设置cookie非常容易.以我的经验，最简单的设置方法是通过 JQuery 插件:

Setting cookies is very easy. In my experience the simplest way to set them is through a JQuery plugin: jquery-cookie.

对于您的任务，您可以设置一个具有随机几乎唯一 ID的cookie(请检查

For your task you can set a cookie with a random almost-unique ID (check this question to know how) the first time the user open your website. For example

$.cookie('user_id', 'the_random_id');

当用户回来时，您可以读取该值

When the user come back you can read that value

user_id = $.cookie('user_id')

并在数据库中检查有关该用户的相对信息.

and check in your database the relative information about that user.

很明显，如果用户不接受cookie或将其删除，则无法识别他.

Obviously if an user does not accept cookies or deletes them you cannot identify him.