查询以计算列中的值的数量

Question

我有一个叫做应用程序的表。使用此列（app_status），其中只能接受这三个值中的一个“已接受”，“已拒绝”或待处理。我想显示每个状态的数量。换句话说，我想要一个能给我类似的查询：

application_status     :     number_of_status
--------------------------------------------
accepted               |         4
--------------------------------------------
rejected:              |         5
--------------------------------------------
pending:               |         10

在Microsoft SQL Server中

Answer 1

请使用GROUP BY。

SELECT app_status, COUNT(app_status) AS NumberOfStatus
FROM application
GROUP BY app_status HAVING (COUNT(app_status)>1)
ORDER BY NumberOfStatus DESC

Answer 2

试试这个：

Select count(case when app_status= 'accepted' then 1 else null end) as Accepted, 
count(case when app_status='rejected' then 1 else null end) as Rejected, 
count(case when app_status='pending'then 1 else null end) as Pending
From Application

- 吉姆

Answer 3

更简单一点：

select application_status, count(application_status) as number_of_status 
from application group by application_status