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();
    }