我需要從sql

Question

中選擇一個具有不同值的列我給出了一個表，其中包含各個部門的列和由各種dhdempno組成的另一列。我需要選擇一個代表部門負責人的獨特dhdempno。一個特定的部門有多個僱員，其中dhdmempno和一個代表部門負責人的獨特dhdempno。我應該執行什麼查詢以獲得結果？

例

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

查詢應返回

abc 2 
asd 6 

Answer 1

試試這個

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

Answer 2

這裏是它會給你正在尋求結果的查詢。

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

使用查詢像

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

會給你相應的部門具有獨特dhdempono記錄

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

使用下面的查詢：

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