hi graham,
there's nothing necessary in repository.xml except the relationship
definition ('konti' (accounts) in the sample).
this feature is afaik documented in the doc files of the distribution.
jakob
----- Original Message -----
From: "Graham Lounder" <[EMAIL PROTECTED]>
To: "OJB Users List" <[EMAIL PROTECTED]>
Sent: Thursday, October 17, 2002 7:30 PM
Subject: RE: Nested Selects
> I saw the addPrefetchedRelationship but I don't know how use it. Do I
have
> to set something up in the repository.xml? What does the word "konti"
> relate to? Is there any documentation on this?
>
> Thanks in advance,
> Graham
>
> -----Original Message-----
> From: Jakob Braeuchi [mailto:jbraeuchi@;gmx.ch]
> Sent: October 17, 2002 2:15 PM
> To: OJB Users List
> Subject: Re: Nested Selects
>
>
> hi graham,
>
> when you do nested select the way you describe then you'll end up with n +
1
> sql statements.
> ojb provides an optimized way to reduce the number of sql select to 2.
this
> is done by prefetched relationships.
>
> suppose you have persons having n adresses. when you define the adress
> relationship as prefetched, all adresses for all persons are retrieved in
> ONE call.
>
> Query query;
> Criteria crit;
>
> crit = new Criteria();
> crit.addOrderByDescending("id");
> crit.addOrderByAscending("geburtsDatum");
> crit.addPrefetchedRelationship("konti");
> query = new QueryByCriteria(Person.class, crit);
> broker.getCollectionByQuery(query);
>
> hth
> jakob
>
> ----- Original Message -----
> From: "Graham Lounder" <[EMAIL PROTECTED]>
> To: "OJB Users List" <[EMAIL PROTECTED]>
> Sent: Thursday, October 17, 2002 1:36 PM
> Subject: Nested Selects
>
>
> > Hey All,
> >
> > Is it possible to use nested selects? What is the best approach to do
> this?
> > In my last project I looped through results of one query, executing
other
> > queries. Is there a better way of doing this? Is there features in OJB
> > that will do this for me? I was thinking of using the Criteria.addSQL()
> and
> > add my own nested select code.
> >
> > Any Ideas?
> > Graham
> >
> > ============================================
> > Graham Lounder
> > Java Developer
> > Spatial Components Division
> > CARIS
> > 264 Rookwood Ave
> > Fredericton NB E3B-2M2
> > Office 506 462-4263
> > Fax 506 459-3849
> > [EMAIL PROTECTED]
> > http://www.spatialcomponents.com
> > ============================================
> >
> >
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