Thank you both Jakob and Thomas. I was able to execute my query after some rework on my repository and finding the docs on the prefetch relationship.
Thanks again, Graham -----Original Message----- From: Jakob Braeuchi [mailto:jbraeuchi@;gmx.ch] Sent: October 17, 2002 3:09 PM To: OJB Users List Subject: Re: Nested Selects 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 > > ============================================ > > > > > > -- > > To unsubscribe, e-mail: <mailto:ojb-user-unsubscribe@;jakarta.apache.org> > > For additional commands, e-mail: <mailto:ojb-user-help@;jakarta.apache.org> > > > > > -- > To unsubscribe, e-mail: <mailto:ojb-user-unsubscribe@;jakarta.apache.org> > For additional commands, e-mail: <mailto:ojb-user-help@;jakarta.apache.org> > > > -- > To unsubscribe, e-mail: <mailto:ojb-user-unsubscribe@;jakarta.apache.org> > For additional commands, e-mail: <mailto:ojb-user-help@;jakarta.apache.org> > -- To unsubscribe, e-mail: <mailto:ojb-user-unsubscribe@;jakarta.apache.org> For additional commands, e-mail: <mailto:ojb-user-help@;jakarta.apache.org> -- To unsubscribe, e-mail: <mailto:ojb-user-unsubscribe@;jakarta.apache.org> For additional commands, e-mail: <mailto:ojb-user-help@;jakarta.apache.org>
