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58a11680d1e222e3ef45942a522c0aabeafad964
sqlite/src/sqlite.h.in
T
drh 9f71c2e002 Added "const" to lots of "char*" parameters in the API. (CVS 298) 
FossilOrigin-Name: 1c448f1fd2a2e103e7464df896174534d02152ed
2001-11-03 23:57:09 +00:00

358 lines
14 KiB
C
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/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.23 2001/11/03 23:57:09 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_
#include <stdarg.h> /* Needed for the definition of va_list */
/*
** The version of the SQLite library.
*/
#define SQLITE_VERSION "--VERS--"
/*
** Make sure we can call this stuff from C++.
*/
#ifdef __cplusplus
extern "C" {
#endif
/*
** The version string is also compiled into the library so that a program
** can check to make sure that the lib*.a file and the *.h file are from
** the same version.
*/
extern const char sqlite_version[];
/*
** The SQLITE_UTF8 macro is defined if the library expects to see
** UTF-8 encoded data. The SQLITE_ISO8859 macro is defined if the
** iso8859 encoded should be used.
*/
#define SQLITE_--ENCODING-- 1
/*
** The following constant holds one of two strings, "UTF-8" or "iso8859",
** depending on which character encoding the SQLite library expects to
** see. The character encoding makes a difference for the LIKE and GLOB
** operators and for the LENGTH() and SUBSTR() functions.
*/
extern const char sqlite_encoding[];
/*
** Each open sqlite database is represented by an instance of the
** following opaque structure.
*/
typedef struct sqlite sqlite;
/*
** A function to open a new sqlite database.
**
** If the database does not exist and mode indicates write
** permission, then a new database is created. If the database
** does not exist and mode does not indicate write permission,
** then the open fails, an error message generated (if errmsg!=0)
** and the function returns 0.
**
** If mode does not indicates user write permission, then the
** database is opened read-only.
**
** The Truth: As currently implemented, all databases are opened
** for writing all the time. Maybe someday we will provide the
** ability to open a database readonly. The mode parameters is
** provide in anticipation of that enhancement.
*/
sqlite *sqlite_open(const char *filename, int mode, char **errmsg);
/*
** A function to close the database.
**
** Call this function with a pointer to a structure that was previously
** returned from sqlite_open() and the corresponding database will by closed.
*/
void sqlite_close(sqlite *);
/*
** The type for a callback function.
*/
typedef int (*sqlite_callback)(void*,int,char**, char**);
/*
** A function to executes one or more statements of SQL.
**
** If one or more of the SQL statements are queries, then
** the callback function specified by the 3rd parameter is
** invoked once for each row of the query result. This callback
** should normally return 0. If the callback returns a non-zero
** value then the query is aborted, all subsequent SQL statements
** are skipped and the sqlite_exec() function returns the SQLITE_ABORT.
**
** The 4th parameter is an arbitrary pointer that is passed
** to the callback function as its first parameter.
**
** The 2nd parameter to the callback function is the number of
** columns in the query result. The 3rd parameter to the callback
** is an array of strings holding the values for each column.
** The 4th parameter to the callback is an array of strings holding
** the names of each column.
**
** The callback function may be NULL, even for queries. A NULL
** callback is not an error. It just means that no callback
** will be invoked.
**
** If an error occurs while parsing or evaluating the SQL (but
** not while executing the callback) then an appropriate error
** message is written into memory obtained from malloc() and
** *errmsg is made to point to that message. The calling function
** is responsible for freeing the memory that holds the error
** message. If errmsg==NULL, then no error message is ever written.
**
** The return value is is SQLITE_OK if there are no errors and
** some other return code if there is an error. The particular
** return value depends on the type of error.
**
** If the query could not be executed because a database file is
** locked or busy, then this function returns SQLITE_BUSY. (This
** behavior can be modified somewhat using the sqlite_busy_handler()
** and sqlite_busy_timeout() functions below.)
*/
int sqlite_exec(
sqlite*, /* An open database */
const char *sql, /* SQL to be executed */
sqlite_callback, /* Callback function */
void *, /* 1st argument to callback function */
char **errmsg /* Error msg written here */
);
/*
** Return values for sqlite_exec()
*/
#define SQLITE_OK 0 /* Successful result */
#define SQLITE_ERROR 1 /* SQL error or missing database */
#define SQLITE_INTERNAL 2 /* An internal logic error in SQLite */
#define SQLITE_PERM 3 /* Access permission denied */
#define SQLITE_ABORT 4 /* Callback routine requested an abort */
#define SQLITE_BUSY 5 /* The database file is locked */
#define SQLITE_LOCKED 6 /* A table in the database is locked */
#define SQLITE_NOMEM 7 /* A malloc() failed */
#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite_interrupt() */
#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
#define SQLITE_NOTFOUND 12 /* (Internal Only) Table or record not found */
#define SQLITE_FULL 13 /* Insertion failed because database is full */
#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
#define SQLITE_EMPTY 16 /* (Internal Only) Database table is empty */
#define SQLITE_SCHEMA 17 /* The database schema changed */
#define SQLITE_TOOBIG 18 /* Too much data for one row of a table */
#define SQLITE_CONSTRAINT 19 /* Abort due to contraint violation */
/* If the parameter to this routine is one of the return value constants
** defined above, then this routine returns a constant text string which
** descripts (in English) the meaning of the return value.
*/
const char *sqlite_error_string(int);
#define sqliteErrStr sqlite_error_string /* Legacy. Do not use in new code. */
/* 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.
