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Re: [eclipselink-users] Lazy loading does not work 
Hi Janne,
Where in your code do you see the relationships traversed? You can turn on EclipseLink logging (persistence unit property: eclipselink.logging.level=FINEST) to see all of the logging. When do you see the SQL that traverses the relationship?
EclipseLink has some functionality that allows LAZY relationships to be traversable after detachment if the connection is available. I am wondering if you are seeing that functionality in action. 

-Tom

janne postilista wrote:

Hi,

I'm using Eclipselink to provide JPA. I'm using GlassFish 3.0.1.

I have a some simple Employer and Person entities with many-to-many
(using join table) and one-to-many relationships. I want to have the
relationships lazy loaded, but it looks like they are always eagerly
loaded. I am aware that lazy/eager is just a hint to the JPA
implementation, but I'm thinking that lazy loading is probably
supposed to work with Eclipselink?

Entities are along the lines of (likely irrelevant lines omitted):


@Entity
@NamedQueries({
    @NamedQuery(name = "Employer.findAllLatest2", query = "select o
from Employer o"),
})
public class Employer implements Serializable {
    @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
    @JoinTable(name = "EMPLOYER_PERSON", joinColumns =
    @JoinColumn(name = "EMPLOYER_ID"), inverseJoinColumns =
    @JoinColumn(name = "PERSON_ID"))
    private Set<Person> persons;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "BOSS_ID")
    private Person boss;
}

@Entity
@NamedQueries({
  @NamedQuery(name = "EmployerPerson.findAll", query = "select o from
EmployerPerson o")
})
@Table(name = "EMPLOYER_PERSON")
@IdClass(EmployerPersonPK.class)
public class EmployerPerson implements Serializable {
    @Id
    @Column(name="EMPLOYER_ID", nullable = false, insertable = false,
            updatable = false)
    private Long employerId;
    @Id
    @Column(name="PERSON_ID", nullable = false, insertable = false,
            updatable = false)
    private Long personId;
    @ManyToOne
    @JoinColumn(name = "EMPLOYER_ID")
    private Employer employer;
    @ManyToOne
    @JoinColumn(name = "PERSON_ID")
    private Person person;
}

@Entity
public class Person implements Serializable {
    @ManyToMany(mappedBy="persons")
    private Set<Employer> employers;

@Stateless
@LocalBean
@TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
public class EmployerService {

    @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
    public List<Employer> findAll() {
        String namedQuery = "Employer.findAllLatest2";
        }
        List<Employer> employers = em.createNamedQuery(namedQuery,
Employer.class).getResultList();
        for (Employer e: employers) {
            em.detach(e);
        }
        return employers;
    }

Now, when I use findAll(), I would expect that Employer objects do not
have the person references fecthed. But they are. Accessing persons
succeeds even though I did add (extraneous) detach() -calls to make
sure the entities are detached after returning from findAll().
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