如何在下面的要求上写查询 [英] How to write query on below requirement

问题描述

创建表LocationInfo

（

Id identity（1,1）主键int，

名称Nvarchar（50）not null，

位置Nvarchar（50）不为空，

图像Nvarchar（50）不为空，

IsValid位

）



我尝试了什么：



如何选择计数（ id），一个图像，一个名称来自表名，其中有效= 1按位置分组？



我试过但我没有得到我认为的确切输出，所以可以请告诉我怎么写查询？

Create Table LocationInfo
(
Id identity(1,1) Primary key int,
Name Nvarchar(50) not null,
Location Nvarchar(50) not null,
Image Nvarchar(50) Not null,
IsValid Bit
)

What I have tried:

How to select count(id),one image,one name from Table Name where Is Valid=1 Group by location ?

I tried but i didnt get exact output what i think,so can u please tell me how to write query?

推荐答案

你想要什么图像？ GROUP BY是关于聚合信息，而不是选择特定行。这可能有助于解释它： SQL GROUP By和列'名称'在选择列表中无效，因为......错误 [ ^ ]



你想要ID的数量，我们得到了 - 但为了得到这个数，你也无法得到单独的行信息。

可能，你正在尝试同时做两个任务 - 要做到这一点，你需要做两个SELECT语句，每个语句收集一行，然后将它们组合起来产生你想要的结果 - 但是我们不能为你做那个，因为我们不知道哪个图像和哪个名字你在寻找 - 而且（我怀疑）你都没有！

What image do you want? GROUP BY is about aggregating information, not selecting a specific row. This may help to explain it: SQL GROUP By and the "Column 'name' is invalid in the select list because..." error[^]

You want a count of IDs, we get that - but to get that count, you can't get individual row information as well.
Probably, you are trying to do two tasks at the same time - and to do that, you would need to do two SELECT statements, each to collect one row, and combine them to produce the result you want - but we can't do that for you because we have no idea which image and which name you are looking for - and neither (I suspect) do you!

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