title: Best way to implement multiple both UUID and ID on each model in Rails
body: <p>Transitioning a large legacy codebase from UUIDs to IDs. This needs to be done in stages to maintain backwards compatibility among many devices.</p>
  
  <p>Current solution is to maintain both a UUID and ID field until we can transition over completely.</p>
  
  <p>What's the best way to do this so that all <code>belongs_to</code> models update both the ID and UUID on each create/update?</p>
  
  <p>Example: Comment model belongs to BlogPost and needs to set both <code>blogpost_id</code> &amp; <code>blogpost_uuid</code> on create/update.</p>