From: <glassfish_at_javadesktop.org>
Date: Fri, 05 Sep 2008 06:39:23 PDT

Hello,

I am trying to do the following:

[code]
@Entity
MyObject {
    @Id
    protected String id;

    @OneToMany(mappedBy = "parent", cascade = CascadeType.PERSIST, fetch = FetchType.LAZY)
    protected Set<ChildObject> children;
}

@Entity
ChildObject {
    @Id
    protected String id;

    @ManyToOne()
    @JoinColumn(name = "parent")
    protected MyObject parent;
}

[/code]

I wonder if it is possible to have only the ID of the MyObject in ChildObject instead of fetching the whole MyObject.

I only need the association from MyObject to ChildObject. When I need ChildObject I just need the ID of MyObject and not the whole MyObject. As ChildObject table stores the ID of the MyObject I though that there would be a way to map an ID like:

[code]
... MyObject stays the same.

@Entity
ChildObject {
    @Id
    protected String id;

    @ManyToOne()
    @JoinColumn(name = "parent")
    protected String parent;
}
[/code]

In my implementation "parent" is mapped to an XML attribute and it really seems like a performance hit to fetch every MyObject for every ChildObject when I want to list (as XML) all the ChildObjects with the parent ID attribute.

Any suggestions are welcome.

Thanks
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