SQL查詢計算同一行上的兩個數量

Question

可能是一個非常簡單的答案，但我是T-SQL的新手，所以可以藉助一些幫助！

我需要一個工作了TotInc第3列 - （減號）TOTEX給我一個TotalDisposableIncome

這裏是我的SQL：

- 這使我在同一總收入和總支出排

SELECT 
    SUM(CASE WHEN Type = '1' THEN Amount ELSE 0 END) as TotalInc, 
    SUM(CASE WHEN Type = '2' THEN Amount ELSE 0 END) as TotEx 
    FROM ClaimFinancials 

謝謝！

Answer 1

你可以使用一個公用表表達式（CTE）：

WITH T1 AS 
(
    SELECT 
     SUM(CASE WHEN Type = '1' THEN Amount ELSE 0 END) as TotalInc, 
     SUM(CASE WHEN Type = '2' THEN Amount ELSE 0 END) as TotEx 
    FROM ClaimFinancials 
) 
SELECT TotalInc, TotEx, TotalInc - TotEx AS TotalDisposableIncome 
FROM T1 

還是普通的子查詢：

SELECT TotalInc, TotEx, TotalInc - TotEx AS TotalDisposableIncome 
FROM 
(
    SELECT 
     SUM(CASE WHEN Type = '1' THEN Amount ELSE 0 END) as TotalInc, 
     SUM(CASE WHEN Type = '2' THEN Amount ELSE 0 END) as TotEx 
    FROM ClaimFinancials 
) T1 

Answer 2

您不能在SELECT子句中的其他地方引用列別名。這是一個選擇。

SELECT TotalInc, TotEx, TotInc - TotEx as TotalDisposable 
FROM (
    SELECT 
    SUM(CASE WHEN Type = '1' THEN Amount ELSE 0 END) as TotalInc, 
    SUM(CASE WHEN Type = '2' THEN Amount ELSE 0 END) as TotEx 
    FROM ClaimFinancials 
    ) AS Total 

Answer 3

SELECT 
    SUM(CASE WHEN Type = '1' THEN Amount ELSE 0 END) as TotalInc, 
    SUM(CASE WHEN Type = '2' THEN Amount ELSE 0 END) as TotEx, 
    SUM(CASE 
    WHEN Type = '1' THEN Amount 
    WHEN Type = '2' Then -Amount 
    ELSE 0 
    END) AS TotalDisposableIncome 
FROM ClaimFinancials 

Answer 4

不止一種方法去做一件事。

WITH T1 AS 
( 
    SELECT 
    Type,  
    SUM(Amount as Total 
    FROM ClaimFinancials 
) 
SELECT 
    Inc.Total as TotalInc, 
    Ex.Total as TotEx, 
    Inc.Total - Ex.Total AS TotalDisposableIncome 
FROM T1 Inc, T2 Ex 
where T1.Type = 1 and T2.Type = 2