<?php
/**
 * CodeIgniter
 *
 * 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		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 3.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * PDO ODBC Database Adapter Class
 *
 * Note: _DB is an extender class that the app controller
 * creates dynamically based on whether the query builder
 * class is being used or not.
 *
 * @package		CodeIgniter
 * @subpackage	Drivers
 * @category	Database
 * @author		EllisLab Dev Team
 * @link		http://codeigniter.com/user_guide/database/
 */
class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {

	/**
	 * Sub-driver
	 *
	 * @var	string
	 */
	public $subdriver = 'odbc';

	/**
	 * Database schema
	 *
	 * @var	string
	 */
	public $schema = 'public';

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

	/**
	 * Identifier escape character
	 *
	 * Must be empty for ODBC.
	 *
	 * @var	string
	 */
	protected $_escape_char = '';

	/**
	 * ESCAPE statement string
	 *
	 * @var	string
	 */
	protected $_like_escape_str = " {escape '%s'} ";

	/**
	 * ORDER BY random keyword
	 *
	 * @var	array
	 */
	protected $_random_keyword = array('RND()', 'RND(%d)');

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

	/**
	 * Class constructor
	 *
	 * Builds the DSN if not already set.
	 *
	 * @param	array	$params
	 * @return	void
	 */
	public function __construct($params)
	{
		parent::__construct($params);

		if (empty($this->dsn))
		{
			$this->dsn = 'odbc:';

			// Pre-defined DSN
			if (empty($this->hostname) && empty($this->HOSTNAME) && empty($this->port) && empty($this->PORT))
			{
				if (isset($this->DSN))
				{
					$this->dsn .= 'DSN='.$this->DSN;
				}
				elseif ( ! empty($this->database))
				{
					$this->dsn .= 'DSN='.$this->database;
				}

				return;
			}

			// If the DSN is not pre-configured - try to build an IBM DB2 connection string
			$this->dsn .= 'DRIVER='.(isset($this->DRIVER) ? '{'.$this->DRIVER.'}' : '{IBM DB2 ODBC DRIVER}').';';

			if (isset($this->DATABASE))
			{
				$this->dsn .= 'DATABASE='.$this->DATABASE.';';
			}
			elseif ( ! empty($this->database))
			{
				$this->dsn .= 'DATABASE='.$this->database.';';
			}

			if (isset($this->HOSTNAME))
			{
				$this->dsn .= 'HOSTNAME='.$this->HOSTNAME.';';
			}
			else
			{
				$this->dsn .= 'HOSTNAME='.(empty($this->hostname) ? '127.0.0.1;' : $this->hostname.';');
			}

			if (isset($this->PORT))
			{
				$this->dsn .= 'PORT='.$this->port.';';
			}
			elseif ( ! empty($this->port))
			{
				$this->dsn .= ';PORT='.$this->port.';';
			}

			$this->dsn .= 'PROTOCOL='.(isset($this->PROTOCOL) ? $this->PROTOCOL.';' : 'TCPIP;');
		}
	}

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

	/**
	 * Show table query
	 *
	 * Generates a platform-specific query string so that the table names can be fetched
	 *
	 * @param	bool	$prefix_limit
	 * @return	string
	 */
	protected function _list_tables($prefix_limit = FALSE)
	{
		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = '".$this->schema."'";

		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
		{
			return $sql." AND table_name LIKE '".$this->escape_like_str($this->dbprefix)."%' "
				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
		}

		return $sql;
	}

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

	/**
	 * Show column query
	 *
	 * Generates a platform-specific query string so that the column names can be fetched
	 *
	 * @param	string	$table
	 * @return	string
	 */
	protected function _list_columns($table = '')
	{
		return 'SELECT column_name FROM information_schema.columns WHERE table_name = '.$this->escape($table);
	}

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

	/**
	 * Update statement
	 *
	 * Generates a platform-specific update string from the supplied data
	 *
	 * @param	string	$table
	 * @param	array	$values
	 * @return	string
	 */
	protected function _update($table, $values)
	{
		$this->qb_limit = FALSE;
		$this->qb_orderby = array();
		return parent::_update($table, $values);
	}

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

	/**
	 * Truncate statement
	 *
	 * 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'
	 *
	 * @param	string	$table
	 * @return	string
	 */
	protected function _truncate($table)
	{
		return 'DELETE FROM '.$table;
	}

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

	/**
	 * Delete statement
	 *
	 * Generates a platform-specific delete string from the supplied data
	 *
	 * @param	string	the table name
	 * @return	string
	 */
	protected function _delete($table)
	{
		$this->qb_limit = FALSE;
		return parent::_delete($table);
	}

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

	/**
	 * LIMIT
	 *
	 * Generates a platform-specific LIMIT clause
	 *
	 * @param	string	$sql	SQL Query
	 * @return	string
	 */
	protected function _limit($sql)
	{
		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$this->qb_limit.' ', $sql);
	}

}

/* End of file pdo_odbc_driver.php */
/* Location: ./system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php */