Merge tag '3.1.5' into dev-ci3

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

1 files changed, 264 insertions, 413 deletions

diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 1823edce8..a2ccd1c80 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -1,648 +1,506 @@
-<?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 1.3.0
  * @filesource
  */
-
-// ------------------------------------------------------------------------
+defined('BASEPATH') OR exit('No direct script access allowed');
 
 /**
  * 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
- * @link		http://codeigniter.com/user_guide/database/
+ * @author		EllisLab Dev Team
+ * @link		https://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_driver extends CI_DB {
 
-	var $dbdriver = 'mssql';
-
-	// The character used for escaping
-	var $_escape_char = '';
-
-	// clause and character used for LIKE escape sequences
-	var $_like_escape_str = " ESCAPE '%s' ";
-	var $_like_escape_chr = '!';
-
-	/**
-	 * The syntax to count rows is slightly different across different
-	 * database engines, so this string appears in each driver and is
-	 * used for the count_all() and count_all_results() functions.
-	 */
-	var $_count_string = "SELECT COUNT(*) AS ";
-	var $_random_keyword = ' ASC'; // not currently supported
-
 	/**
-	 * Non-persistent database connection
+	 * Database driver
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @var	string
 	 */
-	function db_connect()
-	{
-		if ($this->port != '')
-		{
-			$this->hostname .= ','.$this->port;
-		}
-
-		return @mssql_connect($this->hostname, $this->username, $this->password);
-	}
+	public $dbdriver = 'mssql';
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Persistent database connection
+	 * ORDER BY random keyword
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
+	 * @var	array
 	 */
-	function db_pconnect()
-	{
-		if ($this->port != '')
-		{
-			$this->hostname .= ','.$this->port;
-		}
-
-		return @mssql_pconnect($this->hostname, $this->username, $this->password);
-	}
-
-	// --------------------------------------------------------------------
+	protected $_random_keyword = array('NEWID()', 'RAND(%d)');
 
 	/**
-	 * Reconnect
+	 * Quoted identifier flag
 	 *
-	 * Keep / reestablish the db connection if no queries have been
-	 * sent for a length of time exceeding the server's idle timeout
+	 * Whether to use SQL-92 standard quoted identifier
+	 * (double quotes) or brackets for identifier escaping.
 	 *
-	 * @access	public
-	 * @return	void
+	 * @var	bool
 	 */
-	function reconnect()
-	{
-		// not implemented in MSSQL
-	}
+	protected $_quoted_identifier = TRUE;
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Select the database
+	 * Class constructor
 	 *
-	 * @access	private called by the base class
-	 * @return	resource
-	 */
-	function db_select()
-	{
-		// Note: The brackets are required in the event that the DB name
-		// contains reserved characters
-		return @mssql_select_db('['.$this->database.']', $this->conn_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Set client character set
+	 * Appends the port number to the hostname, if needed.
 	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
+	 * @param	array	$params
+	 * @return	void
 	 */
-	function db_set_charset($charset, $collation)
+	public function __construct($params)
 	{
-		// @todo - add support if needed
-		return TRUE;
-	}
+		parent::__construct($params);
 
-	// --------------------------------------------------------------------
-
-	/**
-	 * Execute the query
-	 *
-	 * @access	private called by the base class
-	 * @param	string	an SQL query
-	 * @return	resource
-	 */
-	function _execute($sql)
-	{
-		$sql = $this->_prep_query($sql);
-		return @mssql_query($sql, $this->conn_id);
+		if ( ! empty($this->port))
+		{
+			$this->hostname .= (DIRECTORY_SEPARATOR === '\\' ? ',' : ':').$this->port;
+		}
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Prep the query
-	 *
-	 * If needed, each database adapter can prep the query string
+	 * Non-persistent database connection
 	 *
-	 * @access	private called by execute()
-	 * @param	string	an SQL query
-	 * @return	string
+	 * @param	bool	$persistent
+	 * @return	resource
 	 */
-	function _prep_query($sql)
+	public function db_connect($persistent = FALSE)
 	{
-		return $sql;
-	}
-
-	// --------------------------------------------------------------------
+		$this->conn_id = ($persistent)
+				? mssql_pconnect($this->hostname, $this->username, $this->password)
+				: mssql_connect($this->hostname, $this->username, $this->password);
 
-	/**
-	 * Begin Transaction
-	 *
-	 * @access	public
-	 * @return	bool
-	 */
-	function trans_begin($test_mode = FALSE)
-	{
-		if ( ! $this->trans_enabled)
+		if ( ! $this->conn_id)
 		{
-			return TRUE;
+			return FALSE;
 		}
 
