Find next date for certain record in SQL Server 2008
In SQL Server 2008:
I have two tables, dtlScheme and dtlRenewal, with a one to many relationship (one scheme can have many renewals). dtlRenewal has a unique key (dteEffectiveDate, dtlS开发者_StackOverflow社区chemeID).
Now suppose I have the following data in dtlRenewal:
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
I would like to find for each renewal the next and previous effective date for the scheme. In other words, I need to return this:
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
Thanks
Karl
try this:
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)
The above results is incorrect.
For instance - where previous date is 2005-01-01 00:00:00.000 the next date is 2007-01-01 00:00:00.000 where the next date in above case should be 2006-01-01 00:00:00.000.
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