> SQLITE_MUTEX_STATIC_LRU2
|
|
** </ul>)^
|
|
**
|
|
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
|
|
** cause sqlite3_mutex_alloc() to create
|
|
** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
|
|
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
|
|
** The mutex implementation does not need to make a distinction
|
|
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
|
|
** not want to. ^SQLite will only request a recursive mutex in
|
|
** cases where it really needs one. ^If a faster non-recursive mutex
|
|
** implementation is available on the host platform, the mutex subsystem
|
|
** might return such a mutex in response to SQLITE_MUTEX_FAST.
|
|
**
|
|
** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
|
|
** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
|
|
** a pointer to a static preexisting mutex. ^Six static mutexes are
|
|
** used by the current version of SQLite. Future versions of SQLite
|
|
** may add additional static mutexes. Static mutexes are for internal
|
|
** use by SQLite only. Applications that use SQLite mutexes should
|
|
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
|
|
** SQLITE_MUTEX_RECURSIVE.
|
|
**
|
|
** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
|
|
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
|
|
** returns a different mutex on every call. ^But for the static
|
|
** mutex types, the same mutex is returned on every call that has
|
|
** the same type number.
|
|
**
|
|
** ^The sqlite3_mutex_free() routine deallocates a previously
|
|
** allocated dynamic mutex. ^SQLite is careful to deallocate every
|
|
** dynamic mutex that it allocates. The dynamic mutexes must not be in
|
|
** use when they are deallocated. Attempting to deallocate a static
|
|
** mutex results in undefined behavior. ^SQLite never deallocates
|
|
** a static mutex.
|
|
**
|
|
** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
|
|
** to enter a mutex. ^If another thread is already within the mutex,
|
|
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
|
|
** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
|
|
** upon successful entry. ^(Mutexes created using
|
|
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
|
|
** In such cases the,
|
|
** mutex must be exited an equal number of times before another thread
|
|
** can enter.)^ ^(If the same thread tries to enter any other
|
|
** kind of mutex more than once, the behavior is undefined.
|
|
** SQLite will never exhibit
|
|
** such behavior in its own use of mutexes.)^
|
|
**
|
|
** ^(Some systems (for example, Windows 95) do not support the operation
|
|
** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
|
|
** will always return SQLITE_BUSY. The SQLite core only ever uses
|
|
** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
|
|
**
|
|
** ^The sqlite3_mutex_leave() routine exits a mutex that was
|
|
** previously entered by the same thread. ^(The behavior
|
|
** is undefined if the mutex is not currently entered by the
|
|
** calling thread or is not currently allocated. SQLite will
|
|
** never do either.)^
|
|
**
|
|
** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
|
|
** sqlite3_mutex_leave() is a NULL pointer, then all three routines
|
|
** behave as no-ops.
|
|
**
|
|
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
|
|
*/
|
|
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
|
|
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
|
|
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
|
|
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
|
|
SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
|
|
|
|
/*
|
|
** CAPI3REF: Mutex Methods Object
|
|
**
|
|
** An instance of this structure defines the low-level routines
|
|
** used to allocate and use mutexes.
|
|
**
|
|
** Usually, the default mutex implementations provided by SQLite are
|
|
** sufficient, however the user has the option of substituting a custom
|
|
** implementation for specialized deployments or systems for which SQLite
|
|
** does not provide a suitable implementation. In this case, the user
|
|
** creates and populates an instance of this structure to pass
|
|
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
|
|
** Additionally, an instance of this structure can be used as an
|
|
** output variable when querying the system for the current mutex
|
|
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
|
|
**
|
|
** ^The xMutexInit method defined by this structure is invoked as
|
|
** part of system initialization by the sqlite3_initialize() function.
|
|
** ^The xMutexInit routine is called by SQLite exactly once for each
|
|
** effective call to [sqlite3_initialize()].
|
|
**
|
|
** ^The xMutexEnd method defined by this structure is invoked as
|
|
** part of system shutdown by the sqlite3_shutdown() function. The
|
|
** implementation of this method is expected to release all outstanding
|
|
** resources obtained by the mutex methods implementation, especially
|
|
** those obtained by the xMutexInit method. ^The xMutexEnd()
|
|
** interface is invoked exactly once for each call to [sqlite3_shutdown()].
|
|
**
|
|
** ^(The remaining seven methods defined by this structure (xMutexAlloc,
|
|
** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
|
|
** xMutexNotheld) implement the following interfaces (respectively):
|
|
**
|
|
** <ul>
|
|
** <li> [sqlite3_mutex_alloc()] </li>
|
|
** <li> [sqlite3_mutex_free()] </li>
|
|
** <li> [sqlite3_mutex_enter()] </li>
|
|
** <li> [sqlite3_mutex_try()] </li>
|
|
** <li> [sqlite3_mutex_leave()] </li>
|
|
** <li> [sqlite3_mutex_held()] </li>
|
|
** <li> [sqlite3_mutex_notheld()] </li>
|
|
** </ul>)^
|
|
**
|
|
** The only difference is that the public sqlite3_XXX functions enumerated
|
|
** above silently ignore any invocations that pass a NULL pointer instead
|
|
** of a valid mutex handle. The implementations of the methods defined
|
|
** by this structure are not required to handle this case, the results
|
|
** of passing a NULL pointer instead of a valid mutex handle are undefined
|
|
** (i.e. it is acceptable to provide an implementation that segfaults if
|
|
** it is passed a NULL pointer).
|
|
**
|
|
** The xMutexInit() method must be threadsafe. ^It must be harmless to
|
|
** invoke xMutexInit() multiple times within the same process and without
|
|
** intervening calls to xMutexEnd(). Second and subsequent calls to
|
|
** xMutexInit() must be no-ops.
|
|
**
|
|
** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
|
|
** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
|
|
** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
|
|
** memory allocation for a fast or recursive mutex.
|
|
**
|
|
** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
|
|
** called, but only if the prior call to xMutexInit returned SQLITE_OK.
|
|
** If xMutexInit fails in any way, it is expected to clean up after itself
|
|
** prior to returning.
|
|
*/
|
|
typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
|
|
struct sqlite3_mutex_methods {
|
|
int (*xMutexInit)(void);
|
|
int (*xMutexEnd)(void);
|
|
sqlite3_mutex *(*xMutexAlloc)(int);
|
|
void (*xMutexFree)(sqlite3_mutex *);
|
|
void (*xMutexEnter)(sqlite3_mutex *);
|
|
int (*xMutexTry)(sqlite3_mutex *);
|
|
void (*xMutexLeave)(sqlite3_mutex *);
|
|
int (*xMutexHeld)(sqlite3_mutex *);
|
|
int (*xMutexNotheld)(sqlite3_mutex *);
