IEnumerable.except error
<p>I have two <code>IEnumerable&lt;dynamic&gt;</code> of data retrieved from database tables, called <code>FullSet</code> and <code>InScopeSubSet</code>  . </p>

<p>The second <code>IEnumerable&lt;dynamic&gt;</code> is a subset of the first set (both sets have <code>ChildID</code> as their unique ID)</p>

<p>I would like to create a new <code>IEnumerable&lt;dynamic&gt;</code> that contains only items from x that do not occur in y</p>

<p>I have tried the following but it will not compile. It says:
<em>"extension methods cannot be dynamically dispatched. Consider casting the dynamic arguments or calling the extension method without the extension method syntax"</em></p>

<pre><code> var sql = "SELECT ChildID, FirstName, Surname FROM Child ORDER BY ChildID ASC";
 var FullSet =  DB.Query(sql);

 sql = "
 SELECT UserScope.ChildID, Child.FirstName, Child.Surname 
 FROM UserScope 
 INNER JOIN Child ON UserScope.ChildID=Child.ChildID 
 WHERE UserAccountID = @0 ORDER BY ChildID ASC
    ";
 var InScopeSubSet = DB.Query(sql, UserAccount.UserAccountID);

 var OutScopeSubSet  = FullSet .Except(InScopeSubSet );
</code></pre>
