Hello Fay,

Thank you for the hint.
In the end I narrowed down the problem to self-referencing, composite ID
which is not supported. 

Kludging with a generated syntatic Id helps in cases where object model is
modifiable but it would be wonderful to have this supported at some time. 

Do you think it is possible in a foreseeable future?

https://issues.apache.org/jira/browse/OPENJPA-291

That's a pity since more and more DBs support hierarchical queries natively
(connect-by in oracle, with() in db2, recently postgres) and gives huge
performance kick where complicated traversal is needed in a single query.

Cheers
Krzysztof




Fay Wang wrote:
> 
> Hi,
>        Can you try making AbstractModel an Entity instead of
> MappedSuperClass, and making this class a concrete class as shown below?
> 
> // abstract class that has common identity and some additional fields, it
> is
> //a Key in a map
> @Inheritance(strategy = InheritanceType.JOINED)
> @Entity
> @IdClass(ModelId.ModelImplId.class)
> public class AbstractModel {
> 
> ...
> 
> }
> 
> -Fay
> 
> 
> 
> 
> ----- Original Message ----
> From: Krzysztof <[email protected]>
> To: [email protected]
> Sent: Wednesday, August 5, 2009 9:31:53 AM
> Subject: Key and Value limitations in a Map<Key,Value>
> 
> 
> Hello,
> Seems I am completely knotted in a convoluted class graph without any hint
> from documentation, spec or forum archive. 
> 
> Could somebody enlighten me if it is possible to:
> 
> A. Have a Key in a persistent Map<Key,Value> such as 
> 1. the Key has a composite ID composed of classes which have composite IDs
> themselves? 
> and
> 2. They Key is an abstract class that is also used in a Value as a parent
> in ManyToOne relationship being the part of the Values identity (actual
> objects - parent and Value being rather different entities)
> 
> Hope this example clarifies this rather complicated scenario: 
> 
> //abstract class of which children are Values in a map
> @Entity
> @IdClass(AbstractTS.TSId.class) //TSId covers SomeOtherClass identity too
> @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
> public abstract class AbstractTS
> {
> @id SomeOtherClass parent;
> @id int local_id;
> @OneToMany
> private Map<ModelId, DerivedTS> derivedMap; // DerivedTS inherits from
> AbstractTS - seems to impossible to be mapped properly.
> 
> }
> 
> // abstract class that has common identity and some additional fields, it
> is
> a Key in a map
> @Inheritance(strategy = InheritanceType.JOINED)
> @MappedSuperclass
> @IdClass(ModelId.ModelImplId.class)
> public abstract class AbstractModel { 
> @id  AbstractTS parent;
> @id  int x;
> @id double y;
> 
> @Basic
> @Lob
> double[] some_common_data;
> }
> 
> // Identity domain class, that is in fact stripped down version of an
> abstractModel, both reuse same ID class,  used to retrieve unknown models.
> 
> @IdClass(ModelId.ModelImplId.class)
> @Embeddable
> public class ModelId  {
>     
>     @ManyToOne
>     public AbstractTS parentTS; //could be either DerivedTS or RawTS.
>     @Id
>     @Basic
>     public double some_value;
>     @Id
>     public int modelType;
> 
>     @Basic
>     int some_derived_value;
> 
> }
> 
> @Entity
> @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
> //identity derived from AbstractTS
> public class RawTS extends AbstractTS
> {
> @Basic 
> int some_values;
> }
> 
> @Entity
> @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
> @IdClass(DerivedTS.DerivedTSId.class) // inherits from TSId with
> additional
> Identities for parentTS and parentModel
> public class  DerivedTS extends AbstractTS {
>     @ManyToOne
>     //@PrimaryKeyJoinColumns(..) // possibly to provide direct mappings to
> either RawTS or DerivedTS identity fields
>         @Id
>     private AbstractTS parentTS;
>       
>         @Id
>         @ManyToOne
>         //@PrimaryKeyJoinColumns( {... }) //possibly to provide direct
> mappings to any model derived from AbstractModel
>        private AbstractModel parentModel = null;
> 
> }
> 
> 
> 
> To create any working mapping for
> 
> Map<ModelId, DerivedTS> seems like an impossible mission, I would
> appreciate
> any hints if it is doable at all.
> 
> I tried various combinations of @ManyToOne combined with @PrimaryKeys,
> @MapPrimaryKeys, @ElementCollection etc.
> Persistence.xml lists all the classes, using openjpa 2.0.0 snapshot.
> 
> The last error I got is during enhancement:
>    [java] Exception in thread "main"
> <openjpa-2.0.0-SNAPSHOT-r422266:798026
> fatal user error> org.apache.openjpa.util.MetaDataException: Errors
> encountered while resolving metadata.  See nested exceptions for details.
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.java:578)
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:323)
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.resolveMeta(MetaDataRepository.java:625)
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.java:556)
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:323)
>      [java]     at
> org.apache.openjpa.enhance.PCEnhancer.<init>(PCEnhancer.java:251)
>      [java]     at
> org.apache.openjpa.enhance.PCEnhancer.run(PCEnhancer.java:4593)
>      [java]     at
> org.apache.openjpa.enhance.PCEnhancer.run(PCEnhancer.java:4540)
>      [java]     at
> org.apache.openjpa.enhance.PCEnhancer$1.run(PCEnhancer.java:4510)
>      [java]     at
> org.apache.openjpa.lib.conf.Configurations.launchRunnable(Configurations.java:726)
>      [java]     at
> org.apache.openjpa.lib.conf.Configurations.runAgainstAllAnchors(Configurations.java:711)
>      [java]     at
> org.apache.openjpa.enhance.PCEnhancer.run(PCEnhancer.java:4505)
>      [java]     at
> org.apache.openjpa.enhance.PCEnhancer.main(PCEnhancer.java:4496)
>      [java] Caused by: <openjpa-2.0.0-SNAPSHOT-r422266:798026 fatal user
> error> org.apache.openjpa.util.MetaDataException: Field
> "DerivedTS.parentModel" cannot be a primary key.  It is of an unsupported
> type.
>      [java]     at
> org.apache.openjpa.meta.ClassMetaData.validateAppIdClassPKs(ClassMetaData.java:2105)
>      [java]     at
> org.apache.openjpa.meta.ClassMetaData.validateAppIdClass(ClassMetaData.java:1989)
>      [java]     at
> org.apache.openjpa.meta.ClassMetaData.validateIdentity(ClassMetaData.java:1925)
>      [java]     at
> org.apache.openjpa.meta.ClassMetaData.validateMeta(ClassMetaData.java:1842)
>      [java]     at
> org.apache.openjpa.meta.ClassMetaData.resolve(ClassMetaData.java:1704)
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.processBuffer(MetaDataRepository.java:733)
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.resolveMeta(MetaDataRepository.java:631)
>      [java]     at
> org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.java:556)
>      [java]     ... 12 more
>      [java] NestedThrowables: 
> 
> 
> It fails in validateAppIdClassPKs, but it is hard to guess with what type:
> ...
> 2101          case JavaTypes.PC_UNTYPED:
> 2102                 case JavaTypes.COLLECTION:
> 2103                 case JavaTypes.MAP:
> 2104                 case JavaTypes.OID: // we're validating embedded
> fields
> 2105                     throw new
> MetaDataException(_loc.get("bad-pk-type",
> 2106                         fmds[i]));
> ....
> 
> Does it mean Composite IDs are banned in Map's Key completely?
> 
> 
> Best regards,
> Krzysztof
> -- 
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> 
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