title: REST API, get a list of resources by a specific value - naming conventions
body: <p>Let's say I have an ecommerce site with customer and orders, as would be expected :)
  I have some doubts about resource naming, especially the resource that return all orders by a specific user_id</p>
  
  <p>Some proposals:</p>
  
  <pre><code>1. /orders/?userid={userid}
  2. /orders/customer/{userid}
  3. /customers/{userid}/orders
  </code></pre>
  
  <p>Not my doubts:</p>
  
  <ol>
  <li><p>As a resource that return ALL orders SHOULD NOT exists, the userid become a fundamental parameter, therefore it's not optional as query parameter may suggest</p></li>
  <li><p>Maybe my favourite one, but I'm a bit perplexed if the previous one is the better choice</p></li>
  <li><p>This indeed follow the bad practice 'don't nest the resource'. I don't like to output a different entity (order) from the base (customers)</p></li>
  </ol>
  
  <p>Any suggestions ?</p>