php怎么连接外部mysql

<?php
$servername = "your_server_address";
$username = "your_username";
$password = "your_password";
$dbname = "your_database_name";

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

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}
echo "连接成功";
$conn->close();
?>

<?php
$servername = "your_server_address";
$username = "your_username";
$password = "your_password";
$dbname = "your_database_name";

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);
    echo "连接成功";
} catch (PDOException $e) {
    echo "连接失败: " . $e->getMessage();
}

$conn = null;
?>

GRANT ALL PRIVILEGES ON your_database_name.* TO 'your_username'@'your_server_address';
FLUSH PRIVILEGES;