Mysql SQL查询返回包含另一列数据的列

我有一个表通知连接到表喜欢和评论。当我为用户返回通知时，我也会创建列：喜欢的数量、评论的数量和我喜欢的数量。当进行查询的用户不喜欢某个通知（liked_by_me=0）时，查询工作正常。但是如果他们有（喜欢我=1），我得到的喜欢的数量的值是错误的，并且与评论的数量相同

例如：

1）
-我喜欢=错误
-喜欢=1
-评论=5

返回值：
-被我喜欢=0
-喜欢的数量=1
-注释的数量=5

2）
-我喜欢=真的
-喜欢=2
-评论=5

返回值：
-我喜欢你=1
-喜欢的数量=5
-注释的数量=5

以下是我正在使用的查询：

SELECT notices.*
     , count(comment.id) as number_of_comments
     , count(like1.user_id) as number_of_likes
     , like2.user_id IS NOT NULL AS liked_by_me
     , boards.name as board_name
FROM notices
LEFT JOIN comments as comment
   ON (comment.notice_id = notices.id)
LEFT JOIN likes as like1
   ON (like1.notice_id = notices.id)
LEFT JOIN likes as like2
   ON (like2.notice_id = notices.id 
   AND like2.user_id = $1)
LEFT JOIN boards
   ON (boards.id = notices.board_id)
LEFT OUTER JOIN board_users
   ON (board_users.board_id = notices.board_id)
WHERE board_users.user_id = $1
GROUP BY notices.id
       , boards.name
       , like2.user_id
       , userId

任何帮助都将不胜感激。我已经做了几个小时了，我不认为我能找到问题

谢谢

解决方案： 这是工作查询

SELECT notices.*, 
(SELECT COUNT(user_id) from likes WHERE likes.notice_id = notices.id) AS number_of_likes, 
(SELECT user_id IS NOT NULL from likes WHERE likes.notice_id = notices.id AND likes.user_id = $1) AS liked_by_me, 
count(comments.id) as number_of_comments, boards.name as board_name
FROM notices LEFT JOIN comments ON (comments.notice_id = notices.id) 
LEFT JOIN boards ON (boards.id = notices.board_id) 
LEFT OUTER JOIN board_users ON (board_users.board_id = notices.board_id) 
WHERE board_users.user_id = $1 GROUP BY notices.id, boards.name", user);

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您必须使用子选择。

关于这个问题的优秀文章：

TL；DR:基本上，你必须意识到，你所有的评论和喜欢都被彼此放大了。尝试在不显示group子句的情况下显示查询结果，以查看重复的喜欢/评论是否被计数

编辑：我没有对此进行测试，但这是查询的外观： （也就是说，如果用户只能喜欢一个通知一次，否则您也必须对当前用户的喜好进行分组）

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非常感谢。你的建议真的帮我弄明白了。因此，我尝试在联接中使用subselect，但它们仍然需要分组，并且合谋字段仍然返回错误的值。通过在查询的列声明中添加subselect，我最终获得了正确的值。没有经过测试，但这就是我的想法。我不确定列中的子选择查询的性能如何。

SELECT
    notices.*,
    comments.number_of_comments,
    likes.number_of_likes
    current_user_likes.user_id IS NOT NULL AS liked_by_me
    boards.name AS board_name
FROM notices

LEFT JOIN (
    SELECT
        COUNT(*) AS number_of_comments,
        notice_id
    FROM comments
    GROUP BY notice_id
) AS comments ON comments.notice_id = notices.id

LEFT JOIN (
    SELECT
        COUNT(*) AS number_of_likes,
        notice_id
    FROM likes
    GROUP BY notice_id
) AS likes ON likes.notice_id = notices.id

LEFT JOIN likes AS current_user_likes 
    ON current_user_likes.notice_id = notices.id 
        AND current_user_likes.user_id = $1
LEFT JOIN boards ON boards.id = notices.board_id

INNER JOIN board_users 
    ON board_users.board_id = notices.board_id
        AND board_users.user_id = $1;