How do I select a Random Row using NHibernate's ICriteria API?

Question

Can I select a random row using NHibernate's ICriteria API?

Answer 1

Just as cundh2o said, it's DBMS-specific. But you can subclass the Order class and define your own custom ordering. For example, for SQL Server:

public class RandomOrder: Order {
    public RandomOrder() : base("", true) {}
    public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteriaQuery) {
        return new SqlString("newid()");
    }
}

Answer 2

If you are not limited to using ICriteria, I might recommend using HQL instead for selecting a random row, since it may provide more flexibility to use the Random function supplied by your db provider.

IQuery q = NHibernateSession.CreateQuery("your hql statement here")