title: Optimally querying a database of ratings?
body: <p>I have a table of ratings that stores a user ID, object ID, and a score (+1 or -1). Now, when I want to display a list of objects with their total scores, the number of +1 votes, and the number of -1 votes.</p>
  
  <p>How can I do this efficiently without having to do SELECT COUNT(*) FROM rating WHERE (score = +/-1 AND object_id = ..)? That's two queries per object displayed, which is unacceptable. Is the database design reasonable?</p>