INSERT INTO carrello(session, user, prodotto, quantita, ip, data_aggiunta) VALUES ('42453ec2c03d4c0762a1f5e26a7b18ff', , 257, 1, '54.81.71.187', NOW() ) ON DUPLICATE KEY UPDATE user=user
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 ' 257, 1, '54.81.71.187', NOW() ) ON DUPLICATE KEY UPDATE user=user' at line 1