Apple

The problem described in my previous post only happens when you build a fetch spech on a relation, and then attempt to prefetch another, flattened, many-to-many relationship.

I found the solution in a rather old post by P. Robinson:

http://wodeveloper.com/omniLists/eof/2000/September/msg00099.html

The following code works:

EOQualifier qual = Observation.INDICATOR.is(indicator);

EOEntity myEntity = EOModelGroup.defaultGroup().entityNamed(Observation.ENTITY_NAME);

qual = myEntity.schemaBasedQualifier(qual);

EOFetchSpecification fs = new EOFetchSpecification(Observation.ENTITY_NAME,qual,null);

fs.setPrefetchingRelationshipKeyPaths(new NSArray(new String[] {"dimensions"}));

observations = indicator.editingContext().objectsWithFetchSpecification(fs);

The obligation of building a schema-based qualifier is a bug I guess, and I am a bit disappointed it has not been fixed in 8 years...

JPM

Le 3 nov. 08 à 22:33, Jean Pierre Malrieu a écrit :

Hi,

I have many-to-many relationship between entity Observation and entity Dimension.
This many-to-many is flattened.

I am fetching observations, trying to prefetch the "dimensions" relationship:

   EOQualifier qual = Observation.Indicator.is(indicator);
   EOFetchSpecification fs = new EOFetchSpecification(Observation.ENTITY_NAME,qual,null);
   fs.setPrefetchingRelationshipKeyPaths(new NSArray(new String[] {"dimensions"}));
   observations = indicator.editingContext().objectsWithFetchSpecification(fs);

I am getting the following exception:

java.lang.IllegalStateException: sqlStringForKeyValueQualifier: attempt to generate SQL for com.webobjects.eocontrol.EOKeyValueQualifier (observation.series = (com.fylab.educstat.eos.Series)'<com.fylab.educstat.eos.Series pk:"1000001">') failed because attribute identified by key 'observation.series' was not reachable from from entity 'DimensionObservation'