HQL to CriteriaQuery when using bitwise operators

Question

How do I convert this into a CriteraQuery:

select n
from TagRegistration t
join t.Tag n
where t.Status & :status > 0
order by count(t.ID) desc
       , n.Name asc

Answer 1

Hi!

Did something like that a while ago.

Try something like this.

PropertyProjection projection = Projections.Property("t.ID");
PropertyProjection property = Projections.Property("n.Namn");
ICriteria criteria = session.CreateCriteria<TagRegistration>("t")
                .CreateCriteria("Tag","n")
                .Add(
                        Restrictions.Gt(
                            Projections.SqlProjection("({alias}.ID & 3) as bitWiseResult", new[] { "bitWiseResult" }, new IType[] { NHibernateUtil.Int32 })
                        , 0)
                     )
                .AddOrder(Order.Desc(Projections.Count(projection)))
                .AddOrder(Order.Asc(property))
                .SetProjection(Projections.GroupProperty(projection), Projections.GroupProperty(property))

Note this part {alias}.ID & 3) where I inserted the value directly which isn't very good but it works :)

You could do it better if you look at the test project of NHibernate Nhibernate/Criteria/AddNumberProjection.cs

But you need to do a subQuery to return fully initialized Tag I think this query is better to do in Hql.

Regards