Followers/following database structure

Question

My website has a followers/following system (like Twitter\'s). My dilemma is creating the database structure to handle who\'s following who.

What I came up with was crea

Answer 1

One weakness of that representation is that each relationship is encoded twice: once in the row for the follower and once in the row for the following user, making it harder to maintain data integrity and updates tedious.

I would make one table for users and one table for relationships. The relationship table would look like:

id | follower | following
1  | 23       | 20
2  | 58       | 20
3  | 84       | 20
4  | 20       | 11
...

This way adding new relationships is simply an insert, and removing relationships is a delete. It's also much easier to roll up the counts to determine how many followers a given user has.