每组 Greatest-n MSSQL

Question

我正在使用 SQL-server 2008

我的 table 看起来是这样的：

max_period  Employee ID Preferred Name
2016-10-19 00:00:00.000 16317   James Hello
2015-10-31 00:00:00.000 16317   Jimmy Hello

我试图只获得 max_period 最大的名字，由 Employee_ID

输出如下所示：

max_period  Employee ID Preferred Name
2016-10-19 00:00:00.000 16317   James Hello

谁能帮我解决这个问题？这看起来很简单，但让我很头疼。

Answer 1

你可以尝试使用 row_number() over()

;with cte as (
  select *, RowN = row_number() over (order by max_Period desc) from YourTable
 ) select * from cte where RowN = 1

Answer 2

SELECT *
  FROM (SELECT max(period) as max_period, [Employee ID], [Preferred Name],
           ROW_NUMBER() OVER (PARTITION BY [Employee ID] ORDER BY period DESC)     rank
          FROM STG.tbl_HR_BI_feed
      where [Employee ID] = '16317'
      group by [Employee ID], [Preferred Name], period) a
 WHERE a.rank = 1

Answer 3

;with cte
AS
(
select max_period  ,EmployeeID , PreferredName, ROW_NUMBER() OVER (PARTITION BY Employee_ID ORDER BY max_period DESC) as RN From Table1
)
SELECT * from cte WHERE RN = 1

你也可以用 GROUP BY 来完成

select MAX(max_period), EmployeeID , PreferredName FROM Table1 GROUP BY EmployeeID , PreferredName

每组 Greatest-n MSSQL

Greatest-n per group MSSQL

sql

sql-server

sql-server-2008

greatest-n-per-group