How do I map composite-id with inverse and cascading?

Question

I have a scenario where we have a lookup table with an additional column. Were it not for this column then a simple many-to-many would save the bacon but but now I have to create a third class which of course is fine too. The problem here though is that I can't make cascading work and have to resort to calling Session.SaveOrUpdate(object) three times.

The classes looks like below:

public class ContactMap : ClassMap<Contact>
{
    public ContactMap()
    {
     Id(x => x.Id);
     HasMany(x => x.DeviceContacts)
      .Table("lookup_table")
      .KeyColumn("contact_id")
      .AsSet()
      .Inverse();
    }
}

public class DeviceMap : ClassMap<Device>
{
    public DeviceMap()
    {
     Id(x => x.Id)
      .Not.Nullable();
     HasMany(x => x.DeviceContacts)
      .Table("lookup_table")
      .KeyColumn("device_id")
      .AsSet()
      .Inverse();
    }
}

public class DeviceContactMap : ClassMap<DeviceContact>
{
    public DeviceContactMap()
    {
     CompositeId()
      .KeyReference(x => x.Contact, "contact_id")
      .KeyReference(x => x.Device, "device_id");

     Map(x => x.UId, "contact_uid");
    }
}

Now there has to be a better way of doing this. One thing that crossed my mind was to map the reference as well but that fails with too many parameters.

Answer 1

I found the answer here >> http://stackoverflow.com/questions/1420498/how-to-cascade-save-with-compositeid-in-nhibernate