PHP

how to calculate position of student in class in laravel

$stclass = $request->get('stclass');
        $myclass = Stclass::find($request->get('stclass'))->name;
        $studentId = $request->get('studentId');
        $studentname = Student::find($request->get('studentId'))->surname;

        $session= $request->get('sessionnow');
        $term = $request->get('term');

        $myids = Stclass::find($stclass)->students;
      
        // $dodo = DB::table('results')
        //           -> where('studentClass', $stclass)->where('session', $session)->where('term', $term)
        //           ->selectRaw('results.studentId')->distinct()->get();

          

                
                  
      

         $resultpercent = DB::table('results')
                  -> where('studentClass', $stclass)->where('session', $session)->where('term', $term)->where('studentId', $studentId)
                  ->selectRaw("SUM((results.exam + (results.test1 + results.test2)/2)/2)/(COUNT(results.subject)) as overallpercent")->get();

                   $dodo = DB::table('results')
                  -> where('studentClass', $stclass)->where('session', $session)->where('term', $term)
                  ->selectRaw('results.studentId')->get();

                

         $results = DB::table('results')
                    ->where('studentClass', $stclass)->where('session', $session)->where('term', $term)->where('studentId', $studentId)
                    ->selectRaw('results.*, (results.test1 + results.test2)/2 as cav, (results.exam + (results.test1 + results.test2)/2)/2 as totalmark')->get();

      return view('admin.results.studentresultsheet', compact('results', 'myclass', 'studentname','resultpercent', 'countsubjects'));