text: ALTER TABLE `users`
      ADD COLUMN `middle_name` varchar(45);
  
  ALTER TABLE `users`
      ADD COLUMN `address` varchar(45);
  
  ALTER TABLE `users`
      ADD COLUMN `birthdate` varchar(45);
  
  ALTER TABLE `users`
      ADD COLUMN `phone_number` varchar(45);
  
  ALTER TABLE `roles`
      ADD COLUMN `permissions` varchar(255);
  
  ALTER TABLE `discipline`
      ADD COLUMN `teacher_id` varchar(45);
  
  ALTER TABLE `discipline`
      ADD COLUMN `assistant_id` varchar(45);
  
  ALTER TABLE `discipline`
      ADD CONSTRAINT `discipline_teacher`
      FOREIGN KEY (`teacher_id`)
      REFERENCES `users`(`user_id`)
      ON UPDATE RESTRICT
      ON DELETE RESTRICT;
  
  ALTER TABLE `discipline`
      ADD CONSTRAINT `discipline_assistant`
      FOREIGN KEY (`assistant_id`)
      REFERENCES `users`(`user_id`)
      ON UPDATE RESTRICT
      ON DELETE RESTRICT;
  