我有两张表:一张表载有各位议员提交的诗歌。另一张是会员的桌子。两个表都包含成员的ID (MID和SubMID)。我想展示最新的15首诗。但是,我只想为任何一个作者展示一部作品。
这是可行的,但是如果作者更新了几部作品,它们就会被多次显示:
SELECT * FROM submits, members
WHERE submits.SubMID = members.MID AND submits.sub_approved = 'T'
ORDER BY submits.sub_Last_Update DESC LIMIT 15
您可以在右边的滚动框中看到查询的结果:http://www.Prose-n-Poetry.com
问题是,一位作者可以通过更新几首诗来取代这一主题。
发布于 2013-09-29 03:11:01
SELECT *
FROM members m
JOIN (SELECT s.*
FROM submits s
JOIN (SELECT SubMID, MAX(sub_Last_Update) lastUD
FROM submits
WHERE approved = 'T'
GROUP BY SubMID) l
ON s.SubMID = l.SubMID AND s.sub_Last_Update = l.lastUD) s
ON m.MID = s.SubMID
ORDER BY s.sub_Last_Update DESC
LIMIT 15
发布于 2013-09-29 03:10:10
编辑:如@Barmar评论,这不会给出每个用户最新提交的列表。
试着按成员分组
$query = "
SELECT
*
FROM
submits, members
WHERE
submits.SubMID = members.MID
AND
submits.sub_approved = 'T'
GROUP BY
submits.SubMID
ORDER BY
submits.sub_Last_Update DESC
LIMIT 15
";
https://stackoverflow.com/questions/19073942
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