Order entitydatasource records
<p>I'm trying to order entitydatasource records like this: <code>orderby="Product_Num"</code> 
but it says: </p>

<blockquote>
  <p>'Product_Num' is not a member of 'Transient.collection[productmodel.Products(Nullable=True,DefaultValue=)]'. To extract a property of a collection element, use a subquery to iterate over the collection.</p>
</blockquote>

<p>So, it means that It cannot order collection of Products. It needs some kind of subquery, but I'm not sure what exactly does it need.</p>
