SQL：计算第3个表中的行

Question

我有3个表，第一个表是account_has_account1 ，我在其中存储帐户之间的关系，它的列是account_id, account_id1, status ，其中account_id是紧跟account_id1的帐户， status是具有值active, inactive的枚举类型active, inactive表示active如果该帐户实际上在关注，如果该帐户处于非活动状态，则该帐户停止关注。

第二张表名为account_has_photos ，它存储一个帐户已存储在数据库中的照片，因此它的列是account_id, photos_id ，因此我需要此表从另一个帐户正在关注的一个帐户中获取所有照片。

但是所有这些都有张贴在上面的消息，这是第3个表，名为photos_has_message_photos ，从该表中我只需要统计一张照片中所有已发布消息的数量，列是photos_id, message_photos_id

现在我的查询是这样的：

SELECT account_has_photos.photos_id as id, "photos" as type, account_has_photos.update_at, account_has_photos.account_id
FROM account_has_account1 
    JOIN account_has_photos 
        ON (account_has_photos.account_id = account_has_account1.account_id1 AND account_has_photos.type_id = 17)
WHERE account_has_account1.account_id = 7 AND account_has_account1.`status` = "Active"

它显示了帐户ID为7的帐户中的所有照片，但是在我尝试获取总消息时失败了，我想到进行这样的INNER JOIN ：

INNER JOIN (
        SELECT photos_has_message_photos.photos_id, count(photos_has_message_photos.photos_id) as total
        FROM photos_has_message_photos
    ) posts
        ON(posts.photos_id = account_has_photos.photos_id)

然后我从main posts.total选择，但是它不显示任何行，甚至不显示照片，此时结果为空，我不知道为什么以及要做什么。

完整的查询是这样的：

SELECT account_has_photos.photos_id as id, "photos" as type, account_has_photos.update_at, account_has_photos.account_id, posts.total
FROM account_has_account1 
    JOIN account_has_photos 
        ON (account_has_photos.account_id = account_has_account1.account_id1 AND account_has_photos.type_id = 17)
    INNER JOIN (
        SELECT photos_has_message_photos.photos_id, count(photos_has_message_photos.photos_id) as total
        FROM photos_has_message_photos
    ) posts
        ON(posts.photos_id = account_has_photos.photos_id)
WHERE account_has_account1.account_id = 7 AND account_has_account1.`status` = "Active"

再次，我只需要一共行，这些行是发现的每张照片的消息

Answer 1

尝试此查询更新内部选择

 SELECT ahp.photos_id as id, "photos" as type, ahp.update_at, ahp.account_id,posts.total
FROM account_has_account1 
    JOIN account_has_photos 
        ON (ahp.account_id = account_has_account1.account_id1 AND ahp.type_id = 17) INNER JOIN (
        SELECT phmp.photos_id, count(*) as total FROM photos_has_message_photos GROUP BY phmp.photos_id
    ) posts
        ON(posts.photos_id = ahp.photos_id) WHERE account_has_account1.account_id = 7 AND account_has_account1.`status` = "Active"