Merge branch develop of github.com:/EllisLab/CodeIgniter into session

4 files changed, 309 insertions, 564 deletions

diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index b39bd9360..1714704a8 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -1,100 +1,115 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.1.6 or newer
+ * 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		ExpressionEngine Dev Team
- * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
- * @license		http://codeigniter.com/user_guide/license.html
+ * @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 1.0
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * MS SQL 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		ExpressionEngine Dev Team
+ * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_driver extends CI_DB {
 
-	var $dbdriver = 'mssql';
+	public $dbdriver = 'mssql';
 
 	// The character used for escaping
-	var $_escape_char = '';
+	protected $_escape_char = '"';
 
 	// clause and character used for LIKE escape sequences
-	var $_like_escape_str = " ESCAPE '%s' ";
-	var $_like_escape_chr = '!';
+	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.
-	 */
-	var $_count_string = "SELECT COUNT(*) AS ";
-	var $_random_keyword = ' ASC'; // not currently supported
+	protected $_random_keyword = ' NEWID()';
 
-	/**
-	 * Non-persistent database connection
+	// MSSQL-specific properties
+	protected $_quoted_identifier = TRUE;
+
+	/*
+	 * Constructor
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * Appends the port number to the hostname, if needed.
+	 *
+	 * @param	array
+	 * @return	void
 	 */
-	function db_connect()
+	public function __construct($params)
 	{
-		if ($this->port != '')
+		parent::__construct($params);
+
+		if ( ! empty($this->port))
 		{
-			$this->hostname .= ','.$this->port;
+			$this->hostname .= (DIRECTORY_SEPARATOR === '\\' ? ',' : ':').$this->port;
 		}
-
-		return @mssql_connect($this->hostname, $this->username, $this->password);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Persistent database connection
+	 * Non-persistent database connection
 	 *
-	 * @access	private called by the base class
+	 * @param	bool
 	 * @return	resource
 	 */
-	function db_pconnect()
+	public function db_connect($persistent = FALSE)
 	{
-		if ($this->port != '')
+		$this->conn_id = ($persistent)
+				? @mssql_pconnect($this->hostname, $this->username, $this->password)
+				: @mssql_connect($this->hostname, $this->username, $this->password);
+
+		if ( ! $this->conn_id)
 		{
-			$this->hostname .= ','.$this->port;
+			return FALSE;
 		}
 
-		return @mssql_pconnect($this->hostname, $this->username, $this->password);
+		// Determine how identifiers are escaped
+		$query = $this->query('SELECT CASE WHEN (@@OPTIONS | 256) = @@OPTIONS THEN 1 ELSE 0 END AS qi');
+		$query = $query->row_array();
+		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
+		$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
+
+		return $this->conn_id;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Reconnect
-	 *
-	 * Keep / reestablish the db connection if no queries have been
-	 * sent for a length of time exceeding the server's idle timeout
+	 * Persistent database connection
 	 *
-	 * @access	public
-	 * @return	void
+	 * @return	resource
 	 */
-	function reconnect()
+	public function db_pconnect()
 	{
-		// not implemented in MSSQL
+		return $this->db_connect(TRUE);
 	}
 
 	// --------------------------------------------------------------------
@@ -102,30 +117,25 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Select the database
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @param	string	database name
+	 * @return	bool
 	 */
-	function db_select()
+	public function db_select($database = '')
 	{
+		if ($database === '')
+		{
+			$database = $this->database;
+		}
+
 		// Note: The brackets are required in the event that the DB name
 		// contains reserved characters
-		return @mssql_select_db('['.$this->database.']', $this->conn_id);
-	}
-
-	// --------------------------------------------------------------------
+		if (@mssql_select_db($this->escape_identifiers($database), $this->conn_id))
+		{
+			$this->database = $database;
+			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;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -133,49 +143,25 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Execute the query
 	 *
-	 * @access	private called by the base class
 	 * @param	string	an SQL query
-	 * @return	resource
+	 * @return	mixed	resource if rows are returned, bool otherwise
 	 */
-	function _execute($sql)
+	protected function _execute($sql)
 	{
-		$sql = $this->_prep_query($sql);
 		return @mssql_query($sql, $this->conn_id);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Prep the query
-	 *
-	 * If needed, each database adapter can prep the query string
-	 *
-	 * @access	private called by execute()
-	 * @param	string	an SQL query
-	 * @return	string
-	 */
-	function _prep_query($sql)
-	{
-		return $sql;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Begin Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_begin($test_mode = FALSE)
+	public function trans_begin($test_mode = FALSE)
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -183,10 +169,9 @@ class CI_DB_mssql_driver extends CI_DB {
 		// Reset the transaction failure flag.
 		// If the $test_mode flag is set to TRUE transactions will be rolled back
 		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;
+		$this->_trans_failure = ($test_mode === TRUE);
 
-		$this->simple_query('BEGIN TRAN');
-		return TRUE;
+		return $this->simple_query('BEGIN TRAN');
 	}
 
 	// --------------------------------------------------------------------
@@ -194,24 +179,17 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Commit Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_commit()
+	public function trans_commit()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
 
-		$this->simple_query('COMMIT TRAN');
-		return TRUE;
+		return $this->simple_query('COMMIT TRAN');
 	}
 
 	// --------------------------------------------------------------------
@@ -219,24 +197,17 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Rollback Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_rollback()
+	public function trans_rollback()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
 
-		$this->simple_query('ROLLBACK TRAN');
-		return TRUE;
+		return $this->simple_query('ROLLBACK TRAN');
 	}
 
 	// --------------------------------------------------------------------
@@ -244,12 +215,11 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * 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, $like = FALSE)
+	public function escape_str($str, $like = FALSE)
 	{
 		if (is_array($str))
 		{
@@ -267,7 +237,7 @@ class CI_DB_mssql_driver extends CI_DB {
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
-			$str = str_replace(
+			return str_replace(
 				array($this->_like_escape_chr, '%', '_'),
 				array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
 				$str
@@ -282,10 +252,9 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Affected Rows
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function affected_rows()
+	public function affected_rows()
 	{
 		return @mssql_rows_affected($this->conn_id);
 	}
@@ -293,82 +262,33 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	* Insert ID
-	*
-	* Returns the last id created in the Identity column.
-	*
-	* @access public
-	* @return integer
-	*/
-	function insert_id()
+	 * Insert ID
+	 *
+	 * Returns the last id created in the Identity column.
+	 *
+	 * @return	string
+	 */
+	public function insert_id()
 	{
-		$ver = self::_parse_major_version($this->version());
-		$sql = ($ver >= 8 ? "SELECT SCOPE_IDENTITY() AS last_id" : "SELECT @@IDENTITY AS last_id");
-		$query = $this->query($sql);
-		$row = $query->row();
-		return $row->last_id;
-	}
+		$query = version_compare($this->version(), '8', '>=')
+			? 'SELECT SCOPE_IDENTITY() AS last_id'
+			: 'SELECT @@IDENTITY AS last_id';
 
-	// --------------------------------------------------------------------
-
-	/**
-	* Parse major version
-	*
-	* Grabs the major version number from the
-	* database server version string passed in.
-	*
-	* @access private
-	* @param string $version
-	* @return int16 major version number
-	*/
-	function _parse_major_version($version)
-	{
-		preg_match('/([0-9]+)\.([0-9]+)\.([0-9]+)/', $version, $ver_info);
-		return $ver_info[1]; // return the major version b/c that's all we're interested in.
+		$query = $this->query($query);
+		$query = $query->row();
+		return $query->last_id;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	* Version number query string
-	*
-	* @access public
-	* @return string
-	*/
-	function _version()
-	{
-		return "SELECT @@VERSION AS ver";
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * "Count All" query
-	 *
-	 * Generates a platform-specific query string that counts all records in
-	 * the specified database
+	 * Version number query string
 	 *
-	 * @access	public
-	 * @param	string
 	 * @return	string
 	 */
-	function count_all($table = '')
+	protected function _version()
 	{
-		if ($table == '')
-		{
-			return 0;
-		}
-
-		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));
-
-		if ($query->num_rows() == 0)
-		{
-			return 0;
-		}
-
-		$row = $query->row();
-		$this->_reset_select();
-		return (int) $row->numrows;
+		return 'SELECT @@VERSION AS ver';
 	}
 
