请教一个SQL查询语句的写法
0
悬赏园豆：30
[已解决问题]
解决于 2009-04-17 22:12
Table Parent
Pid Name
1 aa
2 bb
3 ddd
4 aaa
Table Child
Cid Pid Name
1 2 aa
2 1 bb
3 2 bb
4 3 cc
5 3 cd
Table Article
Aid Cid Context
1 3 asdfasdfasdf
2 2 asdfasdfasdfasf
3 3 asdfasdfasdfasdf
4 1 asdfasdfasdfasdf
想从每个Parent分类下相关的任意Child提取3条Article
最佳答案
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WITH OrderedArticle AS
(
SELECT Pid, Aid, ROW_NUMBER() OVER (PARTITION BY Pid ORDER BY Aid) AS Num
FROM Parent
JOIN Child ON Parent.Pid = Child.Pid
JOIN Article ON Child.Cid = Article.Aid
)
SELECT *
FROM OrderedArticle
WHERE Num < 4
