Question

大家好，在此先感谢您的帮助。

我被困在查询的计算列上。我想计算每个订单所需单位的商品库存量如何减少，因此我在CALCULATEDSTOCK列中有剩余的库存信息。

对于每个 ARTICLE＆COLOR＆SIZE 的第一次出现，CALCULATEDSTOCK是“初始”股票，而对于 ARTICLE＆COLOR＆SIZE相同的第二次和下一次出现。 strong> CALCULATEDSTOCK比以前需要的单位减少了，所以我得到了该行的可用库存。

请注意，STOCK始终与直接查询数据库相同。

这是我想要得到的结果：

ORDER ARTICLE COLOR SIZE STOCK NEEDED CALCULATEDSTOCK ----------------------------------------------------------------- 43002 1000 GREY L 13 4 13 43002 1000 GREY XL 20 5 20 43006 1000 GREY XL 20 4 15 43012 1000 GREY XL 20 6 11 43021 1000 GREY XL 20 2 5 43021 1000 PURPLE M 7 2 7 43023 1000 PURPLE L 6 3 6

找到下面我尝试过的内容，但是我无法将LAG命令应用于上一个CALCULATEDSTOCK列，因此我不能计算出超过两行...

SELECT ORDER, ARTICLE, COLOR, SIZE, STOCK, NEEDED, CAST( CASE WHEN ARTICLE = LAG(ARTICLE) OVER (ORDER BY ARTICLE, COLOR, SIZE, ORDER) AND COLOR = LAG(COLOR) OVER (ORDER BY ARTICLE, COLOR, SIZE, ORDER) AND SIZE = LAG(SIZE) OVER (ORDER BY ARTICLE, COLOR, SIZE, ORDER) THEN (lag(STOCK) OVER (ORDER BY ARTICLE, COLOR, SIZE, ORDER)) -(lag(NEEDED) OVER (ORDER BY ARTICLE, COLOR, SIZE, ORDER)) ELSE STOCK END AS decimal(8, 2)) AS CALCULATEDSTOCK .....

在该示例中，有3行具有相同ARTICLE＆COLOR＆SIZE的ORDERS，但可能还有更多行...

非常感谢您的耐心和甜蜜的问候！

Answer 1

我认为您缺少PARTITION。同样，LAG很好，但是如果您只是进行某种总计，SUM加上一点计算就可以了。首先，您在源数据中需要一个ID；重复的列会将其弄乱。

with source (ORDER_id,   ARTICLE,  COLOR ,   SIZE,   STOCK,   NEEDED) as
(
select 43002,   1000   ,  'GREY  ',   'L '  ,   13   ,   4 union all 
select 43002,   1000   ,  'GREY  ',   'XL'  ,   20   ,   5 union all 
select 43006,   1000   ,  'GREY  ',   'XL'  ,   20   ,   4 union all 
select 43012,   1000   ,  'GREY  ',   'XL'  ,   20   ,   6 union all 
select 43021,   1000   ,  'GREY  ',   'XL'  ,   20   ,   2 union all 
select 43021,   1000   ,  'PURPLE',   'M '  ,   7    ,   2 union all 
select 43023,   1000   ,  'PURPLE',   'L '  ,   6    ,   3 
)
select id, order_id, article, color, size, stock, NEEDED, stock + needed - sum(needed) over (partition by ARTICLE, COLOR, SIZE order by id)
from (
    select row_number() over (order by order_id) id, ORDER_id, ARTICLE, COLOR, SIZE, STOCK, NEEDED
    from source
) source_with_id

Answer 2

也许有一种更优雅的方法，但这是一个选择：

; with CTE as (select *
    , stock - sum(needed) over (partition by ARTICLE, color, size order by ORDER) as CalcNeeded
    , lead(ORDER) over (partition by ARTICLE, color, size order by ORDER) as PrevOrder
from MyTable)

select a.ORDER,
       a.ARTICLE,
       a.color,
       a.size,
       a.stock,
       a.needed,
       ISNULL(b.CalcNeeded, a.stock)
from cte a
left join cte b
on a.ARTICLE= b.ARTICLE and a.color = b.color and a.size = b.size
and a.ORDER = b.PrevOrder

具有选择行累积计算功能的SQL SELECT

2 个答案: