Codice PHP:
$query_cat="SELECT * FROM tab_categoria";
$result = mysql_query($query_cat);
while($cat = mysql_fetch_array($result))
{
echo "- ".$cat['nome'];
$query_sub="SELECT * FROM sub_categoria WHERE id=_categoria".$cat['id'];
$result_sub = mysql_query($query_sub);
while($sub = mysql_fetch_array($result_sub))
{
echo "--- ".$sub['prodotto'];
}
}