Merge tag '3.1.5' into dev-ci3

Signed-off-by: Florian Pritz <bluewind@xinu.at>

1 files changed, 146 insertions, 628 deletions

diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index e0e7dab65..6afc999c2 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -1,811 +1,329 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.1.6 or newer
+ * An open source application development framework for PHP
  *
- * @package		CodeIgniter
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc.
- * @license		http://codeigniter.com/user_guide/license.html
- * @author		EllisLab Dev Team
- * @link		http://codeigniter.com
- * @since		Version 2.1.2
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package	CodeIgniter
+ * @author	EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
+ * @license	http://opensource.org/licenses/MIT	MIT License
+ * @link	https://codeigniter.com
+ * @since	Version 2.1.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * PDO Database Adapter Class
  *
  * Note: _DB is an extender class that the app controller
- * creates dynamically based on whether the active record
+ * 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/
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_pdo_driver extends CI_DB {
 
-	var $dbdriver = 'pdo';
-
-	// the character used to excape - not necessary for PDO
-	var $_escape_char = '';
-	var $_like_escape_str;
-	var $_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.
-	 */
-	var $_count_string = "SELECT COUNT(*) AS ";
-	var $_random_keyword;
-
-	var $options = array();
-
-	function __construct($params)
-	{
-		parent::__construct($params);
-
-		// clause and character used for LIKE escape sequences
-		if (strpos($this->hostname, 'mysql') !== FALSE)
-		{
-			$this->_like_escape_str = '';
-			$this->_like_escape_chr = '';
-
-			//Prior to this version, the charset can't be set in the dsn
-			if(is_php('5.3.6'))
-			{
-				$this->hostname .= ";charset={$this->char_set}";
-			}
-
-			//Set the charset with the connection options
-			$this->options['PDO::MYSQL_ATTR_INIT_COMMAND'] = "SET NAMES {$this->char_set}";
-		}
-		elseif (strpos($this->hostname, 'odbc') !== FALSE)
-		{
-			$this->_like_escape_str = " {escape '%s'} ";
-			$this->_like_escape_chr = '!';
-		}
-		else
-		{
-			$this->_like_escape_str = " ESCAPE '%s' ";
-			$this->_like_escape_chr = '!';
-		}
-
-		empty($this->database) OR $this->hostname .= ';dbname='.$this->database;
-
-		$this->trans_enabled = FALSE;
-
-		$this->_random_keyword = ' RND('.time().')'; // database specific random keyword
-	}
-
 	/**
-	 * Non-persistent database connection
+	 * Database driver
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @var	string
 	 */
-	function db_connect()
-	{
-		$this->options['PDO::ATTR_ERRMODE'] = PDO::ERRMODE_SILENT;
-
-		return new PDO($this->hostname, $this->username, $this->password, $this->options);
-	}
-
-	// --------------------------------------------------------------------
+	public $dbdriver = 'pdo';
 
 	/**
-	 * Persistent database connection
+	 * PDO Options
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @var	array
 	 */
-	function db_pconnect()
-	{
-		$this->options['PDO::ATTR_ERRMODE'] = PDO::ERRMODE_SILENT;
-		$this->options['PDO::ATTR_PERSISTENT'] = TRUE;
-	
-		return new PDO($this->hostname, $this->username, $this->password, $this->options);
-	}
+	public $options = array();
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Reconnect
+	 * Class constructor
 	 *
-	 * Keep / reestablish the db connection if no queries have been
-	 * sent for a length of time exceeding the server's idle timeout
+	 * Validates the DSN string and/or detects the subdriver.
 	 *
-	 * @access	public
+	 * @param	array	$params
 	 * @return	void
 	 */
-	function reconnect()
-	{
-		if ($this->db->db_debug)
-		{
-			return $this->db->display_error('db_unsuported_feature');
-		}
-		return FALSE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Select the database
-	 *
-	 * @access	private called by the base class
-	 * @return	resource
-	 */
-	function db_select()
-	{
-		// Not needed for PDO
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	function db_set_charset($charset, $collation)
-	{
-		// @todo - add support if needed
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Version number query string
-	 *
-	 * @access	public
-	 * @return	string
-	 */
-	function _version()
-	{
-		return $this->conn_id->getAttribute(PDO::ATTR_CLIENT_VERSION);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Execute the query
-	 *
-	 * @access	private called by the base class
-	 * @param	string	an SQL query
-	 * @return	object
-	 */
-	function _execute($sql)
+	public function __construct($params)
 	{
-		$sql = $this->_prep_query($sql);
-		$result_id = $this->conn_id->prepare($sql);
+		parent::__construct($params);
 
