title: How to address entity that uses composite identity key in OData Url?
body: <p>I have an <em>entity OrderItem</em> that has <em>OrderId</em> and <em>ProductId</em> integer fields and these two fields form the <em>identity key/primary key</em> for this table.<br>
  I would like to use <em>OData/Web API</em> to expose such entities through a service and to be able to select <em>OrderItem</em> instances by they <strong>composite ID</strong>.  </p>
  
  <p>What should be the format of the <strong>URL</strong>?  </p>
  
  <p>Are there any best practices for handling such scenarios?  </p>