Question

Okay, I have a database, but no tables in it. I have some entity classes. I’m trying to setup Fluent NH to do automappings with automatic schema export.

First, this is possible, right?

Second, if so, what am I doing wrong here:

   private ISessionFactory CreateSessionFactory()
    {
        return Fluently.Configure()
            .Database(MsSqlConfiguration.MsSql2005
                .ConnectionString(c => c.Is(@"Data Source=foo;Initial Catalog=bar;Integrated Security=True")))
            .Mappings(m => m.AutoMappings.Add(AutoPersistenceModel.MapEntitiesFromAssemblyOf<Employee>()
                                                  .Where(t => t.Namespace.Contains("Entities"))))
            .ExposeConfiguration(BuildSchema)
            .BuildSessionFactory();
    }

    private void BuildSchema(Configuration cfg)
    {
        new SchemaExport(cfg).Create(false, true);
    }

I am getting an error “Object reference not set to an instance of an object” on the “.Where” line above. If I take out the .Where condition, I get an error “Late bound operations cannot be performed on types or methods for which ContainsGenericParameters is true.”

EDIT:

Some additional information: I changed the .Where statement to specifically outline which entities to include. I.e. “.Where(t => t.Name.Contains(“Employee”)”, etc. When I did that, I got an error about a missing dependency (NHibernate.ByteCode.Castle). When I resolved that, it works fine. I still don’t understand why this works though.

Answer 1

I believe that the NHibernate.ByteCode.Castle assembly is used to create proxy classes in NHibernate.

I’m guessing that when you tried to create the Schema, or Configuration, a reference to the proxy generator was required. That’s why adding the reference allowed fixed your problem.

You can read a little about NHibernate proxies here: http://nhforge.org/blogs/nhibernate/archive/2008/11/09/nh2-1-0-bytecode-providers.aspx