laravel update from the model code example

Example 1: update query in laravel eloquent

$data = DB::table('cart')
                ->where('crt_id', $id)
               ->update(['crt_status' =>'0']);

Example 2: eloquent first

$user = User::where('mobile', Input::get('mobile'))->get();

if (!$user->isEmpty()){
    $firstUser = $user->first()
}