FetchType.LAZY on Parent's @OneToMany and FetchType.EAGER on Child's @ManyToOne

Question

I have the following model:

public class Parent {

  @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "parent",
      orphanRemoval = true)
  @Fetch(FetchMode.SELECT)
  private List<Child> children = new ArrayList<Child>();

}

public class Child {

  @ManyToOne(fetch = FetchType.EAGER)
  @JoinColumn(name = "parent_id")
  private Parent parent;

}

Is this the correct usage of FetchType ? Am I allowed to use FetchType.LAZY on Parent, but FetchType.EAGER on the Child object? What are the effects of setting the Child's FetchType to FetchType.LAZY as well?

Answer 1

It is ok. You can set the fetch type differently in each part of the relationship.

If you set FetchType.LAZY in the Child, when you get a child entity you will not get directly an instance of the Parent, unless you navigate the relationship inside a managed context.