I am experimenting with NHibernate (version 2.1.0.4000) with Fluent NHibernate Automapping.

My test set of entities persists fine with default integer IDs

I am now trying to use Guid IDs with the entities. Unfortunately changing the Id property to a Guid seems to stop NHibernate inserting objects.

Here is the entity class:

public class User
{
    public virtual int Id { get; private set; }
    public virtual string FirstName { get; set; }
    public virtual string LastName { get; set; }
    public virtual string Email { get; set; }
    public virtual string Password { get; set; }

    public virtual List<UserGroup> Groups { get; set; }

}

And here is the Fluent NHibernate configuration I am using:

        SessionFactory = Fluently.Configure()
                            //.Database(SQLiteConfiguration.Standard.InMemory)
                            .Database(MsSqlConfiguration.MsSql2008.ConnectionString(@"Data Source=.\SQLEXPRESS;Initial Catalog=NHibernateTest;Uid=NHibernateTest;Password=password").ShowSql())
                            .Mappings(m =>
                                m.AutoMappings.Add(
                                    AutoMap.AssemblyOf<TestEntities.User>()
                                            .UseOverridesFromAssemblyOf<UserGroupMappingOverride>()))
                            .ExposeConfiguration(x =>
                                {
                                    x.SetProperty("current_session_context_class","web");
                                })
                            .ExposeConfiguration(Cfg => _configuration = Cfg)
                            .BuildSessionFactory();

Here is the log output when using an integer ID:

16:23:14.287 [4] DEBUG NHibernate.Event.Default.DefaultSaveOrUpdateEventListener - saving transient instance
16:23:14.291 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - saving [TestEntities.User#<null>]
16:23:14.299 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - executing insertions
16:23:14.309 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - executing identity-insert immediately
16:23:14.313 [4] DEBUG NHibernate.Persister.Entity.AbstractEntityPersister - Inserting entity: TestEntities.User (native id)
16:23:14.321 [4] DEBUG NHibernate.AdoNet.AbstractBatcher - Opened new IDbCommand, open IDbCommands: 1
16:23:14.321 [4] DEBUG NHibernate.AdoNet.AbstractBatcher - Building an IDbCommand object for the SqlString: INSERT INTO [User] (FirstName, LastName, Email, Password) VALUES (?, ?, ?, ?); select SCOPE_IDENTITY()
16:23:14.322 [4] DEBUG NHibernate.Persister.Entity.AbstractEntityPersister - Dehydrating entity: [TestEntities.User#<null>]
16:23:14.323 [4] DEBUG NHibernate.Type.StringType - binding null to parameter: 0
16:23:14.323 [4] DEBUG NHibernate.Type.StringType - binding null to parameter: 1
16:23:14.323 [4] DEBUG NHibernate.Type.StringType - binding 'ertr' to parameter: 2
16:23:14.324 [4] DEBUG NHibernate.Type.StringType - binding 'tretret' to parameter: 3
16:23:14.329 [4] DEBUG NHibernate.SQL - INSERT INTO [User] (FirstName, LastName, Email, Password) VALUES (@p0, @p1, @p2, @p3); select SCOPE_IDENTITY();@p0 = NULL, @p1 = NULL, @p2 = 'ertr', @p3 = 'tretret'

and here is the output when using a Guid:

16:50:14.008 [4] DEBUG NHibernate.Event.Default.DefaultSaveOrUpdateEventListener - saving transient instance
16:50:14.012 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - generated identifier: d74e1bd3-1c01-46c8-996c-9d370115780d, using strategy: NHibernate.Id.GuidCombGenerator
16:50:14.013 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - saving [TestEntities.User#d74e1bd3-1c01-46c8-996c-9d370115780d]

This is where it silently fails, with no exception thrown or further log entries.

It looks like it is generating the Guid ID correctly for the new object, but is just not getting any further than that.

Is there something I need to do differently in order to use Guid IDs?

Thanks,

Dan.