mysql> select firstname, name, enrollement_date from player JOIN wizard ON player.wizard_id = wizard.id JOIN team ON player.team_id = team.id where dayofweek(enrollement_date) = 2 and name like 'Gryffindor%' order by enrollement_date asc;
+-----------+------------+------------------+
| firstname | name       | enrollement_date |
+-----------+------------+------------------+
| George    | Gryffindor | 1991-08-26       |
| Alice     | Gryffindor | 1992-02-17       |
| Cadogan   | Gryffindor | 1993-01-04       |
| Godric    | Gryffindor | 1993-08-30       |
| Sirius    | Gryffindor | 1994-01-10       |
| Aberforth | Gryffindor | 1995-04-24       |
| Augusta   | Gryffindor | 1999-10-25       |
+-----------+------------+------------------+
7 rows in set (0,00 sec)

mysql> SELECT team.name, count(*) as nb_team from team join player on player.team_id = team.id group by team_id order by nb_team desc;
+------------+---------+
| name       | nb_team |
+------------+---------+
| Gryffindor |      36 |
| Slytherin  |      21 |
| Ravenclaw  |      15 |
| Hufflepuff |      12 |
+------------+---------+
4 rows in set (0,00 sec)

mysql> select team.name, count(*) as nb_team from team join player on player.team_id = team.id group by team_id having (nb_team) > 14 order by team.name asc;
+------------+---------+
| name       | nb_team |
+------------+---------+
| Gryffindor |      36 |
| Ravenclaw  |      15 |
| Slytherin  |      21 |
+------------+---------+
3 rows in set (0,01 sec)