Merge tag '3.1.5' into dev-ci3

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

1 files changed, 1126 insertions, 550 deletions

diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index c342aacbd..3eb51f734 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1,19 +1,41 @@
-<?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
- * @author		ExpressionEngine Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc.
- * @license		http://codeigniter.com/user_guide/license.html
- * @link		http://codeigniter.com
- * @since		Version 1.0
+ * 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 1.0.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * Database Driver Class
@@ -25,60 +47,322 @@
  * @package		CodeIgniter
  * @subpackage	Drivers
  * @category	Database
- * @author		ExpressionEngine Dev Team
- * @link		http://codeigniter.com/user_guide/database/
+ * @author		EllisLab Dev Team
+ * @link		https://codeigniter.com/user_guide/database/
  */
-class CI_DB_driver {
-
-	var $username;
-	var $password;
-	var $hostname;
-	var $database;
-	var $dbdriver		= 'mysql';
-	var $dbprefix		= '';
-	var $char_set		= 'utf8';
-	var $dbcollat		= 'utf8_general_ci';
-	var $autoinit		= TRUE; // Whether to automatically initialize the DB
-	var $swap_pre		= '';
-	var $port			= '';
-	var $pconnect		= FALSE;
-	var $conn_id		= FALSE;
-	var $result_id		= FALSE;
-	var $db_debug		= FALSE;
-	var $benchmark		= 0;
-	var $query_count	= 0;
-	var $bind_marker	= '?';
-	var $save_queries	= TRUE;
-	var $queries		= array();
-	var $query_times	= array();
-	var $data_cache		= array();
-	var $trans_enabled	= TRUE;
-	var $trans_strict	= TRUE;
-	var $_trans_depth	= 0;
-	var $_trans_status	= TRUE; // Used with transactions to determine if a rollback should occur
-	var $cache_on		= FALSE;
-	var $cachedir		= '';
-	var $cache_autodel	= FALSE;
-	var $CACHE; // The cache class object
-
-	// Private variables
-	var $_protect_identifiers	= TRUE;
-	var $_reserved_identifiers	= array('*'); // Identifiers that should NOT be escaped
-
-	// These are use with Oracle
-	var $stmt_id;
-	var $curs_id;
-	var $limit_used;
-
-
-
-	/**
-	 * Constructor.  Accepts one parameter containing the database
-	 * connection settings.
-	 *
-	 * @param array
-	 */
-	function __construct($params)
+abstract class CI_DB_driver {
+
+	/**
+	 * Data Source Name / Connect string
+	 *
+	 * @var	string
+	 */
+	public $dsn;
+
+	/**
+	 * Username
+	 *
+	 * @var	string
+	 */
+	public $username;
+
+	/**
+	 * Password
+	 *
+	 * @var	string
+	 */
+	public $password;
+
+	/**
+	 * Hostname
+	 *
+	 * @var	string
+	 */
+	public $hostname;
+
+	/**
+	 * Database name
+	 *
+	 * @var	string
+	 */
+	public $database;
+
+	/**
+	 * Database driver
+	 *
+	 * @var	string
+	 */
+	public $dbdriver		= 'mysqli';
+
+	/**
+	 * Sub-driver
+	 *
+	 * @used-by	CI_DB_pdo_driver
+	 * @var	string
+	 */
+	public $subdriver;
+
+	/**
+	 * Table prefix
+	 *
+	 * @var	string
+	 */
+	public $dbprefix		= '';
+
+	/**
+	 * Character set
+	 *
+	 * @var	string
+	 */
+	public $char_set		= 'utf8';
+
+	/**
+	 * Collation
+	 *
+	 * @var	string
+	 */
+	public $dbcollat		= 'utf8_general_ci';
+
+	/**
+	 * Encryption flag/data
+	 *
+	 * @var	mixed
+	 */
+	public $encrypt			= FALSE;
+
+	/**
+	 * Swap Prefix
+	 *
+	 * @var	string
+	 */
+	public $swap_pre		= '';
+
+	/**
+	 * Database port
+	 *
+	 * @var	int
+	 */
+	public $port			= '';
+
+	/**
+	 * Persistent connection flag
+	 *
+	 * @var	bool
+	 */
+	public $pconnect		= FALSE;
+
+	/**
+	 * Connection ID
+	 *
+	 * @var	object|resource
+	 */
+	public $conn_id			= FALSE;
+
+	/**
+	 * Result ID
+	 *
+	 * @var	object|resource
+	 */
+	public $result_id		= FALSE;
+
+	/**
+	 * Debug flag
+	 *
+	 * Whether to display error messages.
+	 *
+	 * @var	bool
+	 */
+	public $db_debug		= FALSE;
+
+	/**
+	 * Benchmark time
+	 *
+	 * @var	int
+	 */
+	public $benchmark		= 0;
+
+	/**
+	 * Executed queries count
+	 *
+	 * @var	int
+	 */
+	public $query_count		= 0;
+
+	/**
+	 * Bind marker
+	 *
+	 * Character used to identify values in a prepared statement.
+	 *
+	 * @var	string
+	 */
+	public $bind_marker		= '?';
+
+	/**
+	 * Save queries flag
+	 *
+	 * Whether to keep an in-memory history of queries for debugging purposes.
+	 *
+	 * @var	bool
+	 */
+	public $save_queries		= TRUE;
+
+	/**
+	 * Queries list
+	 *
+	 * @see	CI_DB_driver::$save_queries
+	 * @var	string[]
+	 */
+	public $queries			= array();
+
+	/**
+	 * Query times
+	 *
+	 * A list of times that queries took to execute.
+	 *
+	 * @var	array
+	 */
+	public $query_times		= array();
+
+	/**
+	 * Data cache
+	 *
+	 * An internal generic value cache.
+	 *
+	 * @var	array
+	 */
+	public $data_cache		= array();
+
+	/**
+	 * Transaction enabled flag
+	 *
+	 * @var	bool
+	 */
+	public $trans_enabled		= TRUE;
+
+	/**
+	 * Strict transaction mode flag
+	 *
+	 * @var	bool
+	 */
+	public $trans_strict		= TRUE;
+
+	/**
+	 * Transaction depth level
+	 *
+	 * @var	int
+	 */
+	protected $_trans_depth		= 0;
+
+	/**
+	 * Transaction status flag
+	 *
+	 * Used with transactions to determine if a rollback should occur.
+	 *
+	 * @var	bool
+	 */
+	protected $_trans_status	= TRUE;
+
+	/**
+	 * Transaction failure flag
+	 *
+	 * Used with transactions to determine if a transaction has failed.
+	 *
+	 * @var	bool
+	 */
+	protected $_trans_failure	= FALSE;
+
+	/**
+	 * Cache On flag
+	 *
+	 * @var	bool
+	 */
+	public $cache_on		= FALSE;
+
+	/**
+	 * Cache directory path
+	 *
+	 * @var	bool
+	 */
+	public $cachedir		= '';
+
+	/**
+	 * Cache auto-delete flag
+	 *
+	 * @var	bool
+	 */
+	public $cache_autodel		= FALSE;
+
+	/**
+	 * DB Cache object
+	 *
+	 * @see	CI_DB_cache
+	 * @var	object
+	 */
+	public $CACHE;
+
+	/**
+	 * Protect identifiers flag
+	 *
+	 * @var	bool
+	 */
+	protected $_protect_identifiers		= TRUE;
+
+	/**
+	 * List of reserved identifiers
+	 *
+	 * Identifiers that must NOT be escaped.
+	 *
+	 * @var	string[]
+	 */
+	protected $_reserved_identifiers	= array('*');
+
+	/**
+	 * Identifier escape character
+	 *
+	 * @var	string
+	 */
+	protected $_escape_char = '"';
+
+	/**
+	 * ESCAPE statement string
+	 *
+	 * @var	string
+	 */
+	protected $_like_escape_str = " ESCAPE '%s' ";
+
+	/**
+	 * ESCAPE character
+	 *
+	 * @var	string
+	 */
+	protected $_like_escape_chr = '!';
+
+	/**
+	 * ORDER BY random keyword
+	 *
+	 * @var	array
+	 */
+	protected $_random_keyword = array('RAND()', 'RAND(%d)');
+
+	/**
+	 * COUNT string
+	 *
+	 * @used-by	CI_DB_driver::count_all()
+	 * @used-by	CI_DB_query_builder::count_all_results()
+	 *
+	 * @var	string
+	 */
+	protected $_count_string = 'SELECT COUNT(*) AS ';
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Class constructor
+	 *
+	 * @param	array	$params
+	 * @return	void
+	 */
+	public function __construct($params)
 	{
 		if (is_array($params))
 		{
@@ -88,7 +372,7 @@ class CI_DB_driver {
 			}
 		}
 
