刚刚找到的解决方案，如果它可以帮助一些。

  $ this-> db-> where（id，1） - >其中（ 'live'OR status ='dead'））; 
 

I am trying to combine Where And OR in Codeigniter via code.

$this->db->where("id",1);
$this->db->where("status","live")->or_where("status","dead");

Appeared result is as query
where id=1 and status='live' OR status='dead'
Whereas i need result for this query.
where id=1 and (status='live' OR status='dead');

NOTE: Please don't give solution of string passed as parameter from where function. That's not fit into my code. I Just simplified my problem above.

Just found solution, if it can help some one.

$this->db->where("id",1)->where("(status='live' OR status='dead')");