Hibernate generating SQL queries when accessing associated entity's id

Question

I have Hibernate Entities that look something like this (getters and setters left out):

@Entity
public class EntityA {
    @ManyToOne(fetch = FetchType.LAZY)         


        

Answer 1

What you say makes sense - that it would not make a DB hit since EntityA contains the parent ID. I am just not sure if the getParent() call actually loads the EntityB object regardless of whether all you're interested in is the ID. You might try marking the children collection (and any other fields) as Lazy if you want to save the DB hit.

@Entity
public class EntityB : SuperEntity {
    @OneToMany(mappedBy = "parent", fetch = FetchType.LAZY)
    @Fetch(FetchMode.SUBSELECT)
    @JoinColumn(name = "parent_id")
    private Set children;
}