不使用游标处理句点和日期

Question

我想解决这个问题，避免使用游标（FETCH）。

问题来了......

1st Table/quantity
------------------
periodid periodstart periodend quantity

1        2010/10/01 2010/10/15    5


2st Table/sold items
-----------------------
periodid periodstart periodend solditems

14343    2010/10/05 2010/10/06    2

现在我想得到以下视图或只是查询结果

Table Table/stock
-----------------------
periodstart periodend itemsinstock

2010/10/01 2010/10/04      5

2010/10/05 2010/10/06      3

2010/10/07 2010/10/15      5

如果不使用游标或不使用单个日期而不是句点似乎不可能解决这个问题。

我将不胜感激任何帮助。

谢谢

Answer 1

DECLARE @t1 TABLE (periodid INT,periodstart DATE,periodend DATE,quantity INT)
DECLARE @t2 TABLE (periodid INT,periodstart DATE,periodend DATE,solditems INT)

INSERT INTO @t1 VALUES(1,'2010-10-01T00:00:00.000','2010-10-15T00:00:00.000',5)
INSERT INTO @t2 VALUES(14343,'2010-10-05T00:00:00.000','2010-10-06T00:00:00.000',2)

DECLARE @D1 DATE

SELECT @D1 = MIN(P) FROM (SELECT MIN(periodstart) P FROM @t1
                          UNION ALL
                          SELECT MIN(periodstart) FROM @t2) D

DECLARE @D2 DATE

SELECT @D2 = MAX(P) FROM (SELECT MAX(periodend) P FROM @t1
                          UNION ALL
                          SELECT MAX(periodend) FROM @t2) D

;WITH 
L0 AS (SELECT 1 AS c UNION ALL SELECT 1),
L1 AS (SELECT 1 AS c FROM L0 A CROSS JOIN L0 B),
L2 AS (SELECT 1 AS c FROM L1 A CROSS JOIN L1 B),
L3 AS (SELECT 1 AS c FROM L2 A CROSS JOIN L2 B),
L4 AS (SELECT 1 AS c FROM L3 A CROSS JOIN L3 B),
Nums AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) AS i FROM L4),
Dates AS(SELECT DATEADD(DAY,i-1,@D1) AS D FROM Nums where i <= 1+DATEDIFF(DAY,@D1,@D2))  , 
Stock As (
SELECT D ,t1.quantity - ISNULL(t2.solditems,0) AS itemsinstock
FROM Dates
LEFT OUTER JOIN @t1 t1 ON t1.periodend >= D and t1.periodstart <= D
LEFT OUTER JOIN @t2 t2 ON t2.periodend >= D and t2.periodstart <= D ),
NStock As (
select D,itemsinstock, ROW_NUMBER() over (order by D) - ROW_NUMBER() over (partition by itemsinstock order by D) AS G
from Stock)
SELECT MIN(D) AS periodstart, MAX(D) AS periodend, itemsinstock 
FROM NStock
GROUP BY G, itemsinstock
ORDER BY periodstart

Answer 2

希望比马丁的更容易阅读。我使用了不同的表和示例数据，希望能够推断出正确的信息：

CREATE TABLE [dbo].[Quantity](
    [PeriodStart] [date] NOT NULL,
    [PeriodEnd] [date] NOT NULL,
    [Quantity] [int] NOT NULL
) ON [PRIMARY]

CREATE TABLE [dbo].[SoldItems](
    [PeriodStart] [date] NOT NULL,
    [PeriodEnd] [date] NOT NULL,
    [SoldItems] [int] NOT NULL
) ON [PRIMARY]

INSERT INTO Quantity (PeriodStart,PeriodEnd,Quantity)
SELECT '20100101','20100115',5

INSERT INTO SoldItems (PeriodStart,PeriodEnd,SoldItems)
SELECT '20100105','20100107',2 union all
SELECT '20100106','20100108',1

