public class Card
    {
        public int Id { get; set; }
        
        public int CardNumber { get; set; }

        public virtual Person Person { get; set; }
    }

    public class Person
    {
        public int Id { get; set; }

        public string Name { get; set; }

        public System.DateTime Date { get; set; }

    }

        public DataTable GetAll()
        {
            using (var context = new MyDbContext())
            {
                IList<Card> cards = context.Cards.ToList();

                return cards.ToDataTable<Card>();
            }
        }

        ClubMember personModel = new Person()
                    {
                        Id = 0,
                        Name = txtName.Text.Trim(),
                        Date = System.DateTime.Now,
                        TimeBack = null,
                        Follower = txtFollower.Text.Trim(),
                        Direction = txtDirection.Text.Trim(),
                        WhoGiveAndSerial = txtWhoGiveAndSerial.Text.Trim(),
                    };
                    Card cardModel = new Card()
                    {
                        Id = 0,
                        CardNumber = Convert.ToInt32(nmcCardNumber.Text.Trim()),
  *                      Person = personModel,
                    };

        public bool Create(Card card)
        {
            using (var context = new MyDbContext())
            {
                context.Cards.Add(card);
                return context.SaveChanges() > 0;
            }
        }

var cards = db.Cards.Select(c => 
                new {
                    CardNumber = c.CardNumber,
                    Name = c.Person.Name,
                    Date = c.Person.Date
                }
            ).ToList();

var db = new MyDbContext()
var card = db.Cards.Find(id);

    public class Person
    {
        public int Id { get; set; }

        public string Name { get; set; }

        public System.DateTime Date { get; set; }

    }

    public class Card
    {
        public int Id { get; set; }
        
        public int CardNumber { get; set; }

        public Person Person{ get; set; }
    }

var member = db.Cards.Include(x => x.Person).Where(i => i.Id == id).SingleOrDefault();

                  Person personModel= new Person()
                    {  Id = id
                        TimeBack = System.DateTime.Now,
                    };
var db = new MyDbContext())
            {
                db.Persons.Attach(personModel);
                db.Entry(personModel).State = EntityState.Modified;                
                return db.SaveChanges() > 0;