Question

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.

I get this error, but I am the only person using the database. I am using Entity Framework 4.1 with DBContext.

I am updating my records and SQL Profiler is showing a queue being sent in. What could be the causes of this issue?

The post:

  [HttpPost]
  public ActionResult EditUser(User user)
  {                 
       uow.UserRepository.Update(user);
       uow.Save();
       return RedirectToAction("Index", "User");

  }

On this call:

  public void Save()
  {
        _context.SaveChanges();
  }

This is how it is attached

  public virtual void Update(TEntity entityToUpdate)
  {
         dbSet.Attach(entityToUpdate);
        context.Entry(entityToUpdate).State = EntityState.Modified;
  }

Update:

public class UnitOfWork : IDisposable
{
    private StudentSchedulingEntities _context = new StudentSchedulingEntities();
    private GenericRepository<User> userRepository;
    private GenericRepository<UserRole> userRoleRepository;
    private bool disposed = false;

    public GenericRepository<User> UserRepository
    {
        get
        {

            if (this.userRepository == null)
            {
                this.userRepository = new GenericRepository<User>(_context);
            }
            return userRepository;
        }
    }
    public GenericRepository<UserRole> UserRoleRepository
    {
        get
        {

            if (this.userRoleRepository == null)
            {
                this.userRoleRepository = new GenericRepository<UserRole>(_context);
            }
            return userRoleRepository;
        }
    }

    public void Save()
    {
        _context.SaveChanges();
    }
    protected virtual void Dispose(bool disposing)
    {
        if (!this.disposed)
        {
            if (disposing)
            {
                _context.Dispose();
            }
        }
        this.disposed = true;
    }
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }
}

Answer 1

The ID field must be there in order to update the information properly. Otherwise, it will be throw a null. (I forgot to put the hidden field for ID in)