Re: [GENERAL] Re: sql question

Ed Loehr wrote:

> > From: Herbert Liechti <Herbert.Liechti@thinx.ch>
> > Subject: sql question
> >
> > I have a sql problem which I can't solve. The following table is defined
> >
> > create table AdressGroup
> > (
> >    AdrGroup_Id                     INTEGER       NOT NULL
> >          DEFAULT NEXTVAL('adrverw_id_seq'),
> >    Zeit                            DATETIME      NOT NULL,
> >    Group_Id                        INTEGER       NOT NULL,
> >    Adress_Id                       INTEGER       NOT NULL
> > );
> >
> > The table assigns adresses to adressgroups.
> >
> > I'd like to select the adresses which belongs to one specific adressGroup and to no other group. If an adress has
morethan one entry in the AdressGroup 
> > table it should not be in the projection.
> >
> > I tried the following:
> >
> > SELECT * FROM adressGroup
> >  WHERE Group_Id = 6
> >    AND EXISTS( SELECT AdrGroup_Id FROM adressGroup ag_alias
> >                 WHERE adressGroup.AdrGroup_Id = ag_alias.AdrGroup_Id
> >                 GROUP BY AdrGroup_Id HAVING COUNT(*) = 1 );
> >
> > When I do this I get the following error:
> >   ERROR:  rewrite: aggregate column of view must be at rigth side in qual
> >   ERROR:  rewrite: aggregate column of view must be at rigth side in qual
> >
> > Does anybody knows the solution? Thanks
> >
>
> Not sure about the error above, other than the apparent typos with "adressGroup", but I think you can get what you're
afterwith this: 
>
> SELECT *
> FROM AdressGroup ag
> WHERE ag.Group_Id = 6 AND NOT EXISTS (
>     SELECT AdrGroup_Id
>     FROM AddressGroup ag2
>     WHERE ag2.AdrGroup_Id = ag.AdrGroup_Id AND ag2.Group_Id <> 6);

The query does not produce the estimated result :-/( It returns all records from
adressgroup 6. It seems that the problem can not be solved in a single sql-statement.
I assume that the above statement joins the table with the alias table with the
subset of adress group 6.
Probably I do it with a temporary table:

Create temp table tempGroup(adrGroup_id integer, groupcounter integer);
INSERT INTO tempGroup
SELECT adrGroup_Id, count(*) FROM adrGroup GROUP BY 1 HAVING COUNT(*) = 1);
SELECT * from adrGroup, tempGroup
 WHERE adrGroup.adrGroup_id = tempGroup.adrGroup_id
   AND adrGroup.group_id = 7;

This is working but without the desired performance :-(

Thanks anyway
Herbie

--
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Herbert Liechti                            E-Mail: Herbert.Liechti@thinx.ch
ThinX networked business services               Stahlrain 10, CH-5200 Brugg
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