$query = "DELETE FROM anagrafica NATURAL JOIN polizza NATURAL JOIN veicolo WHERE Num_Polizza = '$Num_Polizza'";
vi sembra corretta?
a me spunta:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'NATURAL JOIN polizza NATURAL JOIN veicolo WHERE Num_Polizza = '987654321'' at line 1
GRAZIE!