MySQL用户定义函数错误

Question

I'm trying to create a user defined function that will take a user ID as an argument and then display the retailPrice column for that particular row. Can you tell me where I'm going wrong?

DELIMITER $$

CREATE FUNCTION itemPrice(uId DECIMAL(8,2))
RETURNS DECIMAL(8,2)
READS SQL DATA
BEGIN 
    DECLARE r DECIMAL(8,2)
    SELECT INTO retailPrice r FROM item WHERE userId = uId;
    RETURN(r);
END$$

DELIMITER ;

Answer 1

You're missing a ; between the DECLARE statement and the SELECT query. And you have INTO in the wrong place in the query.

DELIMITER $$

CREATE FUNCTION itemPrice(uId DECIMAL(8,2))
RETURNS DECIMAL(8,2)
READS SQL DATA
BEGIN 
    DECLARE r DECIMAL(8,2);
    SELECT retailPrice INTO r FROM item WHERE userId = uId;
    RETURN(r);
END$$

DELIMITER ;