Question

我有两个表用户和相册。在users表中有user_id主键。在其他表专辑中有多行user_id，因为每次用户上传新专辑时，它都会以user_id作为外键上传。我想只选择user_id与其他表（专辑）忽略其他结果集。

我怎样才能做到这一点？

Answer 1

SELECT album.* FROM album LEFT JOIN users ON user.id = album.id WHERE user.id = SOMEIDHERE

我相信这会奏效，你不会给我很多信息。

Answer 2

SELECT  a.*, b.*
FROM    users a
        INNER JOIN album b
            ON a.user_ID = b.user_ID
        INNER JOIN
        (
            SELECT user_ID, MAX(photo_id) max_rec
            FROM album
            GROUP BY    user_ID
        ) c ON b.user_ID = c.user_ID AND
                b.photo_id = c.max_rec

Answer 3

SELECT *
FROM (  SELECT u.*, a.*
        FROM users AS u
        INNER JOIN album AS a
        ON u.user_ID = a.user_ID
        ORDER BY a.created DESC) AS h
GROUP BY user_ID

ORDER BY b.created DESC - ＆gt; ORDER BY你想要的任何行。在这种情况下，选择最新的。

从两个表中选择一行取决于主键（Mysql）？

3 个答案: