Question

获取每篇帖子的最新评论

   SELECT * 
     FROM ( `comments` )
LEFT JOIN  `posts` 
       ON  `posts`.`id` =  `comments`.`case_id` 
    WHERE  `comments`.`user_id` =  '8'
 GROUP BY  `comments`.`case_id` 
 ORDER BY  `comments`.`created_date` DESC

Answer 1

试试这个并告诉我它是否回答了你的问题：

SELECT * FROM comments 
RIGHT JOIN posts ON posts.id = comments.case_id 
WHERE comments.user_id = '8' AND comments.created_date = (SELECT MAX(created_date) FROM comments WHERE case_id = posts.id)

Answer 2

为什么不获取属于该用户的帖子ID列表：

SELECT posts.id
FROM posts
INNER JOIN comments ON posts.id = comments.case_id
WHERE comments.user_id = 8

然后foreach($IDs as $id)：

SELECT * FROM comments
WHERE case_id = ${id}
ORDER BY created_date DESC
LIMIT 1

原始答案：

您只是错过了LIMIT子句：

SELECT * from comments
LEFT JOIN posts ON posts.id = comments.case_id
WHERE comments.user_id = 8
GROUP BY comments.case_id
ORDER BY comments.created_date DESC
LIMIT 1

Answer 3

SELECT
    *
FROM
    posts
LEFT JOIN comments ON comments.case_id = posts.post_id
WHERE
    comments.comments_id IN (
        SELECT
            MAX(comments_id)
        FROM
            comments
        GROUP BY
            case_id
    )
AND comments.user_id = '8'

希望有所帮助

在每篇帖子中获取最近的最新单评

3 个答案: