Window 可以比 2 个 CTE 更好地进行百分比计算的函数？

Question

我试图通过首先在一个 CTE 中获取尺寸级别的总量，然后创建另一个 CTE 来获取文章级别的总量，从而计算一篇文章在整体尺寸级别的百分比。在下面的代码中，它似乎可以工作，但它也很长并且需要运行。

我很好奇是否有更有效的方法，可能使用 OVER 或另一个 window 函数来获得相同的结果。我以前使用过 OVER 但由于它们处于不同的粒度级别，我不太确定。

SQL:

WITH      SumByMaterialCTE (MATERIAL, QUANTITY) --used to get the sum of quantity of an article for all demand 

AS    (SELECT MATERIAL, SUM(QUANTITY) 
                             FROM VW_MRP_ALLOCATION_COMBINED
                             WHERE REQUIREMENT_TYPE <> ''
                             GROUP BY MATERIAL), 

       DemandSizeLevelCTE (MATERIAL, SIZE_LITERAL, SIZE_PERCENT) --used to get a percentage for each size of an article over the total demand

AS     (SELECT DS.MATERIAL, 
               DS.SIZE_LITERAL,
               (SUM(DS.QUANTITY)/SM.QUANTITY) AS 'SIZE_PERCENT'
        FROM VW_MRP_ALLOCATION_COMBINED DS
        JOIN SumByMaterialCTE SM ON DS.MATERIAL = SM.MATERIAL
        WHERE DS.REQUIREMENT_TYPE <> '' 
        GROUP BY DS.MATERIAL, DS.SIZE_LITERAL, SM.QUANTITY)


SELECT DS.MATERIAL, 
       DS.SIZE_LITERAL, 
       DS.SIZE_PERCENT 

FROM   DemandSizeLevelCTE DS

Answer 1

您可以使用 window 函数，对 Material 和大小求和，然后除以 material 的总和，得到每个 material 的每个大小的百分比：

SELECT DISTINCT MATERIAL, SIZE_LITERAL,
       SUM(QUANTITY) OVER (PARTITION BY MATERIAL, SIZE_LITERAL) AS TOTAL_SIZE,
       SUM(QUANTITY) OVER (PARTITION BY MATERIAL) AS TOTAL_MATERIAL,
       100.0 * SUM(QUANTITY) OVER (PARTITION BY MATERIAL, SIZE_LITERAL) /
       SUM(QUANTITY) OVER (PARTITION BY MATERIAL) AS SIZE_PERCENT
FROM VW_MRP_ALLOCATION_COMBINED
ORDER BY MATERIAL, SIZE_LITERAL

我创建了一个示例 demo on SQLFiddle，其输出为：

MATERIAL    SIZE_LITERAL    TOTAL_SIZE  TOTAL_MATERIAL  SIZE_PERCENT
COTTON      L               3           22              13.636363636363
COTTON      M               11          22              50
COTTON      S               8           22              36.363636363636
NYLON       L               10          19              52.631578947368
NYLON       M               2           19              10.526315789473
NYLON       S               4           19              21.052631578947
NYLON       XL              3           19              15.78947368421

Window 可以比 2 个 CTE 更好地进行百分比计算的函数？

Window function that can do a percentage calculation better than 2 CTE's?

sql

sql-server

common-table-expression