CREATE TABLE `Chapters`
(
    `id`      int PRIMARY KEY AUTO_INCREMENT,
    `number`  int  NOT NULL,
    `content` text NOT NULL,
    `note_id` int  NOT NULL
);

ALTER TABLE `Chapters`
    ADD FOREIGN KEY (`note_id`) REFERENCES `Notes` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT;

ALTER TABLE `Notes`
    DROP COLUMN `content`;