print last query in codeigniter

print_r($this->db->last_query());    

$this->db->last_query();

Returns the last query that was run (the query string, not the result). Example:
$str = $this->db->last_query();

// Produces: SELECT * FROM sometable.... 

public function test_db(){    $query = $this->db->get("items");      $str = $this->db->last_query();       echo "<pre>";    print_r($str);    exit;}