title: Yii Many To Many To Many?
body: <p>Let's say I have 3 main tables:
  <code>category</code>, <code>tag</code>, <code>url</code></p>
  
  <p><code>category</code> and <code>tag</code> have a MANY_MANY relationship.</p>
  
  <p><code>tag</code> and <code>url</code> have a MANY_MANY relationship.</p>
  
  <p>I would like from <code>category</code> to retrieve all the linked <code>url</code>.</p>
  
  <p>What is the easiest, most efficient way to do this?</p>
  
  <p>Can I declare a sort of MANY_MANY_MANY relation? Or is this doable in criteria? Or do I have to do it in pure SQL?</p>
  
  <p>I like the idea of Criteria because I will later pass it 'offset' and 'limit' parameters for pagination purposes...</p>