system/database/drivers/pdo/pdo_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 5.2.4 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 - 2012, 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 2.1.0
  * @filesource
  */

 /**
  * PDO Database Adapter Class
  *
  * Note: _DB is an extender class that the app controller
  * creates dynamically based on whether the query builder
  * 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_pdo_driver extends CI_DB {

 	public $dbdriver = 'pdo';

 	// the character used to excape - not necessary for PDO
 	protected $_escape_char = '';

 	// clause and character used for LIKE escape sequences
 	protected $_like_escape_str = " ESCAPE '%s' ";
 	protected $_like_escape_chr = '!';

 	/**
 	 * 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.
 	 */
 	protected $_count_string = 'SELECT COUNT(*) AS ';
 	protected $_random_keyword;

 	// need to track the pdo driver and options
 	public $pdodriver;
 	public $options = array();

 	public function __construct($params)
 	{
 		parent::__construct($params);

 		if (preg_match('/([^;]+):/', $this->dsn, $match) && count($match) == 2)
 		{
 			// If there is a minimum valid dsn string pattern found, we're done
 			// This is for general PDO users, who tend to have a full DSN string.
 			$this->pdodriver = end($match);
 		}
 		else
 		{
 			// Try to build a complete DSN string from params
 			$this->_connect_string($params);
 		}

 		// clause and character used for LIKE escape sequences
 		// this one depends on the driver being used
 		if ($this->pdodriver === 'mysql')
 		{
 			$this->_escape_char = '`';
 			$this->_like_escape_str = '';
 			$this->_like_escape_chr = '\\';
 		}
 		elseif ($this->pdodriver === 'odbc')
 		{
 			$this->_like_escape_str = " {escape '%s'} ";
 		}
 		elseif ( ! in_array($this->pdodriver, array('sqlsrv', 'mssql', 'dblib', 'sybase')))
 		{
 			$this->_escape_char = '"';
 		}

 		$this->trans_enabled = FALSE;
 		$this->_random_keyword = ' RND('.time().')'; // database specific random keyword
 	}

 	/**
 	 * Connection String
 	 *
 	 * @param	array
 	 * @return	void
 	 */
 	protected function _connect_string($params)
 	{
 		if (strpos($this->hostname, ':'))
 		{
 			// hostname generally would have this prototype
 			// $db['hostname'] = 'pdodriver:host(/Server(/DSN))=hostname(/DSN);';
 			// We need to get the prefix (pdodriver used by PDO).
 			$dsnarray = explode(':', $this->hostname);
 			$this->pdodriver = $dsnarray[0];

 			// End dsn with a semicolon for extra backward compability
 			// if database property was not empty.
 			if ( ! empty($this->database))
 			{
 				$this->dsn .= rtrim($this->hostname, ';').';';
 			}
 		}
 		else
 		{
 			// Invalid DSN, display an error
 			if ( ! array_key_exists('pdodriver', $params))
 			{
 				show_error('Invalid DB Connection String for PDO');
 			}

 			// Assuming that the following DSN string format is used:
 			// $dsn = 'pdo://username:password@hostname:port/database?pdodriver=pgsql';
 			$this->dsn = $this->pdodriver.':';

 			// Add hostname to the DSN for databases that need it
 			if ( ! empty($this->hostname)
 				&& strpos($this->hostname, ':') === FALSE
 				&& in_array($this->pdodriver, array('informix', 'mysql', 'pgsql', 'sybase', 'mssql', 'dblib', 'cubrid')))
 			{
 			    $this->dsn .= 'host='.$this->hostname.';';
 			}

 			// Add a port to the DSN for databases that can use it
 			if ( ! empty($this->port) && in_array($this->pdodriver, array('informix', 'mysql', 'pgsql', 'ibm', 'cubrid')))
 			{
 			    $this->dsn .= 'port='.$this->port.';';
 			}
 		}

