存储过程和 MySQL 变量

Question

嗨，我正在尝试创建一个过程，该过程将 ansID 作为参数并更新用户表和答案表中的“分数”字段。

DELIMITER $$
CREATE PROCEDURE UpVoteAnswer(IN _ansID INT)
BEGIN
SET @_userID = SELECT user_id from Answers where id = _ansID;
UPDATE Answers SET score = score + 1 where id = _ansID;
UPDATE Users SET score = score + 1 where id = @_userID;
END
$$
DELIMITER ;



Error:
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'SELECT user_id from Answers where id = _ansID;
UPDATE Answers SET score = score' at line 3

Answer 1

使用任一

SET @_userID = (SELECT user_id from Answers where id = _ansID);

或者

SELECT user_id from Answers where id = _ansID INTO @_userID;