这段php代码为什么没效果？

php

 query('SET NAMES utf8');function cd(){global $pdo;return $pdo->lastInsertId();}function qr($var){global $pdo;return $pdo->query($var);}function fo($var){return qr($var)->fetch();}function fa($var){return qr($var)->fetchALL();}$fp=fo('SELECT * FROM post WHERE id='.$p);echo $fp['title'];echo $fp['content'];?>_