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From Craig L Russell <Craig.Russ...@Sun.COM>
Subject Re: Detecting inconsistencies of mapped-by declarations?
Date Thu, 07 May 2009 17:15:39 GMT
Hi Jörg,

On May 7, 2009, at 9:36 AM, Joerg von Frantzius wrote:

> Hi,
>
> in the XML metadata, it is possible to have multiple FCO fields, e.g.
> B.a1 and B.a2, with identical mapped-by pointing to the same field of
> the same related class, e.g. A.b. In effect this would theoretically
> mean that the FK should be shared among different associations in the
> object model. I don't think that this does make much sense.

I agree.
>
>
> Also it is possible to declare two fields in two different classes,  
> e.g.
> B1.a and B2.a, with the identical mapped-by pointing to the same field
> of the same related class, e.g. A.a. That would mean that in theory  
> two
> FKs would have to be created for the same column, pointing to  
> different
> tables. That neither seems to make sense to me.

I agree.
>
>
> Should the implementation throw an error in such situations, warning  
> the
> user of the erroneous metadata?

Yes.

Craig
>
>
> Regards,
> Jörg
>
> -- 
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Craig L Russell
Architect, Sun Java Enterprise System http://db.apache.org/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!


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