在SELECT語句SQL中的其他聚合函數中使用聚合函數

Question

我有一個相當大的聚合函數，我必須在另一列中使用兩次，有沒有一種方法可以寫下來而不必將第一個函數寫出三遍呢？ 所以我想要這樣的事情：

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

像這樣的東西應該是您根據原始帖子尋找的東西。

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