<?php
/**
*
* @package dbal
* @copyright (c) 2013 phpBB Group
* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
*
*/

namespace phpbb\db\driver;

/**
* MSSQL Database Base Abstraction Layer
* @package dbal
 */
abstract class mssql_base extends \phpbb\db\driver\driver
{
	/**
	* {@inheritDoc}
	*/
	public function sql_concatenate($expr1, $expr2)
	{
		return $expr1 . ' + ' . $expr2;
	}

	/**
	* {@inheritDoc}
	*/
	function sql_escape($msg)
	{
		return str_replace(array("'", "\0"), array("''", ''), $msg);
	}

	/**
	* {@inheritDoc}
	*/
	function sql_lower_text($column_name)
	{
		return "LOWER(SUBSTRING($column_name, 1, DATALENGTH($column_name)))";
	}

	/**
	* Build LIKE expression
	* @access private
	*/
	function _sql_like_expression($expression)
	{
		return $expression . " ESCAPE '\\'";
	}

	/**
	* Build db-specific query data
	* @access private
	*/
	function _sql_custom_build($stage, $data)
	{
		return $data;
	}
}
