Thanks Jeffrey, but your solution does not work.
I have solved it this way:
// 1) Build key parent.
Key kparent =
KeyFactory.createKey(Product.class.getSimpleName(), "product_001");
// 2) Build key child.
Key kchild = KeyFactory.createKey(kparent,
Format.class.getSimpleName(), 985);
Is there any way to get an object without knowing his parent?
Thanks a lot!
On 13 ago, 03:56, jeffrey_t_b <[email protected]> wrote:
> I think that you need a key object first, e.g.
>
> Key formatkey = KeyFactory.createKey(Format.class.getSimpleName(),
> formatId);
> forma = (Format) pm.getObjectById(Format.class, formatkey );
>
> On Aug 10, 11:19 am, aprendiz <[email protected]> wrote:
>
>
>
>
>
>
>
> > Hello, I have a (owner) one-to-many bidirectional relationship.
> > A product can have multiple formats, but a format can only be
> > associated with a product.
>
> > public class Product{
> > @PrimaryKey
> > @Persistent
> > private Key id; // string, by application
> > ...
> > @Persistent(mappedBy = "product")
> > private List <Format> formats;
>
> > }
>
> > public class Format{
> > @PrimaryKey
> > @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
> > private Key id; //numeric, autogenerated
> > ...
> > @Persistent
> > private Product producto;
>
> > }
>
> > Users select a format in a web page (radio button html) and
> > application (servlet) must load the object identified by id.
>
> > My code:
> > forma = (Format) pm.getObjectById(Format.class, formatId); // formatId
> > = 985
>
> > but I get:
> > Could not retrieve entity of kind Format with key Format(985)
>
> > Datastore Viewer shows a entity with ID/Name column = 985.
>
> > How I must load object? What is wrong?
> > Thank you!
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