PHP会员无限级分销

$where = "`userid` > 1";
    $ulist = $db->select($where,'userid,tjuid,username,nickname,mobile','','userid asc');

    //将$ulist数组键名重置为该数组元素的userid值
    foreach($ulist as $val){
        $items[$val['userid']] = $val;
    }

    //利用变量引用实现无限级分类
    foreach ($items as $item){
        $items[$item['tjuid']]['son'][$item['userid']] = &$items[$item['userid']];
    }

    print_r($items[0]['son']);