用户评级的数据库设计

i'm building a user rating system to rate transactions between users. these are the tables i currently have.

user                
user_id  username   email       

rating              
rating_id   date    score   review  user_id

review              
review_id   user_id  rating_id

i'm not understanding how i would display the ratings for the users since i would be pulling the usernames from the same table.. do i create another table for reviewers or reviewed?

Your user_id is the primary key for User table. In your query, use a join on user_id to get the other fields from other tables.