BistroDriveWebApp.Models.DishRepository.UpdateDishRating C# (CSharp) Method

        private void UpdateDishRating(dishreview dr)
        {
            var dishrev = context.dishreviews.Where(r => r.Id_Dish == dr.Id_Dish);
            dish d = GetDishById(dr.Id_Dish);
            if (dishrev.Count() != 0)
            {
                double average = (double)dishrev.Average(r => r.Mark);
                d.Raiting = Convert.ToInt32(Math.Round(average, 0));
            }
            else
            {
                d.Raiting = 0;
            }
            context.SaveChanges();
        }