 	// --------------------------------------------------------------------
@@ -378,22 +298,22 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @access	private
-	 * @param	boolean
+	 * @param	bool
 	 * @return	string
 	 */
-	function _list_tables($prefix_limit = FALSE)
+	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";
+		$sql = 'SELECT '.$this->escape_identifiers('name')
+			.' FROM '.$this->escape_identifiers('sysobjects')
+			.' WHERE '.$this->escape_identifiers('type')." = 'U'";
 
-		// for future compatibility
-		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
+		if ($prefix_limit !== FALSE AND $this->dbprefix !== '')
 		{
-			//$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
-			return FALSE; // not currently supported
+			$sql .= ' AND '.$this->escape_identifiers('name')." LIKE '".$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
-		return $sql;
+		return $sql.' ORDER BY '.$this->escape_identifiers('name');
 	}
 
 	// --------------------------------------------------------------------
@@ -403,11 +323,10 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @access	private
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
 		return "SELECT * FROM INFORMATION_SCHEMA.Columns WHERE TABLE_NAME = '".$table."'";
 	}
@@ -419,82 +338,29 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @access	public
 	 * @param	string	the table name
-	 * @return	object
-	 */
-	function _field_data($table)
-	{
-		return "SELECT TOP 1 * FROM ".$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * The error message string
-	 *
-	 * @access	private
 	 * @return	string
 	 */
-	function _error_message()
+	protected function _field_data($table)
 	{
-		return mssql_get_last_message();
+		return 'SELECT TOP 1 * FROM '.$this->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * The error message number
+	 * Error
 	 *
-	 * @access	private
-	 * @return	integer
-	 */
-	function _error_number()
-	{
-		// Are error numbers supported?
-		return '';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Escape the SQL Identifiers
+	 * Returns an array containing code and message of the last
+	 * database error that has occured.
 	 *
-	 * This function escapes column and table names
-	 *
-	 * @access	private
-	 * @param	string
-	 * @return	string
+	 * @return	array
 	 */
-	function _escape_identifiers($item)
+	public function error()
 	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+		$query = $this->query('SELECT @@ERROR AS code');
+		$query = $query->row();
+		return array('code' => $query->code, 'message' => mssql_get_last_message());
 	}
 
 	// --------------------------------------------------------------------
@@ -505,36 +371,12 @@ class CI_DB_mssql_driver extends CI_DB {
 	 * This function implicitly groups FROM tables so there is no confusion
 	 * about operator precedence in harmony with SQL standards
 	 *
-	 * @access	public
-	 * @param	type
-	 * @return	type
-	 */
-	function _from_tables($tables)
-	{
-		if ( ! is_array($tables))
-		{
-			$tables = array($tables);
-		}
-
-		return implode(', ', $tables);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
+	 * @param	array
 	 * @return	string
 	 */
-	function _insert($table, $keys, $values)
+	protected function _from_tables($tables)
 	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
+		return is_array($tables) ? implode(', ', $tables) : $tables;
 	}
 
 	// --------------------------------------------------------------------
@@ -544,51 +386,47 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
+	 * @param	array	the orderby clause (ignored)
+	 * @param	array	the limit clause (ignored)
+	 * @param	array	the like clause
 	 * @return	string
 	 */
-	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
 	{
-		foreach ($values as $key => $val)
+		foreach($values as $key => $val)
 		{
-			$valstr[] = $key." = ".$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) : '';
+		$where = empty($where) ? '' : ' WHERE '.implode(' ', $where);
 
-		$sql .= $orderby.$limit;
+		if ( ! empty($like))
+		{
+			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
+		}
 
-		return $sql;
+		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).' WHERE '.$where;
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
 	 * 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
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
+	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _truncate($table)
+	protected function _truncate($table)
 	{
-		return "TRUNCATE ".$table;
+		return 'TRUNCATE TABLE '.$table;
 	}
 
 	// --------------------------------------------------------------------
@@ -598,31 +436,24 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the where clause
+	 * @param	array	the like clause
 	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 	{
-		$conditions = '';
-
-		if (count($where) > 0 OR count($like) > 0)
-		{
-			$conditions = "\nWHERE ";
-			$conditions .= implode("\n", $this->ar_where);
+		$conditions = array();
 
-			if (count($where) > 0 && count($like) > 0)
-			{
-				$conditions .= " AND ";
-			}
-			$conditions .= implode("\n", $like);
-		}
+		empty($where) OR $conditions[] = implode(' ', $where);
+		empty($like) OR $conditions[] = implode(' ', $like);
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
+		$conditions = (count($conditions) > 0) ? ' WHERE '.implode(' AND ', $conditions) : '';
 
