按SQL中的计算字段分组

我写了这样的查询

CASE 
              WHEN [col1] = 's' THEN '1'
              WHEN [col1] = 't' THEN '2' 
              WHEN [col1] = 'u' THEN '3' 
              WHEN [col2] = 'v' THEN '4'
.......
END AS product,SUM(col3)
FROM dbo.TableA

我想在产品上分组？
怎么做？

解决方法

您需要做的是为别名的CASE列使用子查询.将查询作为子查询,您可以按别名列进行分组.

select product
from
(
    select
    CASE  
        WHEN [col1] = 's' THEN '1' 
        WHEN [col1] = 't' THEN '2'  
        WHEN [col1] = 'u' THEN '3'  
        WHEN [col2] = 'v' THEN '4'
    END AS product,SUM(col3) as Col3Sum
    FROM dbo.TableA 
) a
group by product