public void Update(Car car)
 {
     using (CarContext context = new CarContext())
     {
         var cars = context.Cars.Where(item => item.Id == car.Id);
         int count = cars.Count();
         context.Cars.RemoveRange(cars);
         context.SaveChanges();
         context.Cars.Add(car);
         context.SaveChanges();
     }
 }
 public void Add(Car car)
 {
     using (CarContext context = new CarContext())
     {
         context.Cars.Add(car);
         context.SaveChanges();
     }
 }
 public void Delete(int id)
 {
     using (CarContext context = new CarContext())
     {
         var cars = context.Cars.Where(item => item.Id == id);
         int count = cars.Count();
         context.Cars.RemoveRange(cars);
         context.SaveChanges();
     }
 }