在SELECT语句SQL中的其他聚合函数中使用聚合函数

Question

我有一个相当大的聚合函数，我必须在另一列中使用两次，有没有一种方法可以写下来而不必将第一个函数写出三遍呢？ 所以我想要这样的事情：

Select
volumet =
CASE When sum(volume)>200, then 200
     Else sum(volume)
END,
sum(volumet * price) / volumet - price2 * volumet as Profit
FROM tablex

Answer 1

Select
sum(volumet * price) / volumet - price2 * volumet as Profit
FROM
(Select
CASE When sum(volume)>200, then 200
     Else sum(volume)
END as volumet, price, price2
FROM tablex) as tableAux

Answer 2

像这样的东西应该是您根据原始帖子寻找的东西。

WITH CTE 
AS
(
    SELECT
        sum(volumet) AS volumet
    ,   price
    ,   price2
    FROM tablex
    group by price, price2
)
, VolumetValues as
(
    select case when volumet > 200 then 200 else volumet end as volumet
        , price
        , price2
    from CTE
)

SELECT 
    (volumet * price) / volumet - price2 * volumet as Profit
FROM VolumetValues