-		log_message('debug', 'Database Driver Class Initialized');
+		log_message('info', 'Database Driver Class Initialized');
 	}
 
 	// --------------------------------------------------------------------
@@ -96,15 +380,17 @@ class CI_DB_driver {
 	/**
 	 * Initialize Database Settings
 	 *
-	 * @access	private Called by the constructor
-	 * @param	mixed
-	 * @return	void
+	 * @return	bool
 	 */
-	function initialize()
+	public function initialize()
 	{
-		// If an existing connection resource is available
-		// there is no need to connect and select the database
-		if (is_resource($this->conn_id) OR is_object($this->conn_id))
+		/* If an established connection is available, then there's
+		 * no need to connect and select the database.
+		 *
+		 * Depending on the database driver, conn_id can be either
+		 * boolean TRUE, a resource or an object.
+		 */
+		if ($this->conn_id)
 		{
 			return TRUE;
 		}
@@ -112,69 +398,139 @@ class CI_DB_driver {
 		// ----------------------------------------------------------------
 
 		// Connect to the database and set the connection ID
-		$this->conn_id = ($this->pconnect == FALSE) ? $this->db_connect() : $this->db_pconnect();
+		$this->conn_id = $this->db_connect($this->pconnect);
 
-		// No connection resource?  Throw an error
+		// No connection resource? Check if there is a failover else throw an error
 		if ( ! $this->conn_id)
 		{
-			log_message('error', 'Unable to connect to the database');
-
-			if ($this->db_debug)
+			// Check if there is a failover set
+			if ( ! empty($this->failover) && is_array($this->failover))
 			{
-				$this->display_error('db_unable_to_connect');
-			}
-			return FALSE;
-		}
+				// Go over all the failovers
+				foreach ($this->failover as $failover)
+				{
+					// Replace the current settings with those of the failover
+					foreach ($failover as $key => $val)
+					{
+						$this->$key = $val;
+					}
 
-		// ----------------------------------------------------------------
+					// Try to connect
+					$this->conn_id = $this->db_connect($this->pconnect);
 
-		// Select the DB... assuming a database name is specified in the config file
-		if ($this->database != '')
-		{
-			if ( ! $this->db_select())
-			{
-				log_message('error', 'Unable to select database: '.$this->database);
-
-				if ($this->db_debug)
-				{
-					$this->display_error('db_unable_to_select', $this->database);
+					// If a connection is made break the foreach loop
+					if ($this->conn_id)
+					{
+						break;
+					}
 				}
-				return FALSE;
 			}
-			else
+
+			// We still don't have a connection?
+			if ( ! $this->conn_id)
 			{
-				// We've selected the DB. Now we set the character set
-				if ( ! $this->db_set_charset($this->char_set, $this->dbcollat))
+				log_message('error', 'Unable to connect to the database');
+
+				if ($this->db_debug)
 				{
-					return FALSE;
+					$this->display_error('db_unable_to_connect');
 				}
 
-				return TRUE;
+				return FALSE;
 			}
 		}
 
+		// Now we set the character set and that's all
+		return $this->db_set_charset($this->char_set);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * DB connect
+	 *
+	 * This is just a dummy method that all drivers will override.
+	 *
+	 * @return	mixed
+	 */
+	public function db_connect()
+	{
 		return TRUE;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
+	 * Persistent database connection
+	 *
+	 * @return	mixed
+	 */
+	public function db_pconnect()
+	{
+		return $this->db_connect(TRUE);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Reconnect
+	 *
+	 * Keep / reestablish the db connection if no queries have been
+	 * sent for a length of time exceeding the server's idle timeout.
+	 *
+	 * This is just a dummy method to allow drivers without such
+	 * functionality to not declare it, while others will override it.
+	 *
+	 * @return	void
+	 */
+	public function reconnect()
+	{
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Select database
+	 *
+	 * This is just a dummy method to allow drivers without such
+	 * functionality to not declare it, while others will override it.
+	 *
+	 * @return	bool
+	 */
+	public function db_select()
+	{
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Last error
+	 *
+	 * @return	array
+	 */
+	public function error()
+	{
+		return array('code' => NULL, 'message' => NULL);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Set client character set
 	 *
-	 * @access	public
-	 * @param	string
 	 * @param	string
-	 * @return	resource
+	 * @return	bool
 	 */
-	function db_set_charset($charset, $collation)
+	public function db_set_charset($charset)
 	{
-		if ( ! $this->_db_set_charset($this->char_set, $this->dbcollat))
+		if (method_exists($this, '_db_set_charset') && ! $this->_db_set_charset($charset))
 		{
-			log_message('error', 'Unable to set database connection charset: '.$this->char_set);
+			log_message('error', 'Unable to set database connection charset: '.$charset);
 
 			if ($this->db_debug)
 			{
-				$this->display_error('db_unable_to_set_charset', $this->char_set);
+				$this->display_error('db_unable_to_set_charset', $charset);
 			}
 
 			return FALSE;
@@ -188,10 +544,9 @@ class CI_DB_driver {
 	/**
 	 * The name of the platform in use (mysql, mssql, etc...)
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function platform()
+	public function platform()
 	{
 		return $this->dbdriver;
 	}
@@ -199,36 +554,39 @@ class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Database Version Number.  Returns a string containing the
-	 * version of the database being used
+	 * Database version number
+	 *
+	 * Returns a string containing the version of the database being used.
+	 * Most drivers will override this method.
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function version()
+	public function version()
 	{
-		if (FALSE === ($sql = $this->_version()))
+		if (isset($this->data_cache['version']))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
+			return $this->data_cache['version'];
 		}
 
-		// Some DBs have functions that return the version, and don't run special
-		// SQL queries per se. In these instances, just return the result.
-		$driver_version_exceptions = array('oci8', 'sqlite', 'cubrid');
-
-		if (in_array($this->dbdriver, $driver_version_exceptions))
-		{
-			return $sql;
-		}
-		else
+		if (FALSE === ($sql = $this->_version()))
 		{
-			$query = $this->query($sql);
-			return $query->row('ver');
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
+
+		$query = $this->query($sql)->row();
+		return $this->data_cache['version'] = $query->ver;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Version number query string
+	 *
+	 * @return	string
+	 */
+	protected function _version()
+	{
+		return 'SELECT VERSION() AS ver';
 	}
 
 	// --------------------------------------------------------------------
@@ -237,32 +595,32 @@ class CI_DB_driver {
 	 * Execute the query
 	 *
 	 * Accepts an SQL string as input and returns a result object upon
-	 * successful execution of a "read" type query.  Returns boolean TRUE
+	 * successful execution of a "read" type query. Returns boolean TRUE
 	 * upon successful execution of a "write" type query. Returns boolean
 	 * FALSE upon failure, and if the $db_debug variable is set to TRUE
 	 * will raise an error.
 	 *
-	 * @access	public
-	 * @param	string	An SQL query string
-	 * @param	array	An array of binding data
+	 * @param	string	$sql
+	 * @param	array	$binds = FALSE		An array of binding data
+	 * @param	bool	$return_object = NULL
 	 * @return	mixed
 	 */
-	function query($sql, $binds = FALSE, $return_object = TRUE)
+	public function query($sql, $binds = FALSE, $return_object = NULL)
 	{
-		if ($sql == '')
+		if ($sql === '')
 		{
-			if ($this->db_debug)
-			{
-				log_message('error', 'Invalid query: '.$sql);
-				return $this->display_error('db_invalid_query');
-			}
-			return FALSE;
+			log_message('error', 'Invalid query: '.$sql);
+			return ($this->db_debug) ? $this->display_error('db_invalid_query') : FALSE;
+		}
+		elseif ( ! is_bool($return_object))
+		{
+			$return_object = ! $this->is_write_type($sql);
 		}
 
