public void InsertOrUpdate(Photo photo)
 {
     if (photo.PhotoId == default(int)) {
         // New entity
         context.Photos.Add(photo);
     } else {
         // Existing entity
         context.Entry(photo).State = EntityState.Modified;
     }
 }
 public ActionResult Create(Photo photo)
 {
     if (ModelState.IsValid) {
         photoRepository.InsertOrUpdate(photo);
         photoRepository.Save();
         return RedirectToAction("Index");
     } else {
         ViewBag.PossibleAlbums = albumRepository.All;
         return View();
     }
 }