Input: 
Teams table:
+---------+-----------+
| team_id | team_name |
+---------+-----------+
| 1       | Ajax      |
| 4       | Dortmund  |
| 6       | Arsenal   |
+---------+-----------+
Matches table:
+--------------+--------------+-----------------+-----------------+
| home_team_id | away_team_id | home_team_goals | away_team_goals |
+--------------+--------------+-----------------+-----------------+
| 1            | 4            | 0               | 1               |
| 1            | 6            | 3               | 3               |
| 4            | 1            | 5               | 2               |
| 6            | 1            | 0               | 0               |
+--------------+--------------+-----------------+-----------------+
Output: 
+-----------+----------------+--------+----------+--------------+-----------+
| team_name | matches_played | points | goal_for | goal_against | goal_diff |
+-----------+----------------+--------+----------+--------------+-----------+
| Dortmund  | 2              | 6      | 6 …

UPDATE tree
SET seq = 1
WHERE id IN (
    SELECT t1.id
    FROM …

[begin_label:] WHILE search_condition DO
    statement_list
END WHILE [end_label]

CREATE PROCEDURE dowhile()
BEGIN
  DECLARE v1 INT …

Department table:
+----+-------+
| id | name  |
+----+-------+
| 1  | IT …

Input: 
Logs table:
+----+-----+
| id | num |
+----+-----+
| 1  | 1   |
| 2  | 1   |
| 3  | 1   |
| 4  | 2   |
| 5  | 1   |
| 6  | 2   |
| 7  | 2   |
+----+-----+
Output: 
+-----------------+
| ConsecutiveNums |
+-----------------+
| 1               |
+-----------------+
Explanation: 1 is the only number that appears consecutively for at least three times.

Input: 
Accounts table:
+----+----------+
| id | name     |
+----+----------+
| 1  | Winston  |
| 7  | Jonathan |
+----+----------+
Logins table:
+----+------------+
| id | login_date |
+----+------------+
| 7  | 2020-05-30 |
| 1  | 2020-05-30 |
| 7  | 2020-05-31 |
| 7  | 2020-06-01 |
| 7  | 2020-06-02 |
| 7  | 2020-06-02 |
| 7  | 2020-06-03 |
| 1  | 2020-06 …