Re: Relationships without FK constraints?

From: Joe Baldwin (
Date: Sat Mar 28 2009 - 10:10:32 EDT

  • Next message: Juergen Saar: "Re: Relationships without FK constraints?"


    Your comments are along the line of what I was considering.

    I have worked on a number of large projects that are database driven
    and have found that you can get yourself (and your design team) into a
    lot of trouble by designing for a single framework. It is my
    experience that a database (even one designed primarily to work with
    Cayenne or RoR) should also be able to function as a stand-alone
    relational database. This way you can leverage other tools like
    report writers and external apps like datasource integrators.

    I used Cayenne-Modeler to reverse engineer my initial database design
    and am now using it quite effectively to manage all of my design
    changes. However, the database still maintains a cogent relational
    perspective even when the Cayenne layer is eliminated.

    The intent of my comments and questions revolve around the state-of-
    the-art wrt best design practices in the context of new and
    experimental frameworks and design patterns.

    "Convention over Configuration" can be useful (and fast) in simple
    implementations (ex: JSP form assignments) but may still be a bit too
    "fuzzy" for the larger scaleable projects.

    These are my current opinions. I am interested in how others look at


    On Mar 28, 2009, at 7:51 AM, Juergen Saar wrote:

    > There are 2 ways ... you can do it in database or in a framework like
    > cayenne
    > The framework way is best for being database independent
    > The database way is best for databases being accessed on different
    > way ...
    > let's say java and .net ... in those constellations you otherwiese
    > would
    > have to do multiple inplementations
    > In most cases you will find a mix of both
    > 2009/3/27 Joe Baldwin <>
    >> I am curious: how are your related-tables managed in a relational
    >> database
    >> without FK's? Is there no RDB perspective in the design?
    >> On Mar 27, 2009, at 2:33 PM, Joseph Schmidt wrote:
    >>> Just reread your question.. Sorry for
    >>>> misleading. This is true, Cayenne
    >>>> cannot know about relationships in DB without FKs. So you
    >>>> have to map them
    >>>> manually
    >>> Adding manually is not efficient for most cases (too big
    >>> databases) :(.
    >>> (This would not convince users to ditch RoR's ActiveRecord for
    >>> Cayenne :(
    >>> ).
    >>> I added a feature request for this:
    >>> since Cayenne could infer these relations if they respect the
    >>> convention.
    >>> Thanks,
    >>> Joseph.

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