codeigniter 3 order
$this->db->order_by('title', 'DESC');
// Produces: ORDER BY `title` DESC
$this->db->order_by('title DESC, name ASC');
// Produces: ORDER BY `title` DESC, `name` ASC
$this->db->order_by('title', 'DESC');
$this->db->order_by('name', 'ASC');
// Produces: ORDER BY `title` DESC, `name` ASC
$this->db->order_by('title', 'RANDOM');
// Produces: ORDER BY RAND()
$this->db->order_by(42, 'RANDOM');
// Produces: ORDER BY RAND(42)