[hibernate-dev] Could UUID be one of the default strategy when AUTO is requested

[Steve Ebersole]

The problem with both of these is the lack of knowing Dialect when building
the mapping model.  5.0 is a first step toward fixing that.  6.0
(metamodel) is the complete step.

In general there are a lot of things we can do knowing the Dialect while
building the mapping model, things we cannot do now.

On Mon, Jan 19, 2015 at 3:44 PM, Gail Badner <gbadner at redhat.com> wrote:

> There are some jiras for using UUIDs (in general, not specifically for
> IDs) for using a single mapping that would work for different dialects:
> - https://hibernate.atlassian.net/browse/HHH-9562
> - https://hibernate.atlassian.net/browse/HHH-9574
>
> It seems that these are related...
>
> ----- Original Message -----
> > From: "Gunnar Morling" <gunnar at hibernate.org>
> > To: "Sanne Grinovero" <sanne at hibernate.org>
> > Cc: "Hibernate Dev" <hibernate-dev at lists.jboss.org>
> > Sent: Monday, January 19, 2015 8:15:42 AM
> > Subject: Re: [hibernate-dev] Could UUID be one of the default strategy
> when AUTO is requested
> >
> > We discussed a while ago whether it should be pluggable how AUTO is
> > resolved:
> >
> https://lists.jboss.org/pipermail/hibernate-dev/2014-November/011948.html
> >
> > I still think that's a good idea.
> >
> > In the case of OGM, it may even be a bit more complex. For example with
> > MongoDB the following should result in IDENTITY being used (which is
> mapped
> > to store-assigned object ids) rather than UUID:
> >
> >     @Id
> >     @GeneratedValue(strategy = GenerationType.AUTO)
> >     @Type(type = "objectid")
> >     String id;
> >
> > So the @Type would have to be taken into account as well for mapping
> AUTO.
> >
> > > For String, I wonder if someone would argue that it should actually map
> > to a string-encoded output of a sequence.. "1", "2" ...
> >
> > I don't think you can use sequences with String (only numeric values), so
> > anyone having this expectation would also be unhappy as of today.
> >
> > --Gunnar
> >
> >
> > 2015-01-19 15:58 GMT+01:00 Sanne Grinovero <sanne at hibernate.org>:
> >
> > > On 19 January 2015 at 13:33, Emmanuel Bernard <emmanuel at hibernate.org>
> > > wrote:
> > > > Hey,
> > > >
> > > > I am throwing an idea, let me know what you think.
> > > > If the return type of the id property of an entity is either String
> or
> > > UUID, could we automatically consider one fo the uuid strategy as the
> one
> > > matching AUTO?
> > >
> > > +1
> > > That seems spot-on for the UUID type.
> > > For String, I wonder if someone would argue that it should actually
> > > map to a string-encoded output of a sequence.. "1", "2" ...
> > > I'd personally agree that this is horrible and it should default to
> > > UUID, just wondering.
> > >
> > > Would this violate any spec?
> > >
> > > >
> > > > It would be useful for Hibernate OGM but I am also thinking that it
> > > makes equal sense to Hibernate ORM users.
> > > >
> > > > Thoughts? I’m sure there are incompatibilities I have not think of.
> > > >
> > > > Emmanuel
> > > > _______________________________________________
> > > > hibernate-dev mailing list
> > > > hibernate-dev at lists.jboss.org
> > > > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> > >
> > > _______________________________________________
> > > hibernate-dev mailing list
> > > hibernate-dev at lists.jboss.org
> > > https://lists.jboss.org/mailman/listinfo/hibernate-dev
> > >
> > _______________________________________________
> > hibernate-dev mailing list
> > hibernate-dev at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/hibernate-dev
>
> _______________________________________________
> hibernate-dev mailing list
> hibernate-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>