public partial class Employee
    {
        public System.Guid ID { get; set; }
        public string LastName { get; set; }
        public string FirstName { get; set; }
        public string Patronymic { get; set; }
        public Nullable<System.DateTime> BirthDay { get; set; }
        public Nullable<System.Guid> DepartmentID { get; set; }
        [DatabaseGenerated(DatabaseGeneratedOption.Computed)]
        public int Age
        {
            get
            {
                if (BirthDay != null)
                    return (DateTime.Now - BirthDay.Value).Days / 365;
                return 0;
            }
            set { }
        }

    }