Does anyone know how NHibernate deals with abstract properties?
This is what I mean:

Data (Abstract)
--------------------
int Id
string Name

Data1 : Data
---------------
DateTime StartDate
DateTime EndDate

Data2 : Data
----------------
string SerialNumber

Then imagine I have a class that has a property of type Data, since it sometimes need to have a Data1, and other times need to have Data2. The whole principle of inheriting.

How does NHibernate deals with this case, since typing Person.Data would give an error since Data is abstract and cannot be instantiated.

Thanks in advance,
Bernardo Heynemann

Just helping clarify...

The Data Table would be like this:

Data
Id
Name
StartDate
EndDate
SerialNumber
DataType --- This is the attribute that differentiate between Data1 and Data2.

Thanks in advance,
Bernardo Heynemann

Anyone? lol...

I´m in need of a solution for this issue (if it does have a solution...).

Thanks in advance,
Bernardo Heynemann

What do you mean by "how does NHibernate deal with this case"? It can deal with this in some cases, and not in others, so you have to specify what you are trying to do.

In general, polymorphic mapping is possible in NHibernate.

Sorry if i was vague.
I´m the lead architect in my company and I want to use nhibernate as our ORM, but I´m curious about two things:
1 - If it can do the above mapping.
2 - How does it do it? (This I want to know as a developer since I couldn´t think of a viable solution for it and it really annoyed me)

Thanks in advance,
Bernardo Heynemann

I think you're looking for the table-per-class-hierachy mapping strategy. Define the mapping for your abstract base class Data, and then use the <subclass> tag to define the mapping for each derived class.

Use the discriminator-value attribute to specify which class maps to which value of the DataType field. Specify a value for the Data abstract class discriminator-value that will never appear in the database (e.g. null). This way, NHibernate will never attempt to instantiate an instance of your abstract base class.