What is the difference between NHibernate Query<> vs QueryOver<>?

Question

I just started with NHibernate (using SQLite) in my current project and I mostly used Query<>, because I was familiar writing db queries in Linq.

Answer 1

About your QueryOver version, I would have written :

int result = Session.QueryOver()
               .Select(Projections.Max(x => x.CustomNumber))
               .SingleOrDefault();

It seems quite readable, and the resulting SQL would be something like :

SELECT max(this_.CustomNumber) as y0_ FROM "BillingDataEntity" this_

Hope this will help