请问有没有这种写法？

原意是想从$this->db['site']拿出两个数相除等平均数作为拿取数据的顺序。一直都显示错误

$this->SELECT = ' ,IF('.$this->db['site'].'.rate_numvote>0,'.$this->db['site'].'.rate_totalvotes/'.$this->db['site'].'.rate_numvote,0) AS

rating';
$this->ORDER = ' ORDER BY rating '.strtoupper($settings['list_order']);