php mysql绑定变量

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // 预处理语句
    $stmt = $conn->prepare("INSERT INTO users (firstname, lastname, email) VALUES (:firstname, :lastname, :email)");
    
    // 绑定变量
    $stmt->bindParam(':firstname', $firstname);
    $stmt->bindParam(':lastname', $lastname);
    $stmt->bindParam(':email', $email);

    // 设置变量并执行
    $firstname = "John";
    $lastname = "Doe";
    $email = "john@example.com";
    $stmt->execute();

    echo "New record created successfully";
} catch(PDOException $e) {
    echo "Error: " . $e->getMessage();
}
$conn = null;
?>

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// 预处理语句
$stmt = $conn->prepare("INSERT INTO users (firstname, lastname, email) VALUES (?, ?, ?)");

// 绑定变量
$stmt->bind_param("sss", $firstname, $lastname, $email);

// 设置变量并执行
$firstname = "John";
$lastname = "Doe";
$email = "john@example.com";
$stmt->execute();

echo "New record created successfully";

$stmt->close();
$conn->close();
?>