-		if (is_object($result_id) && ($result = $result_id->execute()))
+		if (preg_match('/([^:]+):/', $this->dsn, $match) && count($match) === 2)
 		{
-			if (is_numeric(stripos($sql, 'SELECT')))
-			{
-				$this->affect_rows = count($result_id->fetchAll());
-			}
-			else
-			{
-				$this->affect_rows = $result_id->rowCount();
-			}
+			// 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->subdriver = $match[1];
+			return;
 		}
-		else
+		// Legacy support for DSN specified in the hostname field
+		elseif (preg_match('/([^:]+):/', $this->hostname, $match) && count($match) === 2)
 		{
-			$this->affect_rows = 0;
-			$result = FALSE;
+			$this->dsn = $this->hostname;
+			$this->hostname = NULL;
+			$this->subdriver = $match[1];
+			return;
 		}
-
-		return $result;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Prep the query
-	 *
-	 * If needed, each database adapter can prep the query string
-	 *
-	 * @access	private called by execute()
-	 * @param	string	an SQL query
-	 * @return	string
-	 */
-	function _prep_query($sql)
-	{
-		return $sql;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Begin Transaction
-	 *
-	 * @access	public
-	 * @return	bool
-	 */
-	function trans_begin($test_mode = FALSE)
-	{
-		if ( ! $this->trans_enabled)
+		elseif (in_array($this->subdriver, array('mssql', 'sybase'), TRUE))
 		{
-			return TRUE;
+			$this->subdriver = 'dblib';
 		}
-
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		elseif ($this->subdriver === '4D')
 		{
-			return TRUE;
+			$this->subdriver = '4d';
 		}
-
-		// 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.
-		$this->_trans_failure = (bool) ($test_mode === TRUE);
-
-		return $this->conn_id->beginTransaction();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Commit Transaction
-	 *
-	 * @access	public
-	 * @return	bool
-	 */
-	function trans_commit()
-	{
-		if ( ! $this->trans_enabled)
+		elseif ( ! in_array($this->subdriver, array('4d', 'cubrid', 'dblib', 'firebird', 'ibm', 'informix', 'mysql', 'oci', 'odbc', 'pgsql', 'sqlite', 'sqlsrv'), TRUE))
 		{
-			return TRUE;
-		}
+			log_message('error', 'PDO: Invalid or non-existent subdriver');
 
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
-		{
-			return TRUE;
+			if ($this->db_debug)
+			{
+				show_error('Invalid or non-existent PDO subdriver');
+			}
 		}
 
-		$ret = $this->conn->commit();
-		return $ret;
+		$this->dsn = NULL;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Rollback Transaction
+	 * Database connection
 	 *
-	 * @access	public
-	 * @return	bool
+	 * @param	bool	$persistent
+	 * @return	object
 	 */
-	function trans_rollback()
+	public function db_connect($persistent = FALSE)
 	{
-		if ( ! $this->trans_enabled)
+		if ($persistent === TRUE)
 		{
-			return TRUE;
+			$this->options[PDO::ATTR_PERSISTENT] = TRUE;
 		}
 
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		try
 		{
-			return TRUE;
+			return new PDO($this->dsn, $this->username, $this->password, $this->options);
 		}
-
-		$ret = $this->conn_id->rollBack();
-		return $ret;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Escape String
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
-	 * @return	string
-	 */
-	function escape_str($str, $like = FALSE)
-	{
-		if (is_array($str))
+		catch (PDOException $e)
 		{
-			foreach ($str as $key => $val)
+			if ($this->db_debug && empty($this->failover))
 			{
-				$str[$key] = $this->escape_str($val, $like);
+				$this->display_error($e->getMessage(), '', TRUE);
 			}
 
