mysql> use test
Database changed
mysql> create table t1 (c1 int, c2 int as (c1 + 1));
Query OK, 0 rows affected (0.03 sec)

mysql> alter table t1 with validation;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> show warnings;
+---------+------+------------------------------------------------------+
| Level   | Code | Message                                              |
+---------+------+------------------------------------------------------+
| Warning | 8200 | ALTER TABLE WITH VALIDATION is currently unsupported |
+---------+------+------------------------------------------------------+
1 row in set (0.00 sec)

mysql> alter table t1 without validation;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> show warnings;
+---------+------+---------------------------------------------------------+
| Level   | Code | Message                                                 |
+---------+------+---------------------------------------------------------+
| Warning | 8200 | ALTER TABLE WITHOUT VALIDATION is currently unsupported |
+---------+------+---------------------------------------------------------+
1 row in set (0.00 sec)