database design for 'followers' and 'followings'?

Question

Dear database experts/programmers:

I have a mysql table with users information, such as

id      user_id         name etc.
1       userA            
2         


        

Answer 1

Here is my design.

Id    userId(PK)  followerId     followedDate         unfollewedDate
1     123         456            YYYY-MM-DD HH:MI:SS  YYYY-MM-DD HH:MI:SS
...   ...         ...            ...                  ...

I assumed userId - followerId combiation is unique. Dates can be useful. For example I'm thinking about to use if user unfollow and follow again in 5 minutes, it doesn't generate notification. I assume user made it by mistake. And I can analyze following statics by date.