如何获得基于生效日期的成本结果？

Question

现在我有TableB AS B

(Date, Store, Product, Qty)
('4/1/20', '1', 'A', '5'),
('4/9/20', '2', 'A', '5'),
('4/1/20', '2', 'A', '4'),
('4/1/20', '3', 'B', '3'),
('4/2/20', '3', 'B', '1'),
('4/2/20', '5', 'C', '2')

和表D AS D

(Product, Effective, Cost)
('A', '4/1/20', '100'),
('A', '4/8/20', '120'),
('B', '4/1/20', '100'),
('B', '4/8/20', '110'),
('C', '4/1/20', '100')

我想要 SUM(B.Qty * D.Cost) AS TotalCOst 但也需要基于生效日期。

ex IF 商店 1 产品 A 的日期为“4/1/20”，因此总成本为 5100 = 500 但如果商店 1 产品 A 的日期为“4/9/20”，则总成本为 5120 = 600

您能指导我吗？

这是我尝试过的，但结果现在仍然正确。

SELECT
B.Date,
D.Effective,
Datediff(DAY, B.Date, D.Effective) AS Datediff,
B.Store,
B.Product,
SUM(D.Cost) AS Cost,
SUM(D.Cost * B.Qty) AS TotalCost,
CASE WHEN Datediff(DAY, D.Effective, B.Date) >= 0 THEN SUM(D.Cost) ELSE 0 END AS Cost_Temp,
CASE WHEN Datediff(DAY,  D.Effective, B.Date) >= 0 THEN SUM(D.Cost * B.Qty) ELSE 0 END AS TotalCost_Temp
FROM TableB AS B
INNER JOIN TableD AS D ON B.Product = D.Product
GROUP BY
B.Date,
B.Store,
B.Product,
D.Effective
ORDER BY B.Date

Answer 1

诀窍是找到有效的价格。这可以在 SQL Server 中使用

OUTER APPLY

来完成。我们想要做的就是选择表 D 中该日期有效的最新汇率。（我猜这是某种销售日期。）

我们通过简单的查询得到了

SELECT  TOP 1  -- Because we only want the most recent
        D.COST
  FROM
        TableD AS D
 WHERE
        D.EFFECTIVE <= B.DATE  -- Only those prices that could be in effect
   AND  D.PRODUCT = B.PRODUCT  -- Only the product of interest
   AND  D.STORE = B.STORE      -- Only the store of interest
ORDER BY D.EFFECTIVE  DESC     -- To make sure the most recent is first
;

因此，在

OUTER APPLY

中将上述内容作为子选择，您将获得所需的行。我认为案例陈述不再需要。

答案

SELECT
        B.[DATE]
       ,D.EFFECTIVE
       ,DATEDIFF( DAY, B.[DATE], D.EFFECTIVE ) AS 'DATEDIFF'
       ,B.STORE
       ,B.PRODUCT
       ,SUM( D.COST ) AS 'COST'
       ,SUM( D.COST * B.QTY ) AS 'TOTAL_COST'
  FROM
        TableB B
        OUTER APPLY ( SELECT TOP 1 *
                        FROM TableD D1
                       WHERE B.PRODUCT = D1.PRODUCT
                         AND B.[DATE] >= D1.EFFECTIVE
                     ORDER BY D1.EFFECTIVE DESC ) D
GROUP BY
          B.[DATE],
          B.STORE,
          B.PRODUCT,
          D.EFFECTIVE
ORDER BY
          B.[DATE]
;

更多

测试这一点的一个好方法是运行以下查询，该查询显示逐行比较。您可以查看表 A 中每行选择的生效日期以及使用的成本。

SELECT
        B.[DATE]
       ,D.EFFECTIVE
       ,DATEDIFF( DAY, B.[DATE], D.EFFECTIVE ) AS 'DATEDIFF'
       ,B.STORE
       ,B.PRODUCT
       ,D.COST
       ,B.QTY
       ,D.COST * B.QTY      AS 'TOTAL_COST'
  FROM
        TableB AS B
        OUTER APPLY ( SELECT TOP 1 *
                        FROM TableD AS D1
                       WHERE B.PRODUCT = D1.PRODUCT
                         AND B.[DATE] >= D1.EFFECTIVE
                     ORDER BY D1.EFFECTIVE DESC ) D
ORDER BY
          B.[DATE]
;

这是我从中得到的：

+------------+------------+----------+-------+---------+--------+-----+------------+
|    DATE    | EFFECTIVE  | DATEDIFF | STORE | PRODUCT |  COST  | QTY | TOTAL_COST |
+------------+------------+----------+-------+---------+--------+-----+------------+
| 2020-04-01 | 2020-04-01 |        0 |     2 | A       | 100.00 |   4 |     400.00 |
| 2020-04-01 | 2020-04-01 |        0 |     3 | B       | 100.00 |   3 |     300.00 |
| 2020-04-01 | 2020-04-01 |        0 |     1 | A       | 100.00 |   5 |     500.00 |
| 2020-04-02 | 2020-04-01 |       -1 |     3 | B       | 100.00 |   1 |     100.00 |
| 2020-04-02 | 2020-04-01 |       -1 |     5 | C       | 100.00 |   2 |     200.00 |
| 2020-04-09 | 2020-04-08 |       -1 |     2 | A       | 120.00 |   5 |     600.00 |
+------------+------------+----------+-------+---------+--------+-----+------------+