Telerik OpenAccess ORM allows Persistent classes to be inherited by other classes, which could also be made persistent.

In the example above, there is a Book class, which is inheriting from the Product class. The Product class is marked as persistent.
Recompiling the PersistentClasses project triggered an update of the database and the Products table started hosting both Products and Books.

Now you have three options to retrieve the data:

• All Products - you will get both the products and the books but the books won't have their specific properties as they'll be retrieved as their base type
• Only the Books - books will be retrieved as their real type and you'll see their specific properties such as the Pages property.
• All Books as Products - you'll get only the books but they'll appear as their base type (i.e. Product)and you won't see their specific properties.