 		// Verify table prefix and replace if necessary
-		if ( ($this->dbprefix != '' AND $this->swap_pre != '') AND ($this->dbprefix != $this->swap_pre) )
+		if ($this->dbprefix !== '' && $this->swap_pre !== '' && $this->dbprefix !== $this->swap_pre)
 		{
-			$sql = preg_replace("/(\W)".$this->swap_pre."(\S+?)/", "\\1".$this->dbprefix."\\2", $sql);
+			$sql = preg_replace('/(\W)'.$this->swap_pre.'(\S+?)/', '\\1'.$this->dbprefix.'\\2', $sql);
 		}
 
 		// Compile binds if needed
@@ -271,87 +629,88 @@ class CI_DB_driver {
 			$sql = $this->compile_binds($sql, $binds);
 		}
 
-		// Is query caching enabled?  If the query is a "read type"
+		// Is query caching enabled? If the query is a "read type"
 		// we will load the caching class and return the previously
 		// cached query if it exists
-		if ($this->cache_on == TRUE AND stristr($sql, 'SELECT'))
+		if ($this->cache_on === TRUE && $return_object === TRUE && $this->_cache_init())
 		{
-			if ($this->_cache_init())
+			$this->load_rdriver();
+			if (FALSE !== ($cache = $this->CACHE->read($sql)))
 			{
-				$this->load_rdriver();
-				if (FALSE !== ($cache = $this->CACHE->read($sql)))
-				{
-					return $cache;
-				}
+				return $cache;
 			}
 		}
 
-		// Save the  query for debugging
-		if ($this->save_queries == TRUE)
+		// Save the query for debugging
+		if ($this->save_queries === TRUE)
 		{
 			$this->queries[] = $sql;
 		}
 
 		// Start the Query Timer
-		$time_start = list($sm, $ss) = explode(' ', microtime());
+		$time_start = microtime(TRUE);
 
 		// Run the Query
 		if (FALSE === ($this->result_id = $this->simple_query($sql)))
 		{
-			if ($this->save_queries == TRUE)
+			if ($this->save_queries === TRUE)
 			{
 				$this->query_times[] = 0;
 			}
 
 			// This will trigger a rollback if transactions are being used
-			$this->_trans_status = FALSE;
+			if ($this->_trans_depth !== 0)
+			{
+				$this->_trans_status = FALSE;
+			}
+
+			// Grab the error now, as we might run some additional queries before displaying the error
+			$error = $this->error();
+
+			// Log errors
+			log_message('error', 'Query error: '.$error['message'].' - Invalid query: '.$sql);
 
 			if ($this->db_debug)
 			{
-				// grab the error number and message now, as we might run some
-				// additional queries before displaying the error
-				$error_no = $this->_error_number();
-				$error_msg = $this->_error_message();
-
 				// We call this function in order to roll-back queries
-				// if transactions are enabled.  If we don't call this here
+				// if transactions are enabled. If we don't call this here
 				// the error message will trigger an exit, causing the
 				// transactions to remain in limbo.
-				$this->trans_complete();
-
-				// Log and display errors
-				log_message('error', 'Query error: '.$error_msg);
-				return $this->display_error(
-										array(
-												'Error Number: '.$error_no,
-												$error_msg,
-												$sql
-											)
-										);
+				while ($this->_trans_depth !== 0)
+				{
+					$trans_depth = $this->_trans_depth;
+					$this->trans_complete();
+					if ($trans_depth === $this->_trans_depth)
+					{
+						log_message('error', 'Database: Failure during an automated transaction commit/rollback!');
+						break;
+					}
+				}
+
+				// Display errors
+				return $this->display_error(array('Error Number: '.$error['code'], $error['message'], $sql));
 			}
 
 			return FALSE;
 		}
 
 		// Stop and aggregate the query time results
-		$time_end = list($em, $es) = explode(' ', microtime());
-		$this->benchmark += ($em + $es) - ($sm + $ss);
+		$time_end = microtime(TRUE);
+		$this->benchmark += $time_end - $time_start;
 
-		if ($this->save_queries == TRUE)
+		if ($this->save_queries === TRUE)
 		{
-			$this->query_times[] = ($em + $es) - ($sm + $ss);
+			$this->query_times[] = $time_end - $time_start;
 		}
 
 		// Increment the query counter
 		$this->query_count++;
 
-		// Was the query a "write" type?
-		// If so we'll simply return true
-		if ($this->is_write_type($sql) === TRUE)
+		// Will we have a result object instantiated? If not - we'll simply return TRUE
+		if ($return_object !== TRUE)
 		{
-			// If caching is enabled we'll auto-cleanup any
-			// existing files related to this particular URI
-			if ($this->cache_on == TRUE AND $this->cache_autodel == TRUE AND $this->_cache_init())
+			// If caching is enabled we'll auto-cleanup any existing files related to this particular URI
+			if ($this->cache_on === TRUE && $this->cache_autodel === TRUE && $this->_cache_init())
 			{
 				$this->CACHE->delete();
 			}
@@ -359,35 +718,13 @@ class CI_DB_driver {
 			return TRUE;
 		}
 
-		// Return TRUE if we don't need to create a result object
-		// Currently only the Oracle driver uses this when stored
-		// procedures are used
-		if ($return_object !== TRUE)
-		{
-			return TRUE;
-		}
-
 		// Load and instantiate the result driver
+		$driver		= $this->load_rdriver();
+		$RES		= new $driver($this);
 
-		$driver			= $this->load_rdriver();
-		$RES			= new $driver();
-		$RES->conn_id	= $this->conn_id;
-		$RES->result_id	= $this->result_id;
-
-		if ($this->dbdriver == 'oci8')
-		{
-			$RES->stmt_id		= $this->stmt_id;
-			$RES->curs_id		= NULL;
-			$RES->limit_used	= $this->limit_used;
-			$this->stmt_id		= FALSE;
-		}
-
-		// oci8 vars must be set before calling this
-		$RES->num_rows	= $RES->num_rows();
-
-		// Is query caching enabled?  If so, we'll serialize the
+		// Is query caching enabled? If so, we'll serialize the
 		// result object and save it to a cache file.
-		if ($this->cache_on == TRUE AND $this->_cache_init())
+		if ($this->cache_on === TRUE && $this->_cache_init())
 		{
 			// We'll create a new instance of the result object
 			// only without the platform specific driver since
@@ -395,10 +732,10 @@ class CI_DB_driver {
 			// resource ID won't be any good once we've cached the
 			// result object, so we'll have to compile the data
 			// and save it)
-			$CR = new CI_DB_result();
-			$CR->num_rows		= $RES->num_rows();
+			$CR = new CI_DB_result($this);
 			$CR->result_object	= $RES->result_object();
 			$CR->result_array	= $RES->result_array();
+			$CR->num_rows		= $RES->num_rows();
 
 			// Reset these since cached objects can not utilize resource IDs.
 			$CR->conn_id		= NULL;
@@ -415,17 +752,16 @@ class CI_DB_driver {
 	/**
 	 * Load the result drivers
 	 *
-	 * @access	public
 	 * @return	string	the name of the result class
 	 */
-	function load_rdriver()
+	public function load_rdriver()
 	{
 		$driver = 'CI_DB_'.$this->dbdriver.'_result';
 
-		if ( ! class_exists($driver))
+		if ( ! class_exists($driver, FALSE))
 		{
-			include_once(BASEPATH.'database/DB_result.php');
-			include_once(BASEPATH.'database/drivers/'.$this->dbdriver.'/'.$this->dbdriver.'_result.php');
+			require_once(BASEPATH.'database/DB_result.php');
+			require_once(BASEPATH.'database/drivers/'.$this->dbdriver.'/'.$this->dbdriver.'_result.php');
 		}
 
 		return $driver;
@@ -435,19 +771,21 @@ class CI_DB_driver {
 
 	/**
 	 * Simple Query
-	 * This is a simplified version of the query() function.  Internally
+	 * This is a simplified version of the query() function. Internally
 	 * we only use it when running transaction commands since they do
 	 * not require all the features of the main query() function.
 	 *
-	 * @access	public
 	 * @param	string	the sql query
 	 * @return	mixed
 	 */
-	function simple_query($sql)
+	public function simple_query($sql)
 	{
 		if ( ! $this->conn_id)
 		{
-			$this->initialize();
+			if ( ! $this->initialize())
+			{
+				return FALSE;
+			}
 		}
 
 		return $this->_execute($sql);
@@ -459,10 +797,9 @@ class CI_DB_driver {
 	 * Disable Transactions
 	 * This permits transactions to be disabled at run-time.
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function trans_off()
+	public function trans_off()
 	{
 		$this->trans_enabled = FALSE;
 	}
@@ -471,15 +808,18 @@ class CI_DB_driver {
 
