system/database/drivers/mssql/mssql_driver.php - code-igniter-v3-giggi - Gitiles

 <?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 4.3.2 or newer
  *
  * @package		CodeIgniter
  * @author		ExpressionEngine Dev Team
  * @copyright	Copyright (c) 2006, EllisLab, Inc.
  * @license		http://codeigniter.com/user_guide/license.html
  * @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
  * class is being used or not.
  *
  * @package		CodeIgniter
  * @subpackage	Drivers
  * @category	Database
  * @author		ExpressionEngine Dev Team
  * @link		http://codeigniter.com/user_guide/database/
  */
 class CI_DB_mssql_driver extends CI_DB {

 	/**
 	 * 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
 	 *
 	 * @access	private called by the base class
 	 * @return	resource
 	 */
 	function db_connect()
 	{
 		return @mssql_connect($this->hostname, $this->username, $this->password);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Persistent database connection
 	 *
 	 * @access	private called by the base class
 	 * @return	resource
 	 */
 	function db_pconnect()
 	{
 		return @mssql_pconnect($this->hostname, $this->username, $this->password);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Select the database
 	 *
 	 * @access	private called by the base class
 	 * @return	resource
 	 */
 	function db_select()
 	{
 		return @mssql_select_db($this->database, $this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * 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;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * 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);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Prep the query
 	 *
 	 * If needed, each database adapter can prep the query string
 	 *
 	 * @access	private called by execute()
 	 * @param	string	an SQL query
 	 * @return	string
 	 */
 	function _prep_query($sql)
 	{
 		return $sql;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Begin Transaction
 	 *
 	 * @access	public
 	 * @return	bool
 	 */
 	function trans_begin($test_mode = FALSE)
 	{
 		if (! $this->trans_enabled)
 		{
 			return TRUE;
 		}

 		// When transactions are nested we only begin/commit/rollback the outermost ones
 		if ($this->_trans_depth > 0)
 		{
 			return TRUE;
 		}

 		// Reset the transaction failure flag.
 		// If the $test_mode flag is set to TRUE transactions will be rolled back
 		// even if the queries produce a successful result.
 		$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;

 		$this->simple_query('BEGIN TRAN');
 		return TRUE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Commit Transaction
 	 *
 	 * @access	public
 	 * @return	bool
 	 */
 	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)
 		{
 			return TRUE;
 		}

 		$this->simple_query('COMMIT TRAN');
 		return TRUE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Rollback Transaction
 	 *
 	 * @access	public
 	 * @return	bool
 	 */
 	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)
 		{
 			return TRUE;
 		}

 		$this->simple_query('ROLLBACK TRAN');
 		return TRUE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Escape String
 	 *
 	 * @access	public
 	 * @param	string
 	 * @return	string
 	 */
 	function escape_str($str)
 	{
 		// Escape single quotes
 		return str_replace("'", "''", $str);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Affected Rows
 	 *
 	 * @access	public
 	 * @return	integer
 	 */
 	function affected_rows()
 	{
 		return @mssql_rows_affected($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	* 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)
 	{
 		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.
 	}

 	// --------------------------------------------------------------------

 	/**
 	* 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
 	 *
 	 * @access	public
 	 * @param	string
 	 * @return	string
 	 */
 	function count_all($table = '')
 	{
 		if ($table == '')
 			return '0';

 		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows'). " FROM " . $this->_protect_identifiers($this->dbprefix.$table));

 		if ($query->num_rows() == 0)
 			return '0';

 		$row = $query->row();
 		return $row->numrows;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * List table query
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
 	 * @access	private
 	 * @param	boolean
 	 * @return	string
 	 */
 	function _list_tables($prefix_limit = FALSE)
 	{
 		$sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";

 		// for future compatibility
 		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
 		{
 			//$sql .= " LIKE '".$this->dbprefix."%'";
 			return FALSE; // not currently supported
 		}

 		return $sql;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * List column query
 	 *
 	 * 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($table = '')
 	{
 		return "SELECT * FROM INFORMATION_SCHEMA.Columns WHERE TABLE_NAME = '".$this->_escape_table($table)."'";
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Field data query
 	 *
 	 * 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($table)
 	{
 		return "SELECT TOP 1 * FROM ".$this->_escape_table($table);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * The error message string
 	 *
 	 * @access	private
 	 * @return	string
 	 */
 	function _error_message()
 	{
 		// Are errros even supported in MS SQL?
 		return '';
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * The error message number
 	 *
 	 * @access	private
 	 * @return	integer
 	 */
 	function _error_number()
 	{
 		// Are error numbers supported?
 		return '';
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Escape Table Name
 	 *
 	 * This function adds backticks if the table name has a period
 	 * in it. Some DBs will get cranky unless periods are escaped
 	 *
 	 * @access	private
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	function _escape_table($table)
 	{
 		// I don't believe this is necessary with MS SQL.  Not sure, though. - Rick

