<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**

 * CodeIgniter

 *

 * An open source application development framework for PHP 5.1.6 or newer

 *

 * @package		CodeIgniter

 * @author		ExpressionEngine Dev Team

 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.

 * @license		http://codeigniter.com/user_guide/license.html

 * @link		http://codeigniter.com

 * @since		Version 1.0

 * @filesource

 */



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



/**

 * ODBC 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_odbc_driver extends CI_DB {



	var $dbdriver = 'odbc';



	// the character used to excape - not necessary for ODBC

	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;





	function __construct($params)

	{

		parent::__construct($params);



		$this->_random_keyword = ' RND('.time().')'; // database specific random keyword

	}



	/**

	 * Non-persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */

	function db_connect()

	{

		return @odbc_connect($this->hostname, $this->username, $this->password);

	}



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



	/**

	 * Persistent database connection

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */

	function db_pconnect()

	{

		return @odbc_pconnect($this->hostname, $this->username, $this->password);

	}



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



	/**

	 * Reconnect

	 *

	 * Keep / reestablish the db connection if no queries have been

	 * sent for a length of time exceeding the server's idle timeout

	 *

	 * @access	public

	 * @return	void

	 */

	function reconnect()

	{

		// not implemented in odbc

	}



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



	/**

	 * Select the database

	 *

	 * @access	private called by the base class

	 * @return	resource

	 */

	function db_select()

	{

		// Not needed for ODBC

		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;

	}



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



	/**

	 * Version number query string

	 *

	 * @access	public

	 * @return	string

	 */

	function _version()

	{

		return "SELECT version() AS ver";

	}



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



	/**

	 * 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 @odbc_exec($this->conn_id, $sql);

	}



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



	/**

	 * 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;



		return odbc_autocommit($this->conn_id, FALSE);

	}



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



	/**

	 * 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;

		}



		$ret = odbc_commit($this->conn_id);

		odbc_autocommit($this->conn_id, TRUE);

		return $ret;

	}



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



	/**

	 * 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;

		}



		$ret = odbc_rollback($this->conn_id);

		odbc_autocommit($this->conn_id, TRUE);

		return $ret;

	}



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



	/**

	 * 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)

	{

		if (is_array($str))

		{

			foreach ($str as $key => $val)

			{

				$str[$key] = $this->escape_str($val, $like);

			}



			return $str;

		}



		// ODBC doesn't require escaping

		$str = remove_invisible_characters($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;

	}



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



	/**

	 * Affected Rows

	 *

	 * @access	public

	 * @return	integer

	 */

	function affected_rows()

	{

		return @odbc_num_rows($this->conn_id);

	}



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



	/**

	 * Insert ID

	 *

	 * @access	public

	 * @return	integer

	 */

	function insert_id()

	{

		return @odbc_insert_id($this->conn_id);

	}



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



	/**

	 * "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 " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));



		if ($query->num_rows() == 0)

		{

			return 0;

		}



		$row = $query->row();

		$this->_reset_select();

		return (int) $row->numrows;

	}



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



	/**

	 * Show 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)

	{

		$sql = "SHOW TABLES FROM `".$this->database."`";



		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;

	}



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



	/**

	 * Show column query

	 *

	 * Generates a platform-specific query string so that the column names can be fetched

	 *

	 * @access	public

	 * @param	string	the table name

	 * @return	string

	 */

	function _list_columns($table = '')

	{

		return "SHOW COLUMNS FROM ".$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 ".$table;

	}



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



	/**

	 * The error message string

	 *

	 * @access	private

	 * @return	string

	 */

	function _error_message()

	{

		return odbc_errormsg($this->conn_id);

	}



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



	/**

	 * The error message number

	 *

	 * @access	private

	 * @return	integer

	 */

	function _error_number()

	{

		return odbc_error($this->conn_id);

	}



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



	/**

	 * Escape the SQL Identifiers

	 *

	 * This function escapes column and table names

	 *

	 * @access	private

	 * @param	string

	 * @return	string

	 */

	function _escape_identifiers($item)

	{

		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);

	}



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



	/**

	 * 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 ".$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):'';



		$sql = "UPDATE ".$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 $this->_delete($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($where) > 0 OR count($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)

	{

		// Does ODBC doesn't use the LIMIT clause?

		return $sql;

	}



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



	/**

	 * Close DB Connection

	 *

	 * @access	public

	 * @param	resource

	 * @return	void

	 */

	function _close($conn_id)

	{

		@odbc_close($conn_id);

	}





}







/* End of file odbc_driver.php */

/* Location: ./system/database/drivers/odbc/odbc_driver.php */