http://codeigniter.com/forums/viewthread/83145/ - Визард форм

$products = $this->db->get('products')->result();
if (empty($products))
{
    // do something for empty condition
}
else
{
    // show the products...
}  

$this->db->from('pz_super_sun operator');
$this->db->join('p','operator.i_pz_task_property','LEFT OUTER');
$this->db->where('operator.i_pz_super_sun_type',1);
$query = $dhis->db->get();

$this->uri->rsegment(1); // class name
$this->uri->rsegment(2); // function name