public class Phone
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Producer { get; set; }
        public string LongDescription { get; set; }
        public int Price { get; set; }
        public string ImageName { get; set; }
        public byte[] Image { get; set; }
        public string ImageUrl { get; set; }
        public int PurchaseId { get; set; }
        public Purchase Purchase { get; set; }
    }

public class Purchase
    {
        public int PurchaseId { get; set; }
        public string Country { get; set; }
        public string City { get; set; }
        public Phone Phone { get; set; }
        public List<Phone> Phones { get; set; }
    }