title: How to add to linq2sql entity set for master detail if I can't explicitly define the detail?
body: <p>Maybe I'm going about this the wrong way...</p>
  
  <p>I have an Order table and an OrderItem table. I create a new Order using linq2sql generated classes. </p>
  
  <p>I then attempt to get all orderable items out of my database using a query that goes after various tables.</p>
  
  <p>I try to then create a new list of OrderItem from that query, but it squawks that I can't explicitly create the object.</p>
  
  <pre><code>Explicit construction of entity type OrderItem in query is not allowed.
  </code></pre>
  
  <p>Here is the query:</p>
  
  <pre><code>return (from im in dc.MasterItems
                      join c in dc.Categories
                        on im.CATEGORY equals c.CATEGORY1                      
                      select new OrderItem()
                      {
                          OrderItemId = im.ItemId
                      });
  </code></pre>
  
  <p>The idea is to populate the database with all orderable items when a new order is created, and then display them in a grid for updates. I'm taking the results of that query and attempting to use <code>AddRange</code> on <code>Order.OrderItems</code></p>
  
  <p>Is there a proper strategy for accomplishing this using linq2sql?</p>
  
  <p>Thanks in advance for your help.</p>