ORM Mapping.cs

public class UserTable {
  public int user_pk { get; set; }
  public int user_age { get; set; }
  public string user_name { get; set; }
  public Datetime user_birth { get; set; }
  public UserGenderFlag user_gender { get; set; }
}

public enum UserGenderFlag {
  Man,
  Woman
}

public UserTable GetUser(int user_pk) {
  using(var db = new dbEntity()) {
    UserTable user = db.user_tbl.Where(x => x.user_pk == user_pk).FirstOrDefault();
    if(user != null) {
      return user;
    } else {
      return false;
    }
  }
}