Now that I mentioned it, I have a bidirectional association that that forgot
about... I'll check it out. Thanks.
Jon
----- Original Message -----
From: "Christopher Delahunt" <christopher.delahunt_at_oracle.com>
To: <persistence_at_glassfish.dev.java.net>
Sent: Tuesday, February 27, 2007 2:39 PM
Subject: Re: Is it legal to have a JPQL query that has multiple LEFT JOIN
FETCHes?
> Hello Jon,
>
> Could the Event entity being queried have a reference in the cache to the
> object(s) involved in the join that is null? I suspect that this NPE is
> occuring because your object model does not reflect what is in the
> database - ie the database relationship is different from what is in the
> cache, so that TopLink expects an object to exist in the cache that does
> not, based on the database results of the fetch join.
>
> This might occur if the data is stale and so be a bug, or if you have not
> maintained both sides of your references in the cached objects.
>
> Best Regards,
> Chris
>
>
> ----- Original Message -----
> From: "Jon Miller" <jemiller_at_uchicago.edu>
> To: <persistence_at_glassfish.dev.java.net>
> Sent: Tuesday, February 27, 2007 1:04 PM
> Subject: Re: Is it legal to have a JPQL query that has multiple LEFT JOIN
> FETCHes?
>
>
>>I was able to get a similar double LEFT JOIN to work with ManyToOnes, so,
>>it seems it's valid at least in that case. Not sure if that would make a
>>difference. Here it works fine if I'm using the javaagent.
>>
>> Feb 27, 2007 11:59:09 AM edu.uchicago.at.chalk.ChalkService findEvents
>> FINEST: SELECT e FROM Event e LEFT JOIN FETCH e.course LEFT JOIN FETCH
>> e.user ORDER BY e.startTime
>> Feb 27, 2007 11:59:09 AM
>> oracle.toplink.essentials.session.file:/J:/Chalk/ChalkLibrary/build/classes/-Chalk.sql
>> FINE: SELECT t0.PK1, t0.END_DATE, t0.START_DATE, t0.TEXT_FORMAT_TYPE,
>> t0.MESSAGE, t0.DTMODIFIED, t0.EVENT_TYPE, t0.SUBJECT, t0.USERS_PK1,
>> t0.CRSMAIN_PK1, t1.PK1, t1.END_DATE, t1.COURSE_ID, t1.START_DATE,
>> t1.COURSE_DESC, t1.COURSE_NAME, t2.PK1, t2.FIRSTNAME, t2.LASTNAME,
>> t2.EMAIL, t2.MIDDLENAME, t2.USER_ID FROM BB_BB60.CALENDAR t0,
>> BB_BB60.USERS t2, BB_BB60.COURSE_MAIN t1 WHERE ((t1.PK1 (+) =
>> t0.CRSMAIN_PK1) AND (t2.PK1 (+) = t0.USERS_PK1)) ORDER BY t0.START_DATE
>> ASC
>>
>> However, if I'm not using the javaagent, I receive the following NPE. I
>> went back and checked the original query (the one on Items) that I was
>> having problems with and whether the javaagent is enabled or not in that
>> case doesn't make a difference.
>>
>> Feb 27, 2007 11:54:48 AM edu.uchicago.at.chalk.ChalkService findEvents
>> FINEST: SELECT e FROM Event e LEFT JOIN FETCH e.course LEFT JOIN FETCH
>> e.user ORDER BY e.startTime
>> Feb 27, 2007 11:54:48 AM
>> oracle.toplink.essentials.session.file:/J:/Chalk/ChalkLibrary/build/classes/-Chalk.sql
>> FINE: SELECT t0.PK1, t0.START_DATE, t0.END_DATE, t0.DTMODIFIED,
>> t0.MESSAGE, t0.TEXT_FORMAT_TYPE, t0.EVENT_TYPE, t0.SUBJECT, t0.USERS_PK1,
>> t0.CRSMAIN_PK1, t1.PK1, t1.COURSE_NAME, t1.COURSE_ID, t1.START_DATE,
>> t1.COURSE_DESC, t1.END_DATE, t2.PK1, t2.MIDDLENAME, t2.LASTNAME,
>> t2.FIRSTNAME, t2.EMAIL, t2.USER_ID FROM BB_BB60.CALENDAR t0,
>> BB_BB60.USERS t2, BB_BB60.COURSE_MAIN t1 WHERE ((t1.PK1 (+) =
>> t0.CRSMAIN_PK1) AND (t2.PK1 (+) = t0.USERS_PK1)) ORDER BY t0.START_DATE
>> ASC
>> Feb 27, 2007 11:54:51 AM
>> oracle.toplink.essentials.session.file:/J:/Chalk/ChalkLibrary/build/classes/-Chalk
>> WARNING:
>> java.lang.NullPointerException
>> at
>> oracle.toplink.essentials.mappings.ForeignReferenceMapping.buildClone(ForeignReferenceMapping.java:122)
>> at
>> oracle.toplink.essentials.internal.descriptors.ObjectBuilder.populateAttributesForClone(ObjectBuilder.java:2136)
>> at
>> oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.populateAndRegisterObject(UnitOfWorkImpl.java:2836)
>> at
>> oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:673)
>> at
>> oracle.toplink.essentials.internal.sessions.UnitOfWorkIdentityMapAccessor.getAndCloneCacheKeyFromParent(UnitOfWorkIdentityMapAccessor.java:152)
