Return TSubType from nhibernate QueryOver

Question

I am trying to select the children from a parent collection using QueryOver in nhibernate. This is what I am trying to do in HQL:

SELECT as_kitten FROM Cat as_Cat 
JOIN as_Cat.Kittens as_kitten

How does this translate to QueryOver or even using JoinAlias?

IList<Kitten> kittens =  session.QueryOver<Cat>()
        .JoinQueryOver<Kitten>(c => c.Kittens)
        .Select(??)
        .List()

The closest thing I could find so far is NHibernate QueryOver

Cheers

EDIT Assuming this is a one way relationship, ie. kittens dont' know about cat

Is there a one to many relationship between Cat and Kittens (or in your case)? — Cole W
Yeah there is a one to many relationship. Taken the example from nhforge.org/blogs/nhibernate/archive/2009/12/17/… — masdude

Cole W Cole W · Accepted Answer · 2011-07-22T11:20:59

Your example seems rather trivial. If you already have the parent and have the collection mapped as a one to many inside your cat entity then all you would have to do if you were lazy loading is access the collection.

If you only have the id of the parent you could easily do something like this without even needing a join:

IList<Kitten> kittens =  session.QueryOver<Kitten>()
        .Where(k => k.CatId == <parent cat id here>)
        .List<Kitten>()

Return TSubType from nhibernate QueryOver

1 Answers