Re: ALL() question

I finally found a solution:

SELECT specimen_id
FROM specimen_test_bits
GROUP BY specimen_id
HAVING array_accum(test_bit_id) = '{2,3,4}';

.. but I don't think it's very "clean" ..

what do you think ?

Thanks

On Wed, 2007-11-14 at 15:50 +0100, Julien Cigar wrote:
> On Wed, 2007-11-14 at 11:56 +0000, Richard Huxton wrote:
> > Julien Cigar wrote:
> > >
> > > What I would like is a query that returns all the specimen_id of
> > > this table which have _all_ the given test_bit_id.
> > [snip]
> > > With the following I got a syntax error:
> > > select specimen_id
> > > from specimen_test_bits
> > > where test_bit_id = all(1,2,3,4);
> >
> > It's expecting an array here. You'd have to write
> > = all('{1,2,3,4}')
> > But that would have the same problem as...
> >
> > > The following works but no rows are returned :
> > > select specimen_id
> > > from specimen_test_bits
> > > where test_bit_id = all(select id from test_bits where id in (1,2,3,4));
> >
> > It's testing each row individually and of course one row can't match ALL
> > four values.
> >
> > What you want to do is count the distinct values. Something like:
> >
> > SELECT
> > specimen_id
> > FROM foo
> > GROUP BY
> > specimen_id
> > HAVING
> > count(distinct test_bit_id) = 4
> > ;
> >
>
> I don't think it would work, for example if I have:
> specimen_id | test_bit_id
> ------------+------------
> 100 1
> 100 3
> 101 1
> 101 2
>
> the test_bit_ids are parameters, so with the given test_bit_id 1,3 it
> would return specimen_id 101 too, which I don't want ...
> What I would like is the specimen_id which match _exactly_ the given
> test_bit_ids, so it should return only 100 in this example ..
>
> from the documentation ALL() can take a subquery too, not only an ARRAY
> (http://www.postgresql.org/docs/8.2/static/functions-subquery.html)
>
>