On 2/13/08 2:04 PM, "Eric Polino" <[EMAIL PROTECTED]> wrote:
>>> 2. I've read in many places how Cayenne deals with joins for you, but >>> nowhere do I see an example of how its done. Here's an example >>> problem I'm dealing with. >>> >>> Schema: >>> >>> Reservation (n to 1) Site >>> Site (n to 1) >>> Site contains a type field >>> >>> I want to get all the Reservations of a given for a given type of >>> site. In sql I would execute something like, "select * from >>> Reservation, Site, SiteType where SiteType.Name='Something' and >>> Site.typeID = SiteType.id and Reservation.siteID = Site.id" >>> >>> Short of writing an parameterized sql string and executing that in my >>> code, how do I do that with Cayenne? I hope I explained all that well >>> enough...make sense? >> >> Just map the relationships in the modeler. Cayenne takes care of the SQL >> for you. The following guide should help you get started with the modeler: >> >> http://cayenne.apache.org/doc20/tutorial-starting-mapping-project.html > > I've been using the modeler and the relationships are setup, I just > don't know how to do queries based on those relationship...ie the one > mentioned above Sorry. I glossed over the original question. You want to use a qualifier expression: http://cayenne.apache.org/doc/qualifier-expressions.html Expression factory is the easiest way to do this: http://cayenne.apache.org/doc/api/org/apache/cayenne/exp/ExpressionFactory.h tml So, you may have something like: Query q = new SelectQuery(Site.class, ExpressionFactory.matchDbExp(Site.NAME, "Something"); List<Site> sites = context.performQuery(q); for (Site s :sites) { System.out.println(s.getReservation().toString(); } You'll have to make substitutions as appropriate for your actual code. -- Kevin
