system/database/drivers/mysql/mysql_driver.php - code-igniter-v3-giggi - Gitiles

 <?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
  *
  * Licensed under the Open Software License version 3.0
  *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
  * http://opensource.org/licenses/OSL-3.0
  * If you did not receive a copy of the license and are unable to obtain it
  * through the world wide web, please send an email to
  * licensing@ellislab.com so we can send you a copy immediately.
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 1.0
  * @filesource
  */

 // ------------------------------------------------------------------------

 /**
  * MySQL Database Adapter Class
  *
  * Note: _DB is an extender class that the app controller
  * creates dynamically based on whether the active record
  * class is being used or not.
  *
  * @package		CodeIgniter
  * @subpackage	Drivers
  * @category	Database
  * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/database/
  */
 class CI_DB_mysql_driver extends CI_DB {

 	var $dbdriver = 'mysql';

 	// The character used for escaping
 	var	$_escape_char = '`';

 	// clause and character used for LIKE escape sequences - not used in MySQL
 	var $_like_escape_str = '';
 	var $_like_escape_chr = '';

 	/**
 	 * Whether to use the MySQL "delete hack" which allows the number
 	 * of affected rows to be shown. Uses a preg_replace when enabled,
 	 * adding a bit more processing to all queries.
 	 */
 	var $delete_hack = TRUE;

 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is
 	 * used for the count_all() and count_all_results() functions.
 	 */
 	var $_count_string = 'SELECT COUNT(*) AS ';
 	var $_random_keyword = ' RAND()'; // database specific random keyword

 	// whether SET NAMES must be used to set the character set
 	var $use_set_names;

 	/**
 	 * Non-persistent database connection
 	 *
 	 * @access	private called by the base class
 	 * @return	resource
 	 */
 	function db_connect()
 	{
 		if ($this->port != '')
 		{
 			$this->hostname .= ':'.$this->port;
 		}

 		return @mysql_connect($this->hostname, $this->username, $this->password, TRUE);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Persistent database connection
 	 *
 	 * @access	private called by the base class
 	 * @return	resource
 	 */
 	function db_pconnect()
 	{
 		if ($this->port != '')
 		{
 			$this->hostname .= ':'.$this->port;
 		}

 		return @mysql_pconnect($this->hostname, $this->username, $this->password);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Reconnect
 	 *
 	 * Keep / reestablish the db connection if no queries have been
 	 * sent for a length of time exceeding the server's idle timeout
 	 *
 	 * @access	public
 	 * @return	void
 	 */
 	function reconnect()
 	{
 		if (mysql_ping($this->conn_id) === FALSE)
 		{
 			$this->conn_id = FALSE;
 		}
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Select the database
 	 *
 	 * @access	private called by the base class
 	 * @return	resource
 	 */
 	function db_select()
 	{
 		return @mysql_select_db($this->database, $this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Set client character set
 	 *
 	 * @access	public
 	 * @param	string
 	 * @param	string
 	 * @return	resource
 	 */
 	function db_set_charset($charset, $collation)
 	{
 		return function_exists('mysql_set_charset')
 			? @mysql_set_charset($charset, $this->conn_id)
 			: @mysql_query("SET NAMES '".$this->escape_str($charset)."' COLLATE '".$this->escape_str($collation)."'", $this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Version number query string
 	 *
 	 * @access	public
 	 * @return	string
 	 */
 	function _version()
 	{
 		return "SELECT version() AS ver";
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Execute the query
 	 *
 	 * @access	private called by the base class
 	 * @param	string	an SQL query
 	 * @return	resource
 	 */
 	function _execute($sql)
 	{
 		$sql = $this->_prep_query($sql);
 		return @mysql_query($sql, $this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Prep the query
 	 *
 	 * If needed, each database adapter can prep the query string
 	 *
 	 * @access	private called by execute()
 	 * @param	string	an SQL query
 	 * @return	string
 	 */
 	function _prep_query($sql)
 	{
 		// "DELETE FROM TABLE" returns 0 affected rows This hack modifies
 		// the query so that it returns the number of affected rows
 		if ($this->delete_hack === TRUE)
 		{
 			if (preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $sql))
 			{
 				$sql = preg_replace("/^\s*DELETE\s+FROM\s+(\S+)\s*$/", "DELETE FROM \\1 WHERE 1=1", $sql);
 			}
 		}

 		return $sql;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Begin Transaction
 	 *
 	 * @access	public
 	 * @return	bool
 	 */
 	function trans_begin($test_mode = FALSE)
 	{
 		if ( ! $this->trans_enabled)
 		{
 			return TRUE;
 		}

