使用php添加活动类？

class Activity {
    private $title;
    private $description;
    private $date;
    
    public function __construct($title, $description, $date) {
        $this->title = $title;
        $this->description = $description;
        $this->date = $date;
    }
    
    public function getTitle() {
        return $this->title;
    }
    
    public function getDescription() {
        return $this->description;
    }
    
    public function getDate() {
        return $this->date;
    }
    
    public function setTitle($title) {
        $this->title = $title;
    }
    
    public function setDescription($description) {
        $this->description = $description;
    }
    
    public function setDate($date) {
        $this->date = $date;
    }
    
    public function saveToDatabase() {
        // 将活动信息保存到数据库中的代码
    }
    
    // 其他操作活动的方法可以在这里添加
}

$activity = new Activity("活动标题", "活动描述", "2022-01-01");
$activity->saveToDatabase();