(fluent) nhibernate conditional table mapping strategy

Question

I have no control over database schema and have the following (simplified) table structure:

• CityProfile
  • Id
  • Name
• CountryProfile
  • Id
  • Name
• RegionProfile
  • Id
  • Name

I have a .Net enum and class encapsulating the lot:

public enum Scope { Region, Country, City }

public class Profile {
    public Scope Scope { get; set; }
    public int Id { get; set; }
    public string Name { get; set; }
}

I am looking for a mechanism that allows me to map to the correct table, something like:

public class ProfileMap : ClassMap<Profile> {
    public ProfileMap() {
        switch (x => x.Scope) { // <--Invalid code here!
            case Scope.City: Table("CityProfile"); break;
            case Scope.Country: Table("CountryProfile"); break;
            case Scope.Region: Table("RegionProfile"); break;
        }
        Id(x => x.Id);
        Map(x => x.Name);
    }
}

Or have I approached this wrong?

Answer 1

Given that the database schema is fixed, I would map these as 3 separate classes and map to the common interface as an any reference.

class Foo
{
    public virtual IProfile Profile { get; set; }
}

public class FooMap : ClassMap<Foo>
{
    public FooMap()
    {
        ReferencesAny(m => m.Profile)
            .EntityTypeColumn("ProfileType")
            .EntityIdentifierColumn("ProfileId")
            .AddMetaValue<CityProfile>("CityProfile")
            .AddMetaValue<CountryProfile>("CountryProfile")
            .AddMetaValue<RegionProfile>("RegionProfile")
            .IdentityType<int>();
    }
}