I find I need to cast my resultlist but your error doesn't suggest that is
the issue but anyway :

List<Corporation> result = (List<Corporation>)query.getResultList();



-----Original Message-----
From: Zhanming Qi [mailto:[email protected]] 
Sent: Monday, 31 May 2010 11:10 PM
To: [email protected]
Subject: openjpa-2.0 how join fetch work?


Hi,

I have two Entity, Corporation and Division, a simple one to many relation.

@Test
public void testQueryFetchJoins(){
        EntityManager em = entityManagerProvider.get();
        Query query = em.createQuery(
                        "SELECT c " +
                        "       FROM Corporation c JOIN FETCH c.divisions "
+
                        "       WHERE c.name = '" + CORP_A_NAME + "'");
        List<Corporation> result = query.getResultList();
        for (Corporation corporation : result ){
                System.out.println(corporation.getName());  
        }
        em.clear();
}

I test this method, and it print the right SQL Script on console.
but the test does not pass.

This is the failure trace:

<openjpa-2.0.0-r422266:935683 nonfatal general error>
org.apache.openjpa.persistence.PersistenceException: null
FailedObject: SELECT c  FROM Corporation c JOIN FETCH c.divisions
WHERE
c.name = 'Corporation A' [java.lang.String]
        at org.apache.openjpa.kernel.BrokerImpl.find(BrokerImpl.java:986)
        at org.apache.openjpa.kernel.BrokerImpl.find(BrokerImpl.java:885)
        at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.load(JDBCStoreManager.java:1
050)
        at
org.apache.openjpa.jdbc.sql.AbstractResult.load(AbstractResult.java:280)
        at
org.apache.openjpa.jdbc.sql.SelectImpl$SelectResult.load(SelectImpl.java:234
4)
        at
org.apache.openjpa.jdbc.sql.AbstractResult.load(AbstractResult.java:274)
        at
org.apache.openjpa.jdbc.kernel.InstanceResultObjectProvider.getResultObject(
InstanceResultObjectProvider.java:59)
        at
org.apache.openjpa.lib.rop.EagerResultList.<init>(EagerResultList.java:36)
        at org.apache.openjpa.kernel.QueryImpl.toResult(QueryImpl.java:1246)
        at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:1005)
        at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:861)
        at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:792)
        at
org.apache.openjpa.kernel.DelegatingQuery.execute(DelegatingQuery.java:542)
        at
org.apache.openjpa.persistence.QueryImpl.execute(QueryImpl.java:288)
        at
org.apache.openjpa.persistence.QueryImpl.getResultList(QueryImpl.java:302)
        at
com.qizm.tutorial.jpa.model.CorporationTest.testQueryFetchJoins(CorporationT
est.java:210)
        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
org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.
java:44)
        at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.j
ava:15)
        at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.ja
va:41)
        at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.jav
a:20)
        at
org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunne
r.java:79)
        at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.jav
a:71)
        at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.jav
a:49)
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
        at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestRef
erence.java:46)
        at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:3
8)
        at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRu
nner.java:467)
        at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRu
nner.java:683)
        at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.
java:390)
        at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner
.java:197)
Caused by: java.lang.NullPointerException
        at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.setInverseRelation(JDBCStore
Manager.java:489)
        at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.initializeState(JDBCStoreMan
ager.java:449)
        at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.initialize(JDBCStoreManager.
java:342)
        at
org.apache.openjpa.kernel.DelegatingStoreManager.initialize(DelegatingStoreM
anager.java:112)
        at
org.apache.openjpa.kernel.ROPStoreManager.initialize(ROPStoreManager.java:57
)
        at
org.apache.openjpa.kernel.BrokerImpl.initialize(BrokerImpl.java:1005)
        at org.apache.openjpa.kernel.BrokerImpl.find(BrokerImpl.java:963)
        ... 38 more

Here is the openjpa.Log
1672  aUnit  TRACE  [main] openjpa.jdbc.SQL - <t 24512621, conn 2310757>
executing prepstmnt 28730188 
SELECT t0.ID, t0.version, t0.CORPORATION_NAME, t1.CORPORATION_ID, t1.ID, 
        t1.version, t1.CITY, t1.STATE, t1.STREET, t1.ZIP_CODE, t1.mumber, 
        t1.name 
    FROM CORPORATION t0 INNER JOIN DIVISION t1 ON t0.ID = t1.CORPORATION_ID 
    WHERE (t0.CORPORATION_NAME = ?) 
[params=(String) Corporation A]

This SQL is right, but how did I can not pass this:List<Corporation> result
= query.getResultList();

Thanks.
Zhanming
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