-		return "DELETE FROM ".$table.$conditions.$limit;
+		return ($limit)
+			? 'WITH ci_delete AS (SELECT TOP '.$limit.' * FROM '.$table.$conditions.') DELETE FROM ci_delete'
+			: 'DELETE FROM '.$table.$conditions;
 	}
 
 	// --------------------------------------------------------------------
@@ -632,17 +463,37 @@ class CI_DB_mssql_driver extends CI_DB {
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @access	public
 	 * @param	string	the sql query string
-	 * @param	integer	the number of rows to limit the query to
-	 * @param	integer	the offset value
+	 * @param	int	the number of rows to limit the query to
+	 * @param	int	the offset value
 	 * @return	string
 	 */
-	function _limit($sql, $limit, $offset)
+	protected function _limit($sql, $limit, $offset)
 	{
-		$i = $limit + $offset;
+		// As of SQL Server 2012 (11.0.*) OFFSET is supported
+		if (version_compare($this->version(), '11', '>='))
+		{
+			return $sql.' OFFSET '.(int) $offset.' ROWS FETCH NEXT '.(int) $limit.' ROWS ONLY';
+		}
+
+		$limit = $offset + $limit;
+
+		// As of SQL Server 2005 (9.0.*) ROW_NUMBER() is supported,
+		// however an ORDER BY clause is required for it to work
+		if (version_compare($this->version(), '9', '>=') && $offset && ! empty($this->qb_orderby))
+		{
+			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+
+			// We have to strip the ORDER BY clause
+			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
 
-		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$i.' ', $sql);
+			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
+				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
+				."\n) ".$this->escape_identifiers('CI_subquery')
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+		}
+
+		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -650,18 +501,14 @@ class CI_DB_mssql_driver extends CI_DB {
 	/**
 	 * Close DB Connection
 	 *
-	 * @access	public
-	 * @param	resource
 	 * @return	void
 	 */
-	function _close($conn_id)
+	protected function _close()
 	{
-		@mssql_close($conn_id);
+		@mssql_close($this->conn_id);
 	}
 
 }
 
-
-
 /* End of file mssql_driver.php */
 /* Location: ./system/database/drivers/mssql/mssql_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/mssql/mssql_forge.php b/system/database/drivers/mssql/mssql_forge.php
index 70b20ecf8..3a3528f7b 100644
--- a/system/database/drivers/mssql/mssql_forge.php
+++ b/system/database/drivers/mssql/mssql_forge.php
@@ -1,135 +1,94 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.1.6 or newer
+ * 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		ExpressionEngine Dev Team
- * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
- * @license		http://codeigniter.com/user_guide/license.html
+ * @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 1.0
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * MS SQL Forge Class
  *
  * @category	Database
- * @author		ExpressionEngine Dev Team
+ * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_forge extends CI_DB_forge {
 
-	/**
-	 * Create database
-	 *
-	 * @access	private
-	 * @param	string	the database name
-	 * @return	bool
-	 */
-	function _create_database($name)
-	{
-		return "CREATE DATABASE ".$name;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Drop database
-	 *
-	 * @access	private
-	 * @param	string	the database name
-	 * @return	bool
-	 */
-	function _drop_database($name)
-	{
-		return "DROP DATABASE ".$name;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Drop Table
-	 *
-	 * @access	private
-	 * @return	bool
-	 */
-	function _drop_table($table)
-	{
-		return "DROP TABLE ".$this->db->_escape_identifiers($table);
-	}
-
-	// --------------------------------------------------------------------
+	protected $_drop_table	= 'DROP TABLE %s';
 
 	/**
 	 * Create Table
 	 *
-	 * @access	private
 	 * @param	string	the table name
 	 * @param	array	the fields
 	 * @param	mixed	primary key(s)
 	 * @param	mixed	key(s)
-	 * @param	boolean	should 'IF NOT EXISTS' be added to the SQL
-	 * @return	bool
+	 * @param	bool	should 'IF NOT EXISTS' be added to the SQL
+	 * @return	string
 	 */
-	function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	protected function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
 	{
-		$sql = 'CREATE TABLE ';
+		$sql = ($if_not_exists === TRUE)
+			? "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'".$table."') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\n"
+			: '';
 
