如何在同一个select语句中使用count和group by [英] How to use count and group by at the same select statement

问题描述

我有一个具有group by的sql select查询。
我想计算group by语句后的所有记录。
有直接从sql的方法吗？
例如，拥有一个包含用户的表格我想选择不同的城镇和总用户数量

  select town，count（*）from user 
 group by town 
  

有三个城镇和58个用户的结果示例，其中包括所有城市的列和所有行的用户数。总计是：

 城市数
哥本哈根58 
纽约58 
雅典58 
  

解决方案

这将做你想要的（城镇列表，

  select town，count（town）
 from user 
 group by town 
  

您可以使用大多数 GROUP BY 时，聚合函数。

更新（更改问题和意见后）

您可以为用户数量声明一个变量，

  DECLARE @numOfUsers INT 
 SET @numOfUsers = SELECT COUNT（*）FROM用户
 
选择DISTINCT镇，@numOfUsers 
从用户
  

I have an sql select query that has a group by. I want to count all the records after the group by statement. Is there a way for this directly from sql? For example, having a table with users I want to select the different towns and the total number of users

select town, count(*) from user
group by town

I want to have a column with all the towns and another with the number of users in all rows.

An example of the result for having 3 towns and 58 users in total is :

Town         Count
Copenhagen   58
NewYork      58
Athens       58

解决方案

This will do what you want (list of towns, with the number of users in each):

select town, count(town) 
from user
group by town

You can use most aggregate functions when using GROUP BY.

Update (following change to question and comments)

You can declare a variable for the number of users and set it to the number of users then select with that.

DECLARE @numOfUsers INT
SET @numOfUsers = SELECT COUNT(*) FROM user

SELECT DISTINCT town, @numOfUsers
FROM user

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