"IN"条款中的子查询

Question

SELECT * FROM `image_appreciations`
WHERE `image_id` IN(SELECT `id` FROM `images` WHERE `user_id` = '1')

是我当前的查询,它返回零结果

SELECT `id` FROM `images` WHERE `user_id` = '1'

作为子查询返回大约8个id,其中有两个被发现

SELECT * FROM `image_appreciations`
WHERE `image_id` IN(77,89)

这很好.但总之,它失败了.我究竟做错了什么？

Answer 1

这可以使用JOIN.下面是使用隐式短手语法的示例.

SELECT * FROM image_appreciations a, images i
WHERE a.image_id = i.id AND i.user_id = 1