php控制mysql语句

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

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

// 检查连接
if (!$conn) {
    die("连接失败: " . mysqli_connect_error());
}

// 执行查询
$sql = "SELECT id, firstname, lastname FROM MyGuests";
$result = mysqli_query($conn, $sql);

if (mysqli_num_rows($result) > 0) {
    // 输出数据
    while($row = mysqli_fetch_assoc($result)) {
        echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
    }
} else {
    echo "0 结果";
}
mysqli_close($conn);
?>

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

try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    // 设置 PDO 错误模式为异常
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $sql = "SELECT id, firstname, lastname FROM MyGuests";
    $result = $conn->query($sql);

    if ($result->rowCount() > 0) {
        // 输出数据
        while($row = $result->fetch(PDO::FETCH_ASSOC)) {
            echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
        }
    } else {
        echo "0 结果";
    }
} catch(PDOException $e) {
    echo "连接失败: " . $e->getMessage();
}

$conn = null;
?>

$stmt = $conn->prepare("INSERT INTO MyGuests (firstname, lastname, email) VALUES (?, ?, ?)");
$stmt->bind_param("sss", $firstname, $lastname, $email);
$firstname = "John";
$lastname = "Doe";
$email = "john@example.com";
$stmt->execute();

$conn->setAttribute(PDO::ATTR_TIMEOUT, 120); // 设置连接超时时间为120秒

mysqli_close($conn);
// 或
$conn = null;