text: CREATE TABLE book (
    id int GENERATED ALWAYS AS IDENTITY(MINVALUE 0 START WITH 0 CACHE 20) NOT NULL,
    publisher varchar(30),
    cover_state varchar(30),
    item_id int,
    CONSTRAINT fk_item FOREIGN KEY(item_id) REFERENCES items(id) ON DELETE CASCADE,
    PRIMARY KEY (id)
  );
  
  CREATE TABLE label (
    id int GENERATED ALWAYS AS IDENTITY NOT NULL,
    title varchar(50) NOT NULL,
    color varchard(50) NOT NULL,
    PRIMARY KEY(id)
  );
  
  CREATE TABLE items (
    id int GENERATED ALWAYS AS IDENTITY(MINVALUE 0 START WITH 0 CACHE 20) NOT NULL,
    genre int,
    author int,
    label int,
    publish_date date,
    archived boolean,
    author_id int,
    game_id int,
    book_id int,
    CONSTRAINT fk_label FOREIGN KEY(label) REFERENCES label(id) ON DELETE CASCADE,
    CONSTRAINT fk_book FOREIGN KEY(book_id) REFERENCES book(id) ON DELETE CASCADE,
    PRIMARY KEY (id)
  );