connect_error) {    die("连接失败: " . $conn->connect_error);}$sql = "INSERT INTO MyGuests (firstname, lastname, email)VALUES ('John', 'Doe', 'john@example.com');";$sql .= "INSERT INTO MyGuests (firstname, lastname, email)VALUES ('Mary', 'Moe', 'mary@example.com');";$sql .= "INSERT INTO MyGuests (firstname, lastname, email)VALUES ('Julie', 'Dooley', 'julie@example.com')";if ($conn->multi_query($sql) === TRUE) {    echo "新记录插入成功";} else {    echo "Error: " . $sql . "
" . $conn->error;}$conn->close();?>

     " . mysqli_error($conn);} mysqli_close($conn);?>

     setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);     // 开始事务    $conn->beginTransaction();    // SQL 语句    $conn->exec("INSERT INTO MyGuests (firstname, lastname, email)     VALUES ('John', 'Doe', 'john@example.com')");    $conn->exec("INSERT INTO MyGuests (firstname, lastname, email)     VALUES ('Mary', 'Moe', 'mary@example.com')");    $conn->exec("INSERT INTO MyGuests (firstname, lastname, email)     VALUES ('Julie', 'Dooley', 'julie@example.com')");     // 提交事务    $conn->commit();    echo "新记录插入成功";}catch(PDOException $e){    // 如果执行失败回滚    $conn->rollback();    echo $sql . "
" . $e->getMessage();} $conn = null;?>

     connect_error) {    die("连接失败: " . $conn->connect_error);} else {    $sql = "INSERT INTO MyGuests(firstname, lastname, email)  VALUES(?, ?, ?)";     // 为 mysqli_stmt_prepare() 初始化 statement 对象    $stmt = mysqli_stmt_init($conn);     //预处理语句    if (mysqli_stmt_prepare($stmt, $sql)) {        // 绑定参数        mysqli_stmt_bind_param($stmt, 'sss', $firstname, $lastname, $email);         // 设置参数并执行        $firstname = 'John';        $lastname = 'Doe';        $email = 'john@example.com';        mysqli_stmt_execute($stmt);         $firstname = 'Mary';        $lastname = 'Moe';        $email = 'mary@example.com';        mysqli_stmt_execute($stmt);         $firstname = 'Julie';        $lastname = 'Dooley';        $email = 'julie@example.com';        mysqli_stmt_execute($stmt);    }}?>