Context Per Request: How to update Entity

Question

I have a repository class as shown below. There is a method to get entity object – GetPaymentByID. I am retrieving a Payment object and making a change to its PaymentType pr

Answer 1

You need to add (if the data is new) or attach (if the data is edited) the object to the context:

http://blogs.msdn.com/b/adonet/archive/2011/01/29/using-dbcontext-in-ef-feature-ctp5-part-4-add-attach-and-entity-states.aspx

Something along these lines:

public void SaveContextChanges(MyEntityDataModelEDM.Payment paymentEntity)
{
    using (var myObjectContext = new MyEntityDataModelEDM.LibraryReservationSystemEntities(connectionStringVal))
    {
        // use your own logic for determining a "new" entity
        myObjectContext.Entry(paymentEntity).State = 
                (paymentEntity.PaymentID == default(int)) ?  
                               EntityState.Added :
                               EntityState.Modified;

        myObjectContext.SaveChanges();
    }
}