Hey Matt,
Thanks for the response. These are exactly the steps that I took. The problem
that
I am running into is that when I generate my classes the Product Class contains
a List
of Keyword.class not java.lang.String.
I am guessing that since Cayenne 2.0.4 requires persistent classes to extend a
base class
that persisting simple classes/relationships like collections java.lang.String
is not as simple.
The big question is whether it is even possible.
I have read a little on Cayenne 3.0 and it sounds like it is more inline, but
the fact that it is not
stable is a little disconcerting to me since I am writing something that will
be in production before
it is even gets into a release candidate stage.
Any other ideas?
----- Original Message ----
From: Matt Kerr <m...@centralparksoftware.com>
To: user@cayenne.apache.org; Bret Gregory <bmg...@yahoo.com>
Sent: Tuesday, August 25, 2009 10:55:15 PM
Subject: Re: Newbie Question: Mapping a Collection of Strings
Hey Bret -
Unless I'm missing - yes, this is right on the mark for cayenne.
If you have an existing database, the easiest is to create a new model
and use Tools -> Re-engineer Databae Schema, ie
http://cayenne.apache.org/doc/reverse-engineer-database.html
Note- I find there a few quirks in the Modeler, so pay attention to
the fine print like this,
"... you need to select either a DataDomain or one of its children on
the project tree."
If you're starting from scratch - hmm, I'd thought there'd be more
info here, but I'm not seeing it :-?
http://cayenne.apache.org/doc/modeler-guide.html
You'd need to do something *vaguely* like ..
1/ create a Database Entity for each of your tables: Product and
Keyword. This includes defining PK.
2/ then still in the Database Entity - add the Relationship from
Product -> Keyword. You have to open the Inspector (I) to define the
columns which define the join. Set the name of reverse relationship
-which will use the FK you mention.
3/ when that's all set, I'd hit the "C+" (Create Object Entity) to
define your classes.
4/ Tools -> Generate Classes
Hope this helps for now.
-mk
On Tue, Aug 25, 2009 at 10:08 PM, Bret Gregory<bmg...@yahoo.com> wrote:
> I have a DB that looks something like this:
>
> Product
> -ProductId
> -Description
>
> Keyword
> -ProductId
> -Keyword
>
> Where Product -> Keyword is 1:N and Keyword has a FK rel back to Product.
>
> I would like the object model to look something like this:
>
> Product
> -(String) _description
> -(List<String>) _keywords
>
> Is it possible to map collections of simple objects and have them persisted
> by Cayenne? Seems like this would be a pretty common request, but
> I am not seeing a way to do this in the modeler.
>
>
>
>
