Order products in Catalog > Category OpenCart variable by ( MIX - RANDOM )

Question

There is a way to make this code and sort the products not by default OpenCart values but to mix the results in category?

Instead of listing products in category by price but mixing them, random results,

Thank you!

if (isset($this->request->get['sort'])) {
    $sort = $this->request->get['sort'];
} else {
    $sort = 'p.price';
}