Re: vertical inheritance by templating

From: Mike Kienenberger (mkienen..laska.net)
Date: Fri Jun 17 2005 - 15:25:28 EDT

  • Next message: Andrus Adamchik: "Re: vertical inheritance by templating"

    FWD'd from cayenne-user:

    Andrus Adamchik <andru..bjectstyle.org> wrote:
    > Reading the wiki post, I realized the source of our earlier
    misunderstanding.
    >
    > I am looking at the vertical inheritance from the perspective of the base
    > table ("PERSON" in this example). So to me vertical inheritance is just a
    > special case of single table inheritance. I.e. queries can be performed on
    > the inheritance hierarchy root and then Cayenne can determine which
    > subclass to instantiate by applying entity qualifier returned data rows.
    >
    > You look at it from the perspective of the detail tables. And this is what
    > makes it impossible to query across the hierarchy (at least not until we
    > also implement horizontal inheritance).

    I guess I hadn't realized it was confusing at that level.

    But, yeah, vertical inheritance is the opposite of single-table inheritance
    in one respect.

    STI splits a single database table into multiple java objects.
    VI combines several database tables into a single java object.

    -Mike



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