同一SQL Server 2012表上的多个计数

Question

是否有更好的方法根据不同的标准计算id的行？

例如，我有一个包含列的表：

id, state, city

我的查询：

select 
    ID, city, state, UScount, statecount, citycount
from    
    (select count(*) USCount, ID  
     from table 
     group by ID) UScount
inner join 
    (select count(*) stateCount, ID  
     from table 
     group by ID, state) statecount on UScount.ID = Statecount.ID
inner join 
    (select count(*) cityCount, ID  
     from table 
     group by ID, city) citycount on UScount.ID = citycount.ID

我只是想清理它，因为实际上我有大约20种不同的数量并且看起来不太好

Answer 1

您在寻找窗口功能吗？

select t.*,
       count(*) over () as cnt,
       count(*) over (partition by state) as cnt_state,
       count(*) over (partition by state, city) as cnt_state_city
from table t;

我不确定id是否应该成为partition by的一部分。