庫存控制決定因素

Question

我有一個表有庫存，庫存和庫存。我希望根據（庫存缺貨）產生的進程計算進出庫存的差額。即

Stock In |Stock Out|(Stock In - Stock Out)| 

500  | 50 | 450    | 

450  | 100 | 350    | 

我遇到的問題是，缺貨是從原來的股票扣除的500

結果，我有是這樣的：

Stock In |Stock Out|(Stock In - Stock Out)| 

500  | 50 | 450    | 

0  | 100 | 400    | 

0  | 150 | 350    | 

我想這是從他們的分歧結果中扣除的。

這裏是我的查詢：

SELECT Product_Code, SUM(Stock In - Stock Out) AS Stock_Balance 
FROM Daily_Stock_Balance 
GROUP BY Product_Code; 

這是我從上面的查詢得到的結果：

 Stock In |Stock Out|Stock Balance| 

    500  | 50 | 450  | 

       | 100 | 100  | 

       | 150 | 100  | 

下面是我真正的數據庫表

任何幫助將不勝感激。

Answer 1

如何相關列求和：

SELECT Testx.dispatchdate, 
     Testx.stockin, 
     Testx.stockout, 
     (SELECT SUM(stockin) 
     FROM Testx a 
     WHERE a.dispatchdate <= Testx.dispatchdate) AS SumIn, 
     (SELECT SUM(stockout) 
     FROM Testx a 
     WHERE a.dispatchdate <= Testx.dispatchdate) AS SumOut, 
     [sumin] - [sumout]       AS Balance 
FROM Testx 
ORDER BY Testx.dispatchdate;