PHP -用于静态数据库连接类的良好设计模式

<?php

class DatabaseConnection {
    private static $instance = null;
    private $connection;

    private function __construct($host, $user, $password, $database) {
        $this->connection = new mysqli($host, $user, $password, $database);
        if ($this->connection->connect_error) {
            die("Connection failed: " . $this->connection->connect_error);
        }
    }

    public static function getInstance($host, $user, $password, $database) {
        if (self::$instance == null) {
            self::$instance = new DatabaseConnection($host, $user, $password, $database);
        }
        return self::$instance;
    }

    public function getConnection() {
        return $this->connection;
    }

    private function __clone() {}
    private function __wakeup() {}
}

// 使用示例
$db = DatabaseConnection::getInstance('localhost', 'username', 'password', 'database_name');
$conn = $db->getConnection();
$result = $conn->query("SELECT * FROM table_name");