 		// Add the database name to the DSN, if needed
 	    if (stripos($this->dsn, 'dbname') === FALSE
 	       && in_array($this->pdodriver, array('4D', 'pgsql', 'mysql', 'firebird', 'sybase', 'mssql', 'dblib', 'cubrid')))
 	    {
 	        $this->dsn .= 'dbname='.$this->database.';';
 	    }
 	    elseif (stripos($this->dsn, 'database') === FALSE && in_array($this->pdodriver, array('ibm', 'sqlsrv')))
 	    {
 	    	if (stripos($this->dsn, 'dsn') === FALSE)
 	    	{
 		        $this->dsn .= 'database='.$this->database.';';
 	    	}
 	    }
 	    elseif ($this->pdodriver === 'sqlite' && $this->dsn === 'sqlite:')
 	    {
 	        if ($this->database !== ':memory')
 	        {
 	            if ( ! file_exists($this->database))
 	            {
 	                show_error('Invalid DB Connection string for PDO SQLite');
 	            }

 	            $this->dsn .= (strpos($this->database, DIRECTORY_SEPARATOR) !== 0) ? DIRECTORY_SEPARATOR : '';
 	        }

 	        $this->dsn .= $this->database;
 	    }

 	    // Add charset to the DSN, if needed
 	    if ( ! empty($this->char_set) && in_array($this->pdodriver, array('4D', 'mysql', 'sybase', 'mssql', 'dblib', 'oci')))
 	    {
 	        $this->dsn .= 'charset='.$this->char_set.';';
 	    }
 	}

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

 	/**
 	 * Non-persistent database connection
 	 *
 	 * @return	object
 	 */
 	public function db_connect()
 	{
 		return $this->_pdo_connect();
 	}

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

 	/**
 	 * Persistent database connection
 	 *
 	 * @return	object
 	 */
 	public function db_pconnect()
 	{
 		return $this->_pdo_connect(TRUE);
 	}

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

 	/**
 	 * PDO connection
 	 *
 	 * @param	bool
 	 * @return	object
 	 */
 	protected function _pdo_connect($persistent = FALSE)
 	{
 		$this->options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_SILENT;
 		$persistent === FALSE OR $this->options[PDO::ATTR_PERSISTENT] = TRUE;

 		/* Prior to PHP 5.3.6, even if the charset was supplied in the DSN
 		 * on connect - it was ignored. This is a work-around for the issue.
 		 *
 		 * Reference: http://www.php.net/manual/en/ref.pdo-mysql.connection.php
 		 */
 		if ($this->pdodriver === 'mysql' && ! is_php('5.3.6') && ! empty($this->char_set))
 		{
 			$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET NAMES '.$this->char_set
 					.( ! empty($this->db_collat) ? " COLLATE '".$this->dbcollat."'" : '');
 		}

 		// Connecting...
 		try
 		{
 			return new PDO($this->dsn, $this->username, $this->password, $this->options);
 		}
 		catch (PDOException $e)
 		{
 			if ($this->db_debug && empty($this->failover))
 			{
 				$this->display_error($e->getMessage(), '', TRUE);
 			}

 			return FALSE;
 		}
 	}

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

 	/**
 	 * Database version number
 	 *
 	 * @return	string
 	 */
 	public function version()
 	{
 		return isset($this->data_cache['version'])
 			? $this->data_cache['version']
 			: $this->data_cache['version'] = $this->conn_id->getAttribute(PDO::ATTR_SERVER_VERSION);
 	}

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

 	/**
 	 * Execute the query
 	 *
 	 * @param	string	an SQL query
 	 * @return	mixed
 	 */
 	protected function _execute($sql)
 	{
 		return $this->conn_id->query($sql);
 	}

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

 	/**
 	 * Begin Transaction
 	 *
 	 * @return	bool
 	 */
 	public function trans_begin($test_mode = FALSE)
 	{
 		// When transactions are nested we only begin/commit/rollback the outermost ones
 		if ( ! $this->trans_enabled OR $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);

 		return $this->conn_id->beginTransaction();
 	}

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

 	/**
 	 * Commit Transaction
 	 *
 	 * @return	bool
 	 */
 	public function trans_commit()
 	{
 		// When transactions are nested we only begin/commit/rollback the outermost ones
 		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}

 		return $this->conn_id->commit();
 	}

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

 	/**
 	 * Rollback Transaction
 	 *
 	 * @return	bool
 	 */
 	public function trans_rollback()
 	{
 		// When transactions are nested we only begin/commit/rollback the outermost ones
 		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}

 		return $this->conn_id->rollBack();
 	}

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

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

 			return $str;
 		}

 		// Escape the string
 		$str = $this->conn_id->quote($str);

