sql - 按 SQL 中的计算字段进行分组

Question

我写了一个这样的查询

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

我想对产品进行分组？如何做到这一点？

Answer 1

您需要做的是对别名 CASE 列使用子查询。通过将查询作为子查询，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