我如何獲得第四列的

這一語句將產生一個4列的表的總和：我如何獲得第四列的

SELECT shipped.badguy AS badguy, shipped.sdate AS LineDate, 
     'Delivery' AS Legend, -price*quantity AS amount 
    FROM product JOIN shipped ON (product.id = shipped.product) 
UNION 
    SELECT receipt.badguy, receipt.rdate,notes, amount 
    FROM receipt

如何獲得上述產生什麼樣的列第4的總和？

來源

2010-03-16 l--' ' ' ' ' ' ---------' ' ' ' ' ' ' ' ' ' ' '

哪個數據庫？ – 2010-03-16 21:48:25

您的查詢似乎不完整。 – 2010-03-16 21:49:30

我喜歡使用子查詢的一切。

SELECT SUM(results.amount) 
FROM 
(
SELECT -price*quantity AS amount 
    FROM product JOIN shipped ON (product.id = shipped.product) 
UNION 
    SELECT amount 
    FROM 
... 
) results

來源

2010-03-16 21:44:22

sql：error每個派生表都必須有自己的別名 number：1248 – 2010-03-16 21:47:48

哦，是的，你需要一個子查詢的別名。我會添加它。 – 2010-03-16 21:56:01

在Oracle中，子查詢表達式不需要別名。 'select count（dummy）from（select * from dual）;'是完全有效的。 – 2010-03-16 22:22:53

SUM(-price*quantity)

呵呵？

來源

2010-03-16 21:41:49 zerkms

嘗試

sum(price*quantity)

或兩個查詢合併爲

SELECT badguy,rdate,notes,SUM(AMOUNT) FROM(
     SELECT shipped.badguy AS badguy, shipped.sdate AS LineDate, 
     'Delivery' AS Legend, -price*quantity AS amount 
    FROM product JOIN shipped ON (product.id = shipped.product) 
UNION 
    SELECT receipt.badguy, receipt.rdate,notes, amount 
    FROM) A

來源

2010-03-16 21:41:53

將您的查詢包裹在另一個查詢中，其中外部查詢只獲取所需的總和。這使您的查詢子查詢。

SELECT SUM(amount) FROM (
    SELECT shipped.badguy AS badguy, shipped.sdate AS LineDate, 
      'Delivery' AS Legend, -price*quantity AS amount 
     FROM product JOIN shipped ON (product.id = shipped.product) 
    UNION 
    SELECT receipt.badguy, receipt.rdate,notes, amount 
    FROM <...> 
)

來源

2010-03-16 21:49:34

我如何獲得第四列的

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