How to make discriminator table more useful

Question

I'm trying to replicate this table structure from this article.

Here are my POCO's and mappings.

POCO's

public class Item
{
    public virtual int Id { get; set; }
    public virtual Status ItemStatus { get; set; }
}

public abstract class Status
{
    private readonly int _id;
    public static readonly Status Foo = new FooStatus(1);
    public static readonly Status Bar = new BarStatus(2);

    public Status()
    {

    }

    protected Status(int id)
    {
        _id = id;
    }

    public virtual int Id { get { return _id; } }
    public abstract string Name { get; }
    public abstract string BackgroundColor { get; }
}

public class FooStatus : Status
{
    public FooStatus()
    {

    }

    public FooStatus(int id)
        : base(id)
    {

    }

    public override string Name
    {
        get { return "Foo Status"; }
    }

    public override string BackgroundColor
    {
        get { return "White"; }
    }
}

public class BarStatus : Status
{
    public BarStatus()
    {

    }

    public BarStatus(int id)
        : base(id)
    {

    }

    public override string Name
    {
        get { return "Bar Status"; }
    }

    public override string BackgroundColor
    {
        get { return "Black"; }
    }
}

Mappings:

public class ItemMap : ClassMap<Item>
{
    public ItemMap()
    {
        Id(x => x.Id).GeneratedBy.Identity();
        References(x => x.ItemStatus);
    }
}

public class StatusMap : ClassMap<Status>
{
    public StatusMap()
    {
        Id(x => x.Id).GeneratedBy.Assigned();

        DiscriminateSubClassesOnColumn<int>("ItemStatus", 0);
    }
}

public class FooStatusSubMap : SubclassMap<FooStatus>
{
    public FooStatusSubMap()
    {
        Extends<Status>();
        DiscriminatorValue(1);
    }
}

public class BarStatusSubMap : SubclassMap<BarStatus>
{
    public BarStatusSubMap()
    {
        Extends<Status>();
        DiscriminatorValue(2);
    }
}

The issue with this is that it generates my Status table like this:

Id....ItemStatus

1.....1

2.....2

As you can see this is rather useless as both columns always contain the same values.

How can I replicate the image that I linked above?

Answer 1

the key here is, that Id and Discriminatorcolumn must have the same column name

public class StatusMap : ClassMap<Status>
{
    public StatusMap()
    {
        Id(x => x.Id, "ItemStatus").GeneratedBy.Assigned();

        DiscriminateSubClassesOnColumn<int>("ItemStatus", 0);
    }
}