salix/db/routines/vn/functions/getSpecialPrice.sql

DELIMITER $$
CREATE OR REPLACE DEFINER=`vn`@`localhost` FUNCTION `vn`.`getSpecialPrice`(vItemFk int(11),vClientFk int(11))
	RETURNS decimal(10,2)
	NOT DETERMINISTIC
	READS SQL DATA
BEGIN
	DECLARE price DECIMAL(10,2);

	SELECT rate3 INTO price
		FROM vn.priceFixed
		WHERE itemFk = vItemFk
			AND util.VN_CURDATE() BETWEEN started AND ended ORDER BY created DESC LIMIT 1;

	SELECT `value` INTO price
		FROM vn.specialPrice
		WHERE itemFk = vItemFk
			AND (clientFk = vClientFk OR clientFk IS NULL)
            AND started <= util.VN_CURDATE()
            AND (ended >= util.VN_CURDATE() OR ended IS NULL)
        ORDER BY id DESC LIMIT 1;
RETURN price;
END$$
DELIMITER ;