[mysql] trigger errore 1442

[devil1988]

ciao
Il seguente trigger mi restituisce l'errore 1442

DELIMITER |

CREATE TRIGGER ChkUpdateUserRole AFTER UPDATE ON users
FOR EACH ROW
BEGIN
	IF (NEW.role = 'admin' OR  NEW.role <> 'member') THEN
		UPDATE users SET role = OLD.role WHERE id = OLD.id;
	END IF;
END;

| DELIMITER ;

Errore:

Error: 1442 SQLSTATE: HY000 (ER_CANT_UPDATE_USED_TABLE_IN_SF_OR_TRG)
Message: Can't update table 'users' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.

Cosa c'è che non va? :master: