title: Query ContentPart by fields in Orchard CMS
body: <p>I work in Orchard 1.4 where I have a <code>ProductPart</code> content Part that has a <code>IsFeatured</code> Boolean field. It easy to query <code>ProductPart</code> by Projection module in Orchard 1.4.</p>
  
  <p>I want to write a <code>ProductService</code>, and want to query <code>ProductPart</code> where <code>IsFeatured</code> field is true like this:</p>
  
  <pre><code>contentManager.Query&lt;ProductPart,ProductRecord&gt;().Where(x=&gt;x.IsFeatured).ToList()
  </code></pre>
  
  <p>How to get this?</p>