 		// When transactions are nested we only begin/commit/rollback the outermost ones
 		if ($this->_trans_depth > 0)
 		{
 			return TRUE;
 		}

 		// Reset the transaction failure flag.
 		// If the $test_mode flag is set to TRUE transactions will be rolled back
 		// even if the queries produce a successful result.
 		$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;

 		$this->simple_query('SET AUTOCOMMIT=0');
 		$this->simple_query('START TRANSACTION'); // can also be BEGIN or BEGIN WORK
 		return TRUE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Commit Transaction
 	 *
 	 * @access	public
 	 * @return	bool
 	 */
 	function trans_commit()
 	{
 		if ( ! $this->trans_enabled)
 		{
 			return TRUE;
 		}

 		// When transactions are nested we only begin/commit/rollback the outermost ones
 		if ($this->_trans_depth > 0)
 		{
 			return TRUE;
 		}

 		$this->simple_query('COMMIT');
 		$this->simple_query('SET AUTOCOMMIT=1');
 		return TRUE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Rollback Transaction
 	 *
 	 * @access	public
 	 * @return	bool
 	 */
 	function trans_rollback()
 	{
 		if ( ! $this->trans_enabled)
 		{
 			return TRUE;
 		}

 		// When transactions are nested we only begin/commit/rollback the outermost ones
 		if ($this->_trans_depth > 0)
 		{
 			return TRUE;
 		}

 		$this->simple_query('ROLLBACK');
 		$this->simple_query('SET AUTOCOMMIT=1');
 		return TRUE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Escape String
 	 *
 	 * @access	public
 	 * @param	string
 	 * @param	bool	whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
 	function escape_str($str, $like = FALSE)
 	{
 		if (is_array($str))
 		{
 			foreach ($str as $key => $val)
 	   		{
 				$str[$key] = $this->escape_str($val, $like);
 	   		}

 	   		return $str;
 	   	}

 		if (function_exists('mysql_real_escape_string') AND is_resource($this->conn_id))
 		{
 			$str = mysql_real_escape_string($str, $this->conn_id);
 		}
 		elseif (function_exists('mysql_escape_string'))
 		{
 			$str = mysql_escape_string($str);
 		}
 		else
 		{
 			$str = addslashes($str);
 		}

 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
 			$str = str_replace(array('%', '_'), array('\\%', '\\_'), $str);
 		}

 		return $str;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Affected Rows
 	 *
 	 * @access	public
 	 * @return	integer
 	 */
 	function affected_rows()
 	{
 		return @mysql_affected_rows($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Insert ID
 	 *
 	 * @access	public
 	 * @return	integer
 	 */
 	function insert_id()
 	{
 		return @mysql_insert_id($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * "Count All" query
 	 *
 	 * Generates a platform-specific query string that counts all records in
 	 * the specified database
 	 *
 	 * @access	public
 	 * @param	string
 	 * @return	string
 	 */
 	function count_all($table = '')
 	{
 		if ($table == '')
 		{
 			return 0;
 		}

 		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));

 		if ($query->num_rows() == 0)
 		{
 			return 0;
 		}

 		$row = $query->row();
 		$this->_reset_select();
 		return (int) $row->numrows;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * List table query
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
 	 * @access	private
 	 * @param	boolean
 	 * @return	string
 	 */
 	function _list_tables($prefix_limit = FALSE)
 	{
 		$sql = "SHOW TABLES FROM ".$this->_escape_char.$this->database.$this->_escape_char;

