The crossJoinSub method of the query constructor

Using the CROSS JOIN subquery

1use Illuminate\Support\Facades\DB;
2 
3$totalQuery = DB::table('orders')->selectRaw('SUM(price) as total');
4 
5DB::table('orders')
6    ->select('*')
7    ->crossJoinSub($totalQuery, 'overall')
8    ->selectRaw('(price / overall.total) * 100 AS percent_of_total')
9    ->get();

Tip given by @PascalBaljet