What's the better way to implement a condition at NHibernate query?

Question

I am using a generics implementation of Query from NHibernate.
My method:

 public IEnumerable<TEntidade> ObterEntidadesPor(Func<TEntidade, bool> where) { return SessionNH.Query<TEntidade>().Where(where); } 

In this case, the NHibernate first do the "select * from TEntidade" bring all information to memory after all this, he implement the "where" conditional. This are taking to much time.

Is there a better way to do it?

Answer 1

The problem was solved with Expression<func> .

public IEnumerable<TEntidade> ObterEntidadesPor(Expression<Func<TEntidade, bool>> where)
{
    return SessionNH.Query<TEntidade>().Where(where);
}

While searching for answer, a colleague told me that the Func executes the query before build an expression. To build an expression before executing the query, we have to use Expression .

This is also mentioned by @RomanArtiukhin in comments on question.