 		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
 		{
 			$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%'";
 		}

 		return $sql;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Show column query
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	function _list_columns($table = '')
 	{
 		return "SHOW COLUMNS FROM ".$this->_protect_identifiers($table, TRUE, NULL, FALSE);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Field data query
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @return	object
 	 */
 	function _field_data($table)
 	{
 		return "DESCRIBE ".$table;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * The error message string
 	 *
 	 * @access	private
 	 * @return	string
 	 */
 	function _error_message()
 	{
 		return mysql_error($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * The error message number
 	 *
 	 * @access	private
 	 * @return	integer
 	 */
 	function _error_number()
 	{
 		return mysql_errno($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Escape the SQL Identifiers
 	 *
 	 * This function escapes column and table names
 	 *
 	 * @access	private
 	 * @param	string
 	 * @return	string
 	 */
 	function _escape_identifiers($item)
 	{
 		if ($this->_escape_char == '')
 		{
 			return $item;
 		}

 		foreach ($this->_reserved_identifiers as $id)
 		{
 			if (strpos($item, '.'.$id) !== FALSE)
 			{
 				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);

 				// remove duplicates if the user already included the escape
 				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
 			}
 		}

 		if (strpos($item, '.') !== FALSE)
 		{
 			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
 		}
 		else
 		{
 			$str = $this->_escape_char.$item.$this->_escape_char;
 		}

 		// remove duplicates if the user already included the escape
 		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
 	 * about operator precedence in harmony with SQL standards
 	 *
 	 * @access	public
 	 * @param	type
 	 * @return	type
 	 */
 	function _from_tables($tables)
 	{
 		if ( ! is_array($tables))
 		{
 			$tables = array($tables);
 		}

 		return '('.implode(', ', $tables).')';
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Insert statement
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
 	function _insert($table, $keys, $values)
 	{
 		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
 	}

 	// --------------------------------------------------------------------


 	/**
 	 * Replace statement
 	 *
 	 * Generates a platform-specific replace string from the supplied data
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
 	function _replace($table, $keys, $values)
 	{
 		return "REPLACE INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Insert_batch statement
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
 	function _insert_batch($table, $keys, $values)
 	{
 		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES ".implode(', ', $values);
 	}

 	// --------------------------------------------------------------------


 	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
 	 * @param	array	the orderby clause
 	 * @param	array	the limit clause
 	 * @return	string
 	 */
 	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
 	{
 		foreach ($values as $key => $val)
 		{
 			$valstr[] = $key . ' = ' . $val;
 		}

 		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;

 		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';

 		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);

 		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';

 		$sql .= $orderby.$limit;

 		return $sql;
 	}

 	// --------------------------------------------------------------------


 	/**
 	 * Update_Batch statement
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
 	 * @return	string
 	 */
 	function _update_batch($table, $values, $index, $where = NULL)
 	{
 		$ids = array();
 		$where = ($where != '' AND count($where) >=1) ? implode(" ", $where).' AND ' : '';

 		foreach ($values as $key => $val)
 		{
 			$ids[] = $val[$index];

 			foreach (array_keys($val) as $field)
 			{
 				if ($field != $index)
 				{
 					$final[$field][] =  'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
 				}
 			}
 		}

 		$sql = "UPDATE ".$table." SET ";
 		$cases = '';

 		foreach ($final as $k => $v)
 		{
 			$cases .= $k.' = CASE '."\n";
 			foreach ($v as $row)
 			{
 				$cases .= $row."\n";
 			}

 			$cases .= 'ELSE '.$k.' END, ';
 		}

 		$sql .= substr($cases, 0, -2);

 		$sql .= ' WHERE '.$where.$index.' IN ('.implode(',', $ids).')';

 		return $sql;
 	}

 	// --------------------------------------------------------------------


 	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 * If the database does not support the truncate() command
 	 * This function maps to "DELETE FROM table"
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	function _truncate($table)
 	{
 		return "TRUNCATE ".$table;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Delete statement
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the where clause
 	 * @param	string	the limit clause
 	 * @return	string
 	 */
 	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 	{
 		$conditions = '';

 		if (count($where) > 0 OR count($like) > 0)
 		{
 			$conditions = "\nWHERE ";
 			$conditions .= implode("\n", $this->ar_where);

 			if (count($where) > 0 && count($like) > 0)
 			{
 				$conditions .= " AND ";
 			}
 			$conditions .= implode("\n", $like);
 		}

