SELECT * FROM clients;
+----+------------+------+----------------------+----------+--------+
| id | date       | name | email                | city     | code   |
+----+------------+------+----------------------+----------+--------+
|  1 | 2007-10-18 | John | john445@gmail.com    | London   |  23345 |
|  2 | 2010-05-21 | Anna | meow98@yahoo.com     | Milan    |  21785 |
|  3 | 2015-05-03 | Kate | dream21@gmail.com    | New York |  51290 |
|  4 | 2009-06-02 | Mike | hamster_1@gmail.com  | New York | 991334 |
|  5 | 2003-04-19 | Stan | stan39_fr@gmail.ru   | Lyon     |  34521 |
+----+------------+------+----------------------+----------+--------+

SELECT * FROM clients WHERE city LIKE '[LN]%';

SELECT * FROM clients WHERE city RLIKE 'L[oy%]n';
+----+------------+------+-------------------+--------+-------+
| id | date       | name | email             | city   | code  |
+----+------------+------+-------------------+--------+-------+
|  1 | 2007-10-18 | John | john445@gmail.com | London | 23345 |
+----+------------+------+-------------------+--------+-------+

SELECT * FROM clients WHERE city RLIKE 'L[oy%]';
+----+------------+------+--------------------+--------+-------+
| id | date       | name | email              | city   | code  |
+----+------------+------+--------------------+--------+-------+
|  1 | 2007-10-18 | John | john445@gmail.com  | London | 23345 |
|  5 | 2003-04-19 | Stan | stan39_fr@gmail.ru | Lyon   | 34521 |
+----+------------+------+--------------------+--------+-------+