Mailing-List: contact user-help@cayenne.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@cayenne.apache.org
Received-SPF: pass (athena.apache.org: local policy)
Date: Tue, 12 Apr 2011 16:14:47 -0400 (CLT)
From: "Hans C. Poo" <hans@welinux.cl>
To: user@cayenne.apache.org
Subject: Re: Mapping Question
Message-ID: <6bbb7098-44ad-4d03-81b2-9a8944f4ffc5@gondor.welinux.cl>
In-Reply-To: <BANLkTim5a6pte84mavQhe0WHv51vF-fAQA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0

Tony,

I had a similar problem and solved it making the relationship in the reverse sense of what composition dictates.

First create NoteCollection that contains a Collection of Notes.

Entities, Think Topic, Project, Category, Asset must have an "id_note_collection" field. 

Example:

Project --> NoteCollection --> * Note
Asset --> NoteCollection --> * Note

Any Entity that needs a NoteCollection must have an noteCollectionId.

Bye
Hans

----- Mensaje original -----
De: "Tony Giaccone" <tgiaccone@gmail.com>
Para: user@cayenne.apache.org
Enviados: Martes, 12 de Abril 2011 16:43:49
Asunto: Mapping Question

This is more of a generic question, though I'm interested in how it might be
implemented in Cayenne as well.


I have a number of entities, Think Topic, Project, Category, Asset.  On each
one I need to model a to many relationship to Notes, Where a Note is an
object with a subject and a date created and content.

I"m not sure what the best strategy is to map each of these different
entities. I really don't want to create 4 note tables, So that there's a
Topic Note table, and a Project  Note table and  well you get the idea.

I could put a discriminator on the table, so that each entry has it's own
"type" that would solve part of the problem, but they I have to create the
foreign keys relationship.

So I'm just looking for some advice. Have you dealt with a similar
situation, and how did you model in general this solution and in Cayenne in
particular.

Thanks for the help


Tony Giaccone