CREATE TABLE rating (rid DECIMAL, mid DECIMAL, stars DECIMAL, ratingdate TIME)
CREATE TABLE reviewer (rid DECIMAL, name TEXT)
CREATE TABLE movie (mid DECIMAL, title TEXT, year DECIMAL, director TEXT)

What is the average rating star for each reviewer?
SELECT T2.name, AVG(T1.stars) FROM rating AS T1 JOIN reviewer AS T2 ON T1.rid = T2.rid GROUP BY T2.name
SELECT "T2"."name", AVG("T1"."stars") FROM "rating" AS "T1" JOIN "reviewer" AS "T2" ON "T1"."rid" = "T2"."rid" GROUP BY "T2"."name"