public bool edit(Car car)
 {
     using (Software_FactoryEntities context = new Software_FactoryEntities())
     {
         try
         {
             CarEntity aux = context.Car.Single(x => x.car_id == car.car_id);
             aux.company = car.company;
             aux.name = car.name;
             aux.stock = car.stock;
             return true;
         }
         catch (Exception)
         {
             return false;
         }
     }
 }
        public bool create(Car car)
        {
            using (Software_FactoryEntities context = new Software_FactoryEntities())
            {
                try
                {
                    CarEntity aux = new CarEntity();
                    aux.company = car.company;
                    aux.name = car.name;
                    aux.stock = car.stock;

                    context.Car.Add(aux);
                    context.SaveChanges();
                    return true;
                }
                catch (Exception)
                {
                    return false;
                }
            }
        }
        public bool delete(Car car)
        {
            using (Software_FactoryEntities context = new Software_FactoryEntities())
            {
                try
                {
                    int n_id = Convert.ToInt32(car.car_id);
                    CarEntity aux = context.Car.Single(x => x.car_id == n_id);

                    context.Car.Remove(aux);
                    context.SaveChanges();
                    return true;
                }
                catch (Exception)
                {
                    return false;
                }
            }
        }