title: query a sub-collection of a collection with linq
body: <p>I've got a collection of products, and each product object has it's own ProductImages collection.  Each ProductImage object has a IsMainImage bool field.  I'm having a hard time building a Linq query like this:</p>
  
  <pre><code>select products.productimages.imagename where products.productid == 1 and     
  product.productimages.ismainimage == true
  </code></pre>
  
  <p>Can anyone help me figure this out, point me to an online resource where I can learn about writing linq queries like this, or both?</p>
  
  <p>Thank you for your help!</p>