 	/**
 	 * Enable/disable Transaction Strict Mode
+	 *
 	 * When strict mode is enabled, if you are running multiple groups of
-	 * transactions, if one group fails all groups will be rolled back.
-	 * If strict mode is disabled, each group is treated autonomously, meaning
-	 * a failure of one group will not affect any others
+	 * transactions, if one group fails all subsequent groups will be
+	 * rolled back.
 	 *
-	 * @access	public
+	 * If strict mode is disabled, each group is treated autonomously,
+	 * meaning a failure of one group will not affect any others
+	 *
+	 * @param	bool	$mode = TRUE
 	 * @return	void
 	 */
-	function trans_strict($mode = TRUE)
+	public function trans_strict($mode = TRUE)
 	{
 		$this->trans_strict = is_bool($mode) ? $mode : TRUE;
 	}
@@ -489,24 +829,17 @@ class CI_DB_driver {
 	/**
 	 * Start Transaction
 	 *
-	 * @access	public
-	 * @return	void
+	 * @param	bool	$test_mode = FALSE
+	 * @return	bool
 	 */
-	function trans_start($test_mode = FALSE)
+	public function trans_start($test_mode = FALSE)
 	{
 		if ( ! $this->trans_enabled)
 		{
 			return FALSE;
 		}
 
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
-		{
-			$this->_trans_depth += 1;
-			return;
-		}
-
-		$this->trans_begin($test_mode);
+		return $this->trans_begin($test_mode);
 	}
 
 	// --------------------------------------------------------------------
@@ -514,31 +847,23 @@ class CI_DB_driver {
 	/**
 	 * Complete Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_complete()
+	public function trans_complete()
 	{
 		if ( ! $this->trans_enabled)
 		{
 			return FALSE;
 		}
 
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 1)
-		{
-			$this->_trans_depth -= 1;
-			return TRUE;
-		}
-
 		// The query() function will set this flag to FALSE in the event that a query failed
-		if ($this->_trans_status === FALSE)
+		if ($this->_trans_status === FALSE OR $this->_trans_failure === TRUE)
 		{
 			$this->trans_rollback();
 
 			// If we are NOT running in strict mode, we will reset
-			// the _trans_status flag so that subsequent groups of transactions
-			// will be permitted.
+			// the _trans_status flag so that subsequent groups of
+			// transactions will be permitted.
 			if ($this->trans_strict === FALSE)
 			{
 				$this->_trans_status = TRUE;
@@ -548,8 +873,7 @@ class CI_DB_driver {
 			return FALSE;
 		}
 
-		$this->trans_commit();
-		return TRUE;
+		return $this->trans_commit();
 	}
 
 	// --------------------------------------------------------------------
@@ -557,10 +881,9 @@ class CI_DB_driver {
 	/**
 	 * Lets you retrieve the transaction flag to determine if it has failed
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_status()
+	public function trans_status()
 	{
 		return $this->_trans_status;
 	}
@@ -568,44 +891,147 @@ class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Begin Transaction
+	 *
+	 * @param	bool	$test_mode
+	 * @return	bool
+	 */
+	public function trans_begin($test_mode = FALSE)
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return FALSE;
+		}
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		elseif ($this->_trans_depth > 0)
+		{
+			$this->_trans_depth++;
+			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);
+
+		if ($this->_trans_begin())
+		{
+			$this->_trans_depth++;
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @return	bool
+	 */
+	public function trans_commit()
+	{
+		if ( ! $this->trans_enabled OR $this->_trans_depth === 0)
+		{
+			return FALSE;
+		}
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		elseif ($this->_trans_depth > 1 OR $this->_trans_commit())
+		{
+			$this->_trans_depth--;
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @return	bool
+	 */
+	public function trans_rollback()
+	{
+		if ( ! $this->trans_enabled OR $this->_trans_depth === 0)
+		{
+			return FALSE;
+		}
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		elseif ($this->_trans_depth > 1 OR $this->_trans_rollback())
+		{
+			$this->_trans_depth--;
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Compile Bindings
 	 *
-	 * @access	public
 	 * @param	string	the sql statement
 	 * @param	array	an array of bind data
 	 * @return	string
 	 */
-	function compile_binds($sql, $binds)
+	public function compile_binds($sql, $binds)
 	{
-		if (strpos($sql, $this->bind_marker) === FALSE)
+		if (empty($this->bind_marker) OR strpos($sql, $this->bind_marker) === FALSE)
 		{
 			return $sql;
 		}
-
-		if ( ! is_array($binds))
+		elseif ( ! is_array($binds))
 		{
 			$binds = array($binds);
+			$bind_count = 1;
+		}
+		else
+		{
+			// Make sure we're using numeric keys
+			$binds = array_values($binds);
+			$bind_count = count($binds);
 		}
 
-		// Get the sql segments around the bind markers
-		$segments = explode($this->bind_marker, $sql);
+		// We'll need the marker length later
+		$ml = strlen($this->bind_marker);
 
-		// The count of bind should be 1 less then the count of segments
-		// If there are more bind arguments trim it down
-		if (count($binds) >= count($segments)) {
-			$binds = array_slice($binds, 0, count($segments)-1);
+		// Make sure not to replace a chunk inside a string that happens to match the bind marker
+		if ($c = preg_match_all("/'[^']*'|\"[^\"]*\"/i", $sql, $matches))
+		{
+			$c = preg_match_all('/'.preg_quote($this->bind_marker, '/').'/i',
+				str_replace($matches[0],
+					str_replace($this->bind_marker, str_repeat(' ', $ml), $matches[0]),
+					$sql, $c),
+				$matches, PREG_OFFSET_CAPTURE);
+
+			// Bind values' count must match the count of markers in the query
+			if ($bind_count !== $c)
+			{
+				return $sql;
+			}
+		}
+		elseif (($c = preg_match_all('/'.preg_quote($this->bind_marker, '/').'/i', $sql, $matches, PREG_OFFSET_CAPTURE)) !== $bind_count)
+		{
+			return $sql;
 		}
 
-		// Construct the binded query
-		$result = $segments[0];
-		$i = 0;
-		foreach ($binds as $bind)
+		do
 		{
-			$result .= $this->escape($bind);
-			$result .= $segments[++$i];
+			$c--;
+			$escaped_value = $this->escape($binds[$c]);
+			if (is_array($escaped_value))
+			{
+				$escaped_value = '('.implode(',', $escaped_value).')';
+			}
+			$sql = substr_replace($sql, $escaped_value, $matches[0][$c][1], $ml);
 		}
+		while ($c !== 0);
 
