Previous non empty value

Question

Hi,
I have a situation where I have to update the previous non empty date until there is non empty value. Then use the next non empty value. Data is sorted on group id.
for example I am creating new field which update the date column which just for example:
it would be great if there is way to implement using set operation not through cursor.
thanks in advance
Zaim Raza
http://zaimraza.wordpress.com/

Answer 1

CREATE TABLE #C (X CHAR(1) ,Y INT)
INSERT INTO #C values(NULL, 1)
INSERT INTO #C values(NULL, 2)
INSERT INTO #C values(NULL, 3)
INSERT INTO #C values('A', 4)
INSERT INTO #C values(NULL, 1)
INSERT INTO #C values(NULL, 2)
INSERT INTO #C values('B', 3)
SELECT * FROM #C
ALTER TABLE #C ADD ID INT IDENTITY(1,1)
SELECT CASE WHEN X is not null
            THEN X
            ELSE (SELECT MIN(X)
                  FROM #C
                  WHERE ID >= t.ID)
       END AS X,
       Y
FROM #C t
Best Regards,Uri Dimant SQL Server MVP,
http://sqlblog.com/blogs/uri_dimant/
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