 		/*
 		if (strpos($table, '.') !== FALSE)
 		{
 			$table = '"' . str_replace('.', '"."', $table) . '"';
 		}
 		*/

 		return $table;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Protect Identifiers
 	 *
 	 * This function adds backticks if appropriate based on db type
 	 *
 	 * @access	private
 	 * @param	mixed	the item(s)
 	 * @param	boolean	should spaces be backticked
 	 * @param	boolean	only affect the first word
 	 * @return	mixed	the item with backticks
 	 */
 	function _protect_identifiers($item, $first_word_only = FALSE)
 	{
 		if (is_array($item))
 		{
 			$escaped_array = array();

 			foreach($item as $k=>$v)
 			{
 				$escaped_array[$this->_protect_identifiers($k)] = $this->_protect_identifiers($v, $first_word_only);
 			}

 			return $escaped_array;
 		}

 		// This function may get "item1 item2" as a string, and so
 		// we may need ""item1" "item2"" and not ""item1 item2""
 		if (ctype_alnum($item) === FALSE)
 		{
 			if (strpos($item, '.') !== FALSE)
 			{
 				$aliased_tables = implode(".",$this->ar_aliased_tables).'.';
 				$table_name =  substr($item, 0, strpos($item, '.')+1);
 				$item = (strpos($aliased_tables, $table_name) !== FALSE) ? $item = $item : $this->dbprefix.$item;
 			}

 			// This function may get "field >= 1", and need it to return ""field" >= 1"
 			$lbound = ($first_word_only === TRUE) ? '' : '|\s|\(';

 			$item = preg_replace('/(^'.$lbound.')([\w\d\-\_]+?)(\s|\)|$)/iS', '$1"$2"$3', $item);
 		}
 		else
 		{
 			return "\"{$item}\"";
 		}

 		$exceptions = array('AS', '/', '-', '%', '+', '*', 'OR', 'IS');

 		foreach ($exceptions as $exception)
 		{

 			if (stristr($item, " \"{$exception}\" ") !== FALSE)
 			{
 				$item = preg_replace('/ "('.preg_quote($exception).')" /i', ' $1 ', $item);
 			}
 		}
 		return $item;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * From Tables
 	 *
 	 * 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
 	 * @return	string
 	 */
 	function _insert($table, $keys, $values)
 	{
 		return "INSERT INTO ".$this->_escape_table($table)." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Update statement
 	 *
 	 * 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
 	 * @return	string
 	 */
 	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
 	{
 		foreach($values as $key => $val)
 		{
 			$valstr[] = $key." = ".$val;
 		}

 		$limit = (!$limit) ? '' : ' LIMIT '.$limit;

 		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';

 		$sql = "UPDATE ".$this->_escape_table($table)." SET ".implode(', ', $valstr);
 		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
 		$sql .= $orderby.$limit;

 		return $sql;
 	}


 	// --------------------------------------------------------------------

 	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 * If the database does not support the truncate() command
 	 * This function maps to "DELETE FROM table"
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	function _truncate($table)
 	{
 		return "TRUNCATE ".$this->_escape_table($table);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Delete statement
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the where clause
 	 * @param	string	the limit clause
 	 * @return	string
 	 */
 	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 	{
 		$conditions = '';

 		if (count($where) > 0 || count($like) > 0)
 		{
 			$conditions = "\nWHERE ";
 			$conditions .= implode("\n", $this->ar_where);

 			if (count($where) > 0 && count($like) > 0)
 			{
 				$conditions .= " AND ";
 			}
 			$conditions .= implode("\n", $like);
 		}

 		$limit = (!$limit) ? '' : ' LIMIT '.$limit;

 		return "DELETE FROM ".$table.$conditions.$limit;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Limit string
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @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
 	 */
 	function _limit($sql, $limit, $offset)
 	{
 		$i = $limit + $offset;

 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$i.' ', $sql);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Close DB Connection
 	 *
 	 * @access	public
 	 * @param	resource
 	 * @return	void
 	 */
 	function _close($conn_id)
 	{
 		@mssql_close($conn_id);
 	}

