BTW of session_set_save_handler .........

[whisher06]

Hi.
Sorry to disturb you again but
it's the first time I manage with
session_set_save_handler therefore
I'd like to know if this snippet is all right.

<?php
require_once('db.php');
require_once('config.php');
// define 'openSession()' function
function openSession($sessionPath,$sessionName){
    return true;
}
// define 'closeSession()' function
function closeSession(){
    return true;
}
// define 'readSession()' method
function readSession($sessionId){
    global $db;
    // escape session ID
    $sessionId=$db->realEscapeString($sessionId);
    $result=$db->query("SELECT sessiondata FROM sessions WHERE sessionid='$sessionId' AND expiry > NOW()");
    if($result->countRows()>0){
        $row=$result->fetchRow();
        return $row->sessiondata;
    }
    // return empty string
    return "";
}
// define 'writeSession()' function
function writeSession($sessionId,$sessionData){
    global $db;
	$expiry = get_cfg_var('session.gc_maxlifetime')-1;
	// escape session ID
    $sessionId=$db->realEscapeString($sessionId);
	$result=$db->query("SELECT sessionid FROM sessions WHERE sessionid='$sessionId'");
    // check if a new session must be stored or an existing one must be updated 
	($result->countRows()>0)?$db->query("UPDATE sessions SET sessionid='$sessionId',expiry=NOW()+INTERVAL $expiry SECOND,sessiondata='$sessionData' WHERE sessionid='$sessionId'"):$db->query("INSERT INTO sessions (sessionid,expiry,sessiondata) VALUES ('$sessionId',NOW()+INTERVAL $expiry SECOND,'$sessionData')");
    return true;
}
// define 'destroySession()' function
function destroySession($sessionId){
    global $db;
    // escape session ID
   	$sessionId=$db->realEscapeString($sessionId);
   	$db->query("DELETE FROM sessions WHERE sessionid='$sessionId'");
	return true;
}
// define 'gcSession()' function
function gcSession($maxlifetime){
    global $db;
    $db->query("DELETE FROM sessions WHERE expiry < NOW()");
    return true;
}
session_set_save_handler('openSession','closeSession','readSession','writeSession','destroySession','gcSession');
session_start();
class A
{
	public $string;
	public function __construct($string)
   	{
		$this->string = $string;
	}
}
$a = new A('Whisher');
// register some session variables
$_SESSION['username']=$a;
var_dump($_SESSION['username']->string);
?>

and could I get into trouble managing object in this way ?

Thanks in advance.

Bye.