我有一个具有以下结构的表。
LocId Value1 Value1Date
.............................................
1 50 2012-10-20 14:21:00.000
1 70 2012-10-21 14:21:00.000
1 90 2012-10-22 14:21:00.000
1 100 2012-10-23 14:21:00.000
2 20 2012-10-20 14:21:00.000
2 40 2012-10-21 11:21:00.000
2 70 2012-10-22 14:21:00.000
2 80 2012-10-23 14:21:00.000
3 50 2012-10-20 14:21:00.000
3 70 2012-10-21 11:21:00.000
3 80 2012-10-22 14:21:00.000
3 90 2012-10-23 14:21:00.000
我想要实现的是,对于每个 [LocId],我需要最新日期时间(即 2012-10-23)的 [Value1]。返回的表应如下所示:
LocId Value1 Value1Date
.............................................
1 100 2012-10-23 14:21:00.000
2 80 2012-10-23 14:21:00.000
3 90 2012-10-23 14:21:00.000
有人可以帮忙吗?谢谢
最佳答案
您可以像这样在分区上使用排名:
select * from
(select locid, value1, value1date,
rank() over (partition by locid order by value1date desc) as rank
from table1) t
where t.rank=1
参见 SqlFiddle
关于返回每个 ID 的最新记录的 SQL 查询,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15399962/