private void detach_emps(emp entity)
 {
     this.SendPropertyChanging();
     entity.dept = null;
 }
 private void attach_emps(emp entity)
 {
     this.SendPropertyChanging();
     entity.dept = this;
 }
 partial void Updateemp(emp instance);
 partial void Deleteemp(emp instance);
 partial void Insertemp(emp instance);