查找在SQL Server 2008

Question

某些记录下一个日期在SQL Server 2008：

我有两个表，dtlScheme和dtlRenewal，具有一对多的关系（一个方案可以有很多续展）。 dtlRenewal有一个唯一的键（dteEffectiveDate，dtlSchemeID）。

现在假设我有dtlRenewal以下数据：

dtlRenewalID dtlSchemeID dteEffectiveDate 
1    1    1/1/2005 
2    1    1/1/2006 
3    1    1/1/2007 
4    1    1/1/2008 
5    1    1/1/2009 

我想找到每个更新下一个和以前的生效日期方案。换句话说，我需要回到这样的：

dtlRenewalID dtlSchemeID dteEffectiveDate dtePrevious dteNext 
1    1    1/1/2005   NULL   1/1/2006 
2    1    1/1/2006   1/1/2005  1/1/2007 
3    1    1/1/2007   1/1/2006  1/1/2008 
4    1    1/1/2008   1/1/2007  1/1/2009 
5    1    1/1/2009   1/1/2008  NULL 

感谢

卡尔

Answer 1

试试这个：

DECLARE @YourTable table (dtlRenewalID int, dtlSchemeID int, dteEffectiveDate datetime) 
SET NOCOUNT ON 
INSERT @YourTable VALUES (1,1,'1/1/2005') 
INSERT @YourTable VALUES (2,1,'1/1/2006') 
INSERT @YourTable VALUES (3,1,'1/1/2007') 
INSERT @YourTable VALUES (4,1,'1/1/2008') 
INSERT @YourTable VALUES (5,1,'1/1/2009') 
INSERT @YourTable VALUES (6,2,'1/1/2005') --I just repeated the data to make sure 
INSERT @YourTable VALUES (7,2,'1/1/2006') --it would work with multiple dtlSchemeID 
INSERT @YourTable VALUES (8,2,'1/1/2007') --values, which it does 
INSERT @YourTable VALUES (9,2,'1/1/2008') 
INSERT @YourTable VALUES(10,2,'1/1/2009') 
SET NOCOUNT OFF 


;WITH YourTableCTE AS 
(SELECT 
    dtlRenewalID, dtlSchemeID, dteEffectiveDate 
     ,ROW_NUMBER() OVER(PARTITION by dtlSchemeID order by dtlSchemeID,dtlRenewalID) AS RowNumber 
    FROM @YourTable 
) 
SELECT 
    c.dtlRenewalID, c.dtlSchemeID, c.dteEffectiveDate, p.dteEffectiveDate AS dtePrevious, n.dteEffectiveDate AS dteNext 
    FROM YourTableCTE     c 
     LEFT OUTER JOIN YourTableCTE p ON c.dtlSchemeID=p.dtlSchemeID AND c.RowNumber-1=p.RowNumber 
     LEFT OUTER JOIN YourTableCTE n ON c.dtlSchemeID=n.dtlSchemeID AND c.RowNumber+1=n.RowNumber 

OUTPUT：

dtlRenewalID dtlSchemeID dteEffectiveDate  dtePrevious    dteNext 
------------ ----------- ----------------------- ----------------------- ----------------------- 
1   1   2005-01-01 00:00:00.000 NULL     2006-01-01 00:00:00.000 
2   1   2006-01-01 00:00:00.000 2005-01-01 00:00:00.000 2007-01-01 00:00:00.000 
3   1   2007-01-01 00:00:00.000 2006-01-01 00:00:00.000 2008-01-01 00:00:00.000 
4   1   2008-01-01 00:00:00.000 2007-01-01 00:00:00.000 2009-01-01 00:00:00.000 
5   1   2009-01-01 00:00:00.000 2008-01-01 00:00:00.000 NULL 
6   2   2005-01-01 00:00:00.000 NULL     2006-01-01 00:00:00.000 
7   2   2006-01-01 00:00:00.000 2005-01-01 00:00:00.000 2007-01-01 00:00:00.000 
8   2   2007-01-01 00:00:00.000 2006-01-01 00:00:00.000 2008-01-01 00:00:00.000 
9   2   2008-01-01 00:00:00.000 2007-01-01 00:00:00.000 2009-01-01 00:00:00.000 
10   2   2009-01-01 00:00:00.000 2008-01-01 00:00:00.000 NULL 

(10 row(s) affected) 

Answer 2

上述结果是不正确。

例如 - 上一个日期是2005-01-01 00:00:00:00，下一个日期是2007-01-01 00:00:00:00，上述情况下的下一个日期应该是2006-01-01 00 ：00：00.000。