为登录用户创建匿名模式的最佳方法？

Question

I'm working on a Web App similar to a discussion board and I want to give logged in users the ability to switch to an anonymous mode in which their username is not displayed but replaced by an ID when they post or reply to a topic. So the question is what is the best way to generate this ID given that :

• A user has the same ID in the same topic.
• The ID for the same user is different from a topic to another.

I'm in a LAMP environment so if you can suggest any PHP function to generate the ID or a way to store it in MySQL database that will be great.

Thanks !

Answer 1

All you really need is to:

• be able to create an id, which in your case should probably be globally unique
• associate that id with your regular user's id
• be able to track that a unique id belongs to a topic

You can do this easily with one extra table:

table anonymous_ids
-------------------
user_id      INT    (references your user id)
anonymous_id VARCHAR, UNIQUE index
topic_id     INT    (references your threads/topic id)

When a user replies in a topic, you check whether there's already an anonymous id for him in this topic:

SELECT anonymous_id
  FROM anonymous_ids
 WHERE user_id  = {userId}
   AND topic_id = {topicId}

If there is no such id yet, you create it. That's the basic gist of it.