<?php
class Database {
    private static $instance = null;
    private $connection;

    // 私有构造函数，防止外部实例化对象
    private function __construct() {
        // 连接数据库
        $host = "127.0.0.1"; // 数据库主机
        $dbname = "order_service"; // 数据库名称
        $username = "root"; // 数据库用户名
        $password = "root"; // 数据库密码
        try {
            $this->connection = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
            $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        } catch (PDOException $e) {
            // 如果连接失败，抛出异常
            exit("Database connection failed: " . $e->getMessage());
        }
    }

    // 获取数据库连接实例
    public static function getInstance() {
        if (!self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    // 获取数据库连接
    public function getConnection() {
        return $this->connection;
    }
}

?>