	    var bookTemp = _db.Books.FirstOrDefault();
            bookTemp.Price = 100;

            var bookCollection = _db.Books;
            decimal totalPrice = 0;

            foreach (var book in bookCollection)
            {
                totalPrice += book.Price;
            }

            var bookList = _db.Books.ToList();
            foreach (var book in bookList)
            {
                totalPrice += book.Price;
            }

            var bookCollection2 = _db.Books;
            var bookCount1 = bookCollection2.Count();

            var bookCount2 = _db.Books.Count();