*/
void sqlite_interrupt(sqlite*);
/* This function returns true if the given input string comprises
** one or more complete SQL statements.
**
** The algorithm is simple. If the last token other than spaces
** and comments is a semicolon, then return true. otherwise return
** false.
*/
int sqlite_complete(const char *sql);
/*
** This routine identifies a callback function that is invoked
** whenever an attempt is made to open a database table that is
** currently locked by another process or thread. If the busy callback
** is NULL, then sqlite_exec() returns SQLITE_BUSY immediately if
** it finds a locked table. If the busy callback is not NULL, then
** sqlite_exec() invokes the callback with three arguments. The
** second argument is the name of the locked table and the third
** argument is the number of times the table has been busy. If the
** busy callback returns 0, then sqlite_exec() immediately returns
** SQLITE_BUSY. If the callback returns non-zero, then sqlite_exec()
** tries to open the table again and the cycle repeats.
**
** The default busy callback is NULL.
**
** Sqlite is re-entrant, so the busy handler may start a new query.
** (It is not clear why anyone would every want to do this, but it
** is allowed, in theory.) But the busy handler may not close the
** database. Closing the database from a busy handler will delete
** data structures out from under the executing query and will
** probably result in a coredump.
*/
void sqlite_busy_handler(sqlite*, int(*)(void*,const char*,int), void*);
/*
** This routine sets a busy handler that sleeps for a while when a
** table is locked. The handler will sleep multiple times until
** at least "ms" milleseconds of sleeping have been done. After
** "ms" milleseconds of sleeping, the handler returns 0 which
** causes sqlite_exec() to return SQLITE_BUSY.
**
** Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
*/
void sqlite_busy_timeout(sqlite*, int ms);
/*
** This next routine is really just a wrapper around sqlite_exec().
** Instead of invoking a user-supplied callback for each row of the
** result, this routine remembers each row of the result in memory
** obtained from malloc(), then returns all of the result after the
** query has finished.
**
** As an example, suppose the query result where this table:
**
** Name | Age
** -----------------------
** Alice | 43
** Bob | 28
** Cindy | 21
**
** If the 3rd argument were &azResult then after the function returns
** azResult will contain the following data:
**
** azResult[0] = "Name";
** azResult[1] = "Age";
** azResult[2] = "Alice";
** azResult[3] = "43";
** azResult[4] = "Bob";
** azResult[5] = "28";
** azResult[6] = "Cindy";
** azResult[7] = "21";
**
** Notice that there is an extra row of data containing the column
** headers. But the *nrow return value is still 3. *ncolumn is
** set to 2. In general, the number of values inserted into azResult
** will be ((*nrow) + 1)*(*ncolumn).
**
** After the calling function has finished using the result, it should
** pass the result data pointer to sqlite_free_table() in order to
** release the memory that was malloc-ed. Because of the way the
** malloc() happens, the calling function must not try to call
** malloc() directly. Only sqlite_free_table() is able to release
** the memory properly and safely.
**
** The return value of this routine is the same as from sqlite_exec().
*/
int sqlite_get_table(
sqlite*, /* An open database */
const char *sql, /* SQL to be executed */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncolumn, /* Number of result columns written here */
char **errmsg /* Error msg written here */
);
/*
** Call this routine to free the memory that sqlite_get_table() allocated.
*/
void sqlite_free_table(char **result);
/*
** The following routines are wrappers around sqlite_exec() and
** sqlite_get_table(). The only difference between the routines that
** follow and the originals is that the second argument to the
** routines that follow is really a printf()-style format
** string describing the SQL to be executed. Arguments to the format
** string appear at the end of the argument list.
**
** All of the usual printf formatting options apply. In addition, there
** is a "%q" option. %q works like %s in that it substitutes a null-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, so some string variable contains text as follows:
**
** char *zText = "It's a happy day!";
**
** We can use this text in an SQL statement as follows:
**
** sqlite_exec_printf(db, "INSERT INTO table VALUES('%q')",
** callback1, 0, 0, zText);
**
** Because the %q format string is used, the '\'' character in zText
** is escaped and the SQL generated is as follows:
**
** INSERT INTO table1 VALUES('It''s a happy day!')
**
** This is correct. Had we used %s instead of %q, the generated SQL
** would have looked like this:
**
** INSERT INTO table1 VALUES('It's a happy day!');
**
** 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.
*/
int sqlite_exec_printf(
sqlite*, /* An open database */
const char *sqlFormat, /* printf-style format string for the SQL */
sqlite_callback, /* Callback function */
void *, /* 1st argument to callback function */
char **errmsg, /* Error msg written here */
... /* Arguments to the format string. */
);
int sqlite_exec_vprintf(
sqlite*, /* An open database */
const char *sqlFormat, /* printf-style format string for the SQL */
sqlite_callback, /* Callback function */
void *, /* 1st argument to callback function */
char **errmsg, /* Error msg written here */
va_list ap /* Arguments to the format string. */
);
int sqlite_get_table_printf(
sqlite*, /* An open database */
const char *sqlFormat, /* printf-style format string for the SQL */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncolumn, /* Number of result columns written here */
char **errmsg, /* Error msg written here */
... /* Arguments to the format string */
);
int sqlite_get_table_vprintf(
sqlite*, /* An open database */
const char *sqlFormat, /* printf-style format string for the SQL */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncolumn, /* Number of result columns written here */
char **errmsg, /* Error msg written here */
va_list ap /* Arguments to the format string */
);
#ifdef __cplusplus
} /* End of the 'extern "C"' block */
#endif
#endif /* _SQLITE_H_ */
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