DELIMITER $$
CREATE OR REPLACE DEFINER=`vn`@`localhost` FUNCTION `vn`.`buy_getVolume`(vSelf INT)
	RETURNS int(11)
	DETERMINISTIC
BEGIN
/**
 * Calculates the volume occupied by a buy.
 *
 * @param vSelf The buy id
 * @return The volume in cubic centimeters
 */
	DECLARE vItem INT;
	DECLARE vPackaging VARCHAR(10);

	SELECT itemFk, packagingFk INTO vItem, vPackaging
		FROM buy
		WHERE id = vSelf;

	RETURN item_getVolume(vItem, vPackaging);
END$$
DELIMITER ;