Using CMR, I still want to be able to fetch my foreign keys

[pol.leleux]

Hello all,

I'm kind of new to J2EE, JBoss & CMP, CMR. I have several type of relationships in my object model and I made them work using CMR quite easily with XDoclet. I found it was a nice and easy way to put my object model to work and plus it could manage cascade deletes with no code...
Well, all my objects have a primary key which is a unique id and I naturally use these id's as foreign keys in my relationships.

Starting the process of implementation, I was disappointed for 2 reasons :

1) Xdoclet doesn't put the foreign keys in the data objects, the only solution I have is to put them manually in the base class that you can specify and that Xdoclet uses to generate the dataobject

2) It doesn't seem to be possible to fetch the foreign key without fetching the related object, i.e. you need to code something like "getRelatedObject().getId()" (getRelatedObject() is a CMR getter) where I would like to be able to do something like "getRelatedObjectId()" but there is no way to map a "persistent field" to a foreign key generated by CMR without a "duplicate column" problem... Of course the same problem arises with the putter...
I think that when you have a lot of relationships, this could leed to big performance problems, I know that there is a cache but still... or is JBoss smart enough to optimize this ? I think there is a lack in the spec...
or did I miss something ? Is there any kind of other solution ?

Thanks a lot for your help, I will really appreciate.

[dsundstrom]

There is currently no way to fetch the foreign keys directly. Look for this in JBoss 4.0 (when I get to coding it).

[pol.leleux]

I can't wait to see JBoss 4.0 coming out ;)
By the way, what will be in JBoss 4.0, is it supposed to support J2EE 1.4 ?

[dsundstrom]

> By the way, what will be in JBoss 4.0, is it supposed
> to support J2EE 1.4 ?

All sorts of stuff will be in 4.0 (atleast that's the plan), but not much of it has been written yet. JBoss 4.0 is targeted to support EJB 2.1, but I don't know what J2EE version that will match up with.

[kalypso]

I have the same problem here...

But this is a problem of xdoclet and not jboss !

programming without xdoclet you can use all java.lang.* -types as primary-key, even with relations, no problem.

But when you use xdoclet, it creates even for these simple-types always a seperated xxxPk.class.

I didn't find an option to avoid this :-(

[aloubyansky]

Read xdoclet docs carefully. To generate primary key of a simple type:
@ejb.bean
...
primkey-field="id"

@ejb.pk generate="false"