Marc,
Supposedly, this problem is only happening on Oracle.  It's working just fine with DB2 and Derby.  This is a bit long, but here's the call stack for the problem...  I have also attached the java files for the ManagedEntity, Guid, and Agent classes.

1500  TRACE  [main] openjpa.MetaData -     Resolving field "model.X509Cert@31116492.agent".
<4|true|0.0.0> org.apache.openjpa.persistence.ArgumentException : Errors encountered while resolving metadata.  See nested exceptions for details.
    at org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.java:501)
    at org.apache.openjpa.meta.MetaDataRepository.getMetaData (MetaDataRepository.java:283)
    at org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:338)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getClassMetaData(JPQLExpressionBuilder.java :151)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.resolveClassMetaData(JPQLExpressionBuilder.java:131)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java :211)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java:181)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateType(JPQLExpressionBuilder.java :174)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.access$1(JPQLExpressionBuilder.java:173)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder$ParsedJPQL.populate(JPQLExpressionBuilder.java:1658)
    at org.apache.openjpa.kernel.jpql.JPQLParser.populate(JPQLParser.java:52)
    at org.apache.openjpa.kernel.ExpressionStoreQuery.populateFromCompilation(ExpressionStoreQuery.java:145)
    at org.apache.openjpa.kernel.QueryImpl.newCompilation (QueryImpl.java:642)
    at org.apache.openjpa.kernel.QueryImpl.compilationFromCache(QueryImpl.java:623)
    at org.apache.openjpa.kernel.QueryImpl.compileForCompilation(QueryImpl.java:589)
    at org.apache.openjpa.kernel.QueryImpl.compileForExecutor (QueryImpl.java:651)
    at org.apache.openjpa.kernel.QueryImpl.getOperation(QueryImpl.java:1464)
    at org.apache.openjpa.kernel.DelegatingQuery.getOperation(DelegatingQuery.java:120)
    at org.apache.openjpa.persistence.QueryImpl.execute (QueryImpl.java:202)
    at org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:251)
    at jpa.test.LoadTestCase.testLoadAgents(LoadTestCase.java:30)
    at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at junit.framework.TestCase.runTest(TestCase.java:154)
    at junit.framework.TestCase.runBare(TestCase.java:127)
    at junit.framework.TestResult$1.protect(TestResult.java:106)
    at junit.framework.TestResult.runProtected (TestResult.java:124)
    at junit.framework.TestResult.run(TestResult.java:109)
    at junit.framework.TestCase.run(TestCase.java:118)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java :478)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:344)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: <4|true|0.0.0> org.apache.openjpa.persistence.ArgumentException: You cannot join on column "MNGD_ELEMENT.ME_GUID".  It is not managed by a mapping that supports joins.
    at org.apache.openjpa.jdbc.meta.ClassMapping.assertJoinable (ClassMapping.java:235)
    at org.apache.openjpa.jdbc.meta.strats.VerticalClassStrategy.map(VerticalClassStrategy.java:99)
    at org.apache.openjpa.jdbc.meta.ClassMapping.setStrategy(ClassMapping.java:343)
    at org.apache.openjpa.jdbc.meta.RuntimeStrategyInstaller.installStrategy(RuntimeStrategyInstaller.java:52)
    at org.apache.openjpa.jdbc.meta.MappingRepository.prepareMapping(MappingRepository.java:305)
    at org.apache.openjpa.meta.MetaDataRepository.preMapping (MetaDataRepository.java:600)
    at org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.java:487)
    ... 33 more
NestedThrowables:
<4|true|0.0.0> org.apache.openjpa.persistence.ArgumentException : You cannot join on column "MNGD_ELEMENT.ME_GUID".  It is not managed by a mapping that supports joins.
    at org.apache.openjpa.jdbc.meta.ClassMapping.assertJoinable(ClassMapping.java:235)
    at org.apache.openjpa.jdbc.meta.strats.VerticalClassStrategy.map (VerticalClassStrategy.java:99)
    at org.apache.openjpa.jdbc.meta.ClassMapping.setStrategy(ClassMapping.java:343)
    at org.apache.openjpa.jdbc.meta.RuntimeStrategyInstaller.installStrategy(RuntimeStrategyInstaller.java :52)
    at org.apache.openjpa.jdbc.meta.ClassMapping.resolveMapping(ClassMapping.java:768)
    at org.apache.openjpa.meta.ClassMetaData.resolve(ClassMetaData.java:1569)
    at org.apache.openjpa.meta.MetaDataRepository.processBuffer (MetaDataRepository.java:654)
    at org.apache.openjpa.meta.MetaDataRepository.resolveMapping(MetaDataRepository.java:615)
    at org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.java:493)
    at org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:283)
    at org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:338)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getClassMetaData (JPQLExpressionBuilder.java:151)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.resolveClassMetaData(JPQLExpressionBuilder.java:131)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData (JPQLExpressionBuilder.java:211)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java:181)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateType (JPQLExpressionBuilder.java:174)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.access$1(JPQLExpressionBuilder.java:173)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder$ParsedJPQL.populate(JPQLExpressionBuilder.java :1658)
