Fluent NHibernate automap configuration throwing vague error

Question

I'm trying out the automapping capability of Fluent NHibernate, and the same code that worked with explicit ClassMap configurations is failing when building the SessionFactory when I try to move it to automapping.

Here's the code:

public static ISessionFactory GetSessionFactory()
{
    if (_sessionFactory == null)
    {
        _sessionFactory = Fluently.Configure()
            .Database(MsSqlConfiguration.MsSql2008.ConnectionString(c => c.FromConnectionStringWithKey("DB")))
            // It works with the following:
            // .Mappings(m => m.FluentMappings.AddFromAssemblyOf<Customer>())
            // It fails with this:
            .Mappings(m => m.AutoMappings.Add(AutoMap.AssemblyOf<Customer>()))
            .BuildSessionFactory();

    return _sessionFactory;
}

The error I get is:

An invalid or incomplete configuration was used while creating a SessionFactory. Check PotentialReasons collection, and InnerException for more detail.

I get Count = 0 for PotentialReasons and the inner exception is the same as above.

The stacktrace refers to:

at FluentNHibernate.Cfg.FluentConfiguration.BuildSessionFactory() in d:\Builds\FluentNH-v1.x-nh3\src\FluentNHibernate\Cfg\FluentConfiguration.cs:line 113

It seems like I've tried everything to get it to work, and the closest I came was to have the initialization work only to get a Could not find persister for... error when I tried to use the session, and I don't even remember how I was able to get that to happen.

I'm using the build #694 with NHibernate 3.0, SQL 2008 database. Any ideas what I'm doing wrong?

There are usually 3-4 levels of nested inner exception. Have you examined them all? — Aliostad
Wow...I feel like an idiot now! You're absolutely correct - when I drilled down I saw it's an issue mapping enums. In my explicit mappings I just did a CustomType(typeof(MyEnum)) but I'll have to see how that's possible when automapping... — Josh Anderson

Josh Anderson Josh Anderson · Accepted Answer · 2011-03-28T16:13:05

This was a dumb error that Aliostad's comment helped me find. I had an enum type that was stored as an integer in the database, and NHibernate was choking on that. I added an EnumConvention to the setup like this:

_sessionFactory = Fluently.Configure()
    .Database(MsSqlConfiguration.MsSql2008.ConnectionString(c => c.FromConnectionStringWithKey("DB")))
    .Mappings(
        m =>
        m.AutoMappings.Add(AutoMap.AssemblyOf<Customer>(new AutomapConfiguration()).Conventions.
                               Setup(c =>
                                         {
                                             c.Add<PrimaryKeyConvention>();
                                             c.Add<EnumConvention>();
                                             c.Add<CascadeAllConvention>();
                                         })
                               .IgnoreBase(typeof (EntityBase<>))
                               .OverrideAll(map => map.IgnoreProperty("IsValid"))))
    .BuildSessionFactory();

Here's that enum convention:

public class EnumConvention : IUserTypeConvention
{
    public void Accept(IAcceptanceCriteria<IPropertyInspector> criteria)
    {
        criteria.Expect(x => x.Property.PropertyType.IsEnum);
    }

    public void Apply(IPropertyInstance target)
    {
        target.CustomType(target.Property.PropertyType);
    }
}

Fluent NHibernate automap configuration throwing vague error

1 Answers