Re: missing support for db _PROPERTY columns ?

From: Matt Kerr (mat..entralparksoftware.com)
Date: Fri Apr 23 2004 - 11:12:46 EDT

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    > Querying by a foreign key value is like querying by a primary key
    > value. It
    > can be done, but it's not encouraged.

    i'm so new - i guess i'm missing something here ...

    the documentation seems to indicate that cayenne "supports" accessing
    the db via db columns - ??
    and even seems to recommend using this feature at times:

    http://www.objectstyle.org/cayenne/userguide/expressions/path.html
    ~~~~~~~~~~~~~~~~~~~~~~~~~
    Database Path Expressions provide an easy way to navigate through DB
    table joins. Instead of complex join semantics such expressions utilize
    the names of DbRelationships defined in Cayenne DataMap. Translating
    the above object path examples into the DB realm, database path
    expressions might look like this:
       ...
    Though database path expressions are widely used by Cayenne framework
    internally, they are rarely used in applications. There are only a few
    cases when their explicit use is justified.
    ~~~~~~~~~~~~~~~~~~~~~~~~~

    but the modeler/framework doesn't seem to support this feature - ?

    it doesn't define for me the _PROPERTY columns necessary to use this
    API.
    (which is so strange, since i had to enter the name TWICE into the
    model.xml--and once specifically for the data map!?)

    it actually makes total sense to have the db _PROPERY's defined in the
    _auto file ... because that's really what the _auto file is--it exposes
    the top *and* bottom of the abstraction created in the model.xml ...
    what you choose to use is up to the consumer. every solution has it's
    unique set of +/- ... as a framework provider, if you allow both,
    document them and let the caller decide.

    please let me know if i'm reading this wrong.

    thanks!
    -matt



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