 		// If there are duplicated quotes, trim them away
 		if (strpos($str, "'") === 0)
 		{
 			$str = substr($str, 1, -1);
 		}

 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
 			return str_replace(array($this->_like_escape_chr, '%', '_'),
 						array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
 						$str);
 		}

 		return $str;
 	}

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

 	/**
 	 * Affected Rows
 	 *
 	 * @return	int
 	 */
 	public function affected_rows()
 	{
 		return is_object($this->result_id) ? $this->result_id->rowCount() : 0;
 	}

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

 	/**
 	 * Insert ID
 	 *
 	 * @param	string
 	 * @return	int
 	 */
 	public function insert_id($name = NULL)
 	{
 		if ($this->pdodriver === 'pgsql' && $name === NULL && $this->version() >= '8.1')
 		{
 			$query = $this->query('SELECT LASTVAL() AS ins_id');
 			$query = $query->row();
 			return $query->ins_id;
 		}

 		return $this->conn_id->lastInsertId($name);
 	}

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

 	/**
 	 * Show table query
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
 	 * @param	bool
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
 		if ($this->pdodriver == 'pgsql')
 		{
 			// Analog function to show all tables in postgre
 			$sql = "SELECT * FROM information_schema.tables WHERE table_schema = 'public'";
 		}
 		elseif ($this->pdodriver == 'sqlite')
 		{
 			// Analog function to show all tables in sqlite
 			$sql = "SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'";
 		}
 		else
 		{
 			$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
 		}

 		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
 		{
 			return FALSE;
 		}

 		return $sql;
 	}

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

 	/**
 	 * Show column query
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
 	{
 		return 'SHOW COLUMNS FROM '.$this->escape_identifiers($table);
 	}

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

 	/**
 	 * Field data query
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _field_data($table)
 	{
 		if ($this->pdodriver == 'mysql' or $this->pdodriver == 'pgsql')
 		{
 			// Analog function for mysql and postgre
 			return 'SELECT * FROM '.$this->escape_identifiers($table).' LIMIT 1';
 		}
 		elseif ($this->pdodriver == 'oci')
 		{
 			// Analog function for oci
 			return 'SELECT * FROM '.$this->escape_identifiers($table).' WHERE ROWNUM <= 1';
 		}
 		elseif ($this->pdodriver == 'sqlite')
 		{
 			// Analog function for sqlite
 			return 'PRAGMA table_info('.$this->escape_identifiers($table).')';
 		}

 		return 'SELECT TOP 1 FROM '.$this->escape_identifiers($table);
 	}

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

 	/**
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
 	 * database error that has occured.
 	 *
 	 * @return	array
 	 */
 	public function error()
 	{
 		$error = array('code' => '00000', 'message' => '');
 		$pdo_error = $this->conn_id->errorInfo();

 		if (empty($pdo_error[0]))
 		{
 			return $error;
 		}

 		$error['code'] = isset($pdo_error[1]) ? $pdo_error[0].'/'.$pdo_error[1] : $pdo_error[0];
 		if (isset($pdo_error[2]))
 		{
 			 $error['message'] = $pdo_error[2];
 		}

 		return $error;
 	}

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

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

 		return (count($tables) === 1) ? $tables[0] : '('.implode(', ', $tables).')';
 	}

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

 	/**
 	 * Update_Batch statement
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
 	 * @return	string
 	 */
 	protected function _update_batch($table, $values, $index, $where = NULL)
 	{
 		$ids   = array();
 		$where = ($where != '' && 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,
 	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
 		return 'DELETE FROM '.$table;
 	}

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

 	/**
 	 * Limit string
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
 	 * @param	int	the number of rows to limit the query to
 	 * @param	int	the offset value
 	 * @return	string
 	 */
 	protected function _limit($sql, $limit, $offset)
 	{
 		if ($this->pdodriver == 'cubrid' OR $this->pdodriver == 'sqlite')
 		{
 			$offset = ($offset == 0) ? '' : $offset.', ';

 			return $sql.'LIMIT '.$offset.$limit;
 		}
 		else
 		{
 			$sql .= 'LIMIT '.$limit;
 			$sql .= ($offset > 0) ? ' OFFSET '.$offset : '';

 			return $sql;
 		}
 	}

 }

 /* End of file pdo_driver.php */
 /* Location: ./system/database/drivers/pdo/pdo_driver.php */
	<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
	/**
	* CodeIgniter
	*
	* An open source application development framework for PHP 5.2.4 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 - 2012, 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 2.1.0
	* @filesource
	*/

