MySQL Sessionhandler

session.php
<?php
/* Title: Session handler
 * Author: Jurgen Meijer
 * E-mail: [email protected]
 * 
 * Date: 19-04-2008
 * License: GNU/GPL
 * 
 * PHP version: 4+
 * MySQL version 4+
 * 
 * This is a session handler written for PHP5 but may work in PHP4 aswell. This version is a mysql only version.
 * This handler is only tested in PHP5 and MySQL 5.
 * 
 * Note: session.auto_start should be turned off in the php.ini file to allow custom sessionhandling.
 * 
 * SQL:
 * 
	CREATE TABLE session (
	session_id VARCHAR( 32 ) NOT NULL ,
	session_data MEDIUMTEXT NOT NULL ,
	session_garbage TIMESTAMP ON UPDATE CURRENT_TIMESTAMP NOT NULL ,
	PRIMARY KEY (session_id)
	) ENGINE = innodb;
*/

function open_session()
{
	//Global variable to be used within all the functions.
	global $db;
	
	//Connect to the database.
	if($db = mysql_connect('localhost', 'root',''))
	{
		//if succeeded select the database.
		mysql_select_db('sessionhandler');
		return true;
	}
	else
	{
		return false;
	}
}

function close_session()
{
	//Global variable to be used within all the functions.
	global $db;
	
	//Close the connection to the database server by setting the $db variable to NULL.
	$db = NULL;
	return true;
}

function read_session($session_id)
{
	//Global variable to be used within all the functions.
	global $db;
	
	//Selecting the data from the database where the current session_id equals the one in the database.
	$query = "SELECT
				session_data
		  FROM
		  		session
		  WHERE
		  		session_id='".$session_id."' ";
	
	//check if the query succeedes.
	if($result = mysql_query($query))
	{
		//If a row meets the requirement list the data and return it.
		if(mysql_num_rows($result) == 1)
		{
			list($data) = mysql_fetch_array($result, MYSQL_NUM);
			return $data;
		}
		else
		{
			//If there is no result, send back an empty string.
			return '';
		}
	}
	else
	{
		//If the query fails, send back an empty string.
		return '';
	}	
}

function write_session($session_id, $session_data)
{
	//Global variable to be used within all the functions.
	global $db;
		
	//Replace the session_data with the new data.
	
	//* Replace is a SQL function that works as an INSERT/UPDATE.
	//If there is no row, create a new one, else update the current.
	$query = " REPLACE INTO
							session
							(
							session_id,
							session_data,
							session_garbage
							)
							VALUES
							(
							'".$session_id."' ,
							'".$session_data."', 
							CURRENT_TIMESTAMP)";

	
		if(mysql_query($query))
		{
			//if the query succeedes return the affected rows (should allways be 1).
			return mysql_affected_rows(); 
		}
		else
		{
			return false;
		}
						
}

function destroy_session($session_id)
{
	//Global variable to be used within all the functions.
	global $db;
	
	//Delete our session, this function will be called when we use session_destroy().
	$query = "DELETE FROM
						session
			  WHERE
			  		session_id='".$session_id."'";
	
	//If the query succeedes empty the $_SESSION array and return the affected rows.
	if(mysql_query($query))
	{
		$_SESSION = array();
		return mysql_affected_rows();
	}
	else
	{
		return false;
	}
	
}

function clean_session($seconds)
{
	//Global variable to be used within all the functions.
	global $db;
	
	//Delete items older than the amount of seconds wich is defined in the php.ini file. 
	//Default is after the browser is closed(0 seconds).
	$query = "DELETE FROM 
					session
			  WHERE
			 		DATE_ADD(session_garbage, INTERVAL ".$seconds." SECOND) < NOW()";
	
	//Return the affected rows when the query succeedes.
	if(mysql_query($query))
	{
		return mysql_affected_rows();
	}
	else
	{
		return false;
	}
	
}


//Set our brand new sessionhandler to be used by PHP.
session_set_save_handler('open_session','close_session', 'read_session', 'write_session', 'destroy_session', 'clean_session');

//Start the session as you would normally do.
session_start();
?>

En het aanroepen van het script:

<?php

require 'session.php';

$_SESSION['blaat'] = 'LOL';
$_SESSION['schaap'] = 1;


session_write_close();

?>