 		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;

 		return "DELETE FROM ".$table.$conditions.$limit;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Limit string
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @access	public
 	 * @param	string	the sql query string
 	 * @param	integer	the number of rows to limit the query to
 	 * @param	integer	the offset value
 	 * @return	string
 	 */
 	function _limit($sql, $limit, $offset)
 	{
 		if ($offset == 0)
 		{
 			$offset = '';
 		}
 		else
 		{
 			$offset .= ", ";
 		}

 		return $sql."LIMIT ".$offset.$limit;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Close DB Connection
 	 *
 	 * @access	public
 	 * @param	resource
 	 * @return	void
 	 */
 	function _close($conn_id)
 	{
 		@mysql_close($conn_id);
 	}

 }


 /* End of file mysql_driver.php */
 /* Location: ./system/database/drivers/mysql/mysql_driver.php */
	<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
	/**
	* CodeIgniter
	*
	* An open source application development framework for PHP 5.1.6 or newer
	*
	* NOTICE OF LICENSE
	*
	* Licensed under the Open Software License version 3.0
	*
	* This source file is subject to the Open Software License (OSL 3.0) that is
	* bundled with this package in the files license.txt / license.rst. It is
	* also available through the world wide web at this URL:
	* http://opensource.org/licenses/OSL-3.0
	* If you did not receive a copy of the license and are unable to obtain it
	* through the world wide web, please send an email to
	* licensing@ellislab.com so we can send you a copy immediately.
	*
	* @package CodeIgniter
	* @author EllisLab Dev Team
	* @copyright Copyright (c) 2008 - 2011, EllisLab, Inc. (http://ellislab.com/)
	* @license http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
	* @link http://codeigniter.com
	* @since Version 1.0
	* @filesource
	*/

	// ------------------------------------------------------------------------

	/**
	* MySQL Database Adapter Class
	*
	* Note: _DB is an extender class that the app controller
	* creates dynamically based on whether the active record
	* class is being used or not.
	*
	* @package CodeIgniter
	* @subpackage Drivers
	* @category Database
	* @author EllisLab Dev Team
	* @link http://codeigniter.com/user_guide/database/
	*/
	class CI_DB_mysql_driver extends CI_DB {

	var $dbdriver = 'mysql';

	// The character used for escaping
	var $_escape_char = '`';

	// clause and character used for LIKE escape sequences - not used in MySQL
	var $_like_escape_str = '';
	var $_like_escape_chr = '';

	/**
	* Whether to use the MySQL "delete hack" which allows the number
	* of affected rows to be shown. Uses a preg_replace when enabled,
	* adding a bit more processing to all queries.
	*/
	var $delete_hack = TRUE;

	/**
	* The syntax to count rows is slightly different across different
	* database engines, so this string appears in each driver and is
	* used for the count_all() and count_all_results() functions.
	*/
	var $_count_string = 'SELECT COUNT(*) AS ';
	var $_random_keyword = ' RAND()'; // database specific random keyword

	// whether SET NAMES must be used to set the character set
	var $use_set_names;

	/**
	* Non-persistent database connection
	*
	* @access private called by the base class
	* @return resource
	*/
	function db_connect()
	{
	if ($this->port != '')
	{
	$this->hostname .= ':'.$this->port;
	}

	return @mysql_connect($this->hostname, $this->username, $this->password, TRUE);
	}

	// --------------------------------------------------------------------

	/**
	* Persistent database connection
	*
	* @access private called by the base class
	* @return resource
	*/
	function db_pconnect()
	{
	if ($this->port != '')
	{
	$this->hostname .= ':'.$this->port;
	}

	return @mysql_pconnect($this->hostname, $this->username, $this->password);
	}

	// --------------------------------------------------------------------

	/**
	* Reconnect
	*
	* Keep / reestablish the db connection if no queries have been
	* sent for a length of time exceeding the server's idle timeout
	*
	* @access public
	* @return void
	*/
	function reconnect()
	{
	if (mysql_ping($this->conn_id) === FALSE)
	{
	$this->conn_id = FALSE;
	}
	}