-		if ($if_not_exists === TRUE)
-		{
-			$sql .= 'IF NOT EXISTS ';
-		}
+		$sql .= 'CREATE TABLE '.$this->db->escape_identifiers($table).' (';
 
-		$sql .= $this->db->_escape_identifiers($table)." (";
 		$current_field_count = 0;
-
-		foreach ($fields as $field=>$attributes)
+		foreach ($fields as $field => $attributes)
 		{
 			// Numeric field names aren't allowed in databases, so if the key is
 			// numeric, we know it was assigned by PHP and the developer manually
 			// entered the field information, so we'll simply add it to the list
 			if (is_numeric($field))
 			{
-				$sql .= "\n\t$attributes";
+				$sql .= "\n\t".$attributes;
 			}
 			else
 			{
 				$attributes = array_change_key_case($attributes, CASE_UPPER);
 
-				$sql .= "\n\t".$this->db->_protect_identifiers($field);
+				$sql .= "\n\t".$this->db->escape_identifiers($field).' '.$attributes['TYPE'];
 
-				$sql .=  ' '.$attributes['TYPE'];
-
-				if (array_key_exists('CONSTRAINT', $attributes))
+				if (stripos($attributes['TYPE'], 'INT') === FALSE && ! empty($attributes['CONSTRAINT']))
 				{
 					$sql .= '('.$attributes['CONSTRAINT'].')';
 				}
 
-				if (array_key_exists('UNSIGNED', $attributes) && $attributes['UNSIGNED'] === TRUE)
+				if ( ! empty($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
 				{
 					$sql .= ' UNSIGNED';
 				}
 
-				if (array_key_exists('DEFAULT', $attributes))
+				if (isset($attributes['DEFAULT']))
 				{
-					$sql .= ' DEFAULT \''.$attributes['DEFAULT'].'\'';
+					$sql .= " DEFAULT '".$attributes['DEFAULT']."'";
 				}
 
-				if (array_key_exists('NULL', $attributes) && $attributes['NULL'] === TRUE)
-				{
-					$sql .= ' NULL';
-				}
-				else
-				{
-					$sql .= ' NOT NULL';
-				}
+				$sql .= ( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE)
+					? ' NULL' : ' NOT NULL';
 
-				if (array_key_exists('AUTO_INCREMENT', $attributes) && $attributes['AUTO_INCREMENT'] === TRUE)
+				if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE)
 				{
 					$sql .= ' AUTO_INCREMENT';
 				}
@@ -144,30 +103,22 @@ class CI_DB_mssql_forge extends CI_DB_forge {
 
 		if (count($primary_keys) > 0)
 		{
-			$primary_keys = $this->db->_protect_identifiers($primary_keys);
-			$sql .= ",\n\tPRIMARY KEY (" . implode(', ', $primary_keys) . ")";
+			$sql .= ",\n\tPRIMARY KEY (".implode(', ', $this->db->escape_identifiers($primary_keys)).')';
 		}
 
 		if (is_array($keys) && count($keys) > 0)
 		{
 			foreach ($keys as $key)
 			{
-				if (is_array($key))
-				{
-					$key = $this->db->_protect_identifiers($key);
-				}
-				else
-				{
-					$key = array($this->db->_protect_identifiers($key));
-				}
+				$key = is_array($key)
+					? $this->db->escape_identifiers($key)
+					: array($this->db->escape_identifiers($key));
 
-				$sql .= ",\n\tFOREIGN KEY (" . implode(', ', $key) . ")";
+				$sql .= ",\n\tFOREIGN KEY (".implode(', ', $key).')';
 			}
 		}
 
-		$sql .= "\n)";
-
-		return $sql;
+		return $sql."\n)";
 	}
 
 	// --------------------------------------------------------------------
@@ -178,68 +129,29 @@ class CI_DB_mssql_forge extends CI_DB_forge {
 	 * Generates a platform-specific query so that a table can be altered
 	 * Called by add_column(), drop_column(), and column_alter(),
 	 *
-	 * @access	private
 	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
 	 * @param	string	the column name
 	 * @param	string	the table name
 	 * @param	string	the column definition
 	 * @param	string	the default value
-	 * @param	boolean	should 'NOT NULL' be added
+	 * @param	bool	should 'NOT NULL' be added
 	 * @param	string	the field after which we should add the new field
-	 * @return	object
+	 * @return	string
 	 */
-	function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
+	protected function _alter_table($alter_type, $table, $column_name, $column_definition = '', $default_value = '', $null = '', $after_field = '')
 	{
-		$sql = 'ALTER TABLE '.$this->db->_protect_identifiers($table)." $alter_type ".$this->db->_protect_identifiers($column_name);
+		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table).' '.$alter_type.' '.$this->db->escape_identifiers($column_name);
 