>> at
>> oracle.toplink.essentials.internal.sessions.UnitOfWorkIdentityMapAccessor.getFromIdentityMap(UnitOfWorkIdentityMapAccessor.java:90)
>> at
>> oracle.toplink.essentials.internal.sessions.IdentityMapAccessor.getFromIdentityMap(IdentityMapAccessor.java:295)
>> at
>> oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:3075)
>> at
>> oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.registerExistingObject(UnitOfWorkImpl.java:3024)
>> at
>> oracle.toplink.essentials.queryframework.ObjectBuildingQuery.registerIndividualResult(ObjectBuildingQuery.java:319)
>> at
>> oracle.toplink.essentials.internal.descriptors.ObjectBuilder.buildWorkingCopyCloneNormally(ObjectBuilder.java:441)
>> at
>> oracle.toplink.essentials.internal.descriptors.ObjectBuilder.buildObjectInUnitOfWork(ObjectBuilder.java:406)
>> at
>> oracle.toplink.essentials.internal.descriptors.ObjectBuilder.buildObject(ObjectBuilder.java:372)
>> at
>> oracle.toplink.essentials.queryframework.ReportQueryResult.processItem(ReportQueryResult.java:205)
>> at
>> oracle.toplink.essentials.queryframework.ReportQueryResult.buildResult(ReportQueryResult.java:167)
>> at
>> oracle.toplink.essentials.queryframework.ReportQueryResult.<init>(ReportQueryResult.java:83)
>> at
>> oracle.toplink.essentials.queryframework.ReportQuery.buildObject(ReportQuery.java:579)
>> at
>> oracle.toplink.essentials.queryframework.ReportQuery.buildObjects(ReportQuery.java:628)
>> at
>> oracle.toplink.essentials.queryframework.ReportQuery.executeDatabaseQuery(ReportQuery.java:776)
>> at
>> oracle.toplink.essentials.queryframework.DatabaseQuery.execute(DatabaseQuery.java:609)
>> at
>> oracle.toplink.essentials.queryframework.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:677)
>> at
>> oracle.toplink.essentials.queryframework.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:731)
>> at
>> oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2219)
>> at
>> oracle.toplink.essentials.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:937)
>> at
>> oracle.toplink.essentials.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:909)
>> at
>> oracle.toplink.essentials.internal.ejb.cmp3.base.EJBQueryImpl.executeReadQuery(EJBQueryImpl.java:346)
>> at
>> oracle.toplink.essentials.internal.ejb.cmp3.base.EJBQueryImpl.getResultList(EJBQueryImpl.java:453)
>> at
>> edu.uchicago.at.chalk.ChalkService.findEvents(ChalkService.java:121)
>> at
>> edu.uchicago.at.chalk.ChalkServiceTest.testFindEvents(ChalkServiceTest.java:136)
>>
>> Jon
>>
>> ----- Original Message -----
>> From: "Tom Ware" <tom.ware_at_Oracle.com>
>> To: <persistence_at_glassfish.dev.java.net>
>> Sent: Monday, February 19, 2007 3:27 PM
>> Subject: Re: Is it legal to have a JPQL query that has multiple LEFT JOIN
>> FETCHes?
>>
>>
>>> Hi Jon,
>>>
>>> I am a bit surprised you are seeing an issue with the query you list
>>> below.
>>>
>>> Our test framework has some similar queries that work. For instance:
>>>
>>> "SELECT e from Employee e JOIN FETCH e.projects"
>>>
>>> Is the exception trace for your current query the same as for the
>>> previous query?
>>>
>>> BTW: I took a quick look at the BNF for JPQL and it seems your double
>>> joining query is not legal. JPQL requires a range_variable_declaration
>>> for each fetch join. That means:
>>> Item i LEFT JOIN FETCH i.reservations
>>>
>>> Is Legal
>>>
>>> And the second part:
>>>
>>> LEFT JOIN FETCH i.subItems
>>> Is missing something. (you can't join to "Item i" from the previous
>>> clause)
>>>
>>> -Tom
>>>
>>>
>>> Jon Miller wrote:
>>>
>>>>I just tried the following which throws a NPE too. So, it looks like
>>>>it's probably the fact that I'm mapping to the same class rather than
>>>>the fact that I had two LEFT JOINs which is what I thought might have
>>>>been the original problem. Is this a bug?
>>>>
>>>>SELECT i FROM Item i LEFT JOIN FETCH i.subItems ORDER BY i.name
>>>>
>>>>Jon
>>>>
>>>
>>> --
>>> Tom Ware
>>> Principal Software Engineer
>>> Oracle Canada Inc.
>>>
>>> Direct: (613) 783-4598
>>> Email: tom.ware_at_oracle.com
>>>
>>
>