	// --------------------------------------------------------------------

	/**
	* Select the database
	*
	* @access private called by the base class
	* @return resource
	*/
	function db_select()
	{
	return @mysql_select_db($this->database, $this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Set client character set
	*
	* @access public
	* @param string
	* @param string
	* @return resource
	*/
	function db_set_charset($charset, $collation)
	{
	return function_exists('mysql_set_charset')
	? @mysql_set_charset($charset, $this->conn_id)
	: @mysql_query("SET NAMES '".$this->escape_str($charset)."' COLLATE '".$this->escape_str($collation)."'", $this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Version number query string
	*
	* @access public
	* @return string
	*/
	function _version()
	{
	return "SELECT version() AS ver";
	}

	// --------------------------------------------------------------------

	/**
	* Execute the query
	*
	* @access private called by the base class
	* @param string an SQL query
	* @return resource
	*/
	function _execute($sql)
	{
	$sql = $this->_prep_query($sql);
	return @mysql_query($sql, $this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Prep the query
	*
	* If needed, each database adapter can prep the query string
	*
	* @access private called by execute()
	* @param string an SQL query
	* @return string
	*/
	function _prep_query($sql)
	{
	// "DELETE FROM TABLE" returns 0 affected rows This hack modifies
	// the query so that it returns the number of affected rows
	if ($this->delete_hack === TRUE)
	{
	if (preg_match('/^\sDELETE\s+FROM\s+(\S+)\s$/i', $sql))
	{
	$sql = preg_replace("/^\sDELETE\s+FROM\s+(\S+)\s$/", "DELETE FROM \\1 WHERE 1=1", $sql);
	}
	}

	return $sql;
	}

	// --------------------------------------------------------------------

	/**
	* Begin Transaction
	*
	* @access public
	* @return bool
	*/
	function trans_begin($test_mode = FALSE)
	{
	if ( ! $this->trans_enabled)
	{
	return TRUE;
	}

	// When transactions are nested we only begin/commit/rollback the outermost ones
	if ($this->_trans_depth > 0)
	{
	return TRUE;
	}

	// Reset the transaction failure flag.
	// If the $test_mode flag is set to TRUE transactions will be rolled back
	// even if the queries produce a successful result.
	$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;

	$this->simple_query('SET AUTOCOMMIT=0');
	$this->simple_query('START TRANSACTION'); // can also be BEGIN or BEGIN WORK
	return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	* Commit Transaction
	*
	* @access public
	* @return bool
	*/
	function trans_commit()
	{
	if ( ! $this->trans_enabled)
	{
	return TRUE;
	}

	// When transactions are nested we only begin/commit/rollback the outermost ones
	if ($this->_trans_depth > 0)
	{
	return TRUE;
	}

	$this->simple_query('COMMIT');
	$this->simple_query('SET AUTOCOMMIT=1');
	return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	* Rollback Transaction
	*
	* @access public
	* @return bool
	*/
	function trans_rollback()
	{
	if ( ! $this->trans_enabled)
	{
	return TRUE;
	}

	// When transactions are nested we only begin/commit/rollback the outermost ones
	if ($this->_trans_depth > 0)
	{
	return TRUE;
	}

	$this->simple_query('ROLLBACK');
	$this->simple_query('SET AUTOCOMMIT=1');
	return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	* Escape String
	*
	* @access public
	* @param string
	* @param bool whether or not the string will be used in a LIKE condition
	* @return string
	*/
	function escape_str($str, $like = FALSE)
	{
	if (is_array($str))
	{
	foreach ($str as $key => $val)
	{
	$str[$key] = $this->escape_str($val, $like);
	}

	return $str;
	}

	if (function_exists('mysql_real_escape_string') AND is_resource($this->conn_id))
	{
	$str = mysql_real_escape_string($str, $this->conn_id);
	}
	elseif (function_exists('mysql_escape_string'))
	{
	$str = mysql_escape_string($str);
	}
	else
	{
	$str = addslashes($str);
	}