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		// ----------------------------------------------------------------
+
+		// Select the DB... assuming a database name is specified in the config file
+		if ($this->database !== '' && ! $this->db_select())
 		{
-			return TRUE;
+			log_message('error', 'Unable to select database: '.$this->database);
+
+			return ($this->db_debug === TRUE)
+				? $this->display_error('db_unable_to_select', $this->database)
+				: FALSE;
 		}
 
-		// 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;
+		// 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('[', ']');
 
-		$this->simple_query('BEGIN TRAN');
-		return TRUE;
+		return $this->conn_id;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Commit Transaction
+	 * Select the database
 	 *
-	 * @access	public
+	 * @param	string	$database
 	 * @return	bool
 	 */
-	function trans_commit()
+	public function db_select($database = '')
 	{
-		if ( ! $this->trans_enabled)
+		if ($database === '')
 		{
-			return TRUE;
+			$database = $this->database;
 		}
 
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		// Note: Escaping is required in the event that the DB name
+		// contains reserved characters.
+		if (mssql_select_db('['.$database.']', $this->conn_id))
 		{
+			$this->database = $database;
+			$this->data_cache = array();
 			return TRUE;
 		}
 
-		$this->simple_query('COMMIT TRAN');
-		return TRUE;
+		return FALSE;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Rollback Transaction
+	 * Execute the query
 	 *
-	 * @access	public
-	 * @return	bool
+	 * @param	string	$sql	an SQL query
+	 * @return	mixed	resource if rows are returned, bool otherwise
 	 */
-	function trans_rollback()
+	protected function _execute($sql)
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		$this->simple_query('ROLLBACK TRAN');
-		return TRUE;
+		return mssql_query($sql, $this->conn_id);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape String
+	 * Begin Transaction
 	 *
-	 * @access	public
-	 * @param	string
-	 * @param	bool	whether or not the string will be used in a LIKE condition
-	 * @return	string
+	 * @return	bool
 	 */
-	function escape_str($str, $like = FALSE)
+	protected function _trans_begin()
 	{
-		if (is_array($str))
-		{
-			foreach ($str as $key => $val)
-			{
-				$str[$key] = $this->escape_str($val, $like);
-			}
-
-			return $str;
-		}
-
-		// Escape single quotes
-		$str = str_replace("'", "''", remove_invisible_characters($str));
-
-		// escape LIKE condition wildcards
-		if ($like === TRUE)
-		{
-			$str = str_replace(
-				array($this->_like_escape_chr, '%', '_'),
-				array($this->_like_escape_chr.$this->_like_escape_chr, $this->_like_escape_chr.'%', $this->_like_escape_chr.'_'),
-				$str
-			);
-		}
-
-		return $str;
+		return $this->simple_query('BEGIN TRAN');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Affected Rows
+	 * Commit Transaction
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	bool
 	 */
-	function affected_rows()
+	protected function _trans_commit()
 	{
-		return @mssql_rows_affected($this->conn_id);
+		return $this->simple_query('COMMIT TRAN');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	* Insert ID
-	*
-	* Returns the last id created in the Identity column.
-	*
-	* @access public
-	* @return integer
-	*/
-	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;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	* 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)
+	 * Rollback Transaction
+	 *
+	 * @return	bool
+	 */
+	protected function _trans_rollback()
 	{
-		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.
+		return $this->simple_query('ROLLBACK TRAN');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	* Version number query string
-	*
-	* @access public
-	* @return string
-	*/
-	function _version()
+	 * Affected Rows
+	 *
+	 * @return	int
+	 */
+	public function affected_rows()
 	{
-		return "SELECT @@VERSION AS ver";
+		return mssql_rows_affected($this->conn_id);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * "Count All" query
+	 * Insert ID
 	 *
-	 * Generates a platform-specific query string that counts all records in
-	 * the specified database
+	 * Returns the last id created in the Identity column.
 	 *
-	 * @access	public
-	 * @param	string
 	 * @return	string
 	 */
-	function count_all($table = '')
+	public function insert_id()
 	{
-		if ($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;
-		}
+		$query = version_compare($this->version(), '8', '>=')
+			? 'SELECT SCOPE_IDENTITY() AS last_id'
+			: 'SELECT @@IDENTITY AS last_id';
 
