PHP怎么轮循

$sql = "select order_id from myr_order where '".strtotime('-'.$date.' day')."' <= add_time and add_time <= '".mktime()."'";
$order_id = mysql_query($sql);
$num = 0;// 放到外面来试一试
while($t_id = mysql_fetch_array($order_id,MYSQL_ASSOC)){
    $is_in =1;
    $que = mysql_query("select goods_sn,order_id from myr_order_goods where order_id = '".$t_id['order_id']."'");

    $gs = mysql_fetch_object($que);
    if(in_array($gs->goods_sn,$sn) && $is_in){
        $is_in = 1;
    }elseif(in_array($gs->goods_sn,$sn) && !$is_in){
        $is_in = 0;
        break;
    }

    if($is_in){
        $num = $num + 1;
    }elseif(!$is_i){
        continue;
    }
}
  echo $num;