	/**
	* PDO Database Adapter Class
	*
	* Note: _DB is an extender class that the app controller
	* creates dynamically based on whether the query builder
	* 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_pdo_driver extends CI_DB {

	public $dbdriver = 'pdo';

	// the character used to excape - not necessary for PDO
	protected $_escape_char = '';

	// clause and character used for LIKE escape sequences
	protected $_like_escape_str = " ESCAPE '%s' ";
	protected $_like_escape_chr = '!';

	/**
	* 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.
	*/
	protected $_count_string = 'SELECT COUNT(*) AS ';
	protected $_random_keyword;

	// need to track the pdo driver and options
	public $pdodriver;
	public $options = array();

	public function __construct($params)
	{
	parent::__construct($params);

	if (preg_match('/([^;]+):/', $this->dsn, $match) && count($match) == 2)
	{
	// If there is a minimum valid dsn string pattern found, we're done
	// This is for general PDO users, who tend to have a full DSN string.
	$this->pdodriver = end($match);
	}
	else
	{
	// Try to build a complete DSN string from params
	$this->_connect_string($params);
	}

	// clause and character used for LIKE escape sequences
	// this one depends on the driver being used
	if ($this->pdodriver === 'mysql')
	{
	$this->_escape_char = '`';
	$this->_like_escape_str = '';
	$this->_like_escape_chr = '\\';
	}
	elseif ($this->pdodriver === 'odbc')
	{
	$this->_like_escape_str = " {escape '%s'} ";
	}
	elseif ( ! in_array($this->pdodriver, array('sqlsrv', 'mssql', 'dblib', 'sybase')))
	{
	$this->_escape_char = '"';
	}

	$this->trans_enabled = FALSE;
	$this->_random_keyword = ' RND('.time().')'; // database specific random keyword
	}

	/**
	* Connection String
	*
	* @param array
	* @return void
	*/
	protected function _connect_string($params)
	{
	if (strpos($this->hostname, ':'))
	{
	// hostname generally would have this prototype
	// $db['hostname'] = 'pdodriver:host(/Server(/DSN))=hostname(/DSN);';
	// We need to get the prefix (pdodriver used by PDO).
	$dsnarray = explode(':', $this->hostname);
	$this->pdodriver = $dsnarray[0];

	// End dsn with a semicolon for extra backward compability
	// if database property was not empty.
	if ( ! empty($this->database))
	{
	$this->dsn .= rtrim($this->hostname, ';').';';
	}
	}
	else
	{
	// Invalid DSN, display an error
	if ( ! array_key_exists('pdodriver', $params))
	{
	show_error('Invalid DB Connection String for PDO');
	}

	// Assuming that the following DSN string format is used:
	// $dsn = 'pdo://username:password@hostname:port/database?pdodriver=pgsql';
	$this->dsn = $this->pdodriver.':';

	// Add hostname to the DSN for databases that need it
	if ( ! empty($this->hostname)
	&& strpos($this->hostname, ':') === FALSE
	&& in_array($this->pdodriver, array('informix', 'mysql', 'pgsql', 'sybase', 'mssql', 'dblib', 'cubrid')))
	{
	$this->dsn .= 'host='.$this->hostname.';';
	}

	// Add a port to the DSN for databases that can use it
	if ( ! empty($this->port) && in_array($this->pdodriver, array('informix', 'mysql', 'pgsql', 'ibm', 'cubrid')))
	{
	$this->dsn .= 'port='.$this->port.';';
	}
	}

	// Add the database name to the DSN, if needed
	if (stripos($this->dsn, 'dbname') === FALSE
	&& in_array($this->pdodriver, array('4D', 'pgsql', 'mysql', 'firebird', 'sybase', 'mssql', 'dblib', 'cubrid')))
	{
	$this->dsn .= 'dbname='.$this->database.';';
	}
	elseif (stripos($this->dsn, 'database') === FALSE && in_array($this->pdodriver, array('ibm', 'sqlsrv')))
	{
	if (stripos($this->dsn, 'dsn') === FALSE)
	{
	$this->dsn .= 'database='.$this->database.';';
	}
	}
	elseif ($this->pdodriver === 'sqlite' && $this->dsn === 'sqlite:')
	{
	if ($this->database !== ':memory')
	{
	if ( ! file_exists($this->database))
	{
	show_error('Invalid DB Connection string for PDO SQLite');
	}

