Perfect! Time to wrap up this part with a quick summary:

1. When creating a table, add a CHECK constraint on a single column with:

   CREATE TABLE video_game (
     id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
     ...
     hours integer CHECK (hours > 0),
     ...
   );

2. To add a CHECK constraint on multiple columns, use:

   CREATE TABLE video_game (
     id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
     ...
     hours integer,
     price decimal(5, 2),
     CHECK (price/hours < 1.00)
   );

3. To add a CHECK constraint to an existing table, use:

   ALTER TABLE video_game_ranking
   ADD CONSTRAINT video_game_rank_constraint CHECK (rank > 0);

4. To remove a CHECK constraint from an existing table, use:

   ALTER TABLE video_game_ranking
   DROP CONSTRAINT video_game_ranking_award_count_check;

How about a short quiz now?