Setting up an NHibernate repository

Many developers prefer the repository pattern to data access objects. In this recipe, we will show you how to set up the repository pattern with NHibernate.

Getting ready

Set up the Eg.Core project with the model and mappings from Chapter 2, Models and Mappings.

How to do it…

1. Create a new and empty class library project named Eg.Core.Data.

2. Add a reference to Eg.Core project in Chapter 2, Models and Mappings.

3. Add the following IRepository interface:

   public interface IRepository<T>: IEnumerable<T>
     where T : Entity 
   { 
     void Add(T item);
     bool Contains(T item);
     int Count { get; }
     bool Remove(T item);
   }

4. Create a new and empty class library project named Eg.Core.Data.Impl.

5. Add references to the Eg.Core and Eg.Core.Data projects.

6. Add a new abstract class named NHibernateBase using the following code:

   protected readonly ISessionFactory _sessionFactory;
   
   protected virtual ISession session
   {
     get
     {
       return _sessionFactory.GetCurrentSession();
     ...