如何在详细信息中分配标题级别折扣

Question

我有2个表格，标题和详细信息。如下所示，表头将有1条记录，详细信息表将包含多条记录。现在在标题级别上有折扣。我想根据它们的重量分配每个细节项目的折扣并获得实际费率。

感谢。

Answer 1

您需要根据(rate * qty)作为交易总额的百分比来分配折扣：

WITH transaction_totals AS (

    SELECT h.header_id 
      ,h.discount 
      ,SUM(d.rate * d.ty) AS total 
    FROM header h 
     INNER JOIN detail d 
      ON h.header_id = d.header_id 
    GROUP BY h.header_id 
      ,h.discount 

) 

SELECT d.item 
     ,d.rate 
     ,d.qty 
     ,d.total 
     --,d.total/tt.total AS DetailPctTotal 
     ,tt.discount * (d.total/tt.total) AS DetailDiscount 
FROM detail d 
    INNER JOIN transaction_totals tt 
     ON d.header_id = tt.header_id 
;