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Mutex Verification Routines
|
|
**
|
|
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
|
|
** are intended for use inside assert() statements. ^The SQLite core
|
|
** never uses these routines except inside an assert() and applications
|
|
** are advised to follow the lead of the core. ^The SQLite core only
|
|
** provides implementations for these routines when it is compiled
|
|
** with the SQLITE_DEBUG flag. ^External mutex implementations
|
|
** are only required to provide these routines if SQLITE_DEBUG is
|
|
** defined and if NDEBUG is not defined.
|
|
**
|
|
** ^These routines should return true if the mutex in their argument
|
|
** is held or not held, respectively, by the calling thread.
|
|
**
|
|
** ^The implementation is not required to provide versions of these
|
|
** routines that actually work. If the implementation does not provide working
|
|
** versions of these routines, it should at least provide stubs that always
|
|
** return true so that one does not get spurious assertion failures.
|
|
**
|
|
** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
|
|
** the routine should return 1. This seems counter-intuitive since
|
|
** clearly the mutex cannot be held if it does not exist. But
|
|
** the reason the mutex does not exist is because the build is not
|
|
** using mutexes. And we do not want the assert() containing the
|
|
** call to sqlite3_mutex_held() to fail, so a non-zero return is
|
|
** the appropriate thing to do. ^The sqlite3_mutex_notheld()
|
|
** interface should also return 1 when given a NULL pointer.
|
|
*/
|
|
#ifndef NDEBUG
|
|
SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
|
|
SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
|
|
#endif
|
|
|
|
/*
|
|
** CAPI3REF: Mutex Types
|
|
**
|
|
** The [sqlite3_mutex_alloc()] interface takes a single argument
|
|
** which is one of these integer constants.
|
|
**
|
|
** The set of static mutexes may change from one SQLite release to the
|
|
** next. Applications that override the built-in mutex logic must be
|
|
** prepared to accommodate additional static mutexes.
|
|
*/
|
|
#define SQLITE_MUTEX_FAST 0
|
|
#define SQLITE_MUTEX_RECURSIVE 1
|
|
#define SQLITE_MUTEX_STATIC_MASTER 2
|
|
#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
|
|
#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
|
|
#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
|
|
#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
|
|
#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
|
|
#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
|
|
#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
|
|
|
|
/*
|
|
** CAPI3REF: Retrieve the mutex for a database connection
|
|
**
|
|
** ^This interface returns a pointer the [sqlite3_mutex] object that
|
|
** serializes access to the [database connection] given in the argument
|
|
** when the [threading mode] is Serialized.
|
|
** ^If the [threading mode] is Single-thread or Multi-thread then this
|
|
** routine returns a NULL pointer.
|
|
*/
|
|
SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
|
|
|
|
/*
|
|
** CAPI3REF: Low-Level Control Of Database Files
|
|
**
|
|
** ^The [sqlite3_file_control()] interface makes a direct call to the
|
|
** xFileControl method for the [sqlite3_io_methods] object associated
|
|
** with a particular database identified by the second argument. ^The
|
|
** name of the database is "main" for the main database or "temp" for the
|
|
** TEMP database, or the name that appears after the AS keyword for
|
|
** databases that are added using the [ATTACH] SQL command.
|
|
** ^A NULL pointer can be used in place of "main" to refer to the
|
|
** main database file.
|
|
** ^The third and fourth parameters to this routine
|
|
** are passed directly through to the second and third parameters of
|
|
** the xFileControl method. ^The return value of the xFileControl
|
|
** method becomes the return value of this routine.
|
|
**
|
|
** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
|
|
** a pointer to the underlying [sqlite3_file] object to be written into
|
|
** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
|
|
** case is a short-circuit path which does not actually invoke the
|
|
** underlying sqlite3_io_methods.xFileControl method.
|
|
**
|
|
** ^If the second parameter (zDbName) does not match the name of any
|
|
** open database file, then SQLITE_ERROR is returned. ^This error
|
|
** code is not remembered and will not be recalled by [sqlite3_errcode()]
|
|
** or [sqlite3_errmsg()]. The underlying xFileControl method might
|
|
** also return SQLITE_ERROR. There is no way to distinguish between
|
|
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
|
|
** xFileControl method.
|
|
**
|
|
** See also: [SQLITE_FCNTL_LOCKSTATE]
|
|
*/
|
|
SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
|
|
|
|
/*
|
|
** CAPI3REF: Testing Interface
|
|
**
|
|
** ^The sqlite3_test_control() interface is used to read out internal
|
|
** state of SQLite and to inject faults into SQLite for testing
|
|
** purposes. ^The first parameter is an operation code that determines
|
|
** the number, meaning, and operation of all subsequent parameters.
|
|
**
|
|
** This interface is not for use by applications. It exists solely
|
|
** for verifying the correct operation of the SQLite library. Depending
|
|
** on how the SQLite library is compiled, this interface might not exist.
|
|
**
|
|
** The details of the operation codes, their meanings, the parameters
|
|
** they take, and what they do are all subject to change without notice.
|
|
** Unlike most of the SQLite API, this function is not guaranteed to
|
|
** operate consistently from one release to the next.
|
|
*/
|
|
SQLITE_API int sqlite3_test_control(int op, ...);