-		$row = $query->row();
-		$this->_reset_select();
-		return (int) $row->numrows;
+		$query = $this->query($query);
+		$query = $query->row();
+		return $query->last_id;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * List table query
-	 *
-	 * Generates a platform-specific query string so that the table names can be fetched
+	 * Set client character set
 	 *
-	 * @access	private
-	 * @param	boolean
-	 * @return	string
+	 * @param	string	$charset
+	 * @return	bool
 	 */
-	function _list_tables($prefix_limit = FALSE)
+	protected function _db_set_charset($charset)
 	{
-		$sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";
-
-		// for future compatibility
-		if ($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
-		}
-
-		return $sql;
+		return (ini_set('mssql.charset', $charset) !== FALSE);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * List column query
-	 *
-	 * Generates a platform-specific query string so that the column names can be fetched
+	 * Version number query string
 	 *
-	 * @access	private
-	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _list_columns($table = '')
+	protected function _version()
 	{
-		return "SELECT * FROM INFORMATION_SCHEMA.Columns WHERE TABLE_NAME = '".$table."'";
+		return "SELECT SERVERPROPERTY('ProductVersion') AS ver";
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Field data query
+	 * List table query
 	 *
-	 * Generates a platform-specific query so that the column data can be retrieved
+	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @return	object
+	 * @param	bool	$prefix_limit
+	 * @return	string
 	 */
-	function _field_data($table)
+	protected function _list_tables($prefix_limit = FALSE)
 	{
-		return "SELECT TOP 1 * FROM ".$table;
-	}
+		$sql = 'SELECT '.$this->escape_identifiers('name')
+			.' FROM '.$this->escape_identifiers('sysobjects')
+			.' WHERE '.$this->escape_identifiers('type')." = 'U'";
 
-	// --------------------------------------------------------------------
+		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
+		{
+			$sql .= ' AND '.$this->escape_identifiers('name')." LIKE '".$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
+		}
 
-	/**
-	 * The error message string
-	 *
-	 * @access	private
-	 * @return	string
-	 */
-	function _error_message()
-	{
-		return mssql_get_last_message();
+		return $sql.' ORDER BY '.$this->escape_identifiers('name');
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * The error message number
+	 * List column query
+	 *
+	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @access	private
-	 * @return	integer
+	 * @param	string	$table
+	 * @return	string
 	 */
-	function _error_number()
+	protected function _list_columns($table = '')
 	{
-		// Are error numbers supported?
-		return '';
+		return 'SELECT COLUMN_NAME
+			FROM INFORMATION_SCHEMA.Columns
+			WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
+	 * Returns an object with field data
 	 *
-	 * @access	private
-	 * @param	string
-	 * @return	string
+	 * @param	string	$table
+	 * @return	array
 	 */
-	function _escape_identifiers($item)
+	public function field_data($table)
 	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
+		$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, COLUMN_DEFAULT
+			FROM INFORMATION_SCHEMA.Columns
+			WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
 
-		foreach ($this->_reserved_identifiers as $id)
+		if (($query = $this->query($sql)) === FALSE)
 		{
-			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);
-			}
+			return FALSE;
 		}
+		$query = $query->result_object();
 
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
+		$retval = array();
+		for ($i = 0, $c = count($query); $i < $c; $i++)
 		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
+			$retval[$i]			= new stdClass();
+			$retval[$i]->name		= $query[$i]->COLUMN_NAME;
+			$retval[$i]->type		= $query[$i]->DATA_TYPE;
+			$retval[$i]->max_length		= ($query[$i]->CHARACTER_MAXIMUM_LENGTH > 0) ? $query[$i]->CHARACTER_MAXIMUM_LENGTH : $query[$i]->NUMERIC_PRECISION;
+			$retval[$i]->default		= $query[$i]->COLUMN_DEFAULT;
 		}
 
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+		return $retval;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * From Tables
+	 * Error
 	 *
-	 * This function implicitly groups FROM tables so there is no confusion
-	 * about operator precedence in harmony with SQL standards
+	 * Returns an array containing code and message of the last
+	 * database error that has occurred.
 	 *
-	 * @access	public
-	 * @param	type
-	 * @return	type
+	 * @return	array
 	 */
-	function _from_tables($tables)
+	public function error()
 	{
-		if ( ! is_array($tables))
+		// We need this because the error info is discarded by the
+		// server the first time you request it, and query() already
+		// calls error() once for logging purposes when a query fails.
+		static $error = array('code' => 0, 'message' => NULL);
+
+		$message = mssql_get_last_message();
+		if ( ! empty($message))
 		{
-			$tables = array($tables);
+			$error['code']    = $this->query('SELECT @@ERROR AS code')->row()->code;
+			$error['message'] = $message;
 		}
 
