database structure for threads that are editable by many users?

at the moment i have a column "user_id" in the "threads" table cause one thread belongs to an user.

i want to make it like Stackoverflow that one thread can be editable by many users and you can see when they edited, what they edited, roll back changes and so on.

im using symfony, is there a plugin for this?

if no, are there any 3rd part libraries/plugins to download for this 开发者_JAVA百科to integrate to existing database?

cause i have no idea how to implement this. it sounds like mediawiki, something that already exists?

thanks

Using User id as a way of remembering the original creator of the thread. Then just let any user edit a thread, don't limit to only the creator.

To do rollbacks you will need to store versions of your thread. One way would be to have a thread table and a version table.

The thread table would point to the current version, but if you need to rollback you can simply retrieve it from the versions table which should hold the history of all previous versions.