Hello Andrus,
Thanks for the pointer, it works perfect! For reference i used code from:
<http://objectstyle.org/cayenne/lists/cayenne-user/2004/01/0004.html>
and
<http://www.objectstyle.org/cayenne/userguide/dataobjects/unmapped-keys.html>
to get access to my primary key.
Greetings,
Twan
At 18:15 28-6-2004, you wrote:
>Hi there,
>
>the reason of not having a PK column in the object by default (you can
>change this if you want) is more of a "philosophical" one -
>autoincremented PK is meaningless within an object and is just a database
>convenience. So the rule of thumb is to not include such columns in the
>object model, and let Cayenne handle them internally (encapsulated as
>ObjectId). In case PK is meaningful (say "USER_TYPE_CODE" or something),
>it can be mapped as an object property - Cayenne fully supports that.
>
>Now, if you want to use an autoincremented PK in your query, you can still
>do that. There were a few threads about it on the mailing list. For
>example check out this one:
>
>http://objectstyle.org/cayenne/lists/cayenne-user/2004/01/0002.html
>
>Cheers,
>Andrus
>
>
> > Hello people,
> >
> > Today i downloaded and studied the "cayenne-web-app" example, which uses
> > struts en cayenne to create a webapplication which allows people to
> > manage paintings, galleries and artists.
> >
> > It was a interesting and easy to understand example. But i've got a
> > question about the example of something that isn't really clear for me.
> >
> > In the example there is a Artist entity and a table ARTIST where the
> > Artist entities are saved into. The ARTIST table contains of 3 rows,
> > one of them is ID the primary key. My question is about this primary
> > key:
> >
> > Why is the primary key not included as a attribute in the Artist entity,
> > is there maybe a special reason for not to do this?
> >
> > The reason for asking this is that it seems logical to include the ID as
> > a attribute of the Artist entity. Because for example when adding a
> > painting to a artist, you could use:
> > http://localhost:8080/struts/addPainting.do?artistid=2
> > instead of the error phrone:
> > http://localhost:8080/struts/addPainting.do?name=myname
> > (myname doesn't seems to be unique, artistid is as a primary key always
> > unique)
> >
> > Best regards,
> > Twan Kogels
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