Great job. Let's do a quick summary now.

1. To add a default value when defining a table, use:

   CREATE TABLE card_game (
     ...
     min_players integer DEFAULT 2,
     ...
   );

2. To link a sequence to a table, use:

   CREATE TABLE board_game (
     id integer DEFAULT nextval('my_sequence') PRIMARY KEY
   );

   or when using the standard SQL syntax:

   CREATE TABLE board_game (
     id integer DEFAULT NEXT VALUE FOR my_sequence PRIMARY KEY
   );

3. To add a default value to an existing column, use:

   ALTER TABLE therapist
   ALTER COLUMN price SET DEFAULT 60.00;

4. To remove a default value from an existing column, use:

   ALTER TABLE therapist
   ALTER COLUMN full_name DROP DEFAULT;

How about a pop quiz?