February 7, 2008 at 4:06 pm
Hi,
I have a table stores relationship between columns
ColA ColB
1 2
2 1
1 3
3 1
....
4 5
5 6
4 7
7 4
Does someone know how to add the missing relationships like 2-3,3-2 and 5-4,4-6,6-4.....without using cursor?
Thanks
February 7, 2008 at 5:54 pm
Hi,
what kind of relationship you have in between A & B?
Thanks -- Vj
February 8, 2008 at 6:03 am
Are you looking for an Islands and Gaps solution?
This is from Itzik Ben-Gan's Inside TSQL Querying and identifies missing values
SELECT cur+1 AS start_range, nxt-1 AS end_range
FROM (SELECT col1 AS cur,
(SELECT MIN(col1) FROM dbo.T1 AS B
WHERE B.col1 > a.col1) AS nxt
FROM dbo.T1 AS A) AS D
WHERE nxt-cur > 1;
You'd have to find a way to run this for both sets of numbers to identify the missing values. Logically a bit of a twister, but a very simple query.
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