select query using model in laravel code example

Example 1: how to use join in laravel 5.4

DB::table('users')
            ->join('contacts', 'users.id', '=', 'contacts.user_id')
            ->join('orders', 'users.id', '=', 'orders.user_id')
            ->select('users.id', 'contacts.phone', 'orders.price')
            ->get();

Example 2: update query in laravel eloquent

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