    at org.apache.openjpa.kernel.jpql.JPQLParser.populate(JPQLParser.java:52)
    at org.apache.openjpa.kernel.ExpressionStoreQuery.populateFromCompilation(ExpressionStoreQuery.java:145)
    at org.apache.openjpa.kernel.QueryImpl.newCompilation (QueryImpl.java:642)
    at org.apache.openjpa.kernel.QueryImpl.compilationFromCache(QueryImpl.java:623)
    at org.apache.openjpa.kernel.QueryImpl.compileForCompilation(QueryImpl.java:589)
    at org.apache.openjpa.kernel.QueryImpl.compileForExecutor (QueryImpl.java:651)
    at org.apache.openjpa.kernel.QueryImpl.getOperation(QueryImpl.java:1464)
    at org.apache.openjpa.kernel.DelegatingQuery.getOperation(DelegatingQuery.java:120)
    at org.apache.openjpa.persistence.QueryImpl.execute (QueryImpl.java:202)
    at org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:251)
    at jpa.test.LoadTestCase.testLoadAgents(LoadTestCase.java:30)
    at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at junit.framework.TestCase.runTest(TestCase.java:154)
    at junit.framework.TestCase.runBare(TestCase.java:127)
    at junit.framework.TestResult$1.protect(TestResult.java:106)
    at junit.framework.TestResult.runProtected (TestResult.java:124)
    at junit.framework.TestResult.run(TestResult.java:109)
    at junit.framework.TestCase.run(TestCase.java:118)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java :478)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:344)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
<0|true|0.0.0> org.apache.openjpa.persistence.PersistenceException: null
    at org.apache.openjpa.jdbc.meta.ClassMapping.assertStrategy(ClassMapping.java:954)
    at org.apache.openjpa.jdbc.meta.ClassMapping.isPrimaryKeyObjectId( ClassMapping.java:920)
    at org.apache.openjpa.jdbc.meta.ClassMapping.isForeignKeyObjectId(ClassMapping.java:284)
    at org.apache.openjpa.jdbc.meta.strats.RelationFieldStrategy.initialize(RelationFieldStrategy.java :189)
    at org.apache.openjpa.jdbc.meta.FieldMapping.initializeMapping(FieldMapping.java:483)
    at org.apache.openjpa.jdbc.meta.FieldMapping.resolve(FieldMapping.java:402)
    at org.apache.openjpa.jdbc.meta.ClassMapping.initializeMapping (ClassMapping.java:830)
    at org.apache.openjpa.meta.ClassMetaData.resolve(ClassMetaData.java:1574)
    at org.apache.openjpa.meta.MetaDataRepository.resolveMapping(MetaDataRepository.java:624)
    at org.apache.openjpa.meta.MetaDataRepository.resolve (MetaDataRepository.java:493)
    at org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:283)
    at org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:338)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getClassMetaData(JPQLExpressionBuilder.java:151)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.resolveClassMetaData(JPQLExpressionBuilder.java:131)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java:211)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateMetaData(JPQLExpressionBuilder.java :181)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.getCandidateType(JPQLExpressionBuilder.java:174)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder.access$1(JPQLExpressionBuilder.java:173)
    at org.apache.openjpa.kernel.jpql.JPQLExpressionBuilder$ParsedJPQL.populate(JPQLExpressionBuilder.java:1658)
    at org.apache.openjpa.kernel.jpql.JPQLParser.populate(JPQLParser.java:52)
    at org.apache.openjpa.kernel.ExpressionStoreQuery.populateFromCompilation (ExpressionStoreQuery.java:145)
    at org.apache.openjpa.kernel.QueryImpl.newCompilation(QueryImpl.java:642)
    at org.apache.openjpa.kernel.QueryImpl.compilationFromCache(QueryImpl.java:623)
    at org.apache.openjpa.kernel.QueryImpl.compileForCompilation (QueryImpl.java:589)
    at org.apache.openjpa.kernel.QueryImpl.compileForExecutor(QueryImpl.java:651)
    at org.apache.openjpa.kernel.QueryImpl.getOperation(QueryImpl.java:1464)
    at org.apache.openjpa.kernel.DelegatingQuery.getOperation (DelegatingQuery.java:120)
    at org.apache.openjpa.persistence.QueryImpl.execute(QueryImpl.java:202)
    at org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:251)
    at jpa.test.LoadTestCase.testLoadAgents (LoadTestCase.java:30)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at junit.framework.TestCase.runTest(TestCase.java:154)
    at junit.framework.TestCase.runBare(TestCase.java:127)
    at junit.framework.TestResult$1.protect (TestResult.java:106)
    at junit.framework.TestResult.runProtected(TestResult.java:124)
    at junit.framework.TestResult.run(TestResult.java:109)
    at junit.framework.TestCase.run(TestCase.java:118)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:478)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:344)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main (RemoteTestRunner.java:196)