 		// DROP has everything it needs now.
-		if ($alter_type == 'DROP')
+		if ($alter_type === 'DROP')
 		{
 			return $sql;
 		}
 
-		$sql .= " $column_definition";
-
-		if ($default_value != '')
-		{
-			$sql .= " DEFAULT \"$default_value\"";
-		}
-
-		if ($null === NULL)
-		{
-			$sql .= ' NULL';
-		}
-		else
-		{
-			$sql .= ' NOT NULL';
-		}
-
-		if ($after_field != '')
-		{
-			$sql .= ' AFTER ' . $this->db->_protect_identifiers($after_field);
-		}
-
-		return $sql;
-
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Rename a table
-	 *
-	 * Generates a platform-specific query so that a table can be renamed
-	 *
-	 * @access	private
-	 * @param	string	the old table name
-	 * @param	string	the new table name
-	 * @return	string
-	 */
-	function _rename_table($table_name, $new_table_name)
-	{
-		// I think this syntax will work, but can find little documentation on renaming tables in MSSQL
-		$sql = 'ALTER TABLE '.$this->db->_protect_identifiers($table_name)." RENAME TO ".$this->db->_protect_identifiers($new_table_name);
-		return $sql;
+		return $sql.' '.$column_definition
+			.($default_value != '' ? ' DEFAULT "'.$default_value.'"' : '')
+			.($null === NULL ? ' NULL' : ' NOT NULL')
+			.($after_field != '' ? ' AFTER '.$this->db->escape_identifiers($after_field) : '');
 	}
 
 }
diff --git a/system/database/drivers/mssql/mssql_result.php b/system/database/drivers/mssql/mssql_result.php
index 2897ca5a5..aeede3f4b 100644
--- a/system/database/drivers/mssql/mssql_result.php
+++ b/system/database/drivers/mssql/mssql_result.php
@@ -1,40 +1,52 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.1.6 or newer
+ * 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		ExpressionEngine Dev Team
- * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
- * @license		http://codeigniter.com/user_guide/license.html
+ * @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 1.0
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
- * MS SQL Result Class
+ * MSSQL Result Class
  *
  * This class extends the parent result class: CI_DB_result
  *
  * @category	Database
- * @author		ExpressionEngine Dev Team
+ * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/database/
+ * @since	1.3
  */
 class CI_DB_mssql_result extends CI_DB_result {
 
 	/**
 	 * Number of rows in the result set
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function num_rows()
+	public function num_rows()
 	{
-		return @mssql_num_rows($this->result_id);
+		return is_int($this->num_rows)
+			? $this->num_rows
+			: $this->num_rows = @mssql_num_rows($this->result_id);
 	}
 
 	// --------------------------------------------------------------------
@@ -42,10 +54,9 @@ class CI_DB_mssql_result extends CI_DB_result {
 	/**
 	 * Number of fields in the result set
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function num_fields()
+	public function num_fields()
 	{
 		return @mssql_num_fields($this->result_id);
 	}
@@ -57,10 +68,9 @@ class CI_DB_mssql_result extends CI_DB_result {
 	 *
 	 * Generates an array of column names
 	 *
-	 * @access	public
 	 * @return	array
 	 */
-	function list_fields()
+	public function list_fields()
 	{
 		$field_names = array();
 		while ($field = mssql_fetch_field($this->result_id))
@@ -78,20 +88,19 @@ class CI_DB_mssql_result extends CI_DB_result {
 	 *
 	 * Generates an array of objects containing field meta-data
 	 *
-	 * @access	public
 	 * @return	array
 	 */
-	function field_data()
+	public function field_data()
 	{
 		$retval = array();
 		while ($field = mssql_fetch_field($this->result_id))
 		{
-			$F				= new stdClass();
-			$F->name		= $field->name;
-			$F->type		= $field->type;
+			$F		= new stdClass();
+			$F->name	= $field->name;
+			$F->type	= $field->type;
 			$F->max_length	= $field->max_length;
 			$F->primary_key = 0;
-			$F->default		= '';
+			$F->default	= '';
 
