我如何重新编写这个游标来计算运行总数?

所以我有一些代码,每次都会删除并重新创建一个表,然后使用光标遍历并计算股票数量的运行总数。光标的代码如下(表名模糊):

DECLARE @Cust_Name nvarchar(250),
              @Cust_Postcode nvarchar(50),
              @MatchCode_Product nvarchar(50),
              --@Stock int,
              @DateKey nvarchar(8),
              @Ordered int

DECLARE StockCursor CURSOR 
  LOCAL STATIC READ_ONLY FORWARD_ONLY
FOR 
SELECT
       Cust_Name, Cust_Postcode, MatchCode_Product, DateKey
FROM
       WRK_TFT_DEPOT_STOCK
WHERE
    Cust_Name NOT LIKE {redacted}

OPEN StockCursor
FETCH NEXT FROM StockCursor INTO @Cust_Name, @Cust_Postcode, @MatchCode_Product, @DateKey

WHILE @@FETCH_STATUS = 0
BEGIN
       UPDATE
              WRK_TFT_DEPOT_STOCK
       SET

                     Ordered = isnull((
                                  SELECT
                                         sum(cast(MO.Quantity as int))
                                  FROM
                                         {redacted }DE
                                         INNER JOIN {redacted} MO
                                         ON DE.Order_No = MO.Order_No
                                  WHERE
                                         DE.Cust_Name = @Cust_Name
                                         AND
                                         DE.Cust_Postcode = @Cust_Postcode
                                         AND
                                         MatchCode_Product = @MatchCode_Product
                                         AND
                                         CAST(Year(DE.Delivery_Date) AS VARCHAR) + RIGHT('0' + CAST(Month(DE.Delivery_Date) AS VARCHAR), 2) + 
                                            RIGHT('0' + CAST(Day(DE.Delivery_Date) AS VARCHAR), 2)  <= @DateKey
                                         AND DE.Cust_Name NOT LIKE {redacted}
                                     ),0)
       WHERE
              Cust_Name = @Cust_Name
              AND
              Cust_Postcode = @Cust_Postcode
              AND
              MatchCode_Product = @MatchCode_Product
              AND
              DateKey = @DateKey 

       FETCH NEXT FROM StockCursor INTO @Cust_Name, @Cust_Postcode, @MatchCode_Product, @DateKey
END

CLOSE StockCursor
DEALLOCATE StockCursor

UPDATE
       WRK_TFT_DEPOT_STOCK
SET
       Stock = StartStock + Ordered

代码运行得很好,但我的问题是,它需要运行很长时间,随着我将每日数据加载到源表中,运行所需的时间会随着时间的推移而增加。

有谁能帮我更有效地重新写这篇文章吗?从周围看,窗口函数似乎会有很大帮助,但我对它们不熟悉。

“Stock”列是运行总数,“StartStock”是初始金额,“Ordered”是我们需要添加的内容。