Is it possible to create ICriteria/ICriterion from LINQ or HQL?

I am creating a method that c开发者_开发百科an create filter understood by NHibernate (by filter i mean a set of ICriteria object for example) from my abstract filter object.

public static IEnumerable<ICriterion> ToNhCriteria(this MyCriteria criteria)
{
   // T4 generated function
   // lots of result.Add(Expression.Or(Expression.Eq(),Expression.Eq)) expression trees - hard to generate
   // Is there a way to generate HQL/Linq query here istead?
}

then i want to do something like

session.CreateCriteria<Entity>().Add(myCriteria.ToNhCriteria())

to filter entities. The problem is that using Expression. methods (Expression.Or etc) is quite tedious (the method is generated and i have multiple or statements that have to be joined into an expression somehow). Is there a way to avoid using Expression.Or() and create ICrietrion / ICriteria using LINQ or HQL?

Hey, did you check out this question? It shows going from Linq to NHibernate to a MultiCriteria (and on the way transforms a linq query to an ICriteria)

No that is not possible. Why don't you use linq instead of criteria?

Linq is not the best solution unless you want to do filtering on collection-side not on datbase-side using WHERE clauses. Ayende suggests that ICriteria API is well suited for dynamic filter creation, the problem i had with multiple ORs has been tackled by using Restrictions.Disjunction()... that simplified a lot At the time I asked the question I just didn't realize such things exist in NHibernate :)