实现留言板的添加，查询，删除功能，并上传到数据库中，所有数据都存放与数据库。能实现注册登录功能，注册后，将发送信息到用户的邮箱。-The message board add, query, delete function, and upload it to the database, all data is stored with the database. Register login feature, registration will be sent information to the