我有这样的查询:$query="SELECT*FROM`profit_by_campaign`WHEREcampaign_name='myCoolCampaign'ANDrequest_date='2017-10-16'";try{$stmt=$this->dbh->prepare($query);$stmt->execute();$rows=$stmt->fetchAll(PDO::FETCH_ASSOC);}catch(PDOException$e){die('Error:unabletoquery'.$e->getMessage());}获取结果后,我会像这样执行一些逻辑:$to