PHP实例：smarty实现多级分类的方法

<?php
$result=mysql_query("SELECT id,description,parent_id,name,sort_order FROM article_categoey WHERE parent_id=0 order by id");
while ($row = mysql_fetch_array($result)){
$class[]=$row;
//$row['id']是分类id,parent_id是子分类所属id
$result_sub=mysql_query("SELECT id,description,parent_id,name,sort_order FROM article_categoey WHERE parent_id='".$row['id']."' order by id");
while ($row_sub = mysql_fetch_array($result_sub)) {
$subclass[]=$row_sub;
}
$smarty->assign("subclass", $subclass);
}
$smarty->assign("class", $class);
$smarty->display('articles.html');
?>

<ul>
{foreach name=cat from=$class item=cat}
<li><strong>{$cat.name}</strong>[{$cat.id}]</li>
<ul style="padding-left:20px;">
{foreach name=subcat from=$subclass item=subcat}
{if $subcat.parent_id==$cat.id}
<li>{$subcat.name}[{$subcat.parent_id}]</li>
{/if}
{/foreach}
</ul>
{/foreach}
</ul>