SQL:获取一列和相应其他列的最大值
ID| tag | version
-----+-----+-----
1| A | 10
2| A | 20
3| B | 99
3| C | 30
3| F | 40
期望的输出:
1 A 10
2 A 20
3 B 99
如何获取每个 ID 的最大版本以及该版本的相应标签?速度很重要(我有大约 28m 行)，所以嵌套的 Select 不会这样做.此外，一个带有 max(version) 的简单 Group by ID 也不起作用，因为我还需要版本为 max 的相应标签.
How can I get the max version of every ID and the corresponding tag for that version? Speed is important (I have around 28m rows) so a nested Select won't do it. Also a simple Group by ID with a max(version) doesn't work because I also need the corresponding Tag where the version is max.
推荐答案
使用 ROW_NUMBER() :
SELECT s.id,s.tag,s.version FROM (
SELECT t.*,
ROW_NUMBER() OVER(PARTITION BY t.id ORDER BY t.version DESC) as rnk
FROM YourTable t) s
WHERE s.rnk = 1
相关文章