$feedback_list = $feedback -> where(  array("member_id"=>array("in", "1,2"))   ) -> limit($page->firstRow.','.$page->listRows) -> order('add_time desc') -> select();

或者:

$where['member_id'] = array("in","1,2,3");
$feedback_list = $feedback -> where($where) -> limit($page->firstRow.','.$page->listRows) -> order('add_time desc') -> select();