Question

If you will look at the image above. I need to update this table for the null values of the TID which is column third in the table, with the values in between two rows that actually has value.

So in the above example, I need to have rows 44-57 as 040, row 60-87 as 077 etc. One pattern that could be used is that column 2 has INS in the string, which denotes that the value in column 3 is to be changed. So I was thinking about using DATA LIKE ‘INS%’ in some way.

Please let me know what you think of the problem and any possible solutions.

thanks!

Answer 1

DECLARE @x TABLE
(Column1 INT, Column2 VARCHAR(64), TID VARCHAR(10));

INSERT @x VALUES
(42, 'INS{whatever}', '040'),
(43, 'somethingelse', '040'),
(44, 'somethingelse', NULL),
(45, 'somethingelse', NULL),
(46, 'somethingelse', NULL),
(47, 'somethingelse', NULL),
(48, 'somethingelse', NULL),
(49, 'INS{whatever}', '077'),
(50, 'somethingelse', '077'),
(51, 'somethingelse', NULL),
(52, 'somethingelse', NULL);

;WITH x AS (SELECT i = Column1, TID, rn = ROW_NUMBER() OVER (ORDER BY Column1)
    FROM @x WHERE Column2 LIKE 'INS%'
),
y AS (SELECT x.TID, s = x.i, e = COALESCE(x2.i, 2000000000)
FROM x LEFT OUTER JOIN x AS x2 ON x.rn = x2.rn -1
)
UPDATE src SET TID = y.TID
FROM @x AS src
INNER JOIN y ON src.Column1 > y.s AND src.Column1 < y.e;

SELECT * FROM @x;