How to collapse one-to-one parent-child tables into classes with Fluent NHibernate?

How do I map these existing tables to the classes below?

I have the following tables:

CREATE TABLE dbo.UserContact (
  UserContactId int NOT NULL IDENTITY (1, 1),
  UserId int NOT NULL,
  ContactId int NOT NULL,
  UserContactTypeId int NOT NULL,
  FromDt datetime NULL,
  ThruDt datetime NULL,
  CreateDt datetime NOT NULL,
  UpdateDt datetime NULL,
  IsDeleted bit NULL,
  CanSolicit bit NOT NULL
) 

CREATE TABLE dbo.Contact (
  ContactId int NOT NULL IDENTITY (1, 1),
  CreateDt datetime NOT NULL,
  UpdateDt datetime NULL
)

CREATE TABLE dbo.Electronic (
  ContactId int NOT NULL,
  URL nvarchar(512) NOT NULL,
  ElectronicType smallint NULL
)

CREATE TABLE dbo.Phone (
  ContactId int NOT NULL,
  AreaCode nchar(3) NOT NULL,
  PhoneNb nchar(7) NOT NULL,
  Extension nchar(6) NULL,
  PhoneType smallint NULL
)

CREATE TABLE dbo.Postal
(
  ContactId int NOT NULL,
  Street nvarchar(256) NOT NULL,
  Specifier nvarchar(256) NULL,
  GeocodeId int NULL
)

The tables Electronic, Phone and Postal are in a one-to-one relationship with Contact. The table UserContact is in a many-to-one with Contact; UserContact is an association table between User and Contact.

I also have the following classes:

public class Electronic : IntegerKeyEntity
{
    pu开发者_开发技巧blic virtual ContactId { get; set; }
    public virtual DateTime CreateDt { get; set; }
    public virtual DateTime? UpdateDt { get; set; }
    public string Url { get; set; }
    public ElectronicType Type { get; set; }
}

public class Postal : IntegerKeyEntity
{
    public virtual ContactId { get; set; }
    public virtual DateTime CreateDt { get; set; }
    public virtual DateTime? UpdateDt { get; set; }
    public string Street { get; set; }
    public string Specifier { get; set; }
    public Geocode Geocode { get; set; }
}

public class Phone : IntegerKeyEntity
{
    public virtual ContactId { get; set; }
    public virtual DateTime CreateDt { get; set; }
    public virtual DateTime? UpdateDt { get; set; }
    public string AreaCode { get; set; }
    public string PhoneNb { get; set; }
    public string Extension { get; set; }
    public PhoneType Type { get; set; }
}

public class UserContact : IntegerKeyEntity
{
    private ICollection<Electronic> electronics = new HashSet<Electronic>();
    private ICollection<Phone> phones = new HashSet<Phone>();
    private ICollection<Postal> postals = new HashSet<Postal>();

    // props

    public virtual IEnumerable<Electronic> Electronics { get { return electronics; } }
    public virtual IEnumerable<Phone> Phones { get { return phones; } }
    public virtual IEnumerable<Postal> Postals { get { return postals; } }
}

So, I do I get from the four Contact tables (parent and child) down to the three classes? And, how do I map those three classes to the UserContact table. I'm assuming I can have three ILists, one for each class.

I think you're modeling this incorrectly. It appears to me that Electronic, Phone, and Postal extend (inherit from) Contact and this should be expressed in your domain model. Those classes are not related to Contact by one-to-one, they are concrete types that extend the abstract Contact type. If you model it this way you can map Contact using table-per-subclass inheritance mapping.

User would then have a many-to-many-relationship with Contact, and the user's Contacts collection would contain Contacts of any type.

Personally I would put all the Contact types into one table and use the simpler table-per-class mapping.