运行PDO 中的预处理语句时一直不成功，想请教各路好汉指点迷津

Question

 <?php

     $servername ="localhost";

     $username = "root";

     $password = "";

     $dbname = "myDBPDO";

     try{

        $conn = new PDO("mysqli:host=$servername;dbname=$dbname;",$username,$password);

    //设置PDO错误模式为异常

        $conn->serAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);

        //预处理SQL并绑定参数

        $stmt= $conn->prepare("INSERT INTO MyGuests(firstname,lastname,email) VALUES(:firstname,:lastname,:email)");

        $stmt->bindParam(':firstname',$firstname);

        $stmt->bindParam(':lastname',$lastname);

        $stmt->bindParam(':email',$email);

        //传入参数并执行

        $firstname = "Jhon";

        $lastname = "Doe";

        $email = "jhon@example.com";

        $stmt->execute();

        $firstname = "Mary";

        $lastname = "Moe";

        $email = "mary@example.com";

        $stmt->execute();

        $firstname = "Julie";

        $lastname = "Dooley";

        $email = "julie@example.com";

        $stmt->execute();

        echo "新纪录插入成功！";

     }catch(PDOException $e){

        echo  "Error:<br> ".$e->getMessage();

     }

     $conn=null;   

    

    ?>

Answer 1

贴报错  代码  不然没法看。。