[hibernate-dev] IdentifierGenerator, which *may* implement PostInsertIdentifierGenerator

[Jochen Wiedmann]

Hello, Steve,

yes the answer for "why native?" is portability, indeed.

Could you please enlighten me, what the "enhanced" generators
precisely are and why they would fix my problem? At least, I don't
find the term "enhanced" in the IdentifierGeneratorFactory and neither
of the classes implementing IdentiferGenerator in the hibernate
sources contain it.

Thanks,

Jochen


On Fri, Dec 4, 2009 at 4:30 PM, Steve Ebersole <steve at hibernate.org> wrote:
> First I have to ask 'why native?'.  Doing this with the native generator
> will present you with an interesting challenge of how you handle
> IDENTITY or other post-insert style generation.  post-insert means after
> the insert has happened, so how would you be adding your prefix?  And
> even if you answer that, generally speaking columns defined as IDENTITY
> are not eligible for update.
>
> If the answer to 'why native?' is portability, then why not use the
> "enhanced" generators.  These are intended for portability in a much
> better way then native was.
>
> On Fri, 2009-12-04 at 08:50 +0100, Jochen Wiedmann wrote:
>> Hi,
>>
>> for some particular project, I'd like to have a custom
>> IdentifierGenerator, which could be thought of as an extension of the
>> "native" IdentifierGenerator. Basically, it ought to take the id
>> generated by the "native" generator, but then do some magic with it,
>> for example add a prefix. (Yes, I know, don't push me on that, I have
>> already lost my struggle against a "telling ID".)
>>
>> Such an IdGenerator is easily implemented: Create a class, which
>> queries the IdentifierGeneratorFactory for the "native"
>> IdentifierGenerator and use that. (Works fine.)
>>
>> The problem is, that the "native" generator is sometimes implementing
>> PostInsertIdentifierGenerator. Of course, I can have my generator
>> implement PostInsertIdentifierGenerator as well, but that means that
>> it will break on systems without a sequence. OTOH, I can remove the
>> interface, but then it won't work on the other systems.
>>
>> An alternative might be, to add a new "myNative" term to the
>> IdentifierGeneratorFactory, but that class neither allows extension
>> (it's final, for whatever reason) nor does it support extending the
>> map of builtin types.
>>
>> Any ideas?
>>
>> Thanks,
>>
>> Jochen
>>
>>
> --
> Steve Ebersole <steve at hibernate.org>
> Hibernate.org
>
>



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