Mailing-List: contact cayenne-user-help@incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: cayenne-user@incubator.apache.org
Received-SPF: pass (herse.apache.org: domain of malcolm.edgar@gmail.com
 designates 64.233.162.234 as permitted sender)
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
        s=beta; d=gmail.com;
        h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references;
        b=n5gdWK08DbrPVuXpJlkytIqQvXEzuKntTgqtdliiR75laN0ge20IZZ+JWZsEsz7LSI3VUQ24BqYWqBo5aONbtgdyvCWdxJjoQwEy8eYDzycEWUHgO8t9FYxrmaD9+Aglp/slH7JYixEe35d1DH9E2SR6bpzSmmaISQfUt8MnjY8=
Message-ID: <525d8e10611281441q3e837240xfa82d47fdbac818b@mail.gmail.com>
Date: Wed, 29 Nov 2006 09:41:27 +1100
From: "Malcolm Edgar" <malcolm.edgar@gmail.com>
To: cayenne-user@incubator.apache.org
Subject: Re: Persistence and inheritance : a noob question
In-Reply-To: <456CB918.7040305@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
References: <456CA158.1050401@gmail.com>
	 <f65b8ae30611281322n16a1aea9n579558d63bfff59a@mail.gmail.com>
	 <456CB918.7040305@gmail.com>

My 2 bits worth..

I find the single table model works better than modeling class
inheritance through multiple tables. The reason being you have less
referential integrity constraints to worry about when  using a single
table

regards Malcolm

On 11/29/06, Landry Soules <cayenneml@gmail.com> wrote:
> Thanks for your answer, Michael.
> Actually i thought of having one table for Vip, one for Customer, and
> none for Person.
> Because Vip and Customer share some properties (first name, last name etc=
).
> Having 2 tables seems cleaner to me, but if your solution is well
> supported by Cayenne, why not ?
> Would you please have a small code example to help me understand how to
> implement it ?
>
> Thanks
>
> Landry Soules
>
> Michael Gentry a =E9crit :
> > Are you wanting multiple tables or a single table?  Cayenne will
> > currently do a single table mapped to multiple Java classes pretty
> > well.  You have to have a discriminator column (an int or a char, etc)
> > which Cayenne can use to detect which Java class to create.  Such as 1
> > =3D Customer, 2 =3D VIP, etc.
> >
> > /dev/mrg
> >
> >
> > On 11/28/06, Landry Soules <cayenneml@gmail.com> wrote:
> >> Hello,
> >>
> >> I'm a new user of Cayenne, and am facing a design problem. Here it is =
:
> >> I would like to implement the following :
> >> - a Person abstract class (with first name, last name and so on
> >> properties), extended by Customer and Vip classes.
> >> In my mind, Person wouldn't be persistent, whereas Customer and Vip
> >> would, meaning having only customer and vip tables.
> >> Does this fit into the FAQ's CompositeVerticalInheritence, or does exi=
st
> >> a simpler alternative, since i must admit i didn't understand how to u=
se
> >> it ?
> >>
> >> Thanks
> >>
> >> Landry Soules
> >>
> >
>
>