 			$retval[] = $F;
 		}
@@ -104,9 +113,9 @@ class CI_DB_mssql_result extends CI_DB_result {
 	/**
 	 * Free the result
 	 *
-	 * @return	null
+	 * @return	void
 	 */
-	function free_result()
+	public function free_result()
 	{
 		if (is_resource($this->result_id))
 		{
@@ -120,14 +129,13 @@ class CI_DB_mssql_result extends CI_DB_result {
 	/**
 	 * Data Seek
 	 *
-	 * Moves the internal pointer to the desired offset.  We call
+	 * Moves the internal pointer to the desired offset. We call
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
-	 * @access	private
-	 * @return	array
+	 * @return	bool
 	 */
-	function _data_seek($n = 0)
+	protected function _data_seek($n = 0)
 	{
 		return mssql_data_seek($this->result_id, $n);
 	}
@@ -139,10 +147,9 @@ class CI_DB_mssql_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an array
 	 *
-	 * @access	private
 	 * @return	array
 	 */
-	function _fetch_assoc()
+	protected function _fetch_assoc()
 	{
 		return mssql_fetch_assoc($this->result_id);
 	}
@@ -154,16 +161,28 @@ class CI_DB_mssql_result extends CI_DB_result {
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @access	private
+	 * @param	string
 	 * @return	object
 	 */
-	function _fetch_object()
+	protected function _fetch_object($class_name = 'stdClass')
 	{
-		return mssql_fetch_object($this->result_id);
+		$row = @mssql_fetch_object($this->result_id);
+
+		if ($class_name === 'stdClass' OR ! $row)
+		{
+			return $row;
+		}
+
+		$class_name = new $class_name();
+		foreach ($row as $key => $value)
+		{
+			$class_name->$key = $value;
+		}
+
+		return $class_name;
 	}
 
 }
 
-
 /* End of file mssql_result.php */
 /* Location: ./system/database/drivers/mssql/mssql_result.php */
\ No newline at end of file
diff --git a/system/database/drivers/mssql/mssql_utility.php b/system/database/drivers/mssql/mssql_utility.php
index 48ecbc72a..69fcec5f6 100644
--- a/system/database/drivers/mssql/mssql_utility.php
+++ b/system/database/drivers/mssql/mssql_utility.php
@@ -1,82 +1,49 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.1.6 or newer
+ * 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		ExpressionEngine Dev Team
- * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
- * @license		http://codeigniter.com/user_guide/license.html
+ * @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 1.0
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * MS SQL Utility Class
  *
  * @category	Database
- * @author		ExpressionEngine Dev Team
+ * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_utility extends CI_DB_utility {
 
-	/**
-	 * List databases
-	 *
-	 * @access	private
-	 * @return	bool
-	 */
-	function _list_databases()
-	{
-		return "EXEC sp_helpdb"; // Can also be: EXEC sp_databases
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Optimize table query
-	 *
-	 * Generates a platform-specific query so that a table can be optimized
-	 *
-	 * @access	private
-	 * @param	string	the table name
-	 * @return	object
-	 */
-	function _optimize_table($table)
-	{
-		return FALSE; // Is this supported in MS SQL?
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Repair table query
-	 *
-	 * Generates a platform-specific query so that a table can be repaired
-	 *
-	 * @access	private
-	 * @param	string	the table name
-	 * @return	object
-	 */
-	function _repair_table($table)
-	{
-		return FALSE; // Is this supported in MS SQL?
-	}
-
-	// --------------------------------------------------------------------
+	protected $_list_databases	= 'EXEC sp_helpdb'; // Can also be: EXEC sp_databases
+	protected $_optimize_table	= 'ALTER INDEX all ON %s REORGANIZE';
 
 	/**
 	 * MSSQL Export
 	 *
-	 * @access	private
 	 * @param	array	Preferences
-	 * @return	mixed
+	 * @return	bool
 	 */
-	function _backup($params = array())
+	protected function _backup($params = array())
 	{
 		// Currently unsupported
 		return $this->db->display_error('db_unsuported_feature');