Hello.

I have different questions but somewhat related.

a) First, I have seen examples of the use of discriminator, specifying different "string" values for each sub-class. But how can I set it for a subclass to be selected if the field is NULL and the other subclass for not being NULL?

b) Can I have a subclass split system by the use of multiple discriminators? For example:

- If fieldX == "true" and fieldY == "true", subclass A.
- If fieldX == "true" and fieldY == "false", subclass B.
- If fieldX == "false", subclass C.

c) Supposing the last question has no solution (no multiple discriminators), could I have a class ClassA that associates to TABLE1, and a subclass ClassB (that inherits from ClassA) that associates to TABLE1 with a WHERE clause?

Thanks in advance.

I have the same problems as you. But in the current nh you can only have a single column as a discriminator. Therefor, you could create a view that calculates the discriminator value.