我需要从sql

Question

中选择一个具有不同值的列我给出了一个表，其中包含各个部门的列和由各种dhdempno组成的另一列。我需要选择一个代表部门负责人的独特dhdempno。一个特定的部门有多个雇员，其中dhdmempno和一个代表部门负责人的独特dhdempno。我应该执行什么查询以获得结果？

例

Department - dhdempno 
abc   1 
abc   1 
abc   2 
asd   5 
asd   5 
asd   6 

查询应返回

abc 2 
asd 6 

Answer 1

试试这个

select departmentid, count(distinct dhdempno) as counting from your_table 
group by departmentid 

Answer 2

这里是它会给你正在寻求结果的查询。

select Department, dhdempno 
from (
    SELECT Department, dhdempno, count(dhdempno) as counts 
    FROM <your_table_name> 
    group by Department, dhdempno) as sub 
where counts = 1; 

Answer 3

使用查询像

SELECT DEPARTMENT,DHDEMPNO FROM DEPARTMENT 
GROUP BY DEPARTMENT,DHDEMPNO 
HAVING COUNT(DHDEMPNO)=1 

会给你相应的部门具有独特dhdempono记录

Answer 4

SELECT DepartmentId, MAX(dhdempno) 
FROM [Table-name] 
GROUP BY DepartmentId 

Answer 5

select [Department],[dhdempno] from [dbo].[Your_Table_Name] where [dhdempno] in (select [dhdempno] from [dbo].[Your_Table_Name] group by [dhdempno] having count(*) = 1) 

Answer 6

使用下面的查询：

select s.Department, max(s.dhdempno)as dhdempno from 
(
    SELECT DISTINCT DEPARTMENT, dhdempno FROM DUMMY 
) s group by s.Department