使用GROUP BY進行刪除

Question

如何更改此SELECT，因此它是用於刪除的條件？

SELECT COUNT(empid), empid, status, deptid from tableA 
GROUP BY empid, status, deptid HAVING status is null and deptid = 5 

Answer 1

你想刪除什麼？

如果簡單地在DEPTID 5 NULL狀態記錄，使用

WHERE status is NULL and DeptID = 5 

不是很清楚，如果你正在尋找更多的比...

Answer 2

與GROUP BY DELETE可能無法正常工作，我猜。

您可以嘗試以下操作，並查看它是否有效。

DELETE 
FROM tableA 
WHERE status is null AND deptid=5 

Answer 3

DELETE FROM tableA 
WHERE status is null AND deptid = 5 

Answer 4

Delete from tableA a, 
(SELECT COUNT(empid) as count, empid, status, deptid from tableA 
    GROUP BY empid, status, deptid HAVING status is null and deptid = 5) as b 
where a.empid = b.empid 
and a.status = b.status 
and a.deptid = b.deptid 
and b.count > 5 

將類似的東西是你在找什麼？它會刪除所有屬於組的一部分的所有記錄，並且計數> 5

否則，您確實沒有刪除組中的值，並且可以使用簡單的刪除;

Delete from tableA 
where status is null 
and deptid = 5