ScalarList selectList = new ScalarList();

selectList.Add(NW.Order.ShipRegion);

selectList.Add(NW.Order.ShipVia);

SelectQuery query = OQL

  .Select(NW.Order.OrderDate)._(selectList)

  .From(NW.Order);

The SQL statements generated as follows (taking SQL Server as an example)

SELECT

  [Orders].[OrderDate] , [Orders].[ShipRegion] , [Orders].[ShipVia]

FROM [Orders]