根據使用mysql的用戶獲得最多的評論數？

Question

我有這樣的4個表：

posts{id,post,date} 
    comment{id, user_id,post_id, comment, date} 
    tag_post{tag_id,post_id} 
    users{user_id, email,pwd,username} 

我想使這個複雜的查詢，我想從某個話題讓評論者（用戶）的maxiumum數： 即

select the most commeneters(count) on posts that have been tagged with tag_id=39 
LIMIT 5 

感謝:)）

Answer 1

什麼是這樣的：

select users.user_id, count(*) as nb_comments 
from posts 
    inner join tag_posts on tag_posts.post_id = posts.id 
    inner join comment on comment.post_id = posts.id 
    inner join users on users.user_id = comment.user_id 
where tag_posts.tag_id = 39 
group by users.user_id 
order by count(*) desc 
limit 5 

它應該讓你的5個用戶評論最有帖子的標籤39。