Spring Data JPA-在显式删除子级后加载父级将返回具有已删除子级的子级的集合

Question

I have Parent->Child bidirectional relationship as follows...

class Parent{

    @OneToMany(mappedBy="parent", fetch = FetchType.EAGER)
    Collection<Child> children;
}

class Child{
    @ManyToOne
    @JoinColumn(name="PARENT_ID")
    private Parent parent;
}

When i delete child explicitly, and after that load its parent (with all children) i get previously deleted child in children collection of parent... JPA provider is Hibernate...

Child child= childRepo.findOne(CHILD_ID);

childRepo.delete(child);
childRepo.flush();

// next, returns collection without deleted child
Collection<Child> children= childRepo.findAll(); 

Parent parent = parentRepo.findById(PARENT_ID);

/// next, returns collection including deleted child
Collection<Child> parentChildren = parent.getChildren(); 

I don't understand what is the problem? Every find* method executes select (at list, those SELECTs are logged in console) , but they returns different results...

Answer 1

Your ManyToOne is EAGER (by default). Your OneToMany is also EAGER (you explicitely marked it so). So, when you get a child in your first line of code, JPA also loads its parent, and all the children of the parent.

Then you delete the child, but you don't remove it from the parent's chidren. And since the parent's collection of children is already loaded, the deleted child is still in the collection.