带有参数的 MySQL 函数中出现错误

Question

我有MySQL函数，有两个参数，即user_id和post_id

这是我的函数：

CREATE FUNCTION isliked(pid INT, uid INT)
RETURN TABLE
AS
RETURN (EXISTS (SELECT 1 FROM likedata ld WHERE post_id = pid AND user_id = uid
)) as is_liked
END

我尝试使用以下查询调用它：

SELECT posts.id, posts.title, isliked(111,123)
FROM posts

它返回以下错误：

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'RETURN TABLE
AS
RETURN (EXISTS (SELECT 1 FROM likedata ld WHERE post_id = pid AN' at line 2

它应该是这样的返回结果 http://sqlfiddle.com/#!9/91040/5 我是sql的新手，任何帮助都会很棒，提前感谢

Answer 1

如果希望函数返回布尔值，请使用：

CREATE FUNCTION isliked(pid INT, uid INT)
RETURNS BIT
RETURN ( EXISTS ( SELECT 1 FROM likedata ld WHERE post_id = pid AND user_id = uid ) )