-		return $result;
+		return $sql;
 	}
 
 	// --------------------------------------------------------------------
@@ -613,17 +1039,12 @@ class CI_DB_driver {
 	/**
 	 * Determines if a query is a "write" type.
 	 *
-	 * @access	public
 	 * @param	string	An SQL query string
-	 * @return	boolean
+	 * @return	bool
 	 */
-	function is_write_type($sql)
+	public function is_write_type($sql)
 	{
-		if ( ! preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK)\s+/i', $sql))
-		{
-			return FALSE;
-		}
-		return TRUE;
+		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s/i', $sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -631,11 +1052,10 @@ class CI_DB_driver {
 	/**
 	 * Calculate the aggregate query elapsed time
 	 *
-	 * @access	public
-	 * @param	integer	The number of decimal places
-	 * @return	integer
+	 * @param	int	The number of decimal places
+	 * @return	string
 	 */
-	function elapsed_time($decimals = 6)
+	public function elapsed_time($decimals = 6)
 	{
 		return number_format($this->benchmark, $decimals);
 	}
@@ -645,10 +1065,9 @@ class CI_DB_driver {
 	/**
 	 * Returns the total number of queries
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function total_queries()
+	public function total_queries()
 	{
 		return $this->query_count;
 	}
@@ -658,10 +1077,9 @@ class CI_DB_driver {
 	/**
 	 * Returns the last query that was executed
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	string
 	 */
-	function last_query()
+	public function last_query()
 	{
 		return end($this->queries);
 	}
@@ -674,23 +1092,63 @@ class CI_DB_driver {
 	 * Escapes data based on type
 	 * Sets boolean and null types
 	 *
-	 * @access	public
 	 * @param	string
 	 * @return	mixed
 	 */
-	function escape($str)
+	public function escape($str)
 	{
-		if (is_string($str))
+		if (is_array($str))
 		{
-			$str = "'".$this->escape_str($str)."'";
+			$str = array_map(array(&$this, 'escape'), $str);
+			return $str;
+		}
+		elseif (is_string($str) OR (is_object($str) && method_exists($str, '__toString')))
+		{
+			return "'".$this->escape_str($str)."'";
 		}
 		elseif (is_bool($str))
 		{
-			$str = ($str === FALSE) ? 0 : 1;
+			return ($str === FALSE) ? 0 : 1;
+		}
+		elseif ($str === NULL)
+		{
+			return 'NULL';
 		}
-		elseif (is_null($str))
+
+		return $str;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Escape String
+	 *
+	 * @param	string|string[]	$str	Input string
+	 * @param	bool	$like	Whether or not the string will be used in a LIKE condition
+	 * @return	string
+	 */
+	public function escape_str($str, $like = FALSE)
+	{
+		if (is_array($str))
+		{
+			foreach ($str as $key => $val)
+			{
+				$str[$key] = $this->escape_str($val, $like);
+			}
+
+			return $str;
+		}
+
+		$str = $this->_escape_str($str);
+
+		// escape LIKE condition wildcards
+		if ($like === TRUE)
 		{
-			$str = 'NULL';
+			return str_replace(
+				array($this->_like_escape_chr, '%', '_'),
+				array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
+				$str
+			);
 		}
 
 		return $str;
@@ -704,11 +1162,10 @@ class CI_DB_driver {
 	 * Calls the individual driver for platform
 	 * specific escaping for LIKE conditions
 	 *
-	 * @access	public
-	 * @param	string
+	 * @param	string|string[]
 	 * @return	mixed
 	 */
-	function escape_like_str($str)
+	public function escape_like_str($str)
 	{
 		return $this->escape_str($str, TRUE);
 	}
@@ -716,25 +1173,60 @@ class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Platform-dependent string escape
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	protected function _escape_str($str)
+	{
+		return str_replace("'", "''", remove_invisible_characters($str, FALSE));
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Primary
 	 *
-	 * Retrieves the primary key.  It assumes that the row in the first
+	 * Retrieves the primary key. It assumes that the row in the first
 	 * position is the primary key
 	 *
-	 * @access	public
-	 * @param	string	the table name
+	 * @param	string	$table	Table name
 	 * @return	string
 	 */
-	function primary($table = '')
+	public function primary($table)
 	{
 		$fields = $this->list_fields($table);
+		return is_array($fields) ? current($fields) : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * "Count All" query
+	 *
+	 * Generates a platform-specific query string that counts all records in
+	 * the specified database
+	 *
+	 * @param	string
+	 * @return	int
+	 */
+	public function count_all($table = '')
+	{
+		if ($table === '')
+		{
+			return 0;
+		}
 
-		if ( ! is_array($fields))
+		$query = $this->query($this->_count_string.$this->escape_identifiers('numrows').' FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE));
+		if ($query->num_rows() === 0)
 		{
-			return FALSE;
+			return 0;
 		}
 
-		return current($fields);
+		$query = $query->row();
+		$this->_reset_select();
+		return (int) $query->numrows;
 	}
 
 	// --------------------------------------------------------------------
@@ -742,10 +1234,10 @@ class CI_DB_driver {
 	/**
 	 * Returns an array of table names
 	 *
-	 * @access	public
+	 * @param	string	$constrain_by_prefix = FALSE
 	 * @return	array
 	 */
-	function list_tables($constrain_by_prefix = FALSE)
+	public function list_tables($constrain_by_prefix = FALSE)
 	{
 		// Is there a cached result?
 		if (isset($this->data_cache['table_names']))
@@ -755,32 +1247,40 @@ class CI_DB_driver {
 
 		if (FALSE === ($sql = $this->_list_tables($constrain_by_prefix)))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
 
-		$retval = array();
+		$this->data_cache['table_names'] = array();
 		$query = $this->query($sql);
 
-		if ($query->num_rows() > 0)
+		foreach ($query->result_array() as $row)
 		{
-			foreach ($query->result_array() as $row)
+			// Do we know from which column to get the table name?
+			if ( ! isset($key))
 			{
-				if (isset($row['TABLE_NAME']))
+				if (isset($row['table_name']))
 				{
-					$retval[] = $row['TABLE_NAME'];
+					$key = 'table_name';
+				}
+				elseif (isset($row['TABLE_NAME']))
+				{
+					$key = 'TABLE_NAME';
 				}
 				else
 				{
-					$retval[] = array_shift($row);
+					/* We have no other choice but to just get the first element's key.
+					 * Due to array_shift() accepting its argument by reference, if
+					 * E_STRICT is on, this would trigger a warning. So we'll have to
+					 * assign it first.
+					 */
+					$key = array_keys($row);
+					$key = array_shift($key);
 				}
 			}
+
+			$this->data_cache['table_names'][] = $row[$key];
 		}
 
-		$this->data_cache['table_names'] = $retval;
 		return $this->data_cache['table_names'];
 	}
 
@@ -788,24 +1288,24 @@ class CI_DB_driver {
 
 	/**
 	 * Determine if a particular table exists
-	 * @access	public
-	 * @return	boolean
+	 *
+	 * @param	string	$table_name
+	 * @return	bool
 	 */
-	function table_exists($table_name)
+	public function table_exists($table_name)
 	{
-		return ( ! in_array($this->_protect_identifiers($table_name, TRUE, FALSE, FALSE), $this->list_tables())) ? FALSE : TRUE;
+		return in_array($this->protect_identifiers($table_name, TRUE, FALSE, FALSE), $this->list_tables());
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Fetch MySQL Field Names
+	 * Fetch Field Names
 	 *
-	 * @access	public
-	 * @param	string	the table name
+	 * @param	string	$table	Table name
 	 * @return	array
 	 */
-	function list_fields($table = '')
+	public function list_fields($table)
 	{
 		// Is there a cached result?
 		if (isset($this->data_cache['field_names'][$table]))
@@ -813,40 +1313,37 @@ class CI_DB_driver {
 			return $this->data_cache['field_names'][$table];
 		}
 
-		if ($table == '')
-		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_field_param_missing');
-			}
-			return FALSE;
-		}
-
 		if (FALSE === ($sql = $this->_list_columns($table)))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
 
 		$query = $this->query($sql);
+		$this->data_cache['field_names'][$table] = array();
 
-		$retval = array();
 		foreach ($query->result_array() as $row)
 		{
-			if (isset($row['COLUMN_NAME']))
+			// Do we know from where to get the column's name?
+			if ( ! isset($key))
 			{
-				$retval[] = $row['COLUMN_NAME'];
-			}
-			else
-			{
-				$retval[] = current($row);
+				if (isset($row['column_name']))
+				{
+					$key = 'column_name';
+				}
+				elseif (isset($row['COLUMN_NAME']))
+				{
+					$key = 'COLUMN_NAME';
+				}
+				else
+				{
+					// We have no other choice but to just get the first element's key.
+					$key = key($row);
+				}
 			}
+
+			$this->data_cache['field_names'][$table][] = $row[$key];
 		}
 
-		$this->data_cache['field_names'][$table] = $retval;
 		return $this->data_cache['field_names'][$table];
 	}
 
@@ -854,14 +1351,14 @@ class CI_DB_driver {
 
 	/**
 	 * Determine if a particular field exists
-	 * @access	public
+	 *
 	 * @param	string
 	 * @param	string
-	 * @return	boolean
+	 * @return	bool
 	 */
-	function field_exists($field_name, $table_name)
+	public function field_exists($field_name, $table_name)
 	{
-		return ( ! in_array($field_name, $this->list_fields($table_name))) ? FALSE : TRUE;
+		return in_array($field_name, $this->list_fields($table_name));
 	}
 
