从表中获取唯一数据

Question

我有一个包含一些数据的表，如下所示。

我想从表中获取唯一数据，我尝试了下面的代码

SELECT
    sa.EMPID,
    sa.EMPNAME,
    sa.DEPTID
FROM dbo.Sample AS sa
LEFT OUTER JOIN dbo.Sample AS se ON sa.EMPID = se.EMPID

但无法获得结果。

我希望查询得到以下数据

有谁可以帮我解决这个问题..？

Answer 1

试试这个：

SELECT EMPNAME,
       DEPTID,
       MIN(EMPID) AS EMPID
       FROM  dbo.Sample
 GROUP BY EMPNAME, DEPTID

Answer 2

试试这个 -

SELECT EMPID, EMPNAME, DEPTID
FROM (
    SELECT
        EMPID,
        EMPNAME,
        DEPTID,
        RowNum = ROW_NUMBER() OVER (PARTITION BY EMPNAME, DEPTID ORDER BY 1/0)
    FROM dbo.[Sample]
) t
WHERE RowNum = 1

Answer 3

您可group by empname和deptid，并选择最小empid：

SELECT     MIN(sa.EMPID), sa.EMPNAME, sa.DEPTID
FROM       dbo.Sample AS sa LEFT OUTER JOIN
           dbo.Sample AS se ON sa.EMPID = se.EMPID
GROUP BY   sa.EMPNAME, sa.DEPTID

Answer 4

试试这个

With tmp AS
FROM (SELECT S.EMPID,S.EMPNAME,S.DEPTID,RowNum = ROW_NUMBER() OVER (PARTITION BY S.EMPNAME, S.DEPTID ORDER BY S.EMPID)
    FROM dbo.[Sample] S LEFT JOIN dbo.[Sample] T ON T.EMPID = S.EMPID)     
SELECT EMPID,EMPNAME,DEPTID FROM tmp WHERE RowNum = 1

Answer 5

这就是你想要的：

SELECT Min(EMPID) AS EMPID,
EMPNAME,
DEPTID
FROM dbo.Sample
Group By EMPNAME, DEPTID