Question

到目前为止我得到了这个

select user_id,topic_id
from
( select u.user_id, t.topic_id from `user` u inner join `topic` t on t.topic_by =u.user_id 
union 
select u.user_id, c.comment_topic from `user` u inner join `comment` c on c.comment_by=u.user_id
union 
select u.user_id,th.thanks_by from `user` u inner join `thanks` th on th.thanks_by=u.user_id 
)x
where x.user_id=33

但结果只有user_id和topic_id我想知道关于该主题的用户操作示例用户对主题A的评论，用户喜欢主题B，用户发布主题C 并按时间排序。

Answer 1

试试这个......

SELECT u.user_id, t.topic_id, c.comment_topic, th.thanks_by
from user u
LEFT JOIN topic t ON t.topic_by =u.user_id
LEFT JOIN `comment` c on c.comment_by=u.user_id
LEFT JOIN `thanks` th on th.thanks_by=u.user_id
WHERE u.user_id = 33
GROUP BY u.user_id, t.topic_id, c.comment_topic, th.thanks_by

按用户示例帖子主题，评论主题，按主题顺序选择最近的活动

1 个答案: