Hibernate Criteria API: get n random rows

Question

I can\'t figure out how to fetch n random rows from a criteria instance:

Criteria criteria = session.createCriteria(Table.class);
criteria.add(Restrictions.e         


        

Answer 1

The answer by @PSV Bhat is difficult if you are dynamically generating your Criteria. Here is a solution that extends hibernate Order class:

import org.hibernate.Criteria;
import org.hibernate.criterion.Order;

private void addOrderByToCriteria(Criteria criteria) {
    criteria.addOrder(Order.asc("foobar"));
    criteria.addOrder(ORDER_RANDOM);
}

private static final OrderRandom ORDER_RANDOM = new OrderRandom();

private static class OrderRandom extends Order {
    public OrderRandom() {
        super("", false);
    }
    @Override
    public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) {
        return "RANDOM()"; // or RAND() or whatever this is in your dialect
    }
}