dede:list orderby=weight 按权重排序无效问题

//排序方式
  $ordersql = '';
  if($orderby=="senddate" || $orderby=="id") {
   $ordersql=" order by arc.id $orderWay";
  }
  else if($orderby=="hot" || $orderby=="click") {
   $ordersql = " order by arc.click $orderWay";
  }
  else if($orderby=="lastpost") {
   $ordersql = "  order by arc.lastpost $orderWay";
  }
  else if($orderby=="weight") {
   $ordersql = "  order by arc.weight $orderWay";
  }
  else {
   $ordersql=" order by arc.sortrank $orderWay";
  }