库存库存计算查询或/和优化

Question

Remains - 产品的所有交易

Stock - 产品库存

DimDate - 时间表

库存计算：

1. 取需要计算库存的日期，例如日期20050115产品-1仓库-6
2. 以下个月第一天的示例20050201 和Stock 表为同一产品和仓库的weight、stock、cost 取一行。
3. 将Remains 中从选定日期到月底的所有交易相加，并从Stock 表的取行中减去

下个月的第一天我使用这个：

CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime)))-1),DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime))),112)

例如Remains:

|  TIMEKEY | PRODUCT | WAREHOUSE | COST | STOCK | WEIGHT |
|----------|---------|-----------|------|-------|--------|
| 20050114 |       1 |         6 |  100 |     5 |     15 |
| 20050118 |       1 |         6 |  200 |    10 |     30 |
| 20050125 |       1 |         6 | -100 |    -5 |    -15 |

Stock:

|  TIMEKEY | PRODUCT | WAREHOUSE | COST | STOCK | WEIGHT |
|----------|---------|-----------|------|-------|--------|
| 20050201 |       1 |         6 |  515 |    55 |     53 |
| 20050301 |       2 |         8 |   20 |     3 |      2 |
| 20050301 |       3 |         9 |   16 |     2 |      3 |
| 20050301 |       4 |        10 |   49 |     8 |      5 |
| 20050401 |       5 |        26 |   59 |     9 |     10 |

结果（我的查询）按天计算产品 1、仓库 6 和第一个月的库存：

|  DATEKEY | PRODUCT | WAREHOUSE | WEIGHT |  STOCK |   COST |
|----------|---------|-----------|--------|--------|--------|
| 20050101 |       1 |         6 |     23 |     45 |    315 |
| 20050102 |       1 |         6 |     23 |     45 |    315 |
| 20050103 |       1 |         6 |     23 |     45 |    315 |
| 20050104 |       1 |         6 |     23 |     45 |    315 |
| 20050105 |       1 |         6 |     23 |     45 |    315 |
| 20050106 |       1 |         6 |     23 |     45 |    315 |
| 20050107 |       1 |         6 |     23 |     45 |    315 |
| 20050108 |       1 |         6 |     23 |     45 |    315 |
| 20050109 |       1 |         6 |     23 |     45 |    315 |
| 20050110 |       1 |         6 |     23 |     45 |    315 |
| 20050111 |       1 |         6 |     23 |     45 |    315 |
| 20050112 |       1 |         6 |     23 |     45 |    315 |
| 20050113 |       1 |         6 |     23 |     45 |    315 |
| 20050114 |       1 |         6 |     38 |     50 |    415 |
| 20050115 |       1 |         6 |     38 |     50 |    415 |
| 20050116 |       1 |         6 |     38 |     50 |    415 |
| 20050117 |       1 |         6 |     38 |     50 |    415 |
| 20050118 |       1 |         6 |     68 |     60 |    615 |
| 20050119 |       1 |         6 |     68 |     60 |    615 |
| 20050120 |       1 |         6 |     68 |     60 |    615 |
| 20050121 |       1 |         6 |     68 |     60 |    615 |
| 20050122 |       1 |         6 |     68 |     60 |    615 |
| 20050123 |       1 |         6 |     68 |     60 |    615 |
| 20050124 |       1 |         6 |     68 |     60 |    615 |

问题/疑问 产品库存没有结束，所以我需要显示整个月的结果（或我在 where 子句中选择的范围），而不仅仅是 24 天。如果这是不可能的，也许有人可以帮助我用于计算库存的当前查询优化。我正在使用 ms sql 2008r2

SQLFIDDLEExample

SELECT t.DateKey, r.Product, r.Warehouse,
(SELECT [Weight]
FROM Stock
WHERE Timekey = CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime)))-1),DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime))),112)
AND Product = r.Product
AND Warehouse = r.Warehouse)-SUM(r.Weight) AS [Weight],
(SELECT Stock
FROM Stock
WHERE Timekey = CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime)))-1),DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime))),112)
AND Product = r.Product
AND Warehouse = r.Warehouse)-SUM(Stock) as Stock,
(SELECT Cost
FROM Stock
WHERE Timekey = CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime)))-1),DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime))),112)
AND Product = r.Product
AND Warehouse = r.Warehouse)-SUM(Cost) AS Cost
FROM DimDate t, Remains r
WHERE t.DateKey < r.Timekey
AND r.Timekey <= CONVERT(VARCHAR(25),DATEADD(dd,-(DAY(DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime)))-1),DATEADD(mm,1,CAST(convert(varchar,t.DateKey) as datetime))),112)
AND t.DateKey >= 20050101
and r.Product = '1'
and r.Warehouse = 6
GROUP BY t.DateKey, r.Product, r.Warehouse

Answer 1

很难说它在小数据集上是否更快，但以下看起来有更好的查询计划。方法是只加入股票表一次而不是三次。

with x as (
    select
        t.DateKey, 
        r.Product, 
        r.Warehouse, 
        sum(r.Weight) as Weight,
        sum(Stock) as Stock,
        sum(Cost) as Cost,
        (t.DateKey / 100 
            + Case t.DateKey / 100 % 100 when 12 Then 89 else 1 end) 
            * 100 + 1 as TimeKey
    from
        DimDate t, 
        Remains r
    where
        t.DateKey < r.Timekey and 
        r.Timekey <= (
            t.DateKey / 100 
                + Case t.DateKey / 100 % 100 when 12 Then 89 else 1 end) 
                * 100 + 1 and 
        t.DateKey >= 20050101 and 
        r.Product = 1 and 
        r.Warehouse = 6
    group by
        t.DateKey, 
        r.Product, 
        r.Warehouse
) select
    x.DateKey,
    x.Product,
    x.Warehouse,
    s.Weight - x.Weight as Weight,
    s.Stock - x.Stock as Stock,
    s.Cost - x.Cost as Cost
From
    x
        left outer join
    Stock s
        on s.TimeKey = x.TimeKey and
           s.Product = x.Product and
           s.Warehouse = x.Warehouse;

Example SQLFiddle

如果您有机会重新设计此架构，请记住日期数据类型仅使用三个字节，而 int 则使用四个字节。

它可能对整体查询成本贡献不大，但您可以将“下个月开始”值存储为 DimDate 表中的计算列。它使查询更易于阅读。

create table DimDate (
    [DateKey] int,
    StartOfNextMonthKey as (
            DateKey / 100 
            + Case DateKey / 100 % 100 when 12 Then 89 else 1 end
        ) * 100 + 1 persisted
);

那么查询是

with x as (
    select
        t.DateKey, 
        r.Product, 
        r.Warehouse, 
        sum(r.Weight) AS [Weight],
        sum(Stock) as Stock,
        sum(Cost) AS Cost,
        t.StartOfNextMonthKey
    from
        DimDate t, 
        Remains r
    where
        t.DateKey < r.Timekey AND 
        r.Timekey <= t.StartOfNextMonthKey and 
        t.DateKey >= 20050101 and 
        r.Product = 1 and 
        r.Warehouse = 6
    group by
        t.DateKey, 
        r.Product, 
        r.Warehouse,
        t.StartOfNextMonthKey
) select
    x.DateKey,
    x.Product,
    x.Warehouse,
    s.Weight - x.Weight as Weight,
    s.Stock - x.Stock as Stock,
    s.Cost - x.Cost as Cost
From
    x
        left outer join
    Stock s
        on s.TimeKey = x.StartOfNextMonthKey and
           s.Product = x.Product and
           s.Warehouse = x.Warehouse;

Example SQLFiddle