无限极（树状）分类处理

<?php
require 'DaoMysqli.class.php';
$arr = [
'host' => 'localhost',
'user' => 'root',
'pwd' => 123,
'database' => 'db',
'port' => 3306,
'charset' => 'utf8'
];


$dao = DAOMysqli::getSingleton($arr);
$sql = "select * from test;";
$data = $dao -> fetchAll($sql);


$data = tree($data);


echo '<pre>';
var_dump($data);




// 无限极分类(树状分类)
function tree ($list,$fid=0,$level=0) //$level是分类的层级，最顶级分类$level值为0
{
static $arr = array();
foreach ($list as $v)
{
if($v['pid'] == $fid)
{
$v['level'] = $level;
$arr[] = $v;
tree ($list,$v['id'],$level+1);
}
}
return $arr;
}