Is my DataAccessLayer well implemented?

Question

I have 3 projects in my solution :

• An ASP MVC project
• A console app project
• A class library project (the DataAccessLayer)

I didn't want to recreate an ADO.net entity data model for each project so I've "simply" created a new class library project and added the ADO.net entity data model inside it. Is it an usual way to create a data access layer? Any improvements?

The DbContext (DAL project)

public partial class ModelContainer : DbContext
{
    public ModelContainer(): base("name=ModelContainer")
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        throw new UnintentionalCodeFirstException();
    }

    public virtual DbSet<Thread> Thread { get; set; }
    public virtual DbSet<Post> Post { get; set; }
    public virtual DbSet<Forum> Forum { get; set; }
    public virtual DbSet<SubForum> SubForum { get; set; }
    public virtual DbSet<Author> Author { get; set; }
}

Use of the DAL (ASP MVC Controller)

public class ForumController : Controller
{
    private static ModelContainer db = new ModelContainer();

    public ActionResult Index()
    {
        //returns a list of forums
        return View(db.Forum);
    }
}

Answer 1

This is the most used method to implement database access code. Improvements:

• Add a business layer isolating your console/web apps from accessing the data access layer directly. The business layer will provide a business context for the operations. This context abstracts the operations and shortens the required amount of code in the presentation layer.
• Create one or more classes to encapsulate the database operations. So the business layer does not access the context directly. Adding Interfaces as a contract will give you a lot of flexibility. Just to mention the ability to mock these classes in unit tests and the ability to switch implementation.