	$this->dsn .= (strpos($this->database, DIRECTORY_SEPARATOR) !== 0) ? DIRECTORY_SEPARATOR : '';
	}

	$this->dsn .= $this->database;
	}

	// Add charset to the DSN, if needed
	if ( ! empty($this->char_set) && in_array($this->pdodriver, array('4D', 'mysql', 'sybase', 'mssql', 'dblib', 'oci')))
	{
	$this->dsn .= 'charset='.$this->char_set.';';
	}
	}

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

	/**
	* Non-persistent database connection
	*
	* @return object
	*/
	public function db_connect()
	{
	return $this->_pdo_connect();
	}

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

	/**
	* Persistent database connection
	*
	* @return object
	*/
	public function db_pconnect()
	{
	return $this->_pdo_connect(TRUE);
	}

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

	/**
	* PDO connection
	*
	* @param bool
	* @return object
	*/
	protected function _pdo_connect($persistent = FALSE)
	{
	$this->options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_SILENT;
	$persistent === FALSE OR $this->options[PDO::ATTR_PERSISTENT] = TRUE;

	/* Prior to PHP 5.3.6, even if the charset was supplied in the DSN
	* on connect - it was ignored. This is a work-around for the issue.
	*
	* Reference: http://www.php.net/manual/en/ref.pdo-mysql.connection.php
	*/
	if ($this->pdodriver === 'mysql' && ! is_php('5.3.6') && ! empty($this->char_set))
	{
	$this->options[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET NAMES '.$this->char_set
	.( ! empty($this->db_collat) ? " COLLATE '".$this->dbcollat."'" : '');
	}

	// Connecting...
	try
	{
	return new PDO($this->dsn, $this->username, $this->password, $this->options);
	}
	catch (PDOException $e)
	{
	if ($this->db_debug && empty($this->failover))
	{
	$this->display_error($e->getMessage(), '', TRUE);
	}

	return FALSE;
	}
	}

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

	/**
	* Database version number
	*
	* @return string
	*/
	public function version()
	{
	return isset($this->data_cache['version'])
	? $this->data_cache['version']
	: $this->data_cache['version'] = $this->conn_id->getAttribute(PDO::ATTR_SERVER_VERSION);
	}

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

	/**
	* Execute the query
	*
	* @param string an SQL query
	* @return mixed
	*/
	protected function _execute($sql)
	{
	return $this->conn_id->query($sql);
	}

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

	/**
	* Begin Transaction
	*
	* @return bool
	*/
	public function trans_begin($test_mode = FALSE)
	{
	// When transactions are nested we only begin/commit/rollback the outermost ones
	if ( ! $this->trans_enabled OR $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);

	return $this->conn_id->beginTransaction();
	}

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

	/**
	* Commit Transaction
	*
	* @return bool
	*/
	public function trans_commit()
	{
	// When transactions are nested we only begin/commit/rollback the outermost ones
	if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
	{
	return TRUE;
	}

	return $this->conn_id->commit();
	}

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

	/**
	* Rollback Transaction
	*
	* @return bool
	*/
	public function trans_rollback()
	{
	// When transactions are nested we only begin/commit/rollback the outermost ones
	if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
	{
	return TRUE;
	}

	return $this->conn_id->rollBack();
	}

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

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

	return $str;
	}

	// Escape the string
	$str = $this->conn_id->quote($str);

	// If there are duplicated quotes, trim them away
	if (strpos($str, "'") === 0)
	{
	$str = substr($str, 1, -1);
	}

	// escape LIKE condition wildcards
	if ($like === TRUE)
	{
	return str_replace(array($this->_like_escape_chr, '%', '_'),
	array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
	$str);
	}

	return $str;
	}

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

	/**
	* Affected Rows
	*
	* @return int
	*/
	public function affected_rows()
	{
	return is_object($this->result_id) ? $this->result_id->rowCount() : 0;
	}

