织梦list标签orderby=weight 按权重排序无效解决办法

//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";

  }