query: SELECT count(*) FROM useracct WHERE u_id NOT IN (SELECT u_id FROM review)
question: Find the number of users which never wrote no review.
query_toks: SELECT count ( * ) FROM useracct WHERE u_id NOT IN ( SELECT u_id FROM review )
query_toks_no_value: select count ( * ) from useracct where u_id not in ( select u_id from review )
question_toks: Find the number of users which never wrote no review.