Scott, Shawn,

>The OP would like to detect that 4,5,6, and 7 are missing from the
>sequence. Your query would have only found that 7 was missing.

Right! For sequences longer than 1 you need something like...

SELECT
a.id+1 AS 'Missing From',
MIN(b.id)-1 AS 'To'
FROM test AS a, test AS b
WHERE a.id < b.id
GROUP BY a.id
HAVING a.id + 1 < MIN(b.id)
ORDER BY 1;

PB

-----

SGreen@unimin.com wrote:

Peter,

Your query may work for data with single-row gaps (like his example data) but it will not work if the sequence skips more than one number.

Look at this sequence: 1,2,3,8,9,10

The OP would like to detect that 4,5,6, and 7 are missing from the sequence. Your query would have only found that 7 was missing.

Nice try, but sorry. It just won't meet the need.

Shawn Green
Database Administrator
Unimin Corporation - Spruce Pine

Peter Brawley <peter.brawley@earthlink.net> wrote on 08/18/2005 10:56:34 AM: > Scott, > > >How do I execute a query that shows missing ID's like so: > > SELECT id AS i > FROM tbl > WHERE i <> 1 AND NOT EXISTS( > SELECT id FROM tbl WHERE id = i - 1 > ); > > PB > > ----- > > Scott Hamm wrote:
> If I got a table as follows: > > > ID foo > 1 12345 > 2 12346 > 4 12348 > 6 12349 > 7 12388 > 9 12390 > How do I execute a query that shows missing ID's like so: > > 3 > 5 > 8 > > I wouldn't expect for it to show deleted data that was deleted, just show > the "skipped" ID's. > > That way I determine if operator deleted too much (cheating at QC) > > Is it possible? >
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