DELIMITER $$
CREATE OR REPLACE DEFINER=`root`@`localhost` TRIGGER `vn`.`buy_beforeDelete`
	BEFORE DELETE ON `buy`
	FOR EACH ROW
BEGIN 
	IF OLD.printedStickers <> 0 THEN
		CALL util.throw("it is not possible to delete buys with printed labels ");
	END IF;
END$$
DELIMITER ;