Question

I’m trying to enable my application to keep previous versions of entities.

For example, if I have a Book I want to be able to retrieve it at version 1, or at version 5, etc…

public class Book
{
    public virtual int ID {get; set;}
    public virtual string Name {get; set;}
    public virtual int Version {get; set;}
}

I map the version column like this:

Version(x=>x.Version);

This is working. When it’s inserted, the version is 1.
If I pull back that entity by id, edit it, and save it, the version increments to 2.

My question is, how can I keep previous versions?

I’m suspecting some kind of composite on ID | Version…?

Answer 1

As Anton Gogolev pointed out – version property/column is not for auditing but for concurrency control.

NHibernate Envers is a 3rd party auditing lib for NHibernate that might suit your needs.