title: Why does this SQL code give error 1066 (Not unique table/alias: 'customer')?
body: <p>Why does the MySQL query below give error <code>1066 (Not unique table/alias: 'customer')</code>?</p>
  
  <pre><code>SELECT customer.id, customer.firstName, account.id
  FROM customer, account
  INNER JOIN customer
  ON customer.id = account.customerId 
  ORDER BY customer.id
  </code></pre>