如何用PHP实现CMS系统的数据同步功能

CREATE TABLE `articles` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) NOT NULL,
  `content` text NOT NULL,
  `created_at` datetime DEFAULT CURRENT_TIMESTAMP,
  `updated_at` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

<?php
// 连接数据库
$pdo = new PDO('mysql:host=localhost;dbname=your_database_name', 'your_username', 'your_password');

// 处理数据同步请求
if($_POST['action'] === 'sync') {
    $stmt = $pdo->prepare("SELECT * FROM articles WHERE updated_at > :updated_at");
    $stmt->bindValue(':updated_at', $_POST['last_updated']);
    $stmt->execute();
    $articles = $stmt->fetchAll(PDO::FETCH_ASSOC);

    // 返回同步的数据
    echo json_encode($articles);
}
?>

<?php
// 连接主服务器的接口
$api_url = 'http://your_primary_server_url/sync.php';

// 获取上次同步的时间戳
$last_updated = @file_get_contents('last_updated.txt');

// 发送数据同步请求
$data = array('action' => 'sync', 'last_updated' => $last_updated);
$options = array(
    'http' => array(
        'method'  => 'POST',
        'content' => http_build_query($data),
        'header'  => 'Content-type: application/x-www-form-urlencoded'
    )
);
$context  = stream_context_create($options);
$response = @file_get_contents($api_url, false, $context);

// 解析同步的数据
$articles = json_decode($response, true);

// 执行同步操作
if(!empty($articles)) {
    foreach($articles as $article) {
        // 在从服务器上插入或更新数据
        $stmt = $pdo->prepare("REPLACE INTO articles (id, title, content, created_at, updated_at) VALUES (:id, :title, :content, :created_at, :updated_at)");
        $stmt->bindValue(':id', $article['id']);
        $stmt->bindValue(':title', $article['title']);
        $stmt->bindValue(':content', $article['content']);
        $stmt->bindValue(':created_at', $article['created_at']);
        $stmt->bindValue(':updated_at', $article['updated_at']);
        $stmt->execute();
    }

    // 更新最后同步的时间戳
    file_put_contents('last_updated.txt', time());
}
?>