pdp 的连接方法

<?php

 $dsn = "mysql:host=127.0.0.1;dbname=blog_edu";
 try{
 $pdo = new PDO($dsn,'root','');
 $pdo->query("SET NAMES UTF8");
 $result = $pdo->query("SELECT * FROM tag");
 $data = $result->fetchAll(PDO::FETCH_ASSOC);
 echo "<pre>";
 print_r($data);

 }catch (PDOException $e){
 echo $e->getMessage();
 }