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>
