public ActionResult Detail(int id = 0) { ViewBag.Id = id; //Book ViewBookModel viewBook = new ViewBookModel(); viewBook.Books = db.Books.Find(id); //Categories viewBook.Categories = db.Categorys.Where(p => p.CategoryID == viewBook.Books.CategoryID).First(); // viewBook.Books.CountVistor += 1; db.Books.Attach(viewBook.Books); var entry = db.Entry(viewBook.Books); entry.Property(e => e.CountVistor).IsModified = true; // other changed properties db.SaveChanges(); if (viewBook == null) { return HttpNotFound(); } return View(viewBook); }