title: How are these tables related?
body: <p>Say I run an online business where you can order products from my website, and I have a database with two tables:</p>
  
  <p>Table <code>order</code> with the fields <code>order_number, customer_ID, address</code></p>
  
  <p>Table <code>customer</code> with the fields <code>customer_ID, first_name, last_name</code></p>
  
  <p>To get a full, detailed 'report' of the order, I would perform a LEFT JOIN to concatenate data from the order table to include the customer's first and last names along with their address and order number.</p>
  
  <p>My question is, how are these tables related? Are they at all? What would an entity relationship diagram look like? Separately they don't seem to interact and act more like lookup tables for each other.</p>