Yes, it is not defined at all in the specification and I agree that it
should be.
--Gordon
On 11/12/2012 4:37 AM, Christian von Kutzleben wrote:
> Hi Gordon
>
> On Mon, Dec 10, 2012 at 9:21 PM, Gordon Yorke <gordon.yorke_at_oracle.com
> <mailto:gordon.yorke_at_oracle.com>> wrote:
>
> Hello Christian,
> "m_p" would reference a new managed instance of the Address()
> that would be fully copied from the original Address. The
> Address is fully copied because it is a practical way to get a
> managed version of the Address.
> --Gordon
>
>
> While researching more on this issue, I did also find the following
> statement in "Pro JPA 2", p. 161 "Merging Detached Entities":
>
> "If the entity has a relationship to an object that has no persistent
> identity, the outcome of the merge operation is undefined."
>
> So I agree, that what you described is a useful behavior (and that is
> what we do, if cascade-merge is enabled), however this is not really
> defined in the spec,
> and IMO needs clarification.
>
> Thank you!
>
> Christian
>
>
> On 10/12/2012 8:56 AM, Christian von Kutzleben wrote:
>> Dear group,
>>
>> What is supposed to happen in this scenario:
>>
>> @Entity
>> class Person {
>> //...
>> Address address; //cascade-merge or cascade-all are not
>> specified
>> }
>>
>> @Entity
>> class Address {
>> //...
>> }
>>
>> em.getTransaction().begin();
>> Person p = new Person();
>> em.persist(p);
>> em.getTransaction().commit();
>>
>> em.getTransaction().begin();
>> em.detach(p);
>> p.setAddress(new Address());
>> Person m_p = em.merge(p);
>>
>> //what does m_p's "address" field contain? Or should merge throw
>> an exception right away?
>>
>>
>> Thank you!
>>
>> Christian
>>
>> --
>> Christian von Kutzleben
>> Chief Engineer | Versant GmbH
>> (T) +49 40 60990-0 <tel:%2B49%2040%2060990-0>
>> (F) +49 40 60990-113 <tel:%2B49%2040%2060990-113>
>> (E) cvkutzleben_at_versant.com <mailto:cromberg_at_versant.com>
>> www.versant.com <http://www.versant.com> | www.db4o.com
>> <http://www.db4o.com>
>>
>> --
>> Versant
>> GmbH is incorporated in Germany. Company registration number: HRB
>> 54723, Amtsgericht Hamburg. Registered Office: Halenreie 42, 22359
>> Hamburg, Germany. Geschäftsführer: Bernhard Wöbker, Volker John
>>
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>
>
>
>
> --
> Christian von Kutzleben
> Chief Engineer | Versant GmbH
> (T) +49 40 60990-0
> (F) +49 40 60990-113
> (E) cvkutzleben_at_versant.com <mailto:cromberg_at_versant.com>
> www.versant.com <http://www.versant.com> | www.db4o.com
> <http://www.db4o.com>
>
> --
> Versant
> GmbH is incorporated in Germany. Company registration number: HRB
> 54723, Amtsgericht Hamburg. Registered Office: Halenreie 42, 22359
> Hamburg, Germany. Geschäftsführer: Bernhard Wöbker, Volker John
>
> CONFIDENTIALITY
> NOTICE: This e-mail message, including any attachments, is for the sole
> use of the intended recipient(s) and may contain confidential or
> proprietary information. Any unauthorized review, use, disclosure or
> distribution is prohibited. If you are not the intended recipient,
> immediately contact the sender by reply e-mail and destroy all copies of
> the original message.
>