Ok, Thomas...

I�v tried DList in my collections and I�ve noticed two behaviors:

1) Relations 1:n - I�ve need put auto-delete true in order auto-deletes
works
2) Relations m:n - auto-delete must be false. Then, ODMG deletes the
intermediary table rows associates with the object I�m deleting. Not objects
in the other tables. If you put auto-delete true, then ODMG deletes ALL
objects in tables, not only the intermediary table rows.


For example:

1) Invoice:Invoice_lines  auto-delete must be true. So, if I delete an
invoice, ODMG deletes all invoice lines.
2) User-Groups: auto-delte must be false. If I delete an user, ODMG deletes
all rows associates with that user, but not the groups associated with the
user. Vice-versa, if I delete a group, ODMG deletes all intermediary rows,
but not the users associates with that group.

I thinks that�s the correct behavior, don�t?

Greetings.
Jose Galiana

-----Mensaje original-----
De: Thomas Mahler [mailto:[EMAIL PROTECTED]]
Enviado el: martes, 08 de octubre de 2002 21:07
Para: OJB Users List
Asunto: Re: Collections or DCollections?


Hi again,

Jose Galiana wrote:
> So, if I want ODMG deletes objects and their rows in dabatase I must to
use
> DList instead List, don�t?
>

If you want to have it done *automagically*, yes.

>
>
> -----Mensaje original-----
> De: Thomas Mahler [mailto:[EMAIL PROTECTED]]
> Enviado el: martes, 08 de octubre de 2002 20:35
> Para: OJB Users List
> Asunto: Re: Collections or DCollections?
>
>
> Hi Jose,
>
> Jose Galiana wrote:
>
>>Works ODMG better if the collection-description elements in classes are
>>DCollections (DList, etc.. ) than traditional java.util.collection? Why?
>>
>
>
> If you want to have collection that are aware of removing and adding
> items you'll have to use DList.
> If you don't need such a feature you can use normal collections as well.
> The DList collection bring a lot of overhead with them.
> If you need ODMG compatibility you should use them.
>
>
>>If I don�t use auto-delte in ODMG collections, how ODMG deletes the rows
>
> in
>
>>database?
>
>
> ODMG tracks all objects that can be reached from an object that is
> locked to the transaction. Thus the transaction is aware of which object
> must be deleted. The PB kernel cannot do this, as it does not track the
> state of objects.
>
> cheers,
> Thomas
>
>
>>Thanks in advance
>>Jose Galiana
>>
>
>
>
>
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