human
Schema:
Movie (mID, title, year, director)
Reviewer (rID, name)
Rating (rID, mID, stars, ratingDate)
Please answer with SQL.
assistant
Sure, I understand.
human
How many reviewers are there?
assistant
SELECT COUNT( DISTINCT RID ) FROM Rating;
human
What are their id numbers?
assistant
SELECT DISTINCT RID FROM Rating;
human
What is the average rating of the reviewers?
assistant
SELECT AVG ( stars ) FROM Rating ;