 }
	<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
	/**
	* CodeIgniter
	*
	* An open source application development framework for PHP 4.3.2 or newer
	*
	* @package CodeIgniter
	* @author ExpressionEngine Dev Team
	* @copyright Copyright (c) 2006, EllisLab, Inc.
	* @license http://codeigniter.com/user_guide/license.html
	* @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
	* class is being used or not.
	*
	* @package CodeIgniter
	* @subpackage Drivers
	* @category Database
	* @author ExpressionEngine Dev Team
	* @link http://codeigniter.com/user_guide/database/
	*/
	class CI_DB_mssql_driver extends CI_DB {

	/**
	* 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
	*
	* @access private called by the base class
	* @return resource
	*/
	function db_connect()
	{
	return @mssql_connect($this->hostname, $this->username, $this->password);
	}

	// --------------------------------------------------------------------

	/**
	* Persistent database connection
	*
	* @access private called by the base class
	* @return resource
	*/
	function db_pconnect()
	{
	return @mssql_pconnect($this->hostname, $this->username, $this->password);
	}

	// --------------------------------------------------------------------

	/**
	* Select the database
	*
	* @access private called by the base class
	* @return resource
	*/
	function db_select()
	{
	return @mssql_select_db($this->database, $this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* 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;
	}

	// --------------------------------------------------------------------

	/**
	* 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);
	}

	// --------------------------------------------------------------------

	/**
	* Prep the query
	*
	* If needed, each database adapter can prep the query string
	*
	* @access private called by execute()
	* @param string an SQL query
	* @return string
	*/
	function _prep_query($sql)
	{
	return $sql;
	}

	// --------------------------------------------------------------------

	/**
	* Begin Transaction
	*
	* @access public
	* @return bool
	*/
	function trans_begin($test_mode = FALSE)
	{
	if (! $this->trans_enabled)
	{
	return TRUE;
	}

	// When transactions are nested we only begin/commit/rollback the outermost ones
	if ($this->_trans_depth > 0)
	{
	return TRUE;
	}

	// Reset the transaction failure flag.
	// If the $test_mode flag is set to TRUE transactions will be rolled back
	// even if the queries produce a successful result.
	$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;

	$this->simple_query('BEGIN TRAN');
	return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	* Commit Transaction
	*
	* @access public
	* @return bool
	*/
	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)
	{
	return TRUE;
	}

	$this->simple_query('COMMIT TRAN');
	return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	* Rollback Transaction
	*
	* @access public
	* @return bool
	*/
	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)
	{
	return TRUE;
	}

	$this->simple_query('ROLLBACK TRAN');
	return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	* Escape String
	*
	* @access public
	* @param string
	* @return string
	*/
	function escape_str($str)
	{
	// Escape single quotes
	return str_replace("'", "''", $str);
	}

	// --------------------------------------------------------------------

	/**
	* Affected Rows
	*
	* @access public
	* @return integer
	*/
	function affected_rows()
	{
	return @mssql_rows_affected($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* 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)
	{
	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.
	}

	// --------------------------------------------------------------------

	/**
	* 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
	*
	* @access public
	* @param string
	* @return string
	*/
	function count_all($table = '')
	{
	if ($table == '')
	return '0';

	$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows'). " FROM " . $this->_protect_identifiers($this->dbprefix.$table));

	if ($query->num_rows() == 0)
	return '0';

	$row = $query->row();
	return $row->numrows;
	}

	// --------------------------------------------------------------------

	/**
	* List table query
	*
	* Generates a platform-specific query string so that the table names can be fetched
	*
	* @access private
	* @param boolean
	* @return string
	*/
	function _list_tables($prefix_limit = FALSE)
	{
	$sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";

	// for future compatibility
	if ($prefix_limit !== FALSE AND $this->dbprefix != '')
	{
	//$sql .= " LIKE '".$this->dbprefix."%'";
	return FALSE; // not currently supported
	}

	return $sql;
	}

	// --------------------------------------------------------------------

	/**
	* List column query
	*
	* 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($table = '')
	{
	return "SELECT * FROM INFORMATION_SCHEMA.Columns WHERE TABLE_NAME = '".$this->_escape_table($table)."'";
	}

	// --------------------------------------------------------------------

	/**
	* Field data query
	*
	* 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($table)
	{
	return "SELECT TOP 1 * FROM ".$this->_escape_table($table);
	}

	// --------------------------------------------------------------------

	/**
	* The error message string
	*
	* @access private
	* @return string
	*/
	function _error_message()
	{
	// Are errros even supported in MS SQL?
	return '';
	}

	// --------------------------------------------------------------------

	/**
	* The error message number
	*
	* @access private
	* @return integer
	*/
	function _error_number()
	{
	// Are error numbers supported?
	return '';
	}

