Using DbContext inside a Repository Class in Entity Framework - entity-framework

Question

I try to write an MVC n tier application. I have used repository pattern during connecting to the database. In my repository class, I have a Context variable inside repository class. I am not sure that this approach is true. Here are my codes:
public class TTPDbContext : DbContext
{
public TTPDbContext() : base("TTPContext")
{
Database.SetInitializer(new DropCreateDatabaseIfModelChanges<TTPDbContext>());
Database.Log = s => Debug.WriteLine(s);
Configuration.AutoDetectChangesEnabled = true;
}
public DbSet<Kisi> Kisiler { get; set; }
public DbSet<BakanlikBirim> BakanlikBirimleri { get; set; }
public DbSet<DisBirim> DisBirimler { get; set; }
public DbSet<Kullanici> Kullanicilar { get; set; }
public DbSet<Talep> Talepler { get; set; }
public DbSet<UnvanPozisyon> UnvanPozisyonlar { get; set; }
public DbSet<TalepDurum> TalepDurumlar { get; set; }
public DbSet<TalepKagidi> TalepKagidi { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.HasDefaultSchema("OsiTtp");
}
}
Here is the repository class:
public class TTPRepository : ITTPRepository,IDisposable
{
private IErrorHandling _errorHandling;
private TTPDbContext _context;
public TTPRepository()
{
this._errorHandling = new ErrorHandling();
this._context = new TTPDbContext();
}
// other sections has been dismissed for brevity.
public List<DisBirim> GetAllExternalInstitutions()
{
List<DisBirim> result = null;
DbSet<DisBirim> intermediaryresult = null;
try
{
result = new List<DisBirim>();
intermediaryresult = this._context.DisBirimler;
if (intermediaryresult != null)
{
foreach (DisBirim institution in intermediaryresult)
{
result.Add(institution);
}
}
}
catch (Exception Hata)
{
this.yazHata(Hata);
}
return result;
}
public void Dispose()
{
this._context.Dispose();
}
}
I am not sure that is a optimal approach. Do you have any recommandations? Thanks in advance.

Answer 1

I would recommend to read the msdn documentation
Instead of this
public TTPRepository()
{
this._errorHandling = new ErrorHandling();
this._context = new TTPDbContext();
}
try this
public TTPRepository(TTPDbContext context,ErrorHandling errorHandler)
{
this._errorHandling = errorHandler;
this._context = context;
}
By this your repository is ready to work with a context and Error Handler. I always recommend to use something like IErrorHandler and IDbContext rather than concrete classes.
So you have freedom to initialize like this. Even if you use IoC containers you can control the lifetime of your Context.
var yourRepo = new TTPRepository(new TTPDbContext());

Answer 2

When use repository pattern and interface best practice is that use IoC Container for inject DbContext to repository constructor.
If you are using an IoC Container, you can control the lifetime of the DbContext to ensure that all instances of Repository get the same Context.
you must one of IoC containers likes Unity, Ninject, Autofac, ...
Documentation of unity usage Dependency Injection in ASP.NET MVC - An Introduction