Question

I’m experiencing something rather odd. I’m tinkering with NHibernate 3.2 mapping by code and have a very simple object model I’m using just to play.

None of my properties in the entire model are marked as virtual because I dont want lazy loading. I’m mapping by code and in each class mapping I’m setting Lazy(false);

However when it comes to mapping collections, if I try and access a collection after the session has ended I get an error "failed to lazily initialize a collection of role...".

I have to explicitly set collectionMapping.Lazy(CollectionLazy.NoLazy); before it will eager load the collection. It was my understanding that lazy loading was not possible unless your properties in your model were defined at virtuals?

Have I fundamentally missed something?

Answer 1

Virtual properties and methods are only needed for lazy associations (many-to-one or one-to-one) because NHibnerate needs to set a proxy entity on the association property.

Collections (one-to-many and many-to-many) don’t need any virtual properties because only the collection is lazy, not the entities in the collection. NHibernate will always use its own collection classes, even if you disable lazy loading.