Problem with Criteria Querys

Hi,

i am having problems running following code...

import java.util.*;
import javax.persistence.*;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.ParameterExpression;
import javax.persistence.criteria.Root;


public final class MyTestCase {

    public static void main(String[] args)  {
        EntityManagerFactory emf =
            Persistence.createEntityManagerFactory("objectdb:$objectdb/db/test.tmp;drop");
        EntityManager em = emf.createEntityManager();

        em.getTransaction().begin();
        for (double i=0.0; i<10.0;i++){
         em.persist(new DataObject(i));
        }
        em.getTransaction().commit();

        CriteriaBuilder cb = em.getCriteriaBuilder();
  CriteriaQuery<DataObject> q = cb.createQuery(DataObject.class);
  Root<DataObject> d  = q.from(DataObject.class);
  q.select(d);
  ParameterExpression<Double> p1 = cb.parameter(Double.class);
  ParameterExpression<Double> p2 = cb.parameter(Double.class);
  q.where(
   cb.and(
    cb.gt(d.get("lon"),p1),
    cb.lt(d.get("lon"),p2)
   )
  );
  TypedQuery<DataObject> query = em.createQuery(q);
  query.setParameter(p1, 100.0);
  query.setParameter(p2, 150.0);
  List resultList = query.getResultList();
        System.out.println(resultList);

        em.close();
        emf.close();
    }

    @Entity
    public static class DataObject {
     private double lon;
        DataObject(Double lon) {
            this.lon = lon;
        }
        public String toString (){
         return String.valueOf(this.lon);
        }
    }
}

I my eyes it is exactly the same as you did in your manual. But running this gets me following error message:

Exception in thread "main" java.lang.Error: Unresolved compilation problems:
The method gt(Expression<? extends Number>, Expression<? extends Number>) in the type CriteriaBuilder is not applicable for the arguments (Path<Object>, ParameterExpression<Double>)
The method lt(Expression<? extends Number>, Expression<? extends Number>) in the type CriteriaBuilder is not applicable for the arguments (Path<Object>, ParameterExpression<Double>)

at MyTestCase.main(MyTestCase.java:30)

Please help...

This should work:

    ParameterExpression<Double> p1 = cb.parameter(Double.class, "p1");
    ParameterExpression<Double> p2 = cb.parameter(Double.class, "p2");
    Path<Double> lon = d.get("lon");
    q.where(
        cb.and(
            cb.gt(lon, p1),
            cb.lt(lon, p1)
        )
    );

A separate variable for the path is required to get a matching type.

But your example demonstrates an unrelated issue with ObjectDB - there is a problem with parameters with no name. Adding names to the parameters (as shown above) fixes it.

Actually parameters with no name do work. The problem was only with p2 that was defined and set but was not integrated into the query (next build will avoid a NPE in this case).

Thanks, works fine...