using LinqToDB.Mapping; namespace SeniorAssistant.Models.Users { public class Patient : IHasUsername { [Column(IsPrimaryKey = true, CanBeNull = false)] public string Username { get; set; } [Association(ThisKey = "Username", OtherKey = nameof(User.Username), CanBeNull = false)] public User UserData { get; set; } [NotNull] public string Doctor { get; set; } public string Notes { get; set; } } }