legacy.c.svn-base
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上传日期:2022-01-25
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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.
- **
- *************************************************************************
- ** Main file for the SQLite library. The routines in this file
- ** implement the programmer interface to the library. Routines in
- ** other files are for internal use by SQLite and should not be
- ** accessed by users of the library.
- **
- ** $Id: legacy.c,v 1.24 2008/03/21 18:01:14 drh Exp $
- */
- #include "sqliteInt.h"
- #include <ctype.h>
- /*
- ** Execute SQL code. Return one of the SQLITE_ success/failure
- ** codes. Also write an error message into memory obtained from
- ** malloc() and make *pzErrMsg point to that message.
- **
- ** If the SQL is a query, then for each row in the query result
- ** the xCallback() function is called. pArg becomes the first
- ** argument to xCallback(). If xCallback=NULL then no callback
- ** is invoked, even for queries.
- */
- int sqlite3_exec(
- sqlite3 *db, /* The database on which the SQL executes */
- const char *zSql, /* The SQL to be executed */
- sqlite3_callback xCallback, /* Invoke this callback routine */
- void *pArg, /* First argument to xCallback() */
- char **pzErrMsg /* Write error messages here */
- ){
- int rc = SQLITE_OK;
- const char *zLeftover;
- sqlite3_stmt *pStmt = 0;
- char **azCols = 0;
- int nRetry = 0;
- int nCallback;
- if( zSql==0 ) return SQLITE_OK;
- sqlite3_mutex_enter(db->mutex);
- while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){
- int nCol;
- char **azVals = 0;
- pStmt = 0;
- rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);
- assert( rc==SQLITE_OK || pStmt==0 );
- if( rc!=SQLITE_OK ){
- continue;
- }
- if( !pStmt ){
- /* this happens for a comment or white-space */
- zSql = zLeftover;
- continue;
- }
- nCallback = 0;
- nCol = sqlite3_column_count(pStmt);
- while( 1 ){
- int i;
- rc = sqlite3_step(pStmt);
- /* Invoke the callback function if required */
- if( xCallback && (SQLITE_ROW==rc ||
- (SQLITE_DONE==rc && !nCallback && db->flags&SQLITE_NullCallback)) ){
- if( 0==nCallback ){
- if( azCols==0 ){
- azCols = sqlite3DbMallocZero(db, 2*nCol*sizeof(const char*) + 1);
- if( azCols==0 ){
- goto exec_out;
- }
- }
- for(i=0; i<nCol; i++){
- azCols[i] = (char *)sqlite3_column_name(pStmt, i);
- if( !azCols[i] ){
- db->mallocFailed = 1;
- goto exec_out;
- }
- }
- nCallback++;
- }
- if( rc==SQLITE_ROW ){
- azVals = &azCols[nCol];
- for(i=0; i<nCol; i++){
- azVals[i] = (char *)sqlite3_column_text(pStmt, i);
- if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
- db->mallocFailed = 1;
- goto exec_out;
- }
- }
- }
- if( xCallback(pArg, nCol, azVals, azCols) ){
- rc = SQLITE_ABORT;
- goto exec_out;
- }
- }
- if( rc!=SQLITE_ROW ){
- rc = sqlite3_finalize(pStmt);
- pStmt = 0;
- if( rc!=SQLITE_SCHEMA ){
- nRetry = 0;
- zSql = zLeftover;
- while( isspace((unsigned char)zSql[0]) ) zSql++;
- }
- break;
- }
- }
- sqlite3_free(azCols);
- azCols = 0;
- }
- exec_out:
- if( pStmt ) sqlite3_finalize(pStmt);
- if( azCols ) sqlite3_free(azCols);
- rc = sqlite3ApiExit(db, rc);
- if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){
- int nErrMsg = 1 + strlen(sqlite3_errmsg(db));
- *pzErrMsg = sqlite3_malloc(nErrMsg);
- if( *pzErrMsg ){
- memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);
- }
- }else if( pzErrMsg ){
- *pzErrMsg = 0;
- }
- assert( (rc&db->errMask)==rc );
- sqlite3_mutex_leave(db->mutex);
- return rc;
- }