	// --------------------------------------------------------------------

	/**
	* Escape Table Name
	*
	* This function adds backticks if the table name has a period
	* in it. Some DBs will get cranky unless periods are escaped
	*
	* @access private
	* @param string the table name
	* @return string
	*/
	function _escape_table($table)
	{
	// I don't believe this is necessary with MS SQL. Not sure, though. - Rick

	/*
	if (strpos($table, '.') !== FALSE)
	{
	$table = '"' . str_replace('.', '"."', $table) . '"';
	}
	*/

	return $table;
	}

	// --------------------------------------------------------------------

	/**
	* Protect Identifiers
	*
	* This function adds backticks if appropriate based on db type
	*
	* @access private
	* @param mixed the item(s)
	* @param boolean should spaces be backticked
	* @param boolean only affect the first word
	* @return mixed the item with backticks
	*/
	function _protect_identifiers($item, $first_word_only = FALSE)
	{
	if (is_array($item))
	{
	$escaped_array = array();

	foreach($item as $k=>$v)
	{
	$escaped_array[$this->_protect_identifiers($k)] = $this->_protect_identifiers($v, $first_word_only);
	}

	return $escaped_array;
	}

	// This function may get "item1 item2" as a string, and so
	// we may need ""item1" "item2"" and not ""item1 item2""
	if (ctype_alnum($item) === FALSE)
	{
	if (strpos($item, '.') !== FALSE)
	{
	$aliased_tables = implode(".",$this->ar_aliased_tables).'.';
	$table_name = substr($item, 0, strpos($item, '.')+1);
	$item = (strpos($aliased_tables, $table_name) !== FALSE) ? $item = $item : $this->dbprefix.$item;
	}

	// This function may get "field >= 1", and need it to return ""field" >= 1"
	$lbound = ($first_word_only === TRUE) ? '' : '\|\s\|\(';

	$item = preg_replace('/(^'.$lbound.')([\w\d\-\_]+?)(\s\|\)\|$)/iS', '$1"$2"$3', $item);
	}
	else
	{
	return "\"{$item}\"";
	}

	$exceptions = array('AS', '/', '-', '%', '+', '*', 'OR', 'IS');

	foreach ($exceptions as $exception)
	{

	if (stristr($item, " \"{$exception}\" ") !== FALSE)
	{
	$item = preg_replace('/ "('.preg_quote($exception).')" /i', ' $1 ', $item);
	}
	}
	return $item;
	}

	// --------------------------------------------------------------------

	/**
	* From Tables
	*
	* 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
	* @return string
	*/
	function _insert($table, $keys, $values)
	{
	return "INSERT INTO ".$this->_escape_table($table)." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
	}

	// --------------------------------------------------------------------

	/**
	* Update statement
	*
	* 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
	* @return string
	*/
	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
	{
	foreach($values as $key => $val)
	{
	$valstr[] = $key." = ".$val;
	}

	$limit = (!$limit) ? '' : ' LIMIT '.$limit;

	$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';

	$sql = "UPDATE ".$this->_escape_table($table)." SET ".implode(', ', $valstr);
	$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
	$sql .= $orderby.$limit;

	return $sql;
	}


	// --------------------------------------------------------------------

	/**
	* Truncate statement
	*
	* Generates a platform-specific truncate string from the supplied data
	* If the database does not support the truncate() command
	* This function maps to "DELETE FROM table"
	*
	* @access public
	* @param string the table name
	* @return string
	*/
	function _truncate($table)
	{
	return "TRUNCATE ".$this->_escape_table($table);
	}

	// --------------------------------------------------------------------

	/**
	* Delete statement
	*
	* Generates a platform-specific delete string from the supplied data
	*
	* @access public
	* @param string the table name
	* @param array the where clause
	* @param string the limit clause
	* @return string
	*/
	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
	{
	$conditions = '';

	if (count($where) > 0 \|\| count($like) > 0)
	{
	$conditions = "\nWHERE ";
	$conditions .= implode("\n", $this->ar_where);

	if (count($where) > 0 && count($like) > 0)
	{
	$conditions .= " AND ";
	}
	$conditions .= implode("\n", $like);
	}

	$limit = (!$limit) ? '' : ' LIMIT '.$limit;

	return "DELETE FROM ".$table.$conditions.$limit;
	}

	// --------------------------------------------------------------------

	/**
	* Limit string
	*
	* Generates a platform-specific LIMIT clause
	*
	* @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
	*/
	function _limit($sql, $limit, $offset)
	{
	$i = $limit + $offset;

	return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$i.' ', $sql);
	}

	// --------------------------------------------------------------------

	/**
	* Close DB Connection
	*
	* @access public
	* @param resource
	* @return void
	*/
	function _close($conn_id)
	{
	@mssql_close($conn_id);
	}

	}