mysql - 多个 mysql 连接

Question

我需要从三张表中获取信息，一张表中包含信息，另外两张表包含我需要计数的信息。

所以第一个表结构是:

tbl_imgimg_idimg_name

tbl_commentscomment_idimg_idcomment

tbl_votevote_idlogo_id

I want the results to have the count of comments and votes that relate to each logo.

I have a bit of the query which is for the count of comments, but have no idea for the syntax for the second join.

SELECT l.img_id, l.img_name, COUNT(c.comment_id) AS comment_count
FROM tbl_images as l
LEFT OUTER JOIN tbl_comments AS c USING (img_id);

有人能帮忙吗？

Answer 1

这个怎么样:

SELECT l.img_id, l.img_name, 
 (SELECT COUNT(*) FROM tbl_comments c WHERE i.img_id = c.img_id ) AS comment_count,
 (SELECT COUNT(*) FROM tbl_vote v WHERE i.img_id = v.img_id ) AS vote_count
FROM tbl_images i