|
|
|
|
/*
|
|
** CAPI3REF: Testing Interface Operation Codes
|
|
**
|
|
** These constants are the valid operation code parameters used
|
|
** as the first argument to [sqlite3_test_control()].
|
|
**
|
|
** These parameters and their meanings are subject to change
|
|
** without notice. These values are for testing purposes only.
|
|
** Applications should not use any of these parameters or the
|
|
** [sqlite3_test_control()] interface.
|
|
*/
|
|
#define SQLITE_TESTCTRL_FIRST 5
|
|
#define SQLITE_TESTCTRL_PRNG_SAVE 5
|
|
#define SQLITE_TESTCTRL_PRNG_RESTORE 6
|
|
#define SQLITE_TESTCTRL_PRNG_RESET 7
|
|
#define SQLITE_TESTCTRL_BITVEC_TEST 8
|
|
#define SQLITE_TESTCTRL_FAULT_INSTALL 9
|
|
#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
|
|
#define SQLITE_TESTCTRL_PENDING_BYTE 11
|
|
#define SQLITE_TESTCTRL_ASSERT 12
|
|
#define SQLITE_TESTCTRL_ALWAYS 13
|
|
#define SQLITE_TESTCTRL_RESERVE 14
|
|
#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
|
|
#define SQLITE_TESTCTRL_ISKEYWORD 16
|
|
#define SQLITE_TESTCTRL_SCRATCHMALLOC 17
|
|
#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
|
|
#define SQLITE_TESTCTRL_EXPLAIN_STMT 19
|
|
#define SQLITE_TESTCTRL_LAST 19
|
|
|
|
/*
|
|
** CAPI3REF: SQLite Runtime Status
|
|
**
|
|
** ^This interface is used to retrieve runtime status information
|
|
** about the performance of SQLite, and optionally to reset various
|
|
** highwater marks. ^The first argument is an integer code for
|
|
** the specific parameter to measure. ^(Recognized integer codes
|
|
** are of the form [status parameters | SQLITE_STATUS_...].)^
|
|
** ^The current value of the parameter is returned into *pCurrent.
|
|
** ^The highest recorded value is returned in *pHighwater. ^If the
|
|
** resetFlag is true, then the highest record value is reset after
|
|
** *pHighwater is written. ^(Some parameters do not record the highest
|
|
** value. For those parameters
|
|
** nothing is written into *pHighwater and the resetFlag is ignored.)^
|
|
** ^(Other parameters record only the highwater mark and not the current
|
|
** value. For these latter parameters nothing is written into *pCurrent.)^
|
|
**
|
|
** ^The sqlite3_status() routine returns SQLITE_OK on success and a
|
|
** non-zero [error code] on failure.
|
|
**
|
|
** This routine is threadsafe but is not atomic. This routine can be
|
|
** called while other threads are running the same or different SQLite
|
|
** interfaces. However the values returned in *pCurrent and
|
|
** *pHighwater reflect the status of SQLite at different points in time
|
|
** and it is possible that another thread might change the parameter
|
|
** in between the times when *pCurrent and *pHighwater are written.
|
|
**
|
|
** See also: [sqlite3_db_status()]
|
|
*/
|
|
SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Status Parameters
|
|
** KEYWORDS: {status parameters}
|
|
**
|
|
** These integer constants designate various run-time status parameters
|
|
** that can be returned by [sqlite3_status()].
|
|
**
|
|
** <dl>
|
|
** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
|
|
** <dd>This parameter is the current amount of memory checked out
|
|
** using [sqlite3_malloc()], either directly or indirectly. The
|
|
** figure includes calls made to [sqlite3_malloc()] by the application
|
|
** and internal memory usage by the SQLite library. Scratch memory
|
|
** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
|
|
** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
|
|
** this parameter. The amount returned is the sum of the allocation
|
|
** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
|
|
** <dd>This parameter records the largest memory allocation request
|
|
** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
|
|
** internal equivalents). Only the value returned in the
|
|
** *pHighwater parameter to [sqlite3_status()] is of interest.
|
|
** The value written into the *pCurrent parameter is undefined.</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
|
|
** <dd>This parameter records the number of separate memory allocations
|
|
** currently checked out.</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
|
|
** <dd>This parameter returns the number of pages used out of the
|
|
** [pagecache memory allocator] that was configured using
|
|
** [SQLITE_CONFIG_PAGECACHE]. The
|
|
** value returned is in pages, not in bytes.</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
|
|
** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
|
|
** <dd>This parameter returns the number of bytes of page cache
|
|
** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
|
|
** buffer and where forced to overflow to [sqlite3_malloc()]. The
|
|
** returned value includes allocations that overflowed because they
|
|
** where too large (they were larger than the "sz" parameter to
|
|
** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
|
|
** no space was left in the page cache.</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
|
|
** <dd>This parameter records the largest memory allocation request
|
|
** handed to [pagecache memory allocator]. Only the value returned in the
|
|
** *pHighwater parameter to [sqlite3_status()] is of interest.
|
|
** The value written into the *pCurrent parameter is undefined.</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
|
|
** <dd>This parameter returns the number of allocations used out of the
|
|
** [scratch memory allocator] configured using
|
|
** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
|
|
** in bytes. Since a single thread may only have one scratch allocation
|
|
** outstanding at time, this parameter also reports the number of threads
|
|
** using scratch memory at the same time.</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
|
|
** <dd>This parameter returns the number of bytes of scratch memory
|
|
** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
|
|
** buffer and where forced to overflow to [sqlite3_malloc()]. The values
|
|
** returned include overflows because the requested allocation was too
|
|
** larger (that is, because the requested allocation was larger than the
|
|
** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
|
|
** slots were available.
|
|
** </dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
|
|
** <dd>This parameter records the largest memory allocation request
|
|
** handed to [scratch memory allocator]. Only the value returned in the
|
|
** *pHighwater parameter to [sqlite3_status()] is of interest.
|
|
** The value written into the *pCurrent parameter is undefined.</dd>)^
|
|
**
|
|
** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
|
|
** <dd>This parameter records the deepest parser stack. It is only
|
|
** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
|
|
** </dl>
|
|
**
|
|
** New status parameters may be added from time to time.
|
|
*/
|
|
#define SQLITE_STATUS_MEMORY_USED 0
|
|
#define SQLITE_STATUS_PAGECACHE_USED 1
|
|
#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
|
|
#define SQLITE_STATUS_SCRATCH_USED 3
|
|
#define SQLITE_STATUS_SCRATCH_OVERFLOW 4
|
|
#define SQLITE_STATUS_MALLOC_SIZE 5
|
|
#define SQLITE_STATUS_PARSER_STACK 6
|
|
#define SQLITE_STATUS_PAGECACHE_SIZE 7
|
|
#define SQLITE_STATUS_SCRATCH_SIZE 8
|
|
#define SQLITE_STATUS_MALLOC_COUNT 9
|
|
|
|
/*
|
|
** CAPI3REF: Database Connection Status
|
|
**
|
|
** ^This interface is used to retrieve runtime status information
|
|
** about a single [database connection]. ^The first argument is the
|
|
** database connection object to be interrogated. ^The second argument
|
|
** is an integer constant, taken from the set of
|
|
** [SQLITE_DBSTATUS options], that
|
|
** determines the parameter to interrogate. The set of
|
|
** [SQLITE_DBSTATUS options] is likely
|
|
** to grow in future releases of SQLite.
|
|
**
|
|
** ^The current value of the requested parameter is written into *pCur
|
|
** and the highest instantaneous value is written into *pHiwtr. ^If
|
|
** the resetFlg is true, then the highest instantaneous value is
|
|
** reset back down to the current value.
|
|
**
|
|
** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
|
|
** non-zero [error code] on failure.
|
|
**
|
|
** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
|
|
*/
|
|
SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
|
|
|
|
/*
|
|
** CAPI3REF: Status Parameters for database connections
|
|
** KEYWORDS: {SQLITE_DBSTATUS options}
|
|
**
|
|
** These constants are the available integer "verbs" that can be passed as
|
|
** the second argument to the [sqlite3_db_status()] interface.
|
|
**
|
|
** New verbs may be added in future releases of SQLite. Existing verbs
|
|
** might be discontinued. Applications should check the return code from
|
|
** [sqlite3_db_status()] to make sure that the call worked.
|
|
** The [sqlite3_db_status()] interface will return a non-zero error code
|
|
** if a discontinued or unsupported verb is invoked.
|
|
**
|
|
** <dl>
|
|
** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
|
|
** <dd>This parameter returns the number of lookaside memory slots currently
|
|
** checked out.</dd>)^
|
|
**
|
|
** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
|
|
** <dd>This parameter returns the number malloc attempts that were
|
|
** satisfied using lookaside memory. Only the high-water value is meaningful;
|
|
** the current value is always zero.)^
|
|
**
|
|
** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
|
|
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
|
|
** <dd>This parameter returns the number malloc attempts that might have
|
|
** been satisfied using lookaside memory but failed due to the amount of
|
|
** memory requested being larger than the lookaside slot size.
|
|
** Only the high-water value is meaningful;
|
|
** the current value is always zero.)^
|
|
**
|
|
** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
|
|
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
|
|
** <dd>This parameter returns the number malloc attempts that might have
|
|
** been satisfied using lookaside memory but failed due to all lookaside
|
|
** memory already being in use.
|
|
** Only the high-water value is meaningful;
|
|
** the current value is always zero.)^
|
|
**
|
|
** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
|
|
** <dd>This parameter returns the approximate number of of bytes of heap
|
|
** memory used by all pager caches associated with the database connection.)^
|
|
** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
|
|
**
|
|
** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
|
|
** <dd>This parameter returns the approximate number of of bytes of heap
|
|
** memory used to store the schema for all databases associated
|
|
** with the connection - main, temp, and any [ATTACH]-ed databases.)^
|
|
** ^The full amount of memory used by the schemas is reported, even if the
|
|
** schema memory is shared with other database connections due to
|
|
** [shared cache mode] being enabled.
|
|
** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
|
|
**
|
|
** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
|
|
** <dd>This parameter returns the approximate number of of bytes of heap
|
|
** and lookaside memory used by all prepared statements associated with
|
|
** the database connection.)^
|
|
** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
|
|
** </dd>
|
|
**
|
|
** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
|
|
** <dd>This parameter returns the number of pager cache hits that have
|
|
** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
|
|
** is always 0.
|
|
** </dd>
|
|
**
|
|
** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
|
|
** <dd>This parameter returns the number of pager cache misses that have
|
|
** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
|
|
** is always 0.
|
|
** </dd>
|
|
**
|
|
** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
|
|
** <dd>This parameter returns the number of dirty cache entries that have
|
|
** been written to disk. Specifically, the number of pages written to the
|
|
** wal file in wal mode databases, or the number of pages written to the
|
|
** database file in rollback mode databases. Any pages written as part of
|
|
** transaction rollback or database recovery operations are not included.
|
|
** If an IO or other error occurs while writing a page to disk, the effect
|
|
** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
|
|
** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
|
|
** </dd>
|
|
** </dl>
|
|
*/
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
|
|
#define SQLITE_DBSTATUS_CACHE_USED 1
|
|
#define SQLITE_DBSTATUS_SCHEMA_USED 2
|
|
#define SQLITE_DBSTATUS_STMT_USED 3
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
|
|
#define SQLITE_DBSTATUS_CACHE_HIT 7
|
|
#define SQLITE_DBSTATUS_CACHE_MISS 8
|
|
#define SQLITE_DBSTATUS_CACHE_WRITE 9
|
|
#define SQLITE_DBSTATUS_MAX 9 /* Largest defined DBSTATUS */
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Prepared Statement Status
|
|
**
|
|
** ^(Each prepared statement maintains various
|
|
** [SQLITE_STMTSTATUS counters] that measure the number
|
|
** of times it has performed specific operations.)^ These counters can
|
|
** be used to monitor the performance characteristics of the prepared
|
|
** statements. For example, if the number of table steps greatly exceeds
|
|
** the number of table searches or result rows, that would tend to indicate
|
|
** that the prepared statement is using a full table scan rather than
|
|
** an index.
|
|
**
|
|
** ^(This interface is used to retrieve and reset counter values from
|
|
** a [prepared statement]. The first argument is the prepared statement
|
|
** object to be interrogated. The second argument
|
|
** is an integer code for a specific [SQLITE_STMTSTATUS counter]
|
|
** to be interrogated.)^
|
|
** ^The current value of the requested counter is returned.
|
|
** ^If the resetFlg is true, then the counter is reset to zero after this
|
|
** interface call returns.
|
|
**
|
|
** See also: [sqlite3_status()] and [sqlite3_db_status()].
|
|
*/
|
|
SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
|
|
|
|
/*
|
|
** CAPI3REF: Status Parameters for prepared statements
|
|
** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
|
|
**
|
|
** These preprocessor macros define integer codes that name counter
|
|
** values associated with the [sqlite3_stmt_status()] interface.
|
|
** The meanings of the various counters are as follows:
|
|
**
|
|
** <dl>
|
|
** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
|
|
** <dd>^This is the number of times that SQLite has stepped forward in
|
|
** a table as part of a full table scan. Large numbers for this counter
|
|
** may indicate opportunities for performance improvement through
|
|
** careful use of indices.</dd>
|
|
**
|
|
** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
|
|
** <dd>^This is the number of sort operations that have occurred.
|
|
** A non-zero value in this counter may indicate an opportunity to
|
|
** improvement performance through careful use of indices.</dd>
|
|
**
|
|
** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
|
|
** <dd>^This is the number of rows inserted into transient indices that
|
|
** were created automatically in order to help joins run faster.
|
|
** A non-zero value in this counter may indicate an opportunity to
|
|
** improvement performance by adding permanent indices that do not
|
|
** need to be reinitialized each time the statement is run.</dd>
|
|
** </dl>
|
|
*/
|
|
#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
|
|
#define SQLITE_STMTSTATUS_SORT 2
|
|
#define SQLITE_STMTSTATUS_AUTOINDEX 3
|
|
|
|
/*
|
|
** CAPI3REF: Custom Page Cache Object
|
|
**
|
|
** The sqlite3_pcache type is opaque. It is implemented by
|
|
** the pluggable module. The SQLite core has no knowledge of
|
|
** its size or internal structure and never deals with the
|
|
** sqlite3_pcache object except by holding and passing pointers
|
|
** to the object.
|
|
**
|
|
** See [sqlite3_pcache_methods2] for additional information.
|
|
*/
|
|
typedef struct sqlite3_pcache sqlite3_pcache;
|
|
|
|
/*
|
|
** CAPI3REF: Custom Page Cache Object
|
|
**
|
|
** The sqlite3_pcache_page object represents a single page in the
|
|
** page cache. The page cache will allocate instances of this
|
|
** object. Various methods of the page cache use pointers to instances
|
|
** of this object as parameters or as their return value.
|
|
**
|
|
** See [sqlite3_pcache_methods2] for additional information.
|
|
*/
|
|
typedef struct sqlite3_pcache_page sqlite3_pcache_page;
|
|
struct sqlite3_pcache_page {
|
|
void *pBuf; /* The content of the page */
|
|
void *pExtra; /* Extra information associated with the page */
|
|
};
