I know that this might sound strange but due to constraints on the DB this is the way it must be.
What we are trying to do is persist information from an objects state to the DB. This basically involves the state pattern.
For example we have a DoorState which is an interface. This DoorState is implemented by two concrete states (DoorOpen and DoorClosed). The state context object is the Door class.
This might seem simple to persist to the DB using two tables but the problem we have is that it must be persisted to 1 DB.
Ie the Door class’s number attribute is mapped to the DOOR table’s NUMBER column; then the DoorState description attribute is mapped to the DOOR table’s DESC column.
So far things that we have tried range from using hibernates’ subclass inheritance mapping to persist the DoorState; unfortunately this means we have to have to have a separate table for the states. Another approach is to use the component element. This provides the functionality of putting the information into the same table but does not seem to support polymorphism.

The example is pretty simple here but it is being implemented in a more functional way.

Any help would you greatly appreciated.

Thanks.

As I understand "State" instance has no state in this design pattern (context is a persistent object)