sql - 按子字符串分组的查询，返回子字符串结果并按组上的聚合排序

Question

到目前为止，我有这个查询

select count(*) as howMany,sum(Duration) as totalTime 
from [Tmp].[dbo].[tmp2] 
group by SUBSTRING(TextData,1,25) 

可以很好地返回两列：howMany 和 totalTIme。我希望它还返回一个包含 SUBSTRING(TextData,1,25) 结果的列，这对于每个组都是相同的。但是我不确定如何修改查询来完成此操作。

我也想要按totalTime排序的结果，但是下面的尝试编译失败

select * 
from (select count(*) as howMany,sum(Duration) as totalTime 
      from [Tmp].[dbo].[tmp2] 
      group by SUBSTRING(TextData,1,25) ) 
order by totalTime;

Answer 1

select SUBSTRING(TextData,1,25),
    count(*) as howMany,
    sum(Duration) as totalTime 
from [Tmp].[dbo].[tmp2] 
group by SUBSTRING(TextData,1,25)
order by 3 --3rd column

应该做的伎俩。

Answer 2

select SUBSTRING(TextData,1,25) as textdata, count(*) as howMany,sum(Duration) as totalTime
from [Tmp].[dbo].[tmp2] 
group by SUBSTRING(TextData,1,25)
order by sum(duration)

我相信您可以将子字符串位添加到 select 语句中，然后按顺序添加总和。它默认为升序，将 desc 放在语句的末尾以反转它