nHibernate 3.0 queries

Working through the summer of nHibernate tutorials have gotten to the section on queries. Seems there have been changes since that series was made. So I went t开发者_运维百科o the online docs for nHB 3.0 but code such as:

IList cats = session.CreateCriteria(typeof(Cat))
            .Add(Expression.Like("Name", "Fritz%"))
            .Add(Expression.Between("Weight", minWeight, maxWeight))
            .List();

Generates the error "The name 'Expression' does not exist in the current context"

Code like:

return session.CreateCriteria(typeof(DataTransfer.Customer))
            .Add(new NHibernate.Criterion.LikeExpression("Firstname", firstname))
            .Add(new NHibernate.Criterion.LikeExpression("Lastname", lastname))
            .List<Customer>();

Works but it seems that it is missing a number of query methods like GtExpression. Are the online docs up to date, and if so, why can't I use Expression... If the online docs aren't up to date then where do I get a description of the Criterion interface? Thanks

You forgot to add using NHibernate.Criterion;.

Anyway, the Expression class is deprecated. Use Restrictions instead.

Weird thing. I still use Expression.* static methods and these are still work. Are you sure you use the latest version of NH3.0? I use Alpha 2 version.

If you need to make it work urgently, let's try the QueryOver<> feature:

return session.QueryOver<DataTransfer.Customer>()
  .WhereRestrictionOn(u => u.Name).IsLike("Fritz%")
  .AndRestrictionOn(u => u.Weight).IsBetween(minWeight).And(maxWeight)
  .List();

It works well for simple queries