Question

我有一张桌子：

id  cod_pr      Date        nr
-------------------------------
1     22     12.10.2012     2
2     25     12.10.2012     3
3     22     12.11.2012     5
4     25     12.11.2012     2
5     22     12.12.2012     4
6     23     12.10.2012     3

如何从每个cod_pr中仅选择最大日期？

Answer 1

select cod_pr,MAX(Date) from Table
group by cod_pr

Answer 2

如果您想要所有列，可以在CTE中使用ROW_NUMBER：

WITH CTE AS
(
   SELECT id,cod_pr,Date,nr,
      ROW_NUMBER() OVER (PARTITION BY cod_pr ORDER BY Date DESC) AS RN
   FROM dbo.Table
)
SELECT id,cod_pr,Date,nr, FROM CTE WHERE RN = 1

否则您只需使用GROUP BY

即可

SELECT cod_pr, MAX(Date) AS MaxDate
FROM dbo.Table
GROUP BY cod_pr

选择最大（数据）

2 个答案: