using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;

namespace dentapp.Models
{
    public class User
    {

        public enum UserType
        {
            Doctor,
            Patient
        }
        public int Id { get; set; }

        public string UserName { get; set; }

        public string Password { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public long Pesel { get; set; }

        public string Address { get; set; }

        public string Email { get; set; }

        public long PhoneNumber { get; set; }

        public UserType Type { get; set; }

        public virtual ICollection<UserSurgery> UserSurgery { get; set; }

        public User()
        {
            this.UserSurgery = new HashSet<UserSurgery>();
        }

    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace dentapp.Models
{
    public class Surgery
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public DateTime DateTime { get; set; }

        public virtual ICollection<UserSurgery> UserSurgery { get; set; }

        public Surgery()
        {
            this.UserSurgery = new HashSet<UserSurgery>();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace dentapp.Models
{
    public class UserSurgery
    {
        public int UserID { get; set; }
        public int SurgeryID { get; set; }

        public User User { get; set; }
        public Surgery Surgery { get; set; }
    }
}