Answers for "alter table update all fields"

Update all column fileds

$users = DB::table('mails')->distinct('mark')->count('mark');
             
             if ($users == 1){    
                 $mark = Mails::all();
                 $mark->mark = '0';
                 $mark->save();
                 
                 echo 'reset values to 0';
             }else{
                 
                 echo 'DIferent values';
             }