Считать данные с DbSet<T> Code first, linq читае все null а бд создаетьс данные вводяться

namespace HZ
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;
 
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Data.Entity;
 
    //base class for Users, Doctors, Patients, 
    public abstract class Person
    {
        public int ID { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public int Age { get; set; }
        public DateTime BirthDate { get; set; }
 
        public Person(string firstName, string lastName, int age, DateTime birthDate)
        {
            FirstName = firstName;
            LastName = lastName;
            Age = age;
            BirthDate = birthDate;
        }
    }
}

namespace HZ
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;
    using System.Data.Entity;
 
    /// <summary>
    /// Class for Doctors, which inherit properties from base class Person.</summary>
    [Table("Doctors")]
    public class Doctor : Person
    {
        /// <summary>
        /// Property, which mean doctor speciality(for ex: Urologist).</summary>
        public string Speciality { get; set; }
        public virtual List<Patient> Patients { get; set; }
 
        public Doctor(string firstName, string lastName, int age, DateTime birthDate, string speciality)
            : base(firstName, lastName, age, birthDate) { Patients = new List<Patient>(); Speciality = speciality; }
 
        public override string ToString()
        {
            return string.Format("Hi, I'm a Doctor. ID: {0}, FirstName: {1}, LastName: {2}, Age: {3}, BirthDate: {4}, Account: {5}", ID, FirstName, LastName, Age, BirthDate, Speciality);
        }
    }
}

namespace HZ
{
    using System;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;
    using System.Data.Entity;
 
    [Table("Patients")]
    public class Patient : Person
    {
        public string Disease { get; set; }
 
        public Patient(string firstName, string lastName, int age, DateTime birthDate, string disease)
            : base(firstName, lastName, age, birthDate)
        {
            Disease = disease;
        }
 
        public override string ToString()
        {
            return string.Format("Hi, I'm a Patient. ID: {0}, FirstName: {1}, LastName: {2}, Age: {3}, BirthDate: {4}, Account: {5}", ID, FirstName, LastName, Age, BirthDate, Disease);
        }
    }
}

/// <summary>
/// Class, for database.</summary>
namespace HZ
{
    using System.Data.Entity;
 
    /// <summary>
    /// Class, for add Persons to database.</summary>
    public class PersonContext : DbContext
    {
        /// <summary>
        /// Gets and Sets automaticaly. 
        /// Collection of all entities(Persons classes) 
        /// in the context</summary>
        public DbSet<Person> Persons { get; set; }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace HZ
{
    class Program
    {
        static void Main(string[] args)
        {
            CreateDataBase();
            Console.Read();
        }
 
        public static void CreateDataBase()
        {
            using (var context = new PersonContext())
            {
                Doctor doctor = new Doctor("Andrew", "Klichko", AgeCounter(new DateTime(1991, 11, 20)), new DateTime(1991, 11, 20), "Sergion");
                Patient patient = new Patient("Eduard", "Shevchenko", AgeCounter(new DateTime(1997, 08, 15)), new DateTime(1997, 08, 15), "flu");
                doctor.Patients.Add(patient);
                context.Persons.Add(doctor);
                context.Persons.Add(patient);
                context.SaveChanges();//все ок бд создаеться с данными
            
                //тут и есть ошибка, типа линк читает все как нулл
                var collection = from item in context.Persons select item;
//ну и тут ексепшн
                foreach (var item in collection)
                {
                    Console.WriteLine(item);
                };
            }
            Console.WriteLine("All is fine, press Enter");
        }
 
        static int AgeCounter(DateTime BirthDate)
        {
            TimeSpan age = DateTime.Now.Subtract(BirthDate);
            return (age.Days) / 365;
        }
    }
 
}

        public Patient() : this("PatientName", "PatientLastName", 23, new DateTime(1991 - 11 - 20), "Sergion") { }