Entity with simple key referencing another with composite key

Question

I am using Fluent Nhibernate for mapping my classes, and I have the following situation:

User class

public class UsuarioMap : ClassMap<Usuario>
{
    public UsuarioMap()
    {
        Table("USUARIOS");
        Id(x => x.ID, "USUARIO_ID").GeneratedBy.Increment();
        //Comentado para evitar código desnecessário

        References(x => x.Proprietario).Columns("PROPRIETARIO_ID", "SERVIDOR_ID");
    }
}

Proprietary Class Map:

public class ProprietarioMap : ClassMap<Proprietario>
{
    public ProprietarioMap()
    {
        ReadOnly();

        Table("PROPRIETARIOS");
        CompositeId().
            KeyProperty(x => x.ID, "PROPRIETARIO_ID").
            KeyProperty(x => x.ServidorId, "SERVIDOR_ID");

        Id(x => x.ID, "PROPRIETARIO_ID").GeneratedBy.Assigned();

        //Comentado para evitar código desnecessário
    }
}

When trying to save a Usuario, I get a ArgumentOutOfRangeException. The object I try to save is as follows:

var usuario = new Usuario
{
    Proprietario = new Proprietario { ID = 1497196, ServidorId = 2 }
    // Comentado para evitar código desnecessário
};

It’s interesting that if I create a property ProprietarioID in class Usuario and map it, the object is saved smoothly.

What am I doing wrong? Mapping one compound entity into another simple is correct?

Answer 1

I solved the issue by mapping a private field called proprietarioID, and pointing the map to it:

Map(x => x.ProprietarioID).Column("PROPRIETARIO_ID").Access.CamelCaseField(Prefix.None);`

In class Usuario, I changed the constructor to receive a parameter of type Proprietario, with at least ID and ServidorID, and the property Proprietario now only has get, where return the object of the bank. In any case, many thanks @Fernando for the help!

 public virtual Proprietario Proprietario
 {
     get
     {
         if (proprietario != null)
             return proprietario;

         if (proprietarioID == 0 || ServidorID == 0) return null;
         proprietario = new Repository<Proprietario>().Get(proprietarioID, SrvUn);
         return proprietario;
     }
 }

 public Usuario() : this(null)
 {

 }

 public Usuario(Proprietario proprietario)
 {
     if (proprietario == null) return;

     proprietarioID = proprietario.ID;
     this.proprietario = proprietario;
 }