-			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)
-		{
-			$str = 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
-	 *
-	 * @access	public
-	 * @return	integer
-	 */
-	function affected_rows()
-	{
-		return $this->affect_rows;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert ID
-	 * 
-	 * @access	public
-	 * @return	integer
-	 */
-	function insert_id($name=NULL)
-	{
-		//Convenience method for postgres insertid
-		if (strpos($this->hostname, 'pgsql') !== FALSE)
-		{
-			$v = $this->_version();
-
-			$table	= func_num_args() > 0 ? func_get_arg(0) : NULL;
-
-			if ($table == NULL && $v >= '8.1')
-			{
-				$sql='SELECT LASTVAL() as ins_id';
-			}
-			$query = $this->query($sql);
-			$row = $query->row();
-			return $row->ins_id;
-		}
-		else
-		{
-			return $this->conn_id->lastInsertId($name);
+			return FALSE;
 		}
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * "Count All" query
-	 *
-	 * Generates a platform-specific query string that counts all records in
-	 * the specified database
+	 * Database version number
 	 *
-	 * @access	public
-	 * @param	string
 	 * @return	string
 	 */
-	function count_all($table = '')
+	public function version()
 	{
-		if ($table == '')
+		if (isset($this->data_cache['version']))
 		{
-			return 0;
+			return $this->data_cache['version'];
 		}
 
-		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));
-
-		if ($query->num_rows() == 0)
+		// Not all subdrivers support the getAttribute() method
+		try
 		{
-			return 0;
+			return $this->data_cache['version'] = $this->conn_id->getAttribute(PDO::ATTR_SERVER_VERSION);
 		}
-
-		$row = $query->row();
-		$this->_reset_select();
-		return (int) $row->numrows;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Show table query
-	 *
-	 * Generates a platform-specific query string so that the table names can be fetched
-	 *
-	 * @access	private
-	 * @param	boolean
-	 * @return	string
-	 */
-	function _list_tables($prefix_limit = FALSE)
-	{
-		$sql = "SHOW TABLES FROM `".$this->database."`";
-
-		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
+		catch (PDOException $e)
 		{
-			//$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
-			return FALSE; // not currently supported
+			return parent::version();
 		}
-
-		return $sql;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Show column query
-	 *
-	 * Generates a platform-specific query string so that the column names can be fetched
+	 * Execute the query
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @return	string
+	 * @param	string	$sql	SQL query
+	 * @return	mixed
 	 */
-	function _list_columns($table = '')
+	protected function _execute($sql)
 	{
-		return "SHOW COLUMNS FROM ".$table;
+		return $this->conn_id->query($sql);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Field data query
-	 *
-	 * Generates a platform-specific query so that the column data can be retrieved
+	 * Begin Transaction
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @return	object
+	 * @return	bool
 	 */
-	function _field_data($table)
+	protected function _trans_begin()
 	{
-		return "SELECT TOP 1 FROM ".$table;
+		return $this->conn_id->beginTransaction();
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * The error message string
+	 * Commit Transaction
 	 *
-	 * @access	private
-	 * @return	string
+	 * @return	bool
 	 */
-	function _error_message()
+	protected function _trans_commit()
 	{
-		$error_array = $this->conn_id->errorInfo();
-		return $error_array[2];
+		return $this->conn_id->commit();
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * The error message number
+	 * Rollback Transaction
 	 *
-	 * @access	private
-	 * @return	integer
+	 * @return	bool
 	 */
-	function _error_number()
+	protected function _trans_rollback()
 	{
-		return $this->conn_id->errorCode();
+		return $this->conn_id->rollBack();
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
+	 * Platform-dependent string escape
 	 *
-	 * @access	private
 	 * @param	string
 	 * @return	string
 	 */
-	function _escape_identifiers($item)
+	protected function _escape_str($str)
 	{
-		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;
-		}
+		// Escape the string
+		$str = $this->conn_id->quote($str);
 
