2

I am using Hibernate 4.3.6.Final

I have 3 classes :

  • Parent
  • Child
  • Grandchild

As you can imagine, a Parent has many Children, and a Child has many Grandchildren.

class Parent {

@OneToMany(orphanRemoval = true)
@OrderColumn(name = "list_order")
@JoinColumn(name = "parent_id", nullable = false)
@Cascade(value = CascadeType.ALL)
private List<Child> children = new ArrayList<>();
}

class Child {

@ManyToOne(optional = false)
@JoinColumn(name = "parent_id", insertable=false, updatable=false, nullable = false, 
foreignKey = @ForeignKey(name = "fk_child_parent_id"))
private Parent parent;

@OneToMany(orphanRemoval = true, fetch = FetchType.EAGER)
@OrderColumn(name = "list_order")
@JoinColumn(name = "child_id", nullable = false)
@Cascade(value = CascadeType.ALL)
private List<Grandchild> grandchildren = new ArrayList<>();
}

class Grandchild {
@ManyToOne(optional = false)
@JoinColumn(name = "child_id", insertable=false, updatable=false, nullable = false,
foreignKey = @ForeignKey(name = "fk_grandchild_child_id"))
private Child child;
}

I want to LAZY load Children but EAGER load Grandchildren when loading Children.

Which means that :

  • When I access Parent, I want Hibernate to fetch only Parent
  • But if I call parent.getChildren(), I want Hibernate to fetch all children AND grandchildren

I've set EAGER on Child<->Granchild association, but it has no effect : when I call parent.getChildren(), only the children are fetched, not the grandchildren.

Thanks for your help !

UPDATE @Zeus, in my database :

  • Table Parent has "id"
  • Table Child has "id", "parent_id" (foreign key of parent) and "list_order" (used by Hibernate to order the list of children)
  • Table Grandchild has "id", "child_id" (foreign key of child) and "list_order"
Colin Valière
  • 41
  • 3
  • 1
    Which version of the hibernate you have? Also put some code, your associations definition. – Petar Butkovic Sep 24 '14 at 13:52
  • Can you also give your table structure. i'm concerned about the foreignKey attribute in the grandchild. I believe it is not required. You may be mapping one-one with child and grndchild – Zeus Sep 24 '14 at 14:14
  • http://stackoverflow.com/questions/2956171/jpa-2-0-ordercolumn-annotation-in-hibernate-3-5 issue with orderColumn – Zeus Sep 24 '14 at 16:17
  • This is not the same issue... The one you're pointing at is about orderColumn with mappedBy issue, which is not how I mapped my elements. The issue I face is about EAGER fetching... – Colin Valière Sep 24 '14 at 17:24

0 Answers0