Nick has been working on some subselects and Im glad to report that progress has been great! Something like this will work:

SearchCriteriaList vCrits = new SearchCriteriaList();
vCrits.Add( true, "Name", "Nick", "", SearchCriteriaOperator.Like, false)
vCrits.Add( true, "Orders.OrderDate", Date.Parse("2005-01-01"), null, SearchCriteriaOperator.GreaterThan, false);
CustomerList vCusts = new CustomerList();
vCusts.LoadByCriteria( vCrits )

Should return all the orders of the "Nick" customer made since the new year of 2005. Note that the only thing the developer has to do is to define the relationship once between the Customer and the Orders as such:

public class Customer: PDObject
{
   ...
  [OneToMany("ID", "CustomerFK")]
  public OrderList Orders {
     get { return (OrderList) PDList.CreateByAttribute( this, "Orders" ) }
   ...
}

The framework will make use of all this information to generate the appropriate subselect statement in SQL.

Fun stuff!

yk.