 	// --------------------------------------------------------------------
@@ -869,24 +1366,75 @@ class CI_DB_driver {
 	/**
 	 * Returns an object with field data
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @return	object
+	 * @param	string	$table	the table name
+	 * @return	array
 	 */
-	function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table == '')
+		$query = $this->query($this->_field_data($this->protect_identifiers($table, TRUE, NULL, FALSE)));
+		return ($query) ? $query->field_data() : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Escape the SQL Identifiers
+	 *
+	 * This function escapes column and table names
+	 *
+	 * @param	mixed
+	 * @return	mixed
+	 */
+	public function escape_identifiers($item)
+	{
+		if ($this->_escape_char === '' OR empty($item) OR in_array($item, $this->_reserved_identifiers))
 		{
-			if ($this->db_debug)
+			return $item;
+		}
+		elseif (is_array($item))
+		{
+			foreach ($item as $key => $value)
 			{
-				return $this->display_error('db_field_param_missing');
+				$item[$key] = $this->escape_identifiers($value);
 			}
-			return FALSE;
+
+			return $item;
+		}
+		// Avoid breaking functions and literal values inside queries
+		elseif (ctype_digit($item) OR $item[0] === "'" OR ($this->_escape_char !== '"' && $item[0] === '"') OR strpos($item, '(') !== FALSE)
+		{
+			return $item;
 		}
 
-		$query = $this->query($this->_field_data($this->_protect_identifiers($table, TRUE, NULL, FALSE)));
+		static $preg_ec = array();
 
-		return $query->field_data();
+		if (empty($preg_ec))
+		{
+			if (is_array($this->_escape_char))
+			{
+				$preg_ec = array(
+					preg_quote($this->_escape_char[0], '/'),
+					preg_quote($this->_escape_char[1], '/'),
+					$this->_escape_char[0],
+					$this->_escape_char[1]
+				);
+			}
+			else
+			{
+				$preg_ec[0] = $preg_ec[1] = preg_quote($this->_escape_char, '/');
+				$preg_ec[2] = $preg_ec[3] = $this->_escape_char;
+			}
+		}
+
+		foreach ($this->_reserved_identifiers as $id)
+		{
+			if (strpos($item, '.'.$id) !== FALSE)
+			{
+				return preg_replace('/'.$preg_ec[0].'?([^'.$preg_ec[1].'\.]+)'.$preg_ec[1].'?\./i', $preg_ec[2].'$1'.$preg_ec[3].'.', $item);
+			}
+		}
+
+		return preg_replace('/'.$preg_ec[0].'?([^'.$preg_ec[1].'\.]+)'.$preg_ec[1].'?(\.)?/i', $preg_ec[2].'$1'.$preg_ec[3].'$2', $item);
 	}
 
 	// --------------------------------------------------------------------
@@ -894,23 +1442,38 @@ class CI_DB_driver {
 	/**
 	 * Generate an insert string
 	 *
-	 * @access	public
 	 * @param	string	the table upon which the query will be performed
 	 * @param	array	an associative array data of key/values
 	 * @return	string
 	 */
-	function insert_string($table, $data)
+	public function insert_string($table, $data)
 	{
-		$fields = array();
-		$values = array();
+		$fields = $values = array();
 
 		foreach ($data as $key => $val)
 		{
-			$fields[] = $this->_escape_identifiers($key);
+			$fields[] = $this->escape_identifiers($key);
 			$values[] = $this->escape($val);
 		}
 
-		return $this->_insert($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $values);
+		return $this->_insert($this->protect_identifiers($table, TRUE, NULL, FALSE), $fields, $values);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the insert keys
+	 * @param	array	the insert values
+	 * @return	string
+	 */
+	protected function _insert($table, $keys, $values)
+	{
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
 	}
 
 	// --------------------------------------------------------------------
@@ -918,51 +1481,53 @@ class CI_DB_driver {
 	/**
 	 * Generate an update string
 	 *
-	 * @access	public
 	 * @param	string	the table upon which the query will be performed
 	 * @param	array	an associative array data of key/values
 	 * @param	mixed	the "where" statement
 	 * @return	string
 	 */
-	function update_string($table, $data, $where)
+	public function update_string($table, $data, $where)
 	{
-		if ($where == '')
+		if (empty($where))
 		{
-			return false;
+			return FALSE;
 		}
 
+		$this->where($where);
+
 		$fields = array();
 		foreach ($data as $key => $val)
 		{
-			$fields[$this->_protect_identifiers($key)] = $this->escape($val);
+			$fields[$this->protect_identifiers($key)] = $this->escape($val);
 		}
 
-		if ( ! is_array($where))
-		{
-			$dest = array($where);
-		}
-		else
-		{
-			$dest = array();
-			foreach ($where as $key => $val)
-			{
-				$prefix = (count($dest) == 0) ? '' : ' AND ';
-
-				if ($val !== '')
-				{
-					if ( ! $this->_has_operator($key))
-					{
-						$key .= ' =';
-					}
+		$sql = $this->_update($this->protect_identifiers($table, TRUE, NULL, FALSE), $fields);
+		$this->_reset_write();
+		return $sql;
+	}
 
-					$val = ' '.$this->escape($val);
-				}
+	// --------------------------------------------------------------------
 
-				$dest[] = $prefix.$key.$val;
-			}
+	/**
+	 * Update statement
+	 *
+	 * Generates a platform-specific update string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the update data
+	 * @return	string
+	 */
+	protected function _update($table, $values)
+	{
+		foreach ($values as $key => $val)
+		{
+			$valstr[] = $key.' = '.$val;
 		}
 
-		return $this->_update($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $dest);
+		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
+			.$this->_compile_wh('qb_where')
+			.$this->_compile_order_by()
+			.($this->qb_limit ? ' LIMIT '.$this->qb_limit : '');
 	}
 
 	// --------------------------------------------------------------------
@@ -970,19 +1535,50 @@ class CI_DB_driver {
 	/**
 	 * Tests whether the string has an SQL operator
 	 *
-	 * @access	private
 	 * @param	string
 	 * @return	bool
 	 */
-	function _has_operator($str)
+	protected function _has_operator($str)
 	{
-		$str = trim($str);
-		if ( ! preg_match("/(\s|<|>|!|=|is null|is not null)/i", $str))
-		{
-			return FALSE;
-		}
+		return (bool) preg_match('/(<|>|!|=|\sIS NULL|\sIS NOT NULL|\sEXISTS|\sBETWEEN|\sLIKE|\sIN\s*\(|\s)/i', trim($str));
+	}
 
-		return TRUE;
+	// --------------------------------------------------------------------
+
+	/**
+	 * Returns the SQL string operator
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	protected function _get_operator($str)
+	{
+		static $_operators;
+
+		if (empty($_operators))
+		{
+			$_les = ($this->_like_escape_str !== '')
+				? '\s+'.preg_quote(trim(sprintf($this->_like_escape_str, $this->_like_escape_chr)), '/')
+				: '';
+			$_operators = array(
+				'\s*(?:<|>|!)?=\s*',             // =, <=, >=, !=
+				'\s*<>?\s*',                     // <, <>
+				'\s*>\s*',                       // >
+				'\s+IS NULL',                    // IS NULL
+				'\s+IS NOT NULL',                // IS NOT NULL
+				'\s+EXISTS\s*\(.*\)',        // EXISTS(sql)
+				'\s+NOT EXISTS\s*\(.*\)',    // NOT EXISTS(sql)
+				'\s+BETWEEN\s+',                 // BETWEEN value AND value
+				'\s+IN\s*\(.*\)',            // IN(list)
+				'\s+NOT IN\s*\(.*\)',        // NOT IN (list)
+				'\s+LIKE\s+\S.*('.$_les.')?',    // LIKE 'expr'[ ESCAPE '%s']
+				'\s+NOT LIKE\s+\S.*('.$_les.')?' // NOT LIKE 'expr'[ ESCAPE '%s']
+			);
+
+		}
+
+		return preg_match('/'.implode('|', $_operators).'/i', $str, $match)
+			? $match[0] : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -990,14 +1586,12 @@ class CI_DB_driver {
 	/**
 	 * Enables a native PHP function to be run, using a platform agnostic wrapper.
 	 *
-	 * @access	public
-	 * @param	string	the function name
-	 * @param	mixed	any parameters needed by the function
+	 * @param	string	$function	Function name
 	 * @return	mixed
 	 */
-	function call_function($function)
+	public function call_function($function)
 	{
-		$driver = ($this->dbdriver == 'postgre') ? 'pg_' : $this->dbdriver.'_';
+		$driver = ($this->dbdriver === 'postgre') ? 'pg_' : $this->dbdriver.'_';
 
