drag and drop and one query

[eluser]wojtekk[/eluser]
hi
im using script.aculo.us to sort list with drag and drop
In my controller i got method

Code:

function sort()
{
        $ranking = 1;
        foreach ($_POST['tasks_list'] as $id) {    
        $dane = array('ranking' => $ranking);
        $this->Task->update($id,$dane);
            $ranking++;
        }
}

It works but i dont like it because it make a lot of queres(with 100 items in list - 100 updates )
so i made this to made only one

Code:

function sort()
{
        $ranking = 1;
     $querry='';
        foreach ($_POST['tasks_list'] as $id) {
        $querry.=" UPDATE tasks SET ranking = '".$ranking."' WHERE tasks.id ='".$id."';";
            
            $ranking++;
        }
    $this->Task->updateranking($querry);
}

but its dont work
Any suggesttions?