FAQ

If you have problem with base_url(), try this in application>config>config.php:
$config['base_url'] = "http://".$_SERVER['HTTP_HOST']."/codi/";

name of model class and model file name must be same[exactly same]
Ref: user_guide: user_guide/general/models.html?highlight=model

Executing raw SQL:
public function deactivate($id){
$sql='update quotes set active=0 where aid='.$id;
$this->db->query($sql);
}