Hi Jörg,

On Jul 17, 2006, at 9:26 AM, Jörg von Frantzius wrote:

Hello Craig,

if I understand things right, you changed your mind and now you don't see a any problem with JPOX's automatic nulling out of FKs?
Yes, I have changed my mind on this issue.

If that's the case, then I wonder why a user would want to have FK constraints in his schema at all? They wouldn't be of much use then.

If only using JDO, I agree. What matters is the consistency of the object model, which is managed by the JDO implementation without help from the database. But seldom is JDO the only access path to the database.

I may also add that, as far as I know, JPOX nulls out only for one-one bidirectional, not for one-many, so there would be some inconsistency of behaviour here.

Interesting point, but without another level of detail, it's hard to evaluate this statement.

Regards,

Craig

Regards,
Jörg

Craig L Russell schrieb:

2. Deletion of objects when foreign-key is present (JDO-392) (any and all) It seems that there are two different issues: managing the memory model and managing the database. Craig opines that the general case of consistency is already covered in the chapter on mapping, requiring that the object model be consistent after a flush. Object model consistency would disallow a reference to a deleted object, so the natural behavior would be to nullify the reference to the deleted object. For to-many relationships mapped to a foreign key on the other side, the consistency rule would delete the reference from the collection on the one- side of the relationship. So it seems that the JPOX behavior as originally reported is consistent and we might simply document it in the specification.
Why does object model consistency disallow a reference to a deleted object?
<joerg.von.frantzius.vcf>

Craig Russell

Architect, Sun Java Enterprise System http://java.sun.com/products/jdo

408 276-5638 mailto:[EMAIL PROTECTED]

P.S. A good JDO? O, Gasp!


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