Question

如何更改此SELECT以便它是用于删除的标准？

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

Answer 1

你想删除什么？

如果仅使用

在deptId 5中记录具有NULL状态的记录

WHERE status is NULL and DeptID = 5

如果您正在寻找更多信息，那就不太清楚......

Answer 2

使用GROUP BY删除可能无法正常工作，我猜。

您可以尝试以下操作，请查看它是否有效。

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

这样的东西会是你想要的吗？它将删除属于该组的所有记录，其数量为＆gt; 5

否则，您实际上并没有从组中删除值，可以使用简单的删除;

Delete from tableA 
where status is null 
and deptid = 5

使用GROUP BY删除

4 个答案: