Arbitrary reverse relationship limitations

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Sun Aug 05 2007 - 06:32:24 EDT

  • Next message: Malcolm Edgar: "Re: Arbitrary reverse relationship limitations"

    We have two rules related to relationship mapping that we can really
    do well without:

    1. A DbRelationship always requires a reverse DbRelationship.
    2. A to-many ObjRelationship without a reverse to-one is effectively
    read only.

    I've done some work on a project where we've used generic persistent
    classes, and it occurred to me that while the two things above are
    indeed a property of Cayenne runtime, users don't have to worry about
    such low level details. Cayenne can automagically add missing reverse
    relationships in runtime to the corresponding entities, without user
    ever noticing. That simple - don't know why nobody thought of that
    before :-)

    BTW what makes (2) painless is CayenneDataObject that can store
    arbitrary data in it, so a back pointer from toOne side to the toMany
    site can be stored. This won't work in case of POJO's (without extra
    enhancement), but for normal Cayenne we get that functionality out of
    the box.

    Any comments on that?

    Andrus



    This archive was generated by hypermail 2.0.0 : Sun Aug 05 2007 - 06:32:52 EDT