Simple postgresql database for testing purpose

ddl.sql

CREATE SCHEMA library
    AUTHORIZATION postgres;

CREATE SEQUENCE library.books_book_id_seq
    INCREMENT 1
    START 1
    MINVALUE 1
    MAXVALUE 2147483647
    CACHE 1;
    
CREATE SEQUENCE library.orders_order_id_seq
    INCREMENT 1
    START 1
    MINVALUE 1
    MAXVALUE 2147483647
    CACHE 1;

CREATE SEQUENCE library.users_user_id_seq
    INCREMENT 1
    START 1
    MINVALUE 1
    MAXVALUE 2147483647
    CACHE 1;
   
CREATE TABLE library.books
(
    book_id integer NOT NULL DEFAULT nextval('library.books_book_id_seq'::regclass),
    title text COLLATE pg_catalog."default" NOT NULL,
    author text COLLATE pg_catalog."default" NOT NULL,
    isbn text COLLATE pg_catalog."default" NOT NULL,
    year integer NOT NULL,
    CONSTRAINT books_pkey PRIMARY KEY (book_id)
);

CREATE TABLE library.users
(
    user_id integer NOT NULL DEFAULT nextval('library.users_user_id_seq'::regclass),
    first_name text COLLATE pg_catalog."default" NOT NULL,
    last_name text COLLATE pg_catalog."default" NOT NULL,
    CONSTRAINT users_pkey PRIMARY KEY (user_id)
);

CREATE TABLE library.orders
(
    order_id integer NOT NULL DEFAULT nextval('library.orders_order_id_seq'::regclass),
    user_id integer NOT NULL,
    book_id integer NOT NULL,
    quantity integer NOT NULL,
    CONSTRAINT orders_pkey PRIMARY KEY (order_id),
    CONSTRAINT orders_book_id_fkey FOREIGN KEY (book_id)
        REFERENCES library.books (book_id) MATCH SIMPLE
        ON UPDATE NO ACTION
        ON DELETE NO ACTION,
    CONSTRAINT orders_user_id_fkey FOREIGN KEY (user_id)
        REFERENCES library.users (user_id) MATCH SIMPLE
        ON UPDATE NO ACTION
        ON DELETE NO ACTION
);