IF
mysql> mysql> mysql> DELIMITER // mysql> CREATE FUNCTION delivery_day_shipping (delivery_day INT(1)) RETURNS INT(2) -> BEGIN -> -> DECLARE shipping_cost INT(2) DEFAULT 0; -> -> IF delivery_day = 1 THEN -> SET shipping_cost = 20; -> ELSEIF delivery_day = 2 THEN -> SET shipping_cost = 15; -> ELSEIF delivery_day = 3 THEN -> SET shipping_cost = 10; -> ELSE -> SET shipping_cost = 5; -> END IF; -> -> RETURN shipping_cost; -> -> END -> // ERROR 1304 (42000): FUNCTION delivery_day_shipping already exists mysql> DELIMITER ; mysql> mysql>