Re: error on 1:1 relationship - Some parts of PK are missing in s naps hot

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Fri Jan 03 2003 - 13:40:40 EST

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    Hi Dave,

    Dave Paules writes:
    > Hello Andrus,
    >
    > Well, I am not certain what "PK-> dep. PK" means. When I used EOModeler the
    > meaning of "Dependent Primary Key" could mean different things depending on
    > what you were talking about. Usually it meant that if I added a new Employee
    > object and a new RetirementAccount object, the primary key value for the
    > Employee tuple would ALSO be the primary key value for the RetirementAccount
    > tuple.
     

    Yes this is what it means in Cayenne too. Kind of "master-detail"
    relationships. But as you described below, this is not the case in your
    schema.

     

    > 1. What does "To Dep PK" mean in Cayenne Modeler? With regard to your
    > suggestion of setting that checkbox on the db relationship from Employee to
    > RetirementAccount, the modeler will not allow me to check it. When I do
    > check it by setting the xml text to true, the run-time tells me that "the
    > toDependentPK value is incorrectly set to true, unsetting it".

    Sure. This checkbox shoudn't be checked, since my original guess about your
    schema was incorrect. But from the database persoective a relationship from
    Employee to RetirementAccount is "to-many", since RetirementAccount has a
    Foreign Key to Employee. So this should be modeled as "to-many". I am almost
    sure that it was mapping it as "to one" that caused the error.

    I need to think some more how to handle this issue more gracefully in the
    future, for now I suggest changing Employee->Account to be "to many".

    Hope this helps.

    Andrus



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