|
|
|
|
/*
|
|
** CAPI3REF: Application Defined Page Cache.
|
|
** KEYWORDS: {page cache}
|
|
**
|
|
** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
|
|
** register an alternative page cache implementation by passing in an
|
|
** instance of the sqlite3_pcache_methods2 structure.)^
|
|
** In many applications, most of the heap memory allocated by
|
|
** SQLite is used for the page cache.
|
|
** By implementing a
|
|
** custom page cache using this API, an application can better control
|
|
** the amount of memory consumed by SQLite, the way in which
|
|
** that memory is allocated and released, and the policies used to
|
|
** determine exactly which parts of a database file are cached and for
|
|
** how long.
|
|
**
|
|
** The alternative page cache mechanism is an
|
|
** extreme measure that is only needed by the most demanding applications.
|
|
** The built-in page cache is recommended for most uses.
|
|
**
|
|
** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
|
|
** internal buffer by SQLite within the call to [sqlite3_config]. Hence
|
|
** the application may discard the parameter after the call to
|
|
** [sqlite3_config()] returns.)^
|
|
**
|
|
** [[the xInit() page cache method]]
|
|
** ^(The xInit() method is called once for each effective
|
|
** call to [sqlite3_initialize()])^
|
|
** (usually only once during the lifetime of the process). ^(The xInit()
|
|
** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
|
|
** The intent of the xInit() method is to set up global data structures
|
|
** required by the custom page cache implementation.
|
|
** ^(If the xInit() method is NULL, then the
|
|
** built-in default page cache is used instead of the application defined
|
|
** page cache.)^
|
|
**
|
|
** [[the xShutdown() page cache method]]
|
|
** ^The xShutdown() method is called by [sqlite3_shutdown()].
|
|
** It can be used to clean up
|
|
** any outstanding resources before process shutdown, if required.
|
|
** ^The xShutdown() method may be NULL.
|
|
**
|
|
** ^SQLite automatically serializes calls to the xInit method,
|
|
** so the xInit method need not be threadsafe. ^The
|
|
** xShutdown method is only called from [sqlite3_shutdown()] so it does
|
|
** not need to be threadsafe either. All other methods must be threadsafe
|
|
** in multithreaded applications.
|
|
**
|
|
** ^SQLite will never invoke xInit() more than once without an intervening
|
|
** call to xShutdown().
|
|
**
|
|
** [[the xCreate() page cache methods]]
|
|
** ^SQLite invokes the xCreate() method to construct a new cache instance.
|
|
** SQLite will typically create one cache instance for each open database file,
|
|
** though this is not guaranteed. ^The
|
|
** first parameter, szPage, is the size in bytes of the pages that must
|
|
** be allocated by the cache. ^szPage will always a power of two. ^The
|
|
** second parameter szExtra is a number of bytes of extra storage
|
|
** associated with each page cache entry. ^The szExtra parameter will
|
|
** a number less than 250. SQLite will use the
|
|
** extra szExtra bytes on each page to store metadata about the underlying
|
|
** database page on disk. The value passed into szExtra depends
|
|
** on the SQLite version, the target platform, and how SQLite was compiled.
|
|
** ^The third argument to xCreate(), bPurgeable, is true if the cache being
|
|
** created will be used to cache database pages of a file stored on disk, or
|
|
** false if it is used for an in-memory database. The cache implementation
|
|
** does not have to do anything special based with the value of bPurgeable;
|
|
** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
|
|
** never invoke xUnpin() except to deliberately delete a page.
|
|
** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
|
|
** false will always have the "discard" flag set to true.
|
|
** ^Hence, a cache created with bPurgeable false will
|
|
** never contain any unpinned pages.
|
|
**
|
|
** [[the xCachesize() page cache method]]
|
|
** ^(The xCachesize() method may be called at any time by SQLite to set the
|
|
** suggested maximum cache-size (number of pages stored by) the cache
|
|
** instance passed as the first argument. This is the value configured using
|
|
** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
|
|
** parameter, the implementation is not required to do anything with this
|
|
** value; it is advisory only.
|
|
**
|
|
** [[the xPagecount() page cache methods]]
|
|
** The xPagecount() method must return the number of pages currently
|
|
** stored in the cache, both pinned and unpinned.
|
|
**
|
|
** [[the xFetch() page cache methods]]
|
|
** The xFetch() method locates a page in the cache and returns a pointer to
|
|
** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
|
|
** The pBuf element of the returned sqlite3_pcache_page object will be a
|
|
** pointer to a buffer of szPage bytes used to store the content of a
|
|
** single database page. The pExtra element of sqlite3_pcache_page will be
|
|
** a pointer to the szExtra bytes of extra storage that SQLite has requested
|
|
** for each entry in the page cache.
|
|
**
|
|
** The page to be fetched is determined by the key. ^The minimum key value
|
|
** is 1. After it has been retrieved using xFetch, the page is considered
|
|
** to be "pinned".
|
|
**
|
|
** If the requested page is already in the page cache, then the page cache
|
|
** implementation must return a pointer to the page buffer with its content
|
|
** intact. If the requested page is not already in the cache, then the
|
|
** cache implementation should use the value of the createFlag
|
|
** parameter to help it determined what action to take:
|
|
**
|
|
** <table border=1 width=85% align=center>
|
|
** <tr><th> createFlag <th> Behaviour when page is not already in cache
|
|
** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
|
|
** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
|
|
** Otherwise return NULL.
|
|
** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
|
|
** NULL if allocating a new page is effectively impossible.
|
|
** </table>
|
|
**
|
|
** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
|
|
** will only use a createFlag of 2 after a prior call with a createFlag of 1
|
|
** failed.)^ In between the to xFetch() calls, SQLite may
|
|
** attempt to unpin one or more cache pages by spilling the content of
|
|
** pinned pages to disk and synching the operating system disk cache.
|
|
**
|
|
** [[the xUnpin() page cache method]]
|
|
** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
|
|
** as its second argument. If the third parameter, discard, is non-zero,
|
|
** then the page must be evicted from the cache.
|
|
** ^If the discard parameter is
|
|
** zero, then the page may be discarded or retained at the discretion of
|
|
** page cache implementation. ^The page cache implementation
|
|
** may choose to evict unpinned pages at any time.
|
|
**
|
|
** The cache must not perform any reference counting. A single
|
|
** call to xUnpin() unpins the page regardless of the number of prior calls
|
|
** to xFetch().
|
|
**
|
|
** [[the xRekey() page cache methods]]
|
|
** The xRekey() method is used to change the key value associated with the
|
|
** page passed as the second argument. If the cache
|
|
** previously contains an entry associated with newKey, it must be
|
|
** discarded. ^Any prior cache entry associated with newKey is guaranteed not
|
|
** to be pinned.
|
|
**
|
|
** When SQLite calls the xTruncate() method, the cache must discard all
|
|
** existing cache entries with page numbers (keys) greater than or equal
|
|
** to the value of the iLimit parameter passed to xTruncate(). If any
|
|
** of these pages are pinned, they are implicitly unpinned, meaning that
|
|
** they can be safely discarded.
|
|
**
|
|
** [[the xDestroy() page cache method]]
|
|
** ^The xDestroy() method is used to delete a cache allocated by xCreate().
|
|
** All resources associated with the specified cache should be freed. ^After
|
|
** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
|
|
** handle invalid, and will not use it with any other sqlite3_pcache_methods2
|
|
** functions.
|
|
**
|
|
** [[the xShrink() page cache method]]
|
|
** ^SQLite invokes the xShrink() method when it wants the page cache to
|
|
** free up as much of heap memory as possible. The page cache implementation
|
|
** is not obligated to free any memory, but well-behaved implementations should
|
|
** do their best.
|
|
*/
|
|
typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
|
|
struct sqlite3_pcache_methods2 {
|
|
int iVersion;
|
|
void *pArg;
|
|
int (*xInit)(void*);
|
|
void (*xShutdown)(void*);
|
|
sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
|
|
void (*xCachesize)(sqlite3_pcache*, int nCachesize);
|
|
int (*xPagecount)(sqlite3_pcache*);
|
|
sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
|
|
void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
|
|
void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
|
|
unsigned oldKey, unsigned newKey);
|
|
void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
|
|
void (*xDestroy)(sqlite3_pcache*);
|
|
void (*xShrink)(sqlite3_pcache*);
|
|
};
|
|
|
|
/*
|
|
** This is the obsolete pcache_methods object that has now been replaced
|
|
** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
|
|
** retained in the header file for backwards compatibility only.
|
|
*/
|
|
typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
|
|
struct sqlite3_pcache_methods {
|
|
void *pArg;
|
|
int (*xInit)(void*);
|
|
void (*xShutdown)(void*);
|
|
sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
|
|
void (*xCachesize)(sqlite3_pcache*, int nCachesize);
|
|
int (*xPagecount)(sqlite3_pcache*);
|
|
void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
|
|
void (*xUnpin)(sqlite3_pcache*, void*, int discard);
|
|
void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
|
|
void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
|
|
void (*xDestroy)(sqlite3_pcache*);
|
|
};
|
|
|
|
|
|
/*
|
|
** CAPI3REF: Online Backup Object
|
|
**
|
|
** The sqlite3_backup object records state information about an ongoing
|
|
** online backup operation. ^The sqlite3_backup object is created by
|
|
** a call to [sqlite3_backup_init()] and is destroyed by a call to
|
|
** [sqlite3_backup_finish()].
|
|
**
|
|
** See Also: [Using the SQLite Online Backup API]
|
|
*/
|
|
typedef struct sqlite3_backup sqlite3_backup;
