Geografic-Information-System/db/drivers/mysql/execute.c

/**********************************************************
 * MODULE:    mysql
 * AUTHOR(S): Radim Blazek (radim.blazek@gmail.com)
 * PURPOSE:   MySQL database driver
 * COPYRIGHT: (C) 2001 by the GRASS Development Team
 *            This program is free software under the 
 *            GNU General Public License (>=v2). 
 *            Read the file COPYING that comes with GRASS
 *            for details.
 **********************************************************/
#include <stdlib.h>

#include <grass/dbmi.h>
#include <grass/gis.h>
#include <grass/glocale.h>

#include "globals.h"
#include "proto.h"

int db__driver_execute_immediate(dbString *sql)
{
    char     *str;

    init_error();

    /* In addition to standard escape character ' (apostrophe) 
     * MySQL supports also \ (backslash). Because this is not SQL
     * standard, GRASS modules cannot escape all \ in the text
     * because other drivers do not support this feature. 
     * For example, if a text contains string \' GRASS modules 
     * escape ' by another ' and the string passed to the driver is \''
     * MySQL converts \' to ' but second ' remains not escaped and 
     * result is error. 
     * Because of this, all occurencies of \ in sql must be 
     * escaped by \ */
    str = G_str_replace ( db_get_string(sql), "\\", "\\\\" );

    G_debug ( 3, "Escaped SQL: %s", str );

    if ( mysql_query ( connection, str ) != 0 )
    {
	append_error( "Cannot execute: \n" );
	append_error( str );
	append_error( "\n" );
	append_error ( mysql_error(connection) );
	report_error();
	if ( str ) 
	    G_free ( str );
	return DB_FAILED;
    }
    
    if ( str ) 
	G_free ( str );

    return DB_OK;
}

int db__driver_begin_transaction(void)
{
    G_debug (2, "mysql: START TRANSACTION");

    init_error();

    if ( mysql_query ( connection, "START TRANSACTION" ) != 0 )
    {
	append_error( "Cannot start transaction: \n" );
	append_error ( mysql_error(connection) );
	report_error();
	return DB_FAILED;
    }

    return DB_OK;
}

int db__driver_commit_transaction(void)
{
    G_debug (2, "mysql: COMMIT");

    init_error();

    if ( mysql_query ( connection, "COMMIT" ) != 0 )
    {
	append_error( "Cannot commit transaction: \n" );
	append_error ( mysql_error(connection) );
	report_error();
	return DB_FAILED;
    }

    return DB_OK;
}