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

	/**
	* Insert ID
	*
	* @param string
	* @return int
	*/
	public function insert_id($name = NULL)
	{
	if ($this->pdodriver === 'pgsql' && $name === NULL && $this->version() >= '8.1')
	{
	$query = $this->query('SELECT LASTVAL() AS ins_id');
	$query = $query->row();
	return $query->ins_id;
	}

	return $this->conn_id->lastInsertId($name);
	}

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

	/**
	* Show table query
	*
	* Generates a platform-specific query string so that the table names can be fetched
	*
	* @param bool
	* @return string
	*/
	protected function _list_tables($prefix_limit = FALSE)
	{
	if ($this->pdodriver == 'pgsql')
	{
	// Analog function to show all tables in postgre
	$sql = "SELECT * FROM information_schema.tables WHERE table_schema = 'public'";
	}
	elseif ($this->pdodriver == 'sqlite')
	{
	// Analog function to show all tables in sqlite
	$sql = "SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'";
	}
	else
	{
	$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
	}

	if ($prefix_limit !== FALSE AND $this->dbprefix != '')
	{
	return FALSE;
	}

	return $sql;
	}

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

	/**
	* Show column query
	*
	* Generates a platform-specific query string so that the column names can be fetched
	*
	* @param string the table name
	* @return string
	*/
	protected function _list_columns($table = '')
	{
	return 'SHOW COLUMNS FROM '.$this->escape_identifiers($table);
	}

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

	/**
	* Field data query
	*
	* Generates a platform-specific query so that the column data can be retrieved
	*
	* @param string the table name
	* @return string
	*/
	protected function _field_data($table)
	{
	if ($this->pdodriver == 'mysql' or $this->pdodriver == 'pgsql')
	{
	// Analog function for mysql and postgre
	return 'SELECT * FROM '.$this->escape_identifiers($table).' LIMIT 1';
	}
	elseif ($this->pdodriver == 'oci')
	{
	// Analog function for oci
	return 'SELECT * FROM '.$this->escape_identifiers($table).' WHERE ROWNUM <= 1';
	}
	elseif ($this->pdodriver == 'sqlite')
	{
	// Analog function for sqlite
	return 'PRAGMA table_info('.$this->escape_identifiers($table).')';
	}

	return 'SELECT TOP 1 FROM '.$this->escape_identifiers($table);
	}

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

	/**
	* Error
	*
	* Returns an array containing code and message of the last
	* database error that has occured.
	*
	* @return array
	*/
	public function error()
	{
	$error = array('code' => '00000', 'message' => '');
	$pdo_error = $this->conn_id->errorInfo();

	if (empty($pdo_error[0]))
	{
	return $error;
	}

	$error['code'] = isset($pdo_error[1]) ? $pdo_error[0].'/'.$pdo_error[1] : $pdo_error[0];
	if (isset($pdo_error[2]))
	{
	$error['message'] = $pdo_error[2];
	}

	return $error;
	}

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

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

	return (count($tables) === 1) ? $tables[0] : '('.implode(', ', $tables).')';
	}

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

	/**
	* Update_Batch statement
	*
	* Generates a platform-specific batch update string from the supplied data
	*
	* @param string the table name
	* @param array the update data
	* @param array the where clause
	* @return string
	*/
	protected function _update_batch($table, $values, $index, $where = NULL)
	{
	$ids = array();
	$where = ($where != '' && 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,
	* then this method maps to 'DELETE FROM table'
	*
	* @param string the table name
	* @return string
	*/
	protected function _truncate($table)
	{
	return 'DELETE FROM '.$table;
	}

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

	/**
	* Limit string
	*
	* Generates a platform-specific LIMIT clause
	*
	* @param string the sql query string
	* @param int the number of rows to limit the query to
	* @param int the offset value
	* @return string
	*/
	protected function _limit($sql, $limit, $offset)
	{
	if ($this->pdodriver == 'cubrid' OR $this->pdodriver == 'sqlite')
	{
	$offset = ($offset == 0) ? '' : $offset.', ';

	return $sql.'LIMIT '.$offset.$limit;
	}
	else
	{
	$sql .= 'LIMIT '.$limit;
	$sql .= ($offset > 0) ? ' OFFSET '.$offset : '';

	return $sql;
	}
	}

	}

	/* End of file pdo_driver.php */
	/* Location: ./system/database/drivers/pdo/pdo_driver.php */