|
|
|
|
/*
|
|
** CAPI3REF: Online Backup API.
|
|
**
|
|
** The backup API copies the content of one database into another.
|
|
** It is useful either for creating backups of databases or
|
|
** for copying in-memory databases to or from persistent files.
|
|
**
|
|
** See Also: [Using the SQLite Online Backup API]
|
|
**
|
|
** ^SQLite holds a write transaction open on the destination database file
|
|
** for the duration of the backup operation.
|
|
** ^The source database is read-locked only while it is being read;
|
|
** it is not locked continuously for the entire backup operation.
|
|
** ^Thus, the backup may be performed on a live source database without
|
|
** preventing other database connections from
|
|
** reading or writing to the source database while the backup is underway.
|
|
**
|
|
** ^(To perform a backup operation:
|
|
** <ol>
|
|
** <li><b>sqlite3_backup_init()</b> is called once to initialize the
|
|
** backup,
|
|
** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
|
|
** the data between the two databases, and finally
|
|
** <li><b>sqlite3_backup_finish()</b> is called to release all resources
|
|
** associated with the backup operation.
|
|
** </ol>)^
|
|
** There should be exactly one call to sqlite3_backup_finish() for each
|
|
** successful call to sqlite3_backup_init().
|
|
**
|
|
** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
|
|
**
|
|
** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
|
|
** [database connection] associated with the destination database
|
|
** and the database name, respectively.
|
|
** ^The database name is "main" for the main database, "temp" for the
|
|
** temporary database, or the name specified after the AS keyword in
|
|
** an [ATTACH] statement for an attached database.
|
|
** ^The S and M arguments passed to
|
|
** sqlite3_backup_init(D,N,S,M) identify the [database connection]
|
|
** and database name of the source database, respectively.
|
|
** ^The source and destination [database connections] (parameters S and D)
|
|
** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
|
|
** an error.
|
|
**
|
|
** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
|
|
** returned and an error code and error message are stored in the
|
|
** destination [database connection] D.
|
|
** ^The error code and message for the failed call to sqlite3_backup_init()
|
|
** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
|
|
** [sqlite3_errmsg16()] functions.
|
|
** ^A successful call to sqlite3_backup_init() returns a pointer to an
|
|
** [sqlite3_backup] object.
|
|
** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
|
|
** sqlite3_backup_finish() functions to perform the specified backup
|
|
** operation.
|
|
**
|
|
** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
|
|
**
|
|
** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
|
|
** the source and destination databases specified by [sqlite3_backup] object B.
|
|
** ^If N is negative, all remaining source pages are copied.
|
|
** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
|
|
** are still more pages to be copied, then the function returns [SQLITE_OK].
|
|
** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
|
|
** from source to destination, then it returns [SQLITE_DONE].
|
|
** ^If an error occurs while running sqlite3_backup_step(B,N),
|
|
** then an [error code] is returned. ^As well as [SQLITE_OK] and
|
|
** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
|
|
** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
|
|
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
|
|
**
|
|
** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
|
|
** <ol>
|
|
** <li> the destination database was opened read-only, or
|
|
** <li> the destination database is using write-ahead-log journaling
|
|
** and the destination and source page sizes differ, or
|
|
** <li> the destination database is an in-memory database and the
|
|
** destination and source page sizes differ.
|
|
** </ol>)^
|
|
**
|
|
** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
|
|
** the [sqlite3_busy_handler | busy-handler function]
|
|
** is invoked (if one is specified). ^If the
|
|
** busy-handler returns non-zero before the lock is available, then
|
|
** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
|
|
** sqlite3_backup_step() can be retried later. ^If the source
|
|
** [database connection]
|
|
** is being used to write to the source database when sqlite3_backup_step()
|
|
** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
|
|
** case the call to sqlite3_backup_step() can be retried later on. ^(If
|
|
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
|
|
** [SQLITE_READONLY] is returned, then
|
|
** there is no point in retrying the call to sqlite3_backup_step(). These
|
|
** errors are considered fatal.)^ The application must accept
|
|
** that the backup operation has failed and pass the backup operation handle
|
|
** to the sqlite3_backup_finish() to release associated resources.
|
|
**
|
|
** ^The first call to sqlite3_backup_step() obtains an exclusive lock
|
|
** on the destination file. ^The exclusive lock is not released until either
|
|
** sqlite3_backup_finish() is called or the backup operation is complete
|
|
** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
|
|
** sqlite3_backup_step() obtains a [shared lock] on the source database that
|
|
** lasts for the duration of the sqlite3_backup_step() call.
|
|
** ^Because the source database is not locked between calls to
|
|
** sqlite3_backup_step(), the source database may be modified mid-way
|
|
** through the backup process. ^If the source database is modified by an
|
|
** external process or via a database connection other than the one being
|
|
** used by the backup operation, then the backup will be automatically
|
|
** restarted by the next call to sqlite3_backup_step(). ^If the source
|
|
** database is modified by the using the same database connection as is used
|
|
** by the backup operation, then the backup database is automatically
|
|
** updated at the same time.
|
|
**
|
|
** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
|
|
**
|
|
** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
|
|
** application wishes to abandon the backup operation, the application
|
|
** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
|
|
** ^The sqlite3_backup_finish() interfaces releases all
|
|
** resources associated with the [sqlite3_backup] object.
|
|
** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
|
|
** active write-transaction on the destination database is rolled back.
|
|
** The [sqlite3_backup] object is invalid
|
|
** and may not be used following a call to sqlite3_backup_finish().
|
|
**
|
|
** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
|
|
** sqlite3_backup_step() errors occurred, regardless or whether or not
|
|
** sqlite3_backup_step() completed.
|
|
** ^If an out-of-memory condition or IO error occurred during any prior
|
|
** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
|
|
** sqlite3_backup_finish() returns the corresponding [error code].
|
|
**
|
|
** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
|
|
** is not a permanent error and does not affect the return value of
|
|
** sqlite3_backup_finish().
|
|
**
|
|
** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]]
|
|
** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
|
|
**
|
|
** ^Each call to sqlite3_backup_step() sets two values inside
|
|
** the [sqlite3_backup] object: the number of pages still to be backed
|
|
** up and the total number of pages in the source database file.
|
|
** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
|
|
** retrieve these two values, respectively.
|
|
**
|
|
** ^The values returned by these functions are only updated by
|
|
** sqlite3_backup_step(). ^If the source database is modified during a backup
|
|
** operation, then the values are not updated to account for any extra
|
|
** pages that need to be updated or the size of the source database file
|
|
** changing.
|
|
**
|
|
** <b>Concurrent Usage of Database Handles</b>
|
|
**
|
|
** ^The source [database connection] may be used by the application for other
|
|
** purposes while a backup operation is underway or being initialized.
|
|
** ^If SQLite is compiled and configured to support threadsafe database
|
|
** connections, then the source database connection may be used concurrently
|
|
** from within other threads.
|
|
**
|
|
** However, the application must guarantee that the destination
|
|
** [database connection] is not passed to any other API (by any thread) after
|
|
** sqlite3_backup_init() is called and before the corresponding call to
|
|
** sqlite3_backup_finish(). SQLite does not currently check to see
|
|
** if the application incorrectly accesses the destination [database connection]
|
|
** and so no error code is reported, but the operations may malfunction
|
|
** nevertheless. Use of the destination database connection while a
|
|
** backup is in progress might also also cause a mutex deadlock.
|
|
**
|
|
** If running in [shared cache mode], the application must
|
|
** guarantee that the shared cache used by the destination database
|
|
** is not accessed while the backup is running. In practice this means
|
|
** that the application must guarantee that the disk file being
|
|
** backed up to is not accessed by any connection within the process,
|
|
** not just the specific connection that was passed to sqlite3_backup_init().
|
|
**
|
|
** The [sqlite3_backup] object itself is partially threadsafe. Multiple
|
|
** threads may safely make multiple concurrent calls to sqlite3_backup_step().
|
|
** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
|
|
** APIs are not strictly speaking threadsafe. If they are invoked at the
|
|
** same time as another thread is invoking sqlite3_backup_step() it is
|
|
** possible that they return invalid values.
|
|
*/
|
|
SQLITE_API sqlite3_backup *sqlite3_backup_init(
|
|
sqlite3 *pDest, /* Destination database handle */
|
|
const char *zDestName, /* Destination database name */
|
|
sqlite3 *pSource, /* Source database handle */
|
|
const char *zSourceName /* Source database name */
|
|
);
