title: Does this look right for SQL?
body: <p>Prompt:
  The library provides books to borrowers. Each book is described by title, edition, and year of publication, and is uniquely identified using the ISBN. Each borrower is described by his or her name and address and is uniquely identified using a borrower number. The library provides one or more copies of each book and each copy is uniquely identified using a copy number, status indicating if the book is available for loan, and the allowable loan period for a given copy. A borrower may loan one or many books, and the date each book is loaned out and is returned is recorded. Loan number uniquely identifies each book loan.</p>
  
  <pre><code>DROP DATABASE IF EXISTS library;
  CREATE DATABASE library;`
  
  USE library;
  
  
  `DROP TABLE IF EXISTS book CASCADE;
  CREATE TABLE book (
      title   varchar(30) not null,
      edition varchar(10),
      year    char(4),
      ISBN    char(13),
      primary key (ISBN),
  );
  
  DROP TABLE IF EXISTS loan CASCADE;
  CREATE TABLE loan (
      return date varchar(10) not null,
      leave date varchar(10),
      primary key (copy_num),
  );
  
  DROP TABLE IF EXISTS borrower CASCADE;
  CREATE TABLE borrower (
      Name_first  varchar(25) not null,
      Name_last   varchar(25) not null,
      Address varchar(20),
      borrow_num  char(14),
      primary key (borrow_num),
  );
  
  DROP TABLE IF EXISTS copy CASCADE;
  CREATE TABLE copy (
      status  varchar(25) not null,
      loan period varchar(2),
      copy_num    char(13),
      primary key (copy_num),
  );
  </code></pre>