Fluent NHibernate automap base class overrides

I have the following base class.

public abstract class BaseEntity
{
    public virtual long Id { get; set; }
    public virtual DateTime CreateDate { get; set; }
    public virtual DateTime? UpdateDate { get; set; }
    public virtual bool IsDeleted { get; set; }
    public virtual string CreatedBy { get; set; }
}

And it's a base class for all entities.

For example,

public class Task : BaseEntity
{
    public virtual string Name {get;set;}
}

I have an initializer,

public class Initializer
{
    public static AutoPersistenceModel MapEntities()
    {
        var p = AutoMap
            .AssemblyOf<User>(new MyDefaultAutomappingConfiguration())
             .IgnoreBase<BaseEntity>()
            .UseOverridesFromAssemblyOf<Initializer>()
            .Override<BaseEntity>(map =>
            {
                map.Map(b => b.CreateDate).Not.Nullable().Not.Update();
                map.Map(b => b.CreatedBy).Not.Nullable().Length(100);
                map.Map(b => b.ModifiedBy).Length(100);
                map.Map(b => b.DeletedBy).Length(100);
                map.Map(b =&开发者_如何学Gogt; b.IsDeleted).Not.Nullable().Default("0");
            });
        return p;
    }
}

And of course in the database - CreateDate is datetime, null, and CreatedBy is nvarchar(255).

How can I configure this AutoMapper to get these mappings from the base class to all child classes?

You can't override a mapping for a base class since that mapping doesn't actually ever get created. If you want to continue using the Automapper you can create a convention

public class BaseEntityPropertiesConvention : IPropertyConvention
{
    public void Apply(IPropertyInstance instance)
    {
        if (instance.EntityType.IsSubclassOf(typeof(BaseEntity)))
        {
            switch instance.Name
            {
                case "CreatedDate":
                    instance.Not.Nullable().Not.Update();
                    break;
                case "CreatedBy":
                    instance.Not.Nullable().Length(100);
                    break;
                //etc...
            }
        }
    }
}