RAND() order

Hello everybody,

I need to sort data by "Field1" DESC and Rand() together

Could you advice how to update the code:

        $defaultSort = $this->Field1->Expression . " DESC";
        if ($this->getSessionOrderBy() == "" && $defaultSort != "") {
            $this->setSessionOrderBy($defaultSort);
        }

Thanks in advance

You may try the table object's setSqlOrderBy() method.