Question

I have following class ( entity )

@Entity
public class  Magazine {
    private int id ;
    private String magazine;

            //getters and setters
}

// tracking the magazine arrival
@Entity 
public class MagazineIn {
    private int id;
    private java.util.Date inDate;
    private java.util.Date magdate;

    @OneToOne
    private Magazine mag ; 
            //getters and setters

}

Now i want to get all arrival status of all magazine , whether
magazine has in or not

using criteria query

following is code

    CriteriaBuilder cb = em.getCriteriaBuilder();
    CriteriaQuery<Object[]> cq = cb.createQuery(Object[].class);

        Root<MagazineIn> magIn = cq.from(MagazineIn.class);
    Join<Magazine,MagazineIn> mag =  magIn.join("mag" , JoinType.LEFT);

        cq.multiselect(mag.get("magazine") , magIn.get("magdate") , 
            magIn.get("inDate"));
    TypedQuery<Object[]> q = em.createQuery(cq);

But i am not getting all the magazine listing with indate and magdate null.RIGHT JOIN is not supported. What’s wrong?

Answer 1

If the entity relationships changes are not possible you could consider changing the root of your query to Magazine and use a subquery which correlates on the ‘mag’ variable.