When updating cascaded foreign keys, closing foreign key constraints is ignored and invalid.

   CREATE TABLE users (

  id INT PRIMARY KEY,

  name VARCHAR(50)

);

    CREATE TABLE orders (

  id INT PRIMARY KEY,

  user_id INT,

  order_date DATE,

  FOREIGN KEY (user_id) REFERENCES users(id)

);

 ALTER TABLE users  MODIFY COLUMN  `id` tinyint(11) unsigned NOT NULL auto_increment;

 ERROR 1833 (HY000): Cannot change column 'id': used in a foreign key constraint 'orders_ibfk_1' of table 'runzi.orders'

MariaDB [runzi]> SET FOREIGN_KEY_CHECKS=0;

Query OK, 0 rows affected (0.001 sec)

MariaDB [runzi]> ALTER TABLE users  MODIFY COLUMN  `id` tinyint(11) unsigned NOT NULL auto_increment;

ERROR 1833 (HY000): Cannot change column 'id': used in a foreign key constraint 'orders_ibfk_1' of table 'runzi.orders'

MariaDB [runzi]>