Nhibernate的历史

Question

I'm using NHibernate to develop an application in asp.net mvc. I have some entities in my model inherit from Entity abstract class, something like this:

public abstract class Entity
{
    private IList<History> _history = null;

    public virtual long Id { get; set; }
    public virtual IEnumerable<History> History { get { return _history; } }

    public abstract TypeOfHistory GetTypeHistory(); // to return the right type
}

// is it right ?
public enum TypeOfHistory { 
    Product = 1, Employee = 2, Customer = 3
}

public class Product : Entity { /* code */ }
public class Employee : Entity { /* code */ }
public class Customer : Entity { /* code */ }

And I have a History class to have a log of each modify of entity:

public class History
{
    public virtual string Description { get; set; }
    public virtual DateTime Date { get; set; }
    public virtual string User { get; set; }
    public virtual Entity Entity { get; set; }
    public virtual TypeOfHistory Type { get; set; } // is it right ?

    protected History() { }
}

I would like to know, how can I map this History class and History property in Entity class? I mean, I will have a table for Product, another table for Employee, and another for Customer etc and only one table called History for all entities (product, customer etc), but I won't create a foreign key. I was thinking in create a field to save the type of entity but I don't know how to do it work and map the property to filter in right way. (based on type). I know how to use the Listerens in nhibernate to do the log.

Thanks

Answer 1

Just a suggestion... Have you considered using an Auditing Framework? Hibernate (java's) has Hibernate Envers which does a wonderful job with very simple setup. And it seems that there is a port to .NET: https://bitbucket.org/RogerKratz/nhibernate.envers