How to select the least count of items in fluent nHibernate via a linq query?

Question

So I got a fluent nHibernate table like this:

public class AnsweredQuestionDb
{
    public virtual long Id { get; set; }
    public virtual QuestionDb Question { get; set; }
    public virtual AnswerDb Answer { get; set; }

}

QuestionDb and AnswerDb are other fluent nHibernate tables.

So I want to select the least answered Question. So if Question A was ansered 3 times and Question B,C and D where answerd 4 times the result should be Question A.

This is the point i am actually working with:

var leastAnswerdQuestion = (from t in m_dbSession.Query<AnsweredQuestionDb>()
                            group t.Id by t.Question into groups
                            select groups.ToList().Sum()).ToList()[0];

but this throws an exception and has no or order by inside. Is this even possible to do in one query?

I hope it is clear what I want to do.

I assume in sql this will look like this:

SELECT Question_id, count(Question_id)
FROM AnsweredQuestionDb
GROUP BY Question_id
ORDER By count(Question_id)

Answer 1

So with the help of Svyatoslav Danyliv I created this:

Of course this is not perfect but it serves the purpurse:

QuestionDb nextQuestion = null;
var grouped =  (from t in m_dbSession.Query<AnsweredQuestionDb>()
               group t by t.Question.Id into g
               orderby g.Count()
               select new
               {
                   QuestionId = g.Key,
                   Count = g.Count()
               }).ToList();

var keys = grouped.Select(o => o.QuestionId).ToList();
var notAnswered = (from t in m_dbSession.Query<QuestionDb>()
                   where 
                   !keys.Contains(t.Id)
                   select t).ToList().First();

if (notAnswered != null)
{
    nextQuestion = notAnswered;
}
else
{
    if (grouped.Count() == 0)
    {
        nextQuestion = (from t in m_dbSession.Query<QuestionDb>()
                        select t).ToList().First();
    }
    else
    {
        var leastAnsweredId = grouped
            .OrderBy(x => x.Count)
            .Select(x => x.QuestionId)
            .FirstOrDefault();

        nextQuestion = (from t in m_dbSession.Query<QuestionDb>()
                        where t.Id == leastAnsweredId
                        select t).ToList().FirstOrDefault();
    }
}