如何將日期範圍錶轉換爲基於行的視圖？

Question

我面臨嚴峻的形勢。到目前爲止我找不到解決方案。

我有一張表格給出了基於日期範圍的信息。我希望按日期分解這些信息。所以我正在尋求將範圍轉換爲行結構。

額外的困難是日期範圍中「句點」的數量是可變的。 「週期」由日期範圍和一個週期內的天數進行扣除。

更具體地，上表中的一個線我已經一個

• ID
• 範圍的起始日期
• END_DATE範圍
• 數days_in_the_period的
• numbers_periods
• 適用於範圍中的每個期間的價格

這裏是初始表的結構和預期的結果：

CREATE TABLE Start(
Key    VARCHAR(11) NOT NULL PRIMARY KEY 
,Start_date   VARCHAR(27) NOT NULL 
,End_Date   VARCHAR(27) NOT NULL 
,Days_in_the_period INTEGER NOT NULL 
,Nbr_periods  INTEGER NOT NULL 
,Pricing   VARCHAR(6) NOT NULL 
); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2000-06-01 00:00:00.0000000','2001-12-01 00:00:00.0000000',30,19,'800,87'); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2002-01-01 00:00:00.0000000','2005-12-01 00:00:00.0000000',30,48,'440,32'); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2006-01-01 00:00:00.0000000','2007-02-01 00:00:00.0000000',30,14,'282,68'); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2007-03-01 00:00:00.0000000','2008-03-01 00:00:00.0000000',30,13,'283,99'); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2008-04-01 00:00:00.0000000','2009-01-01 00:00:00.0000000',60,5,'281,81'); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2009-02-01 00:00:00.0000000','2009-03-01 00:00:00.0000000',30,2,'281,81'); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2009-04-01 00:00:00.0000000','2019-07-01 00:00:00.0000000',30,124,'281,81'); 
INSERT INTO Start(Key,Start_date,End_Date,Days_in_the_period,Nbr_periods,Pricing) VALUES ('010-1280001','2019-08-01 00:00:00.0000000','2019-08-01 00:00:00.0000000',0,1,'372,96'); 

預期

Key     Date    Pricing Days_in_the_period 

---

010-1280001 2000-06-01 00:00 ：00.0000000 800,87 30
010-1280001 2000-07-0 1 00：00：00.0000000 800,87 30
... ... ... ...
010-1280001 2008-04-01 00：00：00.0000000 281,81 60
010-1280001 2008-06-01 00：00：00.0000000 281,81 60
... ... ... ...
010-1280001 2019年8月1日00：00：00.0000000 372,96 0

的信息，初始表包含約10萬條記錄。 有沒有人對我有一個好主意？

請恢復任何澄清， Tartino。

Answer 1

你可以用遞歸CTE的幫助下做到這一點：

;WITH cte AS (
    SELECT * 
    FROM YourTable 
    UNION ALL 
    SELECT c.[key], 
      DATEADD(month,c.Days_in_the_period/30,c.[Start_Date]), 
      c.End_Date, 
      c.Days_in_the_period, 
      c.Nbr_periods, 
      c.Pricing 
    FROM cte c 
    INNER JOIN YourTable y 
     ON y.[key] = c.[key] AND c.End_Date = y.End_Date 
    WHERE y.End_Date >=DATEADD(month,c.Days_in_the_period/30,c.[Start_Date]) 
) 


SELECT [key], 
     [Start_Date] as [Date], 
     Pricing, 
     Days_in_the_period 
FROM cte 
ORDER BY [key], [Start_Date] 

另一種方法是使用日曆表，並與你的表加入。