Specification Pattern for Querying against DataBase using NHibernate

Question

How Do You Implement Specification Pattern for querying database using NHibernate?(without LINQ to NHibernate).I read a lot about Specification Pattern but most of them was about Validation and Querying Memory collection objects.

Best method as far as I know using DetachedCriteria in Specification Interface like this.

interface ISpecification<T> {

 bool IsSatisfiedBy(T object);

 DetachedCriteria CreateCriteria();

}

Is there any alternative or better way to do this?

Answer 1

This is not nessary better, but can be an alternative

interface ISpecification<T> 
{
   bool IsSatisfiedBy(T object);

   Func<T, bool> Predicate { get; }
}

Easy to use over linq (to nhibernate) and memory-collections.