public function info_students()
 {
     $session = new session_supervisor();
     $id = $session->Get_id_user();
     $db = new data_base(tpl_students::students(), array(tpl_students::id(), tpl_students::first_name(), tpl_students::last_name(), data_base::select_multiple_table(tpl_college::college(), tpl_college::college() . '.' . tpl_college::id(), tpl_students::students() . '.' . tpl_students::id_college(), tpl_college::name(), tpl_college::college() . '_' . tpl_college::name()), data_base::select_multiple_table(tpl_university::university(), tpl_university::university() . '.' . tpl_university::id(), tpl_students::students() . '.' . tpl_students::id_college(), tpl_university::name(), tpl_university::university() . '_' . tpl_university::name()), data_base::select_multiple_table(tpl_specialty::specialty(), tpl_specialty::specialty() . '.' . tpl_specialty::id(), tpl_students::students() . '.' . tpl_students::id_college(), tpl_specialty::name(), tpl_specialty::specialty() . '_' . tpl_specialty::name())), array(tpl_students::id_supervisor() => $id, tpl_students::status() => 1));
     return $db->get_where();
 }
 public function index()
 {
     $lib_students = new session_students();
     $lib_supervisor = new session_supervisor();
     if ($lib_students->get_login_students()) {
         redirect('students/home_stu');
     } else {
         if ($lib_supervisor->get_login_supervisors()) {
             redirect('supervisor/home_sup');
         } else {
             $template = new render_site();
             $template->page_index();
         }
     }
 }
 public function logout()
 {
     $lib_supervisor = new session_supervisor();
     $lib_supervisor->remove_login_supervisors();
     redirect('site');
 }