NHibernate Linq Query - Select Sub Queries - linq

Question

I'm new to NHibernate and not great at Linq, but this is seriously kicking my butt, and I can't find any really clear examples on SO.
I need to get Thread information from the database, but I need to include a subquery that does a count on the number of Posts on a particular thread.
Here is a SQL Statement
Select ID, ThreadName,
(Select Count(Posts.ID) From Posts Where ThreadID = Threads.ID) as Replies
From Threads
And Class Structure:
Class Thread
Property ID as Integer
Property ThreadName as String
Property Replies as Integer
End Class
Class Post
Property ID as Integer
Property ThreadID as Integer
Property PostText as String
End Class
Any help would be much appreciated. And bonus points to supply both a LINQ example and a one using the NHibernate syntax.

Answer 1

So the query would be like this:
C#
var query =
from thrs in session.Query<YourNamespace.Thread>() // in C# Thread would need
select new YourNamespace.Thread // precise NS to distinguish System.Threading
{
ID = thrs.ID,
ThreadName = thrs.ThreadName,
Replies = thrs.Posts.Count()
};
var list = query.ToList(); // the above statement was executed
VB:
Dim query = From t As Thread In session.Query(Of Thread)()
Select New Thread With {
.ID = t.ID,
.ThreadName= t.ThreadName,
.Replies = t.Posts.Count
}
Dim list as List(of Thread) = query.ToList()
The very important think here is, that the Thread must have a mapping to the collection of Posts
C#
public class Thread
{
...
// really sorry for C# ... I will learn VB syntax ...
public virtual IList<Post> Posts { get; set; }
VB
Public Class Thread
Public Overridable Property Posts As IList(Of Post)
If this collection of Posts, would be mapped in NHibernate, then the above LINQ syntax will work out of the box