MongoQuery不适用于PHP

Question

我试图用php跟踪查询但不返回记录

PHP

$keyword = "/.*".$_POST['keyword'].".*/";   
$query = array("evnt_name" => $keyword);
if($cursor = $db->mycollname->find($query)){
   return $cursor;
}

我已经How to query MongoDB with "like"?

了