现在的实际查询是：

;WITH Dates as (
    select PeriodStart as DateVal from SoldItems union select PeriodEnd from SoldItems union select PeriodStart from Quantity union select PeriodEnd from Quantity
), Periods as (
    select d1.DateVal as StartDate, d2.DateVal as EndDate
    from Dates d1 inner join Dates d2 on d1.DateVal < d2.DateVal left join Dates d3 on d1.DateVal < d3.DateVal and d3.DateVal < d2.DateVal where d3.DateVal is null
), QuantitiesSold as (
    select StartDate,EndDate,COALESCE(SUM(si.SoldItems),0) as Quantity
    from Periods p left join SoldItems si on p.StartDate < si.PeriodEnd and si.PeriodStart < p.EndDate
    group by StartDate,EndDate
)
select StartDate,EndDate,q.Quantity - qs.Quantity
from QuantitiesSold qs inner join Quantity q on qs.StartDate < q.PeriodEnd and q.PeriodStart < qs.EndDate

结果是：

StartDate   EndDate (No column name)
2010-01-01  2010-01-05  5
2010-01-05  2010-01-06  3
2010-01-06  2010-01-07  2
2010-01-07  2010-01-08  4
2010-01-08  2010-01-15  5

说明：我正在使用三个通用表表达式。第一个（日期）是从涉及的两个表中收集我们正在讨论的所有日期。第二个（期间）从日期 CTE 中选择连续值。然后，第三个 (QuantitiesSold) 在 SoldItems 表中查找与这些时间段重叠的项目，并将它们的总数加在一起。外部选择中剩下的就是从数量表中存储的总量中减去这些数量

Answer 3

约翰，你可以做的是一个 WHILE 循环。在循环之前声明并初始化 2 个变量，一个是开始日期，另一个是结束日期。然后，您的循环将如下所示：

WHILE(@StartEnd <= @EndDate)
BEGIN
  --processing goes here
  SET @StartEnd = @StartEnd + 1
END

您需要将期间定义存储在另一个表中，以便您可以在临时表需要时检索这些并输出行。

如果您需要任何更详细的示例，或者我是否理解错误，请告诉我！

Answer 4

达米安，

我试图完全理解您的解决方案并在大规模数据上对其进行测试，但我收到您的代码的以下错误。

消息 102，级别 15，状态 1，第 20 行

“日期”附近的语法不正确。

消息 102，级别 15，状态 1，第 22 行

“,”附近的语法不正确。

消息 102，级别 15，状态 1，第 25 行

“,”附近的语法不正确。

Answer 5

Damien，

根据您的解决方案，我还希望获得 StockItems 的整洁显示，而不会重叠日期。这个解决方案怎么样？

CREATE TABLE [dbo].[SoldItems](
    [PeriodStart] [datetime] NOT NULL,
    [PeriodEnd] [datetime] NOT NULL,
    [SoldItems] [int] NOT NULL
) ON [PRIMARY]


INSERT INTO SoldItems (PeriodStart,PeriodEnd,SoldItems)
SELECT '20100105','20100106',2 union all
SELECT '20100105','20100108',3 union all
SELECT '20100115','20100116',1 union all
SELECT '20100101','20100120',10


;WITH Dates as (
    select PeriodStart as DateVal from SoldItems
    union 
    select PeriodEnd from SoldItems 
    union
    select PeriodStart from Quantity
    union
    select PeriodEnd from Quantity

), Periods as (
    select d1.DateVal as StartDate, d2.DateVal  as EndDate
    from Dates d1 
    inner join Dates d2 on d1.DateVal < d2.DateVal 
    left join Dates d3 on d1.DateVal < d3.DateVal and 
    d3.DateVal < d2.DateVal where d3.DateVal is null

), QuantitiesSold as (
    select StartDate,EndDate,SUM(si.SoldItems) as Quantity
    from Periods p left join SoldItems si on p.StartDate < si.PeriodEnd and si.PeriodStart < p.EndDate
    group by StartDate,EndDate
)

select StartDate,EndDate, qs.Quantity
from QuantitiesSold qs
where qs.quantity is not null