title: Need help understanding the correct way of making relations between many to many tables
body: <p><a href="https://i.stack.imgur.com/wBvkC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wBvkC.png" alt="enter image description here" /></a></p>
  <p>I need to know if my relationships made between many to many tables are correct.
  Books_Authors = Books should be able to have multiple authors, and authors should be able to be assigned to multiple books, correct?</p>
  <p>Loans table, my tought was that one User should be able to make multiple loans, but one copy of a book should only be able to be loaned once at a time. correct?</p>
  <p>is my relations and keys set up correctly to uphold this logic?</p>