Question

I have a parent object with a child collection containing one element, the child collection contains a “grandchild” collection containing 3 elements.

I am loading the parent object from the database using NHibernate as follows

Parent parentObject = session.Query<Parent>()
    .FetchMany(x => x.Children)
    .ThenFetchMany(x => x.GrandChildren)
    .Where(x => x.Id = "someparentid")
    .Single();

What I’m finding is that there are duplicate children objects (3 in total) attached to the parent object when there should be only one. (There are 3 grandchild objects correctly attached to each child.) Eager loading the children collection only works correctly.

Do you know how I can achieve loading of the full parent object without duplicate children?

Answer 1

I was able to use the answer here using QueryOver, it correctly loads the objects while generating efficient SQL (selects per table instead of one huge join).