laravel when where code example

Example 1: laravel with and where

$projects = Project::whereHas('projectOffers', function ($offer) {
            $offer->where('teacher_id', "Ahmed");
            $offer->where('status_id', "Accepted");
        })->where('status_id', "inprogress")->get();

Example 2: laravel where

$users = DB::table('users')
                ->whereDate('created_at', '2016-12-31')
                ->get();