Go there...
http://code.google.com/intl/fr-FR/appengine/docs/java/datastore/relationship
s.html#Polymorphic_Relationships
... And you'll read this :
" Even though the JDO specification includes support for polymorphic
relationships, polymorhpic relationships are not yet supported in the App
Engine JDO implementation. This is a limitation we hope to remove in future
releases of the product. If you need to refer to multiple types of objects
via a common base class we recommend following the same strategy we
recommend for implementing unowned relationships: store a Key reference."
Bye.
On 08/09/10 02:14, "lisandrodc" <lisandr...@gmail.com> wrote:
> Thanks Cyrille, but..
> Might someone confirm to me authentically that really inheritance is
> not supported?
> If it is like that, a serious enough failing....
> On the part of the documentation of google it does not confirm it but
> he
> does not deny it either...
> The error is "error.
> org.datanucleus.exceptions.NoPersistenceInformationException: The
> class "com.onwebconsulting.inventory.model.Part" is required to be
> persistable yet no Meta-Data/Annotations can be found for this class.
> Please check that the Meta-Data/annotations is defined in a valid
> file"
>
> Regards
> Lisandro
> On 7 sep, 09:48, Cyrille Vincey <crll...@gmail.com> wrote:
>> I have read somewhere in the appengine doc that class inheritance is not
>> really supported by JDO yet...
>>
>> On 07/09/10 00:39, "lisandrodc" <lisandr...@gmail.com> wrote:
>>
>>> Hi all,
>>> I've used hibernate for a while, and I'm having a bit of trouble
>>> switching to JDO. I have several entities that all entities will
>>> share. Rather than a parent table, I'd prefer these columns be
>>> embedded directly in each entity. As such, I've defined my abstract
>>> entity and child entity in the classes below. However, whenever I
>>> try
>>> to run my unit tests or the jetty environment, I always receive the
>>> following error.
>>> org.datanucleus.exceptions.NoPersistenceInformationException: The
>>> class "com.onwebconsulting.inventory.model.Part" is required to be
>>> persistable yet no Meta-Data/Annotations can be found for this class.
>>> Please check that the Meta-Data/annotations is defined in a valid
>>> file
>>> location.]]
>>> According to my Eclipse console I have 1 class that has been
>>> Enhanced. Any ideas what I'm doing wrong?
>>> DataNucleus Enhancer completed with success for 1 classes. Timings :
>>> input=268 ms, enhance=51 ms, total=319 ms. Consult the log for full
>>> details
>>> @Inheritance(strategy = InheritanceStrategy.NEW_TABLE)
>>> public class Part extends Auditable{
>>> @Persistent
>>> private String name;
>>> @Persistent
>>> private String description;
>>> @Persistent
>>> private String partNumber;
>>> @Persistent
>>> private long quantity;
>>> @Persistent
>>> private String manuacturersPartNumber;
>>> @Persistent
>>> private String manufacturerName;
>>> @Persistent
>>> private String suppliersPartNumber;
>>> @Persistent
>>> private String supplierName;
>>> @Persistent
>>> private String supplierWebsite;
>>> @Persistent
>>> private float salePrice;
>>> @Persistent
>>> private float supplierPrice;
>>> ... Getters and Setters
>>> }
>>> @PersistenceCapable(identityType = IdentityType.APPLICATION)
>>> @Inheritance(strategy = InheritanceStrategy.SUBCLASS_TABLE)
>>> public abstract class Auditable {
>>> @PrimaryKey
>>> @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
>>> private Key id;
>>> @Persistent
>>> private Date createDate;
>>> @Persistent
>>> private Date updatedDate;
>>> @Persistent
>>> private long version;
>>> public Key getId() {
>>> return id;
>>> }
>>> public Date getCreateDate() {
>>> return createDate;
>>> }
>>> public Date getUpdatedDate() {
>>> return updatedDate;
>>> }
>>> public long getVersion(){
>>> return version;
>>> }
>>
>>
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