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

[Steve Ebersole]

http://in.relation.to/Bloggers/New323HibernateIdentifierGenerators

On Sun, 2009-12-06 at 14:53 +0100, Jochen Wiedmann wrote:
> 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
> >
> >
> 
> 
> 
-- 
Steve Ebersole <steve at hibernate.org>
Hibernate.org