dedecms取得三级分类及子分类

<li>{dede:type typeid='1'}<a href='[field:typelink/]' class="depth_1">[field:typename/]</a>{/dede:type}
<ul>{dede:channelartlist typeid='top'  typeid='1'}
<li><a href='{dede:field name='typeurl'/}'>{dede:field name='typename'/}</a>

    <ul>
{dede:sql sql='Select * from dede_arctype where reid=~id~  ORDER BY id limit 0,20'}
<li><a href="[field:typedir function='str_replace("{cmspath}","",@me)'/]" >[field:typename/]</a></li>
{/dede:sql}
</ul>

</li>