Control monousuario en Opencart

CREATE TABLE control_session(
id INT NOT NULL AUTO_INCREMENT, 
PRIMARY KEY(id),
name VARCHAR(300), 
sessionid VARCHAR(300));

//insertamos en la tabla el id del customer y la sesión
 
$session1=  $this->session->getId();
$name    = $this->customer->getId();
 
$sql12="insert into control_session (sessionid,name ) values ('$session1','$name')";
 
$this->db->query($sql12);
$pruebastock1 = mysql_query($sql12);
 
// recuperamos la última sesión abierta.
$sql1="SELECT max(id), sessionid from control_session
WHERE name='prueba'";
 
$lanzaquery = mysql_query($sql1);
$recuperaid = mysql_fetch_array($lanzaquery);
$sessionid2 = $recuperaid['sessionid'];
 
echo "**********";
echo $sessionid2;
echo "**********";

//comparamos el customer y la session
 
$session1=  $this->session->getId();
$name    = $this->customer->getId();
 
echo "select";
$sql12="SELECT max(id) id from control_session
WHERE name='$name'" ;
 
$result = mysql_query($sql12);
$lanzaquery2 = mysql_fetch_array($result);
$result1 = $lanzaquery2['id'];
 
$sql123="SELECT max(id) id from control_session
WHERE name='$name' and sessionid='$session1'";
 
$result = mysql_query($sql123);
$lanzaquery3 = mysql_fetch_array($result);
$result2 = $lanzaquery3['id'];
echo '*'.$this->document->getTitle().'*';
echo "-----";
 
if ($result1==$result2){
echo 'Go!';
}else{
if ('My Account'==$this->document->getTitle()){
echo "Fuera";
}else {
session_destroy();
header("Refresh:0; url=index.php?route=common/home"); 
}
}