Query per estrapolazione voci menu

[psycho54h]

<?php

while ($menu=mysql_fetch_object($res)) { 
    if ($menu->category_id != $prev_cat) {
        echo "$menu->category_name
$menu->category_name -> $menu->subcategory_name";}
    else {
        echo "$menu->category_name -> $menu->subcategory_name";
    } 
}

$prev_cat = $menu->category_id;
?>