Setting CustomSqlType on References

I have a situation where my primary key is a char(2) in SqlServer 2008, and I want to reference it in a one-to-many relationship, but the ManyToOneBuilder (which is returned by ClassMap<>.References()) doesn't have a CustomSqlType() method. Specifically:

public class State
{
    // state FIPS code is 2 characters
    public virtual string StateCode { get; set; }
    public virtual ICollection<County> { get; set; }
}

public class County
{
    // state-county FIPS code is 5 characters
    public virtual string StateCountyCode { get; set; }
    public virtual State State { get; set; }
}
public class StateMap : ClassMap<State>
{
    public StateMap()
    {
        Id(e => e.StateCode).CustomSqlType("char(2)").GeneratedBy.Assigned();
    }
}

public class CountyMap : ClassMap<County>
{
    public Co开发者_StackOverflow社区untyMap()
    {
        Id(e => e.StateCountyCode).CustomSqlType("char(5)").GeneratedBy.Assigned();
        References(e => e.State, "StateCode")
        // Here's what I want to do, but can't because the method is not 
        // implemented on the class ManyToOneBuilder:
            .CustomSqlType("char(2)");
    }
}

Is there any way to accomplish this without modifying the ManyToOneBuilder? Is there a way to automatically map the FK (i.e. County.StateCode) to the correct type? It's trivial to add CustomSqlType to ManyToOneBuilder, but is that the right thing to do?

Keep your mapping definition as is, add your "State" column definition with

.CustomSqlType("char(2)")

and set for this column Insert=false and update=false.

I've the same problem and in AutoMapping I use this code:

mapping.Map(x => x.IdUniArticolo)
     .CustomSqlType("varchar(50)")
     .Not.Insert().Not.Update();

mapping.References(x => x.Articolo)
     .Column("IdUniArticolo").PropertyRef("IdUniArticolo");

Keep in mind that if NHibernate itself doesn't support it, then Fluent NHibernate can't, and I don't NHibernate supports the scenario you have. I had a similar problem in that I had a 2 column composite key on a table and on one of the fields, I wanted to use an enumerated type which had a custom IUserType to translate it to its appropriate code value in the DB. Couldn't do it, so I was stuck keeping the property of the string type rather than the enumerated type.