What are the name of all the reviewers?
select name from reviewer
What are the ids of the movies that are reviewed by Brittany Harris?
select t1.mid from rating as t1 join reviewer as t2 on t1.rid = t2.rid where t2.name = "Brittany Harris"
Show me the ids of movies except those.
select mid from rating except select t1.mid from rating as t1 join reviewer as t2 on t1.rid = t2.rid where t2.name = "Brittany Harris"