DROP PROCEDURE IF EXISTS `vn`.`ticketRefund_beforeUpsert`;

DELIMITER $$
$$
CREATE DEFINER=`root`@`localhost` PROCEDURE `vn`.`ticketRefund_beforeUpsert`(vRefundTicketFk INT, vOriginalTicketFk INT)
BEGIN
	DECLARE vAlreadyExists BOOLEAN DEFAULT FALSE; 

	IF vRefundTicketFk = vOriginalTicketFk THEN
		CALL util.throw('Original ticket and refund ticket has same id');
	END IF;

    SELECT COUNT(*) INTO vAlreadyExists
		FROM ticketRefund 
		WHERE originalTicketFk = vOriginalTicketFk; 
	
	IF vAlreadyExists > 0 THEN
		CALL util.throw('This ticket is already a refund');
	END IF;
END$$
DELIMITER ;