thinkphp里数据嵌套循环，thinkphp嵌套循环

<volist name=<span>"</span><span>list</span><span>"</span> id=<span>"</span><span>vo</span><span>"</span>>
    <volist name=<span>"</span><span>vo['sub']</span><span>"</span> id=<span>"</span><span>sub</span><span>"</span>><span>
        {$sub.name}
    </span></volist>
</volist>

<表1_1>
  <表2_1/>
  <表2_2>
</表1_1>
<表1_2>
  <表2_3/>
  <表2_4>
</表1_2>

　　　　 $m=M(<span>'</span><span>表1</span><span>'</span><span>);
        $m1</span>=M(<span>'</span><span>表2</span><span>'</span><span>);

        $parent</span>=$m-><span>select</span><span>();

        </span><span>foreach</span>($parent <span>as</span> $n=><span> $val){
            $parent[$n][</span><span>'</span><span>voo</span><span>'</span>]=$m1-><span>where</span>(<span>'</span><span>表2里和表1相关联的字段=</span><span>'</span>.$val[<span>'</span><span>表1id</span><span>'</span>].<span>''</span>)-><span>select</span><span>();
        }
        $</span><span>this</span>->assign(<span>'</span><span>list</span><span>'</span><span>,$parent);
        $</span><span>this</span>->display();

        <volist name=<span>"</span><span>list</span><span>"</span> id=<span>"</span><span>vo</span><span>"</span>>
                <li><b>{$vo.id}</b></li>
                <volist name=<span>"</span><span>vo['voo']</span><span>"</span> id=<span>"</span><span>sub</span><span>"</span>>
                    <li>{$sub.title}</li>
                </volist>
            </volist>