Have a look at the following site to get an idea of the ODMG API.
http://db.apache.org/ojb/site.html#docu/tutorials/odmg-tutorial.html
The container is defined in the repository.xml file.
cheers,
-A
On Fri, 2004-07-02 at 07:01, Martin I. Levi wrote:
> Aren't you supposed to do something like:
>
> select A.a, A.b, A.B.c, A.C.d, A.C.D.e, A.C.D.f from A,B,C,D;
>
> ???
>
> And THE BIG question is... when you perform an OQLQuery.execute() this
> returns and Object what critery should I follow to choose the container
> to store the resulting objects?
>
>
>
> On Thu, 2004-07-01 at 19:49, Auckyboy wrote:
> > I'll take a stab at it.
> >
> > when performing OQL queries using OJB, you get back the complete object
> > A with references to B, C and further objects if they exist otherwise
> > they are null.
> >
> > Assuming you have the following objects..
> >
> > A{
> > B b;
> > int bId;
> > C c;
> > int cId;
> > }
> >
> > and
> >
> > C{
> > D d;
> > int dId;
> > }
> >
> >
> > D{
> > id;
> > name;
> > }
> > Now you want A where B, C and D are defined...
> >
> > select a from A where bID != 0 and cId!=0 and c.dId!=0
> >
> > this in effect would give you A where B,C and D are defined.
> >
> > However, as a suggestion, if you need to perform queries on A, B, C
> > etc..its better to use...
> >
> > select a from A where c.d.name = "somename"
> >
> >
> > HTH
> > -A
> >
> > On Thu, 2004-07-01 at 10:19, Martin I. Levi wrote:
> > > Hi!
> > >
> > > Well, here I am with the ODMG 3.0 book trying to perform OQL querys
> > > through OJB but I really think I just dont get it.
> > > Lets suppose I have a table A with FK to B and C where C has a FK to D
> > > Something like this:
> > > B
> > > /
> > > A
> > > \
> > > C
> > > \
> > > D
> > >
> > > Which are mapped to the objects A, B, C and D.
> > > Now I want to perform a query which in SQL would be:
> > >
> > > SELECT A.a, A.b, B.c, C.d, D.e, D.f
> > > FROM A,B,C,D
> > > WHERE A.B_key = B.B_key
> > > AND A.C_key = C.C_key
> > > AND C.D_key = D.D_key
> > > ;
> > >
> > > My questions are...
> > > 1) how could I do this on an OQL query through OJB?
> > > 2) which kind of container should I use to store the result? An
> > > ArrayList does always do the trick?, I suppose it doesn't...
> > >
> > > Any help will be useful!
> > >
> > > --
> > > Saludos,
> > >
> > > Martin I. Levi
> > >
> > > Centre TecnolÃgic de TransferenciÃncia de Calor
> > > Universitat PolitÃcnica de Catalunya
> > > www.cttc.upc.edu
> > >
> > >
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> > >
> >
> >
> >
> >
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>
> --
> Saludos,
>
> Martin I. Levi
>
> Centre TecnolÃgic de TransferenciÃncia de Calor
> Universitat PolitÃcnica de Catalunya
> www.cttc.upc.edu
>
>
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