how to write join query 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: join multiple query in laravel

$select->joinSub(
                    $selectSubQry,
                    'ag',
                    'ag.id',
                    '=',
                    'agp.userId'
                );