 		if (FALSE === strpos($driver, $function))
 		{
@@ -1006,24 +1600,12 @@ class CI_DB_driver {
 
 		if ( ! function_exists($function))
 		{
-			if ($this->db_debug)
-			{
-				return $this->display_error('db_unsupported_function');
-			}
-			return FALSE;
-		}
-		else
-		{
-			$args = (func_num_args() > 1) ? array_splice(func_get_args(), 1) : null;
-			if (is_null($args))
-			{
-				return call_user_func($function);
-			}
-			else
-			{
-				return call_user_func_array($function, $args);
-			}
+			return ($this->db_debug) ? $this->display_error('db_unsupported_function') : FALSE;
 		}
+
+		return (func_num_args() > 1)
+			? call_user_func_array($function, array_slice(func_get_args(), 1))
+			: call_user_func($function);
 	}
 
 	// --------------------------------------------------------------------
@@ -1031,11 +1613,10 @@ class CI_DB_driver {
 	/**
 	 * Set Cache Directory Path
 	 *
-	 * @access	public
 	 * @param	string	the path to the cache directory
 	 * @return	void
 	 */
-	function cache_set_path($path = '')
+	public function cache_set_path($path = '')
 	{
 		$this->cachedir = $path;
 	}
@@ -1045,13 +1626,11 @@ class CI_DB_driver {
 	/**
 	 * Enable Query Caching
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	bool	cache_on value
 	 */
-	function cache_on()
+	public function cache_on()
 	{
-		$this->cache_on = TRUE;
-		return TRUE;
+		return $this->cache_on = TRUE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1059,31 +1638,27 @@ class CI_DB_driver {
 	/**
 	 * Disable Query Caching
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	bool	cache_on value
 	 */
-	function cache_off()
+	public function cache_off()
 	{
-		$this->cache_on = FALSE;
-		return FALSE;
+		return $this->cache_on = FALSE;
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
 	 * Delete the cache files associated with a particular URI
 	 *
-	 * @access	public
-	 * @return	void
+	 * @param	string	$segment_one = ''
+	 * @param	string	$segment_two = ''
+	 * @return	bool
 	 */
-	function cache_delete($segment_one = '', $segment_two = '')
+	public function cache_delete($segment_one = '', $segment_two = '')
 	{
-		if ( ! $this->_cache_init())
-		{
-			return FALSE;
-		}
-		return $this->CACHE->delete($segment_one, $segment_two);
+		return $this->_cache_init()
+			? $this->CACHE->delete($segment_one, $segment_two)
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1091,17 +1666,13 @@ class CI_DB_driver {
 	/**
 	 * Delete All cache files
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	bool
 	 */
-	function cache_delete_all()
+	public function cache_delete_all()
 	{
-		if ( ! $this->_cache_init())
-		{
-			return FALSE;
-		}
-
-		return $this->CACHE->delete_all();
+		return $this->_cache_init()
+			? $this->CACHE->delete_all()
+			: FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -1109,22 +1680,17 @@ class CI_DB_driver {
 	/**
 	 * Initialize the Cache Class
 	 *
-	 * @access	private
-	 * @return	void
+	 * @return	bool
 	 */
-	function _cache_init()
+	protected function _cache_init()
 	{
-		if (is_object($this->CACHE) AND class_exists('CI_DB_Cache'))
+		if ( ! class_exists('CI_DB_Cache', FALSE))
 		{
-			return TRUE;
+			require_once(BASEPATH.'database/DB_cache.php');
 		}
-
-		if ( ! class_exists('CI_DB_Cache'))
+		elseif (is_object($this->CACHE))
 		{
-			if ( ! @include(BASEPATH.'database/DB_cache.php'))
-			{
-				return $this->cache_off();
-			}
+			return TRUE;
 		}
 
 		$this->CACHE = new CI_DB_Cache($this); // pass db object to support multiple db connections and returned db objects
@@ -1136,15 +1702,28 @@ class CI_DB_driver {
 	/**
 	 * Close DB Connection
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function close()
+	public function close()
 	{
-		if (is_resource($this->conn_id) OR is_object($this->conn_id))
+		if ($this->conn_id)
 		{
-			$this->_close($this->conn_id);
+			$this->_close();
+			$this->conn_id = FALSE;
 		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Close DB Connection
+	 *
+	 * This method would be overridden by most of the drivers.
+	 *
+	 * @return	void
+	 */
+	protected function _close()
+	{
 		$this->conn_id = FALSE;
 	}
 
@@ -1153,49 +1732,54 @@ class CI_DB_driver {
 	/**
 	 * Display an error message
 	 *
-	 * @access	public
 	 * @param	string	the error message
 	 * @param	string	any "swap" values
-	 * @param	boolean	whether to localize the message
-	 * @return	string	sends the application/error_db.php template
+	 * @param	bool	whether to localize the message
+	 * @return	string	sends the application/views/errors/error_db.php template
 	 */
-	function display_error($error = '', $swap = '', $native = FALSE)
+	public function display_error($error = '', $swap = '', $native = FALSE)
 	{
 		$LANG =& load_class('Lang', 'core');
 		$LANG->load('db');
 
 		$heading = $LANG->line('db_error_heading');
 
-		if ($native == TRUE)
+		if ($native === TRUE)
 		{
-			$message = $error;
+			$message = (array) $error;
 		}
 		else
 		{
-			$message = ( ! is_array($error)) ? array(str_replace('%s', $swap, $LANG->line($error))) : $error;
+			$message = is_array($error) ? $error : array(str_replace('%s', $swap, $LANG->line($error)));
 		}
 
 		// Find the most likely culprit of the error by going through
 		// the backtrace until the source file is no longer in the
 		// database folder.
-
 		$trace = debug_backtrace();
-
 		foreach ($trace as $call)
 		{
-			if (isset($call['file']) && strpos($call['file'], BASEPATH.'database') === FALSE)
+			if (isset($call['file'], $call['class']))
 			{
-				// Found it - use a relative path for safety
-				$message[] = 'Filename: '.str_replace(array(BASEPATH, APPPATH), '', $call['file']);
-				$message[] = 'Line Number: '.$call['line'];
+				// We'll need this on Windows, as APPPATH and BASEPATH will always use forward slashes
+				if (DIRECTORY_SEPARATOR !== '/')
+				{
+					$call['file'] = str_replace('\\', '/', $call['file']);
+				}
 
-				break;
+				if (strpos($call['file'], BASEPATH.'database') === FALSE && strpos($call['class'], 'Loader') === FALSE)
+				{
+					// Found it - use a relative path for safety
+					$message[] = 'Filename: '.str_replace(array(APPPATH, BASEPATH), '', $call['file']);
+					$message[] = 'Line Number: '.$call['line'];
+					break;
+				}
 			}
 		}
 
 		$error =& load_class('Exceptions', 'core');
 		echo $error->show_error($heading, $message, 'error_db');
-		exit;
+		exit(8); // EXIT_DATABASE
 	}
 
