du behöver bara kontrollera Codeigniter-dokumentationen
$this->db->select('sss.*, c.country_name, c.country_code ');
$this->db->from('(SELECT gr.*
FROM (`be_goldrate` as `gr`)
WHERE `gr`.`country_id` != 0
AND `gr`.`rate_type` = "calculated"
ORDER BY gr.date DESC) as sss');
$this->db->join('be_countries as c','c.country_id = sss.country_id','left');
$this->db->group_by('sss.country_id');
rapportera om något fel