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

1 files changed, 181 insertions, 334 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