query: SELECT Stuid ,  sum(hours_played) FROM Plays_games GROUP BY Stuid
question: Show all student ids and the number of hours a-played.
query_toks: SELECT Stuid , sum ( hours_played ) FROM Plays_games GROUP BY Stuid
query_toks_no_value: select stuid , sum ( hours_played ) from plays_games group by stuid
question_toks: Show all student ids and the number of hours a-played.