On 1/2/07, Marc Prud'hommeaux <mprudhom@apache.org> wrote:

Interesting ... sounds like a legit bug, then (although it bears
noting that byte[] primary keys aren't actually allowed by the JPA
spec, as per section 2.1.4 ... support for them is an OpenJPA
extension).

My guess is that this only affects Oracle, due to our special
handling of blobs. It'd be interesting to see if any other databases
that support byte[] primary keys exhibit this problem.



On Jan 2, 2007, at 7:23 PM, Igor Fedorenko wrote:

> You can use use RAW(16) to store GUIDs in Oracle. This datatype is
> allowed in primary keys.
>
> --
> Regards,
> Igor
>
> Dain Sundstrom wrote:
>> Can you have java field of type byte[] that maps to a NUMERIC (or
>> heck a varchar) in he db?  I'm guessing that Kevin's guid is a
>> fixed 128 bit number.  If it is and he can map it to a non-blob
>> type, it should be possible to join with any database system.
>> -dain
>> On Jan 2, 2007, at 3:09 PM, Marc Prud'hommeaux wrote:
>>> Kevin-
>>>
>>>> Also, this exception is supposedly only being produced with
>>>> Oracle, not
>>>> DB2.  (I have not been able to verify that yet.)  This would
>>>> seem to
>>>> indicate that it's dictionary-specific, but I'm not seeing
>>>> anything there
>>>> yet...
>>>
>>> Does Oracle even support blob primary keys? My recollection is
>>> that it didn't...
>>>
>>> I suspect that the problem might be that since Oracle has a
>>> number of problems with in-line blobs in statements, we
>>> frequently issue a separate statement to load and store blobs
>>> from and to rows, but if it is the primary key, then we might be
>>> conflicting with that. Can you post the complete stack trace?
>>>
>>>
>>>
>>>
>>> On Jan 2, 2007, at 6:03 PM, Kevin Sutter wrote:
>>>
>>>> Hi,
>>>> Some experimenting with the @IdClass support is producing a strange
>>>> exception message when attempting to map an id field of type byte
>>>> [].
>>>> According to the OpenJPA documentation, we need to use an
>>>> Identity Class to
>>>> use byte[] as the id field type.  Something like this:
>>>>
>>>> @Entity
>>>> @IdClass (jpa.classes.Guid.class)
>>>> @Table(name="AGENT", schema="CDB")
>>>> public class Agent {
>>>>
>>>>    @Id
>>>>    @Column(name="ME_GUID")
>>>>    private byte[] guid;
>>>> ...
>>>>
>>>> The Guid class has also been created with a single instance
>>>> variable of type
>>>> byte[]:
>>>>
>>>> public class Guid implements Serializable {
>>>>    private byte[] guid;
>>>> ...
>>>>
>>>> But, during the loading of the database, I am getting the
>>>> following error...
>>>>
>>>> org.apache.openjpa.util.MetaDataException: You cannot join on
>>>> column "
>>>> AGENT.ME_GUID".  It is not managed by a mapping that supports joins
>>>>
>>>> First off, the exception is confusing since I don't believe I am
>>>> attempting
>>>> to do a join.  The guid column is in the same table as the Agent.
>>>>
>>>> Also, this exception is supposedly only being produced with
>>>> Oracle, not
>>>> DB2.  (I have not been able to verify that yet.)  This would
>>>> seem to
>>>> indicate that it's dictionary-specific, but I'm not seeing
>>>> anything there
>>>> yet...
>>>>
>>>> I am in the process of validating the problem, but I thought I
>>>> would drop a
>>>> line to the team to see if it rings any bells...
>>>>
>>>> Thanks,
>>>> Kevin
>