|
|
SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
|
|
SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
|
|
SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
|
|
SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
|
|
|
|
/*
|
|
** CAPI3REF: Unlock Notification
|
|
**
|
|
** ^When running in shared-cache mode, a database operation may fail with
|
|
** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
|
|
** individual tables within the shared-cache cannot be obtained. See
|
|
** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
|
|
** ^This API may be used to register a callback that SQLite will invoke
|
|
** when the connection currently holding the required lock relinquishes it.
|
|
** ^This API is only available if the library was compiled with the
|
|
** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
|
|
**
|
|
** See Also: [Using the SQLite Unlock Notification Feature].
|
|
**
|
|
** ^Shared-cache locks are released when a database connection concludes
|
|
** its current transaction, either by committing it or rolling it back.
|
|
**
|
|
** ^When a connection (known as the blocked connection) fails to obtain a
|
|
** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
|
|
** identity of the database connection (the blocking connection) that
|
|
** has locked the required resource is stored internally. ^After an
|
|
** application receives an SQLITE_LOCKED error, it may call the
|
|
** sqlite3_unlock_notify() method with the blocked connection handle as
|
|
** the first argument to register for a callback that will be invoked
|
|
** when the blocking connections current transaction is concluded. ^The
|
|
** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
|
|
** call that concludes the blocking connections transaction.
|
|
**
|
|
** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
|
|
** there is a chance that the blocking connection will have already
|
|
** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
|
|
** If this happens, then the specified callback is invoked immediately,
|
|
** from within the call to sqlite3_unlock_notify().)^
|
|
**
|
|
** ^If the blocked connection is attempting to obtain a write-lock on a
|
|
** shared-cache table, and more than one other connection currently holds
|
|
** a read-lock on the same table, then SQLite arbitrarily selects one of
|
|
** the other connections to use as the blocking connection.
|
|
**
|
|
** ^(There may be at most one unlock-notify callback registered by a
|
|
** blocked connection. If sqlite3_unlock_notify() is called when the
|
|
** blocked connection already has a registered unlock-notify callback,
|
|
** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
|
|
** called with a NULL pointer as its second argument, then any existing
|
|
** unlock-notify callback is canceled. ^The blocked connections
|
|
** unlock-notify callback may also be canceled by closing the blocked
|
|
** connection using [sqlite3_close()].
|
|
**
|
|
** The unlock-notify callback is not reentrant. If an application invokes
|
|
** any sqlite3_xxx API functions from within an unlock-notify callback, a
|
|
** crash or deadlock may be the result.
|
|
**
|
|
** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
|
|
** returns SQLITE_OK.
|
|
**
|
|
** <b>Callback Invocation Details</b>
|
|
**
|
|
** When an unlock-notify callback is registered, the application provides a
|
|
** single void* pointer that is passed to the callback when it is invoked.
|
|
** However, the signature of the callback function allows SQLite to pass
|
|
** it an array of void* context pointers. The first argument passed to
|
|
** an unlock-notify callback is a pointer to an array of void* pointers,
|
|
** and the second is the number of entries in the array.
|
|
**
|
|
** When a blocking connections transaction is concluded, there may be
|
|
** more than one blocked connection that has registered for an unlock-notify
|
|
** callback. ^If two or more such blocked connections have specified the
|
|
** same callback function, then instead of invoking the callback function
|
|
** multiple times, it is invoked once with the set of void* context pointers
|
|
** specified by the blocked connections bundled together into an array.
|
|
** This gives the application an opportunity to prioritize any actions
|
|
** related to the set of unblocked database connections.
|
|
**
|
|
** <b>Deadlock Detection</b>
|
|
**
|
|
** Assuming that after registering for an unlock-notify callback a
|
|
** database waits for the callback to be issued before taking any further
|
|
** action (a reasonable assumption), then using this API may cause the
|
|
** application to deadlock. For example, if connection X is waiting for
|
|
** connection Y's transaction to be concluded, and similarly connection
|
|
** Y is waiting on connection X's transaction, then neither connection
|
|
** will proceed and the system may remain deadlocked indefinitely.
|
|
**
|
|
** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
|
|
** detection. ^If a given call to sqlite3_unlock_notify() would put the
|
|
** system in a deadlocked state, then SQLITE_LOCKED is returned and no
|
|
** unlock-notify callback is registered. The system is said to be in
|
|
** a deadlocked state if connection A has registered for an unlock-notify
|
|
** callback on the conclusion of connection B's transaction, and connection
|
|
** B has itself registered for an unlock-notify callback when connection
|
|
** A's transaction is concluded. ^Indirect deadlock is also detected, so
|
|
** the system is also considered to be deadlocked if connection B has
|
|
** registered for an unlock-notify callback on the conclusion of connection
|
|
** C's transaction, where connection C is waiting on connection A. ^Any
|
|
** number of levels of indirection are allowed.
|
|
**
|
|
** <b>The "DROP TABLE" Exception</b>
|
|
**
|
|
** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
|
|
** always appropriate to call sqlite3_unlock_notify(). There is however,
|
|
** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
|
|
** SQLite checks if there are any currently executing SELECT statements
|
|
** that belong to the same connection. If there are, SQLITE_LOCKED is
|
|
** returned. In this case there is no "blocking connection", so invoking
|
|
** sqlite3_unlock_notify() results in the unlock-notify callback being
|
|
** invoked immediately. If the application then re-attempts the "DROP TABLE"
|
|
** or "DROP INDEX" query, an infinite loop might be the result.
|
|
**
|
|
** One way around this problem is to check the extended error code returned
|
|
** by an sqlite3_step() call. ^(If there is a blocking connection, then the
|
|
** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
|
|
** the special "DROP TABLE/INDEX" case, the extended error code is just
|
|
** SQLITE_LOCKED.)^
|
|
*/
|
|
SQLITE_API int sqlite3_unlock_notify(
|
|
sqlite3 *pBlocked, /* Waiting connection */
|
|
void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
|
|
void *pNotifyArg /* Argument to pass to xNotify */
|
|
);
|
|
|
|
|
|
/*
|
|
** CAPI3REF: String Comparison
|
|
**
|
|
** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
|
|
** and extensions to compare the contents of two buffers containing UTF-8
|
|
** strings in a case-independent fashion, using the same definition of "case
|
|
** independence" that SQLite uses internally when comparing identifiers.
|
|
*/
|
|
SQLITE_API int sqlite3_stricmp(const char *, const char *);
|
|
SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
|
|
|
|
/*
|
|
** CAPI3REF: Error Logging Interface
|
|
**
|
|
** ^The [sqlite3_log()] interface writes a message into the error log
|
|
** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
|
|
** ^If logging is enabled, the zFormat string and subsequent arguments are
|
|
** used with [sqlite3_snprintf()] to generate the final output string.
|
|
**
|
|
** The sqlite3_log() interface is intended for use by extensions such as
|
|
** virtual tables, collating functions, and SQL functions. While there is
|
|
** nothing to prevent an application from calling sqlite3_log(), doing so
|
|
** is considered bad form.
|
|
**
|
|
** The zFormat string must not be NULL.
|
|
**
|
|
** To avoid deadlocks and other threading problems, the sqlite3_log() routine
|
|
** will not use dynamically allocated memory. The log message is stored in
|
|
** a fixed-length buffer on the stack. If the log message is longer than
|
|
** a few hundred characters, it will be truncated to the length of the
|
|
** buffer.
|
|
*/
|
|
SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
|
|
|
|
/*
|
|
** CAPI3REF: Write-Ahead Log Commit Hook
|
|
**
|
|
** ^The [sqlite3_wal_hook()] function is used to register a callback that
|
|
** will be invoked each time a database connection commits data to a
|
|
** [write-ahead log] (i.e. whenever a transaction is committed in
|
|
** [journal_mode | journal_mode=WAL mode]).
|
|
**
|
|
** ^The callback is invoked by SQLite after the commit has taken place and
|
|
** the associated write-lock on the database released, so the implementation
|
|
** may read, write or [checkpoint] the database as required.
|
|
**
|
|
** ^The first parameter passed to the callback function when it is invoked
|
|
** is a copy of the third parameter passed to sqlite3_wal_hook() when
|
|
** registering the callback. ^The second is a copy of the database handle.
|
|
** ^The third parameter is the name of the database that was written to -
|
|
** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
|
|
** is the number of pages currently in the write-ahead log file,
|
|
** including those that were just committed.
|
|
**
|
|
** The callback function should normally return [SQLITE_OK]. ^If an error
|
|
** code is returned, that error will propagate back up through the
|
|
** SQLite code base to cause the statement that provoked the callback
|
|
** to report an error, though the commit will have still occurred. If the
|
|
** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
|
|
** that does not correspond to any valid SQLite error code, the results
|
|
** are undefined.
|
|
**
|
|
** A single database handle may have at most a single write-ahead log callback
|
|
** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
|
|
** previously registered write-ahead log callback. ^Note that the
|
|
** [sqlite3_wal_autocheckpoint()] interface and the
|
|
** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
|
|
** those overwrite any prior [sqlite3_wal_hook()] settings.
|
|
*/
|
|
SQLITE_API void *sqlite3_wal_hook(
|
|
sqlite3*,
|
|
int(*)(void *,sqlite3*,const char*,int),
|
|
void*
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Configure an auto-checkpoint
