有关无限极分类并排序问题

$sql   ="select * from ec_admin_role  where ar_state=1 order by ar_level";
$roles = $g_db->getAll($sql);
$g_db->close();
$list=roletree($roles,0);//调用函数按父级id进行排序
foreach($list as $k=>$v) {
$list[$k][‘ar_name‘] = str_repeat(‘----‘,$v[‘ar_level‘]).$v[‘ar_name‘].‘<br>‘;
}


//将角色经排序
function roletree($arr,$id=0) {
    $subs = array(); // 子孙数组
    foreach($arr as $v) {
        if($v[‘ar_parent_id‘] == $id) {
            $subs[] = $v;
            $subs = array_merge($subs,roletree($arr,$v[‘ar_id‘]));
        }
    }
    return $subs;
}