Re: [eclipselink-users] Outer joined one-to-many question

[Laird Nelson <ljnelson@xxxxxxxxx>]

On Mon, Aug 19, 2013 at 2:04 PM, Andrei Ilitchev <andrei.ilitchev@xxxxxxxxxx> wrote:

Should be something like:

"SELECT e FROM Employee e LEFT OUTER JOIN e.projects projects WHERE (e.projects IS EMPTY OR EXISTS(SELECT p FROM Project p WHERE (p IN(e.projects) AND p.name LIKE 'A%')))"

Now I'm even more confused.  :-)

I get the gist of what you're saying.

Now I'm getting NullPointerExceptions from inside EclipseLink.

My old query said this:

SELECT p.id

  FROM Parent p

  LEFT OUTER JOIN p.children child

 WHERE child IS NULL OR child.x = 'y' ....

My new query says this:

SELECT p.id

  FROM Parent p

  LEFT OUTER JOIN p.children child

 WHERE child IS EMPTY OR child.x = 'y' ....

Doing this causes this:

Query failed to prepare, unexpected error occurred: [java.lang.NullPointerException].

Internal Exception: java.lang.NullPointerException

Query: JPAQuery(name="Parent.foobar" )

at org.eclipse.persistence.exceptions.QueryException.prepareFailed(QueryException.java:1555)

at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:625)

at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:575)

at org.eclipse.persistence.internal.sessions.AbstractSession.processJPAQueries(AbstractSession.java:2161)

at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:442)

at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.postConnectDatasource(DatabaseSessionImpl.java:676)

at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.login(DatabaseSessionImpl.java:634)

at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:208)

at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:488)

... 39 more

Caused by: java.lang.NullPointerException

at org.eclipse.persistence.internal.jpa.parsing.EmptyCollectionComparisonNode.generateExpression(EmptyCollectionComparisonNode.java:57)

Is there something about the join alias ("child") that is causing this? Or...?

Best,

Laird

 

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