Hi All,
I am new to NHibernate but relations are driving me crazy.

My simple database is user, role and function. Each user has a single role. Role and function are many-to-many.
So the database roughly looks like:
User: UserID (PK), Name, RoleID (FK)
Role: RoleID (PK), Name
Function: FunctionID (PK), Name
Role_Function: RoleID (PK), FunctionID (PK)

What should be my User, Role and Function mapping files (or a link to a tutorial that explains one-to-many, many-to-one and one-to-one relations)?

I have created the User class/mapping file with RoleID and it worked successfully. However when I change from RoleID to Role I cannot save any user because I got the exception "cannot insert null in User.RoleID"?

Thanks in advance,
Shehab.

Hi All,
I found the answer. I was really desperate, that's why I posted here.
The following link http://sdesmedt.wordpress.com/2006/09/04/nhibernate-part-4-mapping-techniques-for-aggregation-one-to-many-mapping/ provides the answer.

In short, in the user.hbm.xml I added this line

and in the Role.hbm.xml I added these lines


In User.cs I added

and in Role.cs I added


Now when I create a User object and set its Role, it is saved in the database with the appropriate RoleID.

Again sorry for posting and answering myself but it was really depressing to spend a lot of hours on such a simple thing.

Best regards,
Shehab.