> php artisan migrate:rollback --pretend
Rolling back: 2020_11_07_102400_add_messagegroup_parent_id_to_messages_table
AddMessagegroupParentIdToMessagesTable: ALTER TABLE messages CHANGE messagegroup_id messagegroup_id BIGINT UNSIGNED NOT NULL COMMENT 'メッセージ階層'
AddMessagegroupParentIdToMessagesTable: alter table `messages` drop `messagegroup_parent_id`