	// escape LIKE condition wildcards
	if ($like === TRUE)
	{
	$str = str_replace(array('%', '_'), array('\\%', '\\_'), $str);
	}

	return $str;
	}

	// --------------------------------------------------------------------

	/**
	* Affected Rows
	*
	* @access public
	* @return integer
	*/
	function affected_rows()
	{
	return @mysql_affected_rows($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Insert ID
	*
	* @access public
	* @return integer
	*/
	function insert_id()
	{
	return @mysql_insert_id($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* "Count All" query
	*
	* Generates a platform-specific query string that counts all records in
	* the specified database
	*
	* @access public
	* @param string
	* @return string
	*/
	function count_all($table = '')
	{
	if ($table == '')
	{
	return 0;
	}

	$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));

	if ($query->num_rows() == 0)
	{
	return 0;
	}

	$row = $query->row();
	$this->_reset_select();
	return (int) $row->numrows;
	}

	// --------------------------------------------------------------------

	/**
	* List table query
	*
	* Generates a platform-specific query string so that the table names can be fetched
	*
	* @access private
	* @param boolean
	* @return string
	*/
	function _list_tables($prefix_limit = FALSE)
	{
	$sql = "SHOW TABLES FROM ".$this->_escape_char.$this->database.$this->_escape_char;

	if ($prefix_limit !== FALSE AND $this->dbprefix != '')
	{
	$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%'";
	}

	return $sql;
	}

	// --------------------------------------------------------------------

	/**
	* Show column query
	*
	* Generates a platform-specific query string so that the column names can be fetched
	*
	* @access public
	* @param string the table name
	* @return string
	*/
	function _list_columns($table = '')
	{
	return "SHOW COLUMNS FROM ".$this->_protect_identifiers($table, TRUE, NULL, FALSE);
	}

	// --------------------------------------------------------------------

	/**
	* Field data query
	*
	* Generates a platform-specific query so that the column data can be retrieved
	*
	* @access public
	* @param string the table name
	* @return object
	*/
	function _field_data($table)
	{
	return "DESCRIBE ".$table;
	}

	// --------------------------------------------------------------------

	/**
	* The error message string
	*
	* @access private
	* @return string
	*/
	function _error_message()
	{
	return mysql_error($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* The error message number
	*
	* @access private
	* @return integer
	*/
	function _error_number()
	{
	return mysql_errno($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Escape the SQL Identifiers
	*
	* This function escapes column and table names
	*
	* @access private
	* @param string
	* @return string
	*/
	function _escape_identifiers($item)
	{
	if ($this->_escape_char == '')
	{
	return $item;
	}

	foreach ($this->_reserved_identifiers as $id)
	{
	if (strpos($item, '.'.$id) !== FALSE)
	{
	$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);

	// remove duplicates if the user already included the escape
	return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
	}
	}

	if (strpos($item, '.') !== FALSE)
	{
	$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
	}
	else
	{
	$str = $this->_escape_char.$item.$this->_escape_char;
	}

	// remove duplicates if the user already included the escape
	return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
	}

	// --------------------------------------------------------------------

	/**
	* From Tables
	*
	* This function implicitly groups FROM tables so there is no confusion
	* about operator precedence in harmony with SQL standards
	*
	* @access public
	* @param type
	* @return type
	*/
	function _from_tables($tables)
	{
	if ( ! is_array($tables))
	{
	$tables = array($tables);
	}

	return '('.implode(', ', $tables).')';
	}

	// --------------------------------------------------------------------

	/**
	* Insert statement
	*
	* Generates a platform-specific insert string from the supplied data
	*
	* @access public
	* @param string the table name
	* @param array the insert keys
	* @param array the insert values
	* @return string
	*/
	function _insert($table, $keys, $values)
	{
	return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
	}

	// --------------------------------------------------------------------


	/**
	* Replace statement
	*
	* Generates a platform-specific replace string from the supplied data
	*
	* @access public
	* @param string the table name
	* @param array the insert keys
	* @param array the insert values
	* @return string
	*/
	function _replace($table, $keys, $values)
	{
	return "REPLACE INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
	}

