$mysql = new MySQLi('localhost','root','','test');

$mysql->query("set names gb2312");

/**

 * 获取无限分类列表(树形查询) 主要用于后台的栏目列表

 */

$sql = 'select ac_name,concat(path,"-",ac_id) as bpath from article_class order by bpath,ac_id';

$result = $mysql->query($sql);

while($row = $result->fetch_assoc()){

    echo $row['ac_name'].'<br />';

}

echo '<hr />';

/**

 * 指定分类获取全部的父类(逆向查询) 主要用于编辑文章时获取该文章的相关分类

 */

$ac_id = 10;

$sqlonly = 'select * from article_class where ac_id='.$ac_id;

$resultonly = $mysql->query($sqlonly);

$pclass = array();

$curclass = '';

while ($rowonly = $resultonly->fetch_assoc()){

    $curclass = $rowonly['ac_name'];

    $arrpaht = explode('-',$rowonly['path']);

    $arrpaht = implode(',',$arrpaht);

    $sqlall = 'select * from article_class where ac_id in ('.$arrpaht.') order by ac_id';

    $resultall = $mysql->query($sqlall);

    while($rowall = $resultall->fetch_assoc()){

        $pclass[] = $rowall['ac_name'];

    }

}

array_push($pclass,$curclass);

echo '<pre>';

    print_r($pclass);

echo '</pre>';

echo '<hr />';

/**

 * 指定分类获取下一级分类 主要用于展开分类时显示下一级分类使用

 */

function getNextClass($ac_id){

    global $mysql;

    $sql = 'select * from article_class where pid='.$ac_id;

    $resultnext = $mysql->query($sql);

    while($rownext = $resultnext->fetch_assoc()){

        echo $rownext['ac_name'].'<br />';

    }

}

getNextClass(1);