 	// --------------------------------------------------------------------
@@ -1203,29 +1787,13 @@ class CI_DB_driver {
 	/**
 	 * Protect Identifiers
 	 *
-	 * This function adds backticks if appropriate based on db type
-	 *
-	 * @access	private
-	 * @param	mixed	the item to escape
-	 * @return	mixed	the item with backticks
-	 */
-	function protect_identifiers($item, $prefix_single = FALSE)
-	{
-		return $this->_protect_identifiers($item, $prefix_single);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Protect Identifiers
-	 *
-	 * This function is used extensively by the Active Record class, and by
+	 * This function is used extensively by the Query Builder class, and by
 	 * a couple functions in this class.
 	 * It takes a column or table name (optionally with an alias) and inserts
-	 * the table prefix onto it.  Some logic is necessary in order to deal with
-	 * column names that include the path.  Consider a query like this:
+	 * the table prefix onto it. Some logic is necessary in order to deal with
+	 * column names that include the path. Consider a query like this:
 	 *
-	 * SELECT * FROM hostname.database.table.column AS c FROM hostname.database.table
+	 * SELECT hostname.database.table.column AS c FROM hostname.database.table
 	 *
 	 * Or a query with aliasing:
 	 *
@@ -1236,14 +1804,13 @@ class CI_DB_driver {
 	 * insert the table prefix (if it exists) in the proper position, and escape only
 	 * the correct identifiers.
 	 *
-	 * @access	private
 	 * @param	string
 	 * @param	bool
 	 * @param	mixed
 	 * @param	bool
 	 * @return	string
 	 */
-	function _protect_identifiers($item, $prefix_single = FALSE, $protect_identifiers = NULL, $field_exists = TRUE)
+	public function protect_identifiers($item, $prefix_single = FALSE, $protect_identifiers = NULL, $field_exists = TRUE)
 	{
 		if ( ! is_bool($protect_identifiers))
 		{
@@ -1253,37 +1820,48 @@ class CI_DB_driver {
 		if (is_array($item))
 		{
 			$escaped_array = array();
-
 			foreach ($item as $k => $v)
 			{
-				$escaped_array[$this->_protect_identifiers($k)] = $this->_protect_identifiers($v);
+				$escaped_array[$this->protect_identifiers($k)] = $this->protect_identifiers($v, $prefix_single, $protect_identifiers, $field_exists);
 			}
 
 			return $escaped_array;
 		}
 
+		// This is basically a bug fix for queries that use MAX, MIN, etc.
+		// If a parenthesis is found we know that we do not need to
+		// escape the data or add a prefix. There's probably a more graceful
+		// way to deal with this, but I'm not thinking of it -- Rick
+		//
+		// Added exception for single quotes as well, we don't want to alter
+		// literal strings. -- Narf
+		if (strcspn($item, "()'") !== strlen($item))
+		{
+			return $item;
+		}
+
 		// Convert tabs or multiple spaces into single spaces
-		$item = preg_replace('/[\t ]+/', ' ', $item);
+		$item = preg_replace('/\s+/', ' ', trim($item));
 
 		// If the item has an alias declaration we remove it and set it aside.
-		// Basically we remove everything to the right of the first space
-		if (strpos($item, ' ') !== FALSE)
+		// Note: strripos() is used in order to support spaces in table names
+		if ($offset = strripos($item, ' AS '))
 		{
-			$alias = strstr($item, ' ');
-			$item = substr($item, 0, - strlen($alias));
+			$alias = ($protect_identifiers)
+				? substr($item, $offset, 4).$this->escape_identifiers(substr($item, $offset + 4))
+				: substr($item, $offset);
+			$item = substr($item, 0, $offset);
 		}
-		else
+		elseif ($offset = strrpos($item, ' '))
 		{
-			$alias = '';
+			$alias = ($protect_identifiers)
+				? ' '.$this->escape_identifiers(substr($item, $offset + 1))
+				: substr($item, $offset);
+			$item = substr($item, 0, $offset);
 		}
-
-		// This is basically a bug fix for queries that use MAX, MIN, etc.
-		// If a parenthesis is found we know that we do not need to
-		// escape the data or add a prefix.  There's probably a more graceful
-		// way to deal with this, but I'm not thinking of it -- Rick
-		if (strpos($item, '(') !== FALSE)
+		else
 		{
-			return $item.$alias;
+			$alias = '';
 		}
 
 		// Break the string apart if it contains periods, then insert the table prefix
@@ -1291,12 +1869,15 @@ class CI_DB_driver {
 		// with an alias. While we're at it, we will escape the components
 		if (strpos($item, '.') !== FALSE)
 		{
-			$parts	= explode('.', $item);
+			$parts = explode('.', $item);
 
 			// Does the first segment of the exploded item match
-			// one of the aliases previously identified?  If so,
+			// one of the aliases previously identified? If so,
 			// we have nothing more to do other than escape the item
-			if (in_array($parts[0], $this->ar_aliased_tables))
+			//
+			// NOTE: The ! empty() condition prevents this method
+			//       from breaking when QB isn't enabled.
+			if ( ! empty($this->qb_aliased_tables) && in_array($parts[0], $this->qb_aliased_tables))
 			{
 				if ($protect_identifiers === TRUE)
 				{
@@ -1304,17 +1885,18 @@ class CI_DB_driver {
 					{
 						if ( ! in_array($val, $this->_reserved_identifiers))
 						{
-							$parts[$key] = $this->_escape_identifiers($val);
+							$parts[$key] = $this->escape_identifiers($val);
 						}
 					}
 
 					$item = implode('.', $parts);
 				}
+
 				return $item.$alias;
 			}
 
-			// Is there a table prefix defined in the config file?  If not, no need to do anything
-			if ($this->dbprefix != '')
+			// Is there a table prefix defined in the config file? If not, no need to do anything
+			if ($this->dbprefix !== '')
 			{
 				// We now add the table prefix based on some logic.
 				// Do we have 4 segments (hostname.database.table.column)?
@@ -1338,19 +1920,18 @@ class CI_DB_driver {
 
 				// This flag is set when the supplied $item does not contain a field name.
 				// This can happen when this function is being called from a JOIN.
-				if ($field_exists == FALSE)
+				if ($field_exists === FALSE)
 				{
 					$i++;
 				}
 
 				// Verify table prefix and replace if necessary
-				if ($this->swap_pre != '' && strncmp($parts[$i], $this->swap_pre, strlen($this->swap_pre)) === 0)
+				if ($this->swap_pre !== '' && strpos($parts[$i], $this->swap_pre) === 0)
 				{
-					$parts[$i] = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $parts[$i]);
+					$parts[$i] = preg_replace('/^'.$this->swap_pre.'(\S+?)/', $this->dbprefix.'\\1', $parts[$i]);
 				}
-
 				// We only add the table prefix if it does not already exist
-				if (substr($parts[$i], 0, strlen($this->dbprefix)) != $this->dbprefix)
+				elseif (strpos($parts[$i], $this->dbprefix) !== 0)
 				{
 					$parts[$i] = $this->dbprefix.$parts[$i];
 				}
@@ -1361,31 +1942,30 @@ class CI_DB_driver {
 
 			if ($protect_identifiers === TRUE)
 			{
-				$item = $this->_escape_identifiers($item);
+				$item = $this->escape_identifiers($item);
 			}
 
 			return $item.$alias;
 		}
 
-		// Is there a table prefix?  If not, no need to insert it
-		if ($this->dbprefix != '')
+		// Is there a table prefix? If not, no need to insert it
+		if ($this->dbprefix !== '')
 		{
 			// Verify table prefix and replace if necessary
-			if ($this->swap_pre != '' && strncmp($item, $this->swap_pre, strlen($this->swap_pre)) === 0)
+			if ($this->swap_pre !== '' && strpos($item, $this->swap_pre) === 0)
 			{
-				$item = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $item);
+				$item = preg_replace('/^'.$this->swap_pre.'(\S+?)/', $this->dbprefix.'\\1', $item);
 			}
-
 			// Do we prefix an item with no segments?
-			if ($prefix_single == TRUE AND substr($item, 0, strlen($this->dbprefix)) != $this->dbprefix)
+			elseif ($prefix_single === TRUE && strpos($item, $this->dbprefix) !== 0)
 			{
 				$item = $this->dbprefix.$item;
 			}
 		}
 
-		if ($protect_identifiers === TRUE AND ! in_array($item, $this->_reserved_identifiers))
+		if ($protect_identifiers === TRUE && ! in_array($item, $this->_reserved_identifiers))
 		{
-			$item = $this->_escape_identifiers($item);
+			$item = $this->escape_identifiers($item);
 		}
 
 		return $item.$alias;
@@ -1394,9 +1974,8 @@ class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Dummy method that allows Active Record class to be disabled
-	 *
-	 * This function is used extensively by every db driver.
+	 * Dummy method that allows Query Builder class to be disabled
+	 * and keep count_all() working.
 	 *
 	 * @return	void
 	 */
@@ -1405,6 +1984,3 @@ class CI_DB_driver {
 	}
 
 }
-
-/* End of file DB_driver.php */
-/* Location: ./system/database/DB_driver.php */
\ No newline at end of file