(Fluent) NHibernate dictionary mapping with class Key

Question

Domain:

class Category   
   string Name 
class Product   
   IDictionary<string, Product> Parents

Tables:

   Categories (ID, Name) 
   Products (ID)
   ProductParents (ID, ParentID, ChildID, CategoryID)

The questions: I need to get list of parent products. Is it possible to map parent products to dictionary so that I can do: product.Parents["CategoryName"] and it will give me a list of parent products for the given category.

Or maybe

product.Parents[Category("CategoryName")]

if I use

IDictionary<Category, Product> Parents

Or how do I do this? Maybe a method like product.GetParentProducts(string category) instead of properties? I'd rather use dictionary, though.

Notice that I don't really want to introduce ProductMapping class.

Answer 1

This is possible with NHibernate; what you're looking for is called a ternary association.

This is currently not available in Fluent NHibernate, but I'm working to add it. However, it probably won't be available for some time yet, due to the "replumbing" going on in FNH. Your best bet might be to use a standard HBM file for this mapping.

If you want to investigate further into doing it in FNH (note: you'll have to maintain your own local copy of the library), you can see what I've done at github.