ThinkPHP按月统计订单总金额

$list = $m->where($where)
          ->field("SUM(`stream_money`) as stream_money,FROM_UNIXTIME(time,‘%Y-%m‘) as months")
          ->group(‘months‘)
          ->limit($Page->firstRow.‘,‘.$Page->listRows)//分页，用不到可省略
          ->order(‘months desc‘)
          ->select();

         // 实例化一个空模型，没有对应任何数据表
        $Dao = M();
        $sql = "SELECT FROM_UNIXTIME(time,‘%Y%m‘) months,COUNT(id) COUNT,SUM(stream_money) stream_money FROM qp_dap_stream  WHERE type = 2 GROUP BY months desc";
        $res = $Dao ->execute($sql);   //主要针对执行curd    //返回影响行数
        $lists = $Dao->query($sql);