-		return implode(', ', $tables);
+		return $error;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
+	 * Update statement
 	 *
-	 * Generates a platform-specific insert string from the supplied data
+	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
+	 * @param	string	$table
+	 * @param	array	$values
 	 * @return	string
 	 */
-	function _insert($table, $keys, $values)
+	protected function _update($table, $values)
 	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
+		$this->qb_limit = FALSE;
+		$this->qb_orderby = array();
+		return parent::_update($table, $values);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update statement
+	 * Truncate statement
 	 *
-	 * Generates a platform-specific update string from the supplied data
+	 * Generates a platform-specific truncate string from the supplied data
+	 *
+	 * If the database does not support the TRUNCATE statement,
+	 * then this method maps to 'DELETE FROM table'
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
+	 * @param	string	$table
 	 * @return	string
 	 */
-	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	protected function _truncate($table)
 	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key." = ".$val;
-		}
-
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
+		return 'TRUNCATE TABLE '.$table;
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
-	 * Truncate statement
+	 * Delete 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"
+	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @access	public
-	 * @param	string	the table name
+	 * @param	string	$table
 	 * @return	string
 	 */
-	function _truncate($table)
+	protected function _delete($table)
 	{
-		return "TRUNCATE ".$table;
+		if ($this->qb_limit)
+		{
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+		}
+
+		return parent::_delete($table);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Delete statement
+	 * LIMIT
 	 *
-	 * Generates a platform-specific delete string from the supplied data
+	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @access	public
-	 * @param	string	the table name
-	 * @param	array	the where clause
-	 * @param	string	the limit clause
+	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
-	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _limit($sql)
 	{
-		$conditions = '';
+		$limit = $this->qb_offset + $this->qb_limit;
 
-		if (count($where) > 0 OR count($like) > 0)
+		// 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', '>=') && $this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$conditions = "\nWHERE ";
-			$conditions .= implode("\n", $this->ar_where);
+			$orderby = $this->_compile_order_by();
 
-			if (count($where) > 0 && count($like) > 0)
+			// We have to strip the ORDER BY clause
+			$sql = trim(substr($sql, 0, strrpos($sql, $orderby)));
+
+			// Get the fields to select from our subquery, so that we can avoid CI_rownum appearing in the actual results
+			if (count($this->qb_select) === 0)
 			{
-				$conditions .= " AND ";
+				$select = '*'; // Inevitable
+			}
+			else
+			{
+				// Use only field names and their aliases, everything else is out of our scope.
+				$select = array();
+				$field_regexp = ($this->_quoted_identifier)
+					? '("[^\"]+")' : '(\[[^\]]+\])';
+				for ($i = 0, $c = count($this->qb_select); $i < $c; $i++)
+				{
+					$select[] = preg_match('/(?:\s|\.)'.$field_regexp.'$/i', $this->qb_select[$i], $m)
+						? $m[1] : $this->qb_select[$i];
+				}
+				$select = implode(', ', $select);
 			}
-			$conditions .= implode("\n", $like);
-		}
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
+			return 'SELECT '.$select." FROM (\n\n"
+				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.trim($orderby).') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
+				."\n\n) ".$this->escape_identifiers('CI_subquery')
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
+		}
 
-		return "DELETE FROM ".$table.$conditions.$limit;
+		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
+	 * Insert batch statement
 	 *
-	 * Generates a platform-specific LIMIT clause
+	 * Generates a platform-specific insert string from the supplied data.
 	 *
-	 * @access	public
-	 * @param	string	the sql query string
-	 * @param	integer	the number of rows to limit the query to
-	 * @param	integer	the offset value
-	 * @return	string
+	 * @param	string	$table	Table name
+	 * @param	array	$keys	INSERT keys
+	 * @param	array	$values	INSERT values
+	 * @return	string|bool
 	 */
-	function _limit($sql, $limit, $offset)
+	protected function _insert_batch($table, $keys, $values)
 	{
-		$i = $limit + $offset;
+		// Multiple-value inserts are only supported as of SQL Server 2008
+		if (version_compare($this->version(), '10', '>='))
+		{
+			return parent::_insert_batch($table, $keys, $values);
+		}
 
-		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$i.' ', $sql);
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -650,18 +508,11 @@ 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