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+		// If there are duplicated quotes, trim them away
+		return ($str[0] === "'")
+			? substr($str, 1, -1)
+			: $str;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
-	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
+	 * Affected Rows
 	 *
-	 * @access	public
-	 * @param	type
-	 * @return	type
+	 * @return	int
 	 */
-	function _from_tables($tables)
+	public function affected_rows()
 	{
-		if ( ! is_array($tables))
-		{
-			$tables = array($tables);
-		}
-
-		return (count($tables) == 1) ? $tables[0] : '('.implode(', ', $tables).')';
+		return is_object($this->result_id) ? $this->result_id->rowCount() : 0;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * 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).")";
-	}
-	
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert_batch statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
+	 * Insert ID
 	 *
-	 * @access  public
-	 * @param   string  the table name
-	 * @param   array   the insert keys
-	 * @param   array   the insert values
-	 * @return  string
+	 * @param	string	$name
+	 * @return	int
 	 */
-	function _insert_batch($table, $keys, $values)
+	public function insert_id($name = NULL)
 	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES ".implode(', ', $values);
+		return $this->conn_id->lastInsertId($name);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update statement
+	 * Field data query
 	 *
-	 * Generates a platform-specific update string from the supplied data
+	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @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
+	 * @param	string	$table
 	 * @return	string
 	 */
-	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	protected function _field_data($table)
 	{
-		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 $sql;
+		return 'SELECT TOP 1 * FROM '.$this->protect_identifiers($table);
 	}
-	
+
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update_Batch statement
+	 * Error
 	 *
-	 * Generates a platform-specific batch update string from the supplied data
+	 * Returns an array containing code and message of the last
+	 * database error that has occurred.
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @return	string
+	 * @return	array
 	 */
-	function _update_batch($table, $values, $index, $where = NULL)
+	public function error()
 	{
-		$ids = array();
-		$where = ($where != '' AND count($where) >=1) ? implode(" ", $where).' AND ' : '';
+		$error = array('code' => '00000', 'message' => '');
+		$pdo_error = $this->conn_id->errorInfo();
 
-		foreach ($values as $key => $val)
+		if (empty($pdo_error[0]))
 		{
-			$ids[] = $val[$index];
-
-			foreach (array_keys($val) as $field)
-			{
-				if ($field != $index)
-				{
-					$final[$field][] =  'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
-				}
-			}
+			return $error;
 		}
 
-		$sql = "UPDATE ".$table." SET ";
-		$cases = '';
-
-		foreach ($final as $k => $v)
+		$error['code'] = isset($pdo_error[1]) ? $pdo_error[0].'/'.$pdo_error[1] : $pdo_error[0];
+		if (isset($pdo_error[2]))
 		{
-			$cases .= $k.' = CASE '."\n";
-			foreach ($v as $row)
-			{
-				$cases .= $row."\n";
-			}
-
-			$cases .= 'ELSE '.$k.' END, ';
+			 $error['message'] = $pdo_error[2];
 		}
 
-		$sql .= substr($cases, 0, -2);
-
-		$sql .= ' WHERE '.$where.$index.' IN ('.implode(',', $ids).')';
-
-		return $sql;
+		return $error;
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
 	 * 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 $this->_delete($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
+	 * If the database does not support the TRUNCATE statement,
+	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @access	public
-	 * @param	string	the sql query string
-	 * @param	integer	the number of rows to limit the query to
-	 * @param	integer	the offset value
+	 * @param	string	$table
 	 * @return	string
 	 */
-	function _limit($sql, $limit, $offset)
-	{
-		if (strpos($this->hostname, 'cubrid') !== FALSE || strpos($this->hostname, 'sqlite') !== FALSE)
-		{
-			if ($offset == 0)
-			{
-				$offset = '';
-			}
-			else
-			{
-				$offset .= ", ";
-			}
-
-			return $sql."LIMIT ".$offset.$limit;
-		}
-		else
-		{
-			$sql .= "LIMIT ".$limit;
-
-			if ($offset > 0)
-			{
-				$sql .= " OFFSET ".$offset;
-			}
-			
-			return $sql;
-		}
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Close DB Connection
-	 *
-	 * @access	public
-	 * @param	resource
-	 * @return	void
-	 */
-	function _close($conn_id)
+	protected function _truncate($table)
 	{
-		$this->conn_id = null;
+		return 'TRUNCATE TABLE '.$table;
 	}
 
-
 }
-
-
-
-/* End of file pdo_driver.php */
-/* Location: ./system/database/drivers/pdo/pdo_driver.php */
\ No newline at end of file