|
|
**
|
|
** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
|
|
** [sqlite3_wal_hook()] that causes any database on [database connection] D
|
|
** to automatically [checkpoint]
|
|
** after committing a transaction if there are N or
|
|
** more frames in the [write-ahead log] file. ^Passing zero or
|
|
** a negative value as the nFrame parameter disables automatic
|
|
** checkpoints entirely.
|
|
**
|
|
** ^The callback registered by this function replaces any existing callback
|
|
** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
|
|
** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
|
|
** configured by this function.
|
|
**
|
|
** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
|
|
** from SQL.
|
|
**
|
|
** ^Every new [database connection] defaults to having the auto-checkpoint
|
|
** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
|
|
** pages. The use of this interface
|
|
** is only necessary if the default setting is found to be suboptimal
|
|
** for a particular application.
|
|
*/
|
|
SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
|
|
|
|
/*
|
|
** CAPI3REF: Checkpoint a database
|
|
**
|
|
** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
|
|
** on [database connection] D to be [checkpointed]. ^If X is NULL or an
|
|
** empty string, then a checkpoint is run on all databases of
|
|
** connection D. ^If the database connection D is not in
|
|
** [WAL | write-ahead log mode] then this interface is a harmless no-op.
|
|
**
|
|
** ^The [wal_checkpoint pragma] can be used to invoke this interface
|
|
** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the
|
|
** [wal_autocheckpoint pragma] can be used to cause this interface to be
|
|
** run whenever the WAL reaches a certain size threshold.
|
|
**
|
|
** See also: [sqlite3_wal_checkpoint_v2()]
|
|
*/
|
|
SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
|
|
|
|
/*
|
|
** CAPI3REF: Checkpoint a database
|
|
**
|
|
** Run a checkpoint operation on WAL database zDb attached to database
|
|
** handle db. The specific operation is determined by the value of the
|
|
** eMode parameter:
|
|
**
|
|
** <dl>
|
|
** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
|
|
** Checkpoint as many frames as possible without waiting for any database
|
|
** readers or writers to finish. Sync the db file if all frames in the log
|
|
** are checkpointed. This mode is the same as calling
|
|
** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked.
|
|
**
|
|
** <dt>SQLITE_CHECKPOINT_FULL<dd>
|
|
** This mode blocks (calls the busy-handler callback) until there is no
|
|
** database writer and all readers are reading from the most recent database
|
|
** snapshot. It then checkpoints all frames in the log file and syncs the
|
|
** database file. This call blocks database writers while it is running,
|
|
** but not database readers.
|
|
**
|
|
** <dt>SQLITE_CHECKPOINT_RESTART<dd>
|
|
** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after
|
|
** checkpointing the log file it blocks (calls the busy-handler callback)
|
|
** until all readers are reading from the database file only. This ensures
|
|
** that the next client to write to the database file restarts the log file
|
|
** from the beginning. This call blocks database writers while it is running,
|
|
** but not database readers.
|
|
** </dl>
|
|
**
|
|
** If pnLog is not NULL, then *pnLog is set to the total number of frames in
|
|
** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
|
|
** the total number of checkpointed frames (including any that were already
|
|
** checkpointed when this function is called). *pnLog and *pnCkpt may be
|
|
** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
|
|
** If no values are available because of an error, they are both set to -1
|
|
** before returning to communicate this to the caller.
|
|
**
|
|
** All calls obtain an exclusive "checkpoint" lock on the database file. If
|
|
** any other process is running a checkpoint operation at the same time, the
|
|
** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a
|
|
** busy-handler configured, it will not be invoked in this case.
|
|
**
|
|
** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive
|
|
** "writer" lock on the database file. If the writer lock cannot be obtained
|
|
** immediately, and a busy-handler is configured, it is invoked and the writer
|
|
** lock retried until either the busy-handler returns 0 or the lock is
|
|
** successfully obtained. The busy-handler is also invoked while waiting for
|
|
** database readers as described above. If the busy-handler returns 0 before
|
|
** the writer lock is obtained or while waiting for database readers, the
|
|
** checkpoint operation proceeds from that point in the same way as
|
|
** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
|
|
** without blocking any further. SQLITE_BUSY is returned in this case.
|
|
**
|
|
** If parameter zDb is NULL or points to a zero length string, then the
|
|
** specified operation is attempted on all WAL databases. In this case the
|
|
** values written to output parameters *pnLog and *pnCkpt are undefined. If
|
|
** an SQLITE_BUSY error is encountered when processing one or more of the
|
|
** attached WAL databases, the operation is still attempted on any remaining
|
|
** attached databases and SQLITE_BUSY is returned to the caller. If any other
|
|
** error occurs while processing an attached database, processing is abandoned
|
|
** and the error code returned to the caller immediately. If no error
|
|
** (SQLITE_BUSY or otherwise) is encountered while processing the attached
|
|
** databases, SQLITE_OK is returned.
|
|
**
|
|
** If database zDb is the name of an attached database that is not in WAL
|
|
** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
|
|
** zDb is not NULL (or a zero length string) and is not the name of any
|
|
** attached database, SQLITE_ERROR is returned to the caller.
|
|
*/
|
|
SQLITE_API int sqlite3_wal_checkpoint_v2(
|
|
sqlite3 *db, /* Database handle */
|
|
const char *zDb, /* Name of attached database (or NULL) */
|
|
int eMode, /* SQLITE_CHECKPOINT_* value */
|
|
int *pnLog, /* OUT: Size of WAL log in frames */
|
|
int *pnCkpt /* OUT: Total number of frames checkpointed */
|
|
);
|
|
|
|
/*
|
|
** CAPI3REF: Checkpoint operation parameters
|
|
**
|
|
** These constants can be used as the 3rd parameter to
|
|
** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()]
|
|
** documentation for additional information about the meaning and use of
|
|
** each of these values.
|
|
*/
|
|
#define SQLITE_CHECKPOINT_PASSIVE 0
|
|
#define SQLITE_CHECKPOINT_FULL 1
|
|
#define SQLITE_CHECKPOINT_RESTART 2
|
|
|
|
/*
|
|
** CAPI3REF: Virtual Table Interface Configuration
|
|
**
|
|
** This function may be called by either the [xConnect] or [xCreate] method
|
|
** of a [virtual table] implementation to configure
|
|
** various facets of the virtual table interface.
|
|
**
|
|
** If this interface is invoked outside the context of an xConnect or
|
|
** xCreate virtual table method then the behavior is undefined.
|
|
**
|
|
** At present, there is only one option that may be configured using
|
|
** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
|
|
** may be added in the future.
|
|
*/
|
|
SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
|
|
|
|
/*
|
|
** CAPI3REF: Virtual Table Configuration Options
|
|
**
|
|
** These macros define the various options to the
|
|
** [sqlite3_vtab_config()] interface that [virtual table] implementations
|
|
** can use to customize and optimize their behavior.
|
|
**
|
|
** <dl>
|
|
** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
|
|
** <dd>Calls of the form
|
|
** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
|
|
** where X is an integer. If X is zero, then the [virtual table] whose
|
|
** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
|
|
** support constraints. In this configuration (which is the default) if
|
|
** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
|
|
** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
|
|
** specified as part of the users SQL statement, regardless of the actual
|
|
** ON CONFLICT mode specified.
|
|
**
|
|
** If X is non-zero, then the virtual table implementation guarantees
|
|
** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
|
|
** any modifications to internal or persistent data structures have been made.
|
|
** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
|
|
** is able to roll back a statement or database transaction, and abandon
|
|
** or continue processing the current SQL statement as appropriate.
|
|
** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
|
|
** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
|
|
** had been ABORT.
|
|
**
|
|
** Virtual table implementations that are required to handle OR REPLACE
|
|
** must do so within the [xUpdate] method. If a call to the
|
|
** [sqlite3_vtab_on_conflict()] function indicates that the current ON
|
|
** CONFLICT policy is REPLACE, the virtual table implementation should
|
|
** silently replace the appropriate rows within the xUpdate callback and
|
|
** return SQLITE_OK. Or, if this is not possible, it may return
|
|
** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
|
|
** constraint handling.
|
|
** </dl>
|
|
*/
|
|
#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
|
|
|
|
/*
|
|
** CAPI3REF: Determine The Virtual Table Conflict Policy
|
|
**
|
|
** This function may only be called from within a call to the [xUpdate] method
|
|
** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
|
|
** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
|
|
** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
|
|
** of the SQL statement that triggered the call to the [xUpdate] method of the
|
|
** [virtual table].
|
|
*/
|
|
SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
|
|
|
|
/*
|
|
** CAPI3REF: Conflict resolution modes
|
|
**
|
|
** These constants are returned by [sqlite3_vtab_on_conflict()] to
|
|
** inform a [virtual table] implementation what the [ON CONFLICT] mode
|
|
** is for the SQL statement being evaluated.
|
|
**
|
|
** Note that the [SQLITE_IGNORE] constant is also used as a potential
|
|
** return value from the [sqlite3_set_authorizer()] callback and that
|
|
** [SQLITE_ABORT] is also a [result code].
|
|
*/
|
|
#define SQLITE_ROLLBACK 1
|
|
/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
|
|
#define SQLITE_FAIL 3
|
|
/* #define SQLITE_ABORT 4 // Also an error code */
|
|
#define SQLITE_REPLACE 5
|
|
|
|
|
|
|
|
/*
|
|
** Undo the hack that converts floating point types to integer for
|
|
** builds on processors without floating point support.
|
|
*/
|
|
#ifdef SQLITE_OMIT_FLOATING_POINT
|
|
# undef double
|
|
#endif
|
|
|
|
#ifdef __cplusplus
|
|
} /* End of the 'extern "C"' block */
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
** 2010 August 30
|
|
**
|
|
** The author disclaims copyright to this source code. In place of
|
|
** a legal notice, here is a blessing:
|
|
**
|
|
** May you do good and not evil.
|
|
** May you find forgiveness for yourself and forgive others.
|
|
** May you share freely, never taking more than you give.
|
|
**
|
|
*************************************************************************
|
|
*/
|
|
|
|
#ifndef _SQLITE3RTREE_H_
|
|
#define _SQLITE3RTREE_H_
|
|
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
|
|
|
|
/*
|
|
** Register a geometry callback named zGeom that can be used as part of an
|
|
** R-Tree geometry query as follows:
|
|
**
|
|
** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
|
|
*/
|
|
SQLITE_API int sqlite3_rtree_geometry_callback(
|
|
sqlite3 *db,
|
|
const char *zGeom,
|
|
#ifdef SQLITE_RTREE_INT_ONLY
|
|
int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes),
|
|
#else
|
|
int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes),
|
|
#endif
|
|
void *pContext
|
|
);
|
|
|
|
|
|
/*
|
|
** A pointer to a structure of the following type is passed as the first
|
|
** argument to callbacks registered using rtree_geometry_callback().
|
|
*/
|
|
struct sqlite3_rtree_geometry {
|
|
void *pContext; /* Copy of pContext passed to s_r_g_c() */
|
|
int nParam; /* Size of array aParam[] */
|
|
double *aParam; /* Parameters passed to SQL geom function */
|
|
void *pUser; /* Callback implementation user data */
|
|
void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
|
|
};
|
|
|
|
|
|
#ifdef __cplusplus
|
|
} /* end of the 'extern "C"' block */
|
|
#endif
|
|
|
|
#endif /* ifndef _SQLITE3RTREE_H_ */
|
|
|