从数据库导出到xls (laravel 5)

public function export(){
    view('tester');

    $assignments = DB::table('assignments')
        ->join('projects', 'assignments.project_id', '=', 'projects.id')
        ->join('people', 'assignments.person_id', '=', 'people.id')
        ->join('tasks', 'assignments.id', '=', 'tasks.assignment_id')
        ->select('assignments.*', 'projects.name','people.firstname','people.lastname', 'tasks.description','tasks.hours_spent')
        ->get();

    Excel::create('projects', function($excel) use($assignments) {
        $excel->sheet('Sheet 1', function($sheet) use($assignments) {
            $sheet->fromArray($assignments);
        });
    })->export('xls');


}
public function export(){
    view('tester');