	// --------------------------------------------------------------------

	/**
	* Insert_batch statement
	*
	* Generates a platform-specific insert string from the supplied data
	*
	* @access public
	* @param string the table name
	* @param array the insert keys
	* @param array the insert values
	* @return string
	*/
	function _insert_batch($table, $keys, $values)
	{
	return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES ".implode(', ', $values);
	}

	// --------------------------------------------------------------------


	/**
	* Update statement
	*
	* Generates a platform-specific update string from the supplied data
	*
	* @access public
	* @param string the table name
	* @param array the update data
	* @param array the where clause
	* @param array the orderby clause
	* @param array the limit clause
	* @return string
	*/
	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
	{
	foreach ($values as $key => $val)
	{
	$valstr[] = $key . ' = ' . $val;
	}

	$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;

	$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';

	$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);

	$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';

	$sql .= $orderby.$limit;

	return $sql;
	}

	// --------------------------------------------------------------------


	/**
	* Update_Batch statement
	*
	* Generates a platform-specific batch update string from the supplied data
	*
	* @access public
	* @param string the table name
	* @param array the update data
	* @param array the where clause
	* @return string
	*/
	function _update_batch($table, $values, $index, $where = NULL)
	{
	$ids = array();
	$where = ($where != '' AND count($where) >=1) ? implode(" ", $where).' AND ' : '';

	foreach ($values as $key => $val)
	{
	$ids[] = $val[$index];

	foreach (array_keys($val) as $field)
	{
	if ($field != $index)
	{
	$final[$field][] = 'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
	}
	}
	}

	$sql = "UPDATE ".$table." SET ";
	$cases = '';

	foreach ($final as $k => $v)
	{
	$cases .= $k.' = CASE '."\n";
	foreach ($v as $row)
	{
	$cases .= $row."\n";
	}

	$cases .= 'ELSE '.$k.' END, ';
	}

	$sql .= substr($cases, 0, -2);

	$sql .= ' WHERE '.$where.$index.' IN ('.implode(',', $ids).')';

	return $sql;
	}

	// --------------------------------------------------------------------


	/**
	* Truncate statement
	*
	* Generates a platform-specific truncate string from the supplied data
	* If the database does not support the truncate() command
	* This function maps to "DELETE FROM table"
	*
	* @access public
	* @param string the table name
	* @return string
	*/
	function _truncate($table)
	{
	return "TRUNCATE ".$table;
	}

	// --------------------------------------------------------------------

	/**
	* Delete statement
	*
	* Generates a platform-specific delete string from the supplied data
	*
	* @access public
	* @param string the table name
	* @param array the where clause
	* @param string the limit clause
	* @return string
	*/
	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
	{
	$conditions = '';

	if (count($where) > 0 OR count($like) > 0)
	{
	$conditions = "\nWHERE ";
	$conditions .= implode("\n", $this->ar_where);

	if (count($where) > 0 && count($like) > 0)
	{
	$conditions .= " AND ";
	}
	$conditions .= implode("\n", $like);
	}

	$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;

	return "DELETE FROM ".$table.$conditions.$limit;
	}

	// --------------------------------------------------------------------

	/**
	* Limit string
	*
	* Generates a platform-specific LIMIT clause
	*
	* @access public
	* @param string the sql query string
	* @param integer the number of rows to limit the query to
	* @param integer the offset value
	* @return string
	*/
	function _limit($sql, $limit, $offset)
	{
	if ($offset == 0)
	{
	$offset = '';
	}
	else
	{
	$offset .= ", ";
	}

	return $sql."LIMIT ".$offset.$limit;
	}

	// --------------------------------------------------------------------

	/**
	* Close DB Connection
	*
	* @access public
	* @param resource
	* @return void
	*/
	function _close($conn_id)
	{
	@mysql_close($conn_id);
	}

	}


	/* End of file mysql_driver.php */
	/* Location: ./system/database/drivers/mysql/mysql_driver.php */