SQL functions on DB class

Hello,

Is there a way to run SQL function with the CI db class?(ie: COMPRESS(?))

In slim framework I'm using it in this way:

PHP Code:

$data = array(
       "userid" => $userid,
      "data" => $this->db->func('COMPRESS(?)', [json_encode($data)]),
);

 $db_insert = $this->db->insert("products", $data); 


Is there something similar in CI?

Thanks!