当子查询重新显示更多值时如何显示数据 [英] How to show data when sub query rerurn more vaule

问题描述

Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

我有写查询，其中有2个子查询
1返回198行
其他人返回168，请告诉我们如何解决此问题

喊叫已删除-KH [/编辑]

I have write query which has 2 sub query
1 return 198 row
And other one return 168 so tell how to solve this problem

Shouting removed - KH[/Edit]

推荐答案

亲爱的朋友，

您可以使用Distinct或Group by或Top1.
它会为您提供帮助.但是请确保满足您的要求.

Dear Friend,

You can use Distinct or Group by or Top 1.
It will help you. But make sure that, your requirement is fulfilled.

而不是=，请使用In

我认为您的查询看起来像是

Instead of =, use In

I think your query will be looking something like

select * from employee where empid=(select empid from employee where dept='SE')

所以现在发生了什么，子查询将返回多行，但由于您提到了条件"="，所以它返回错误.

在这种情况下，您必须使用IN或存在

So now what happens, the subquery will return you more than one row but since you mentioned condition''='', it returns error.

In that case, you have to use IN or exists

select * from employee where empid in (select empid from employee where dept='SE')

如果使用！=，则不要使用.

但请注意:不使用将影响性能，使用不存在

In case if you used !=, then use not in.

But note: Not in will affect performance use not exists

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