OQL query not working

Here in a simplified form the OQL query I try to execute. select ac/ID as name, sum(aItemVerlof/AantalUren) as aantalurenverlof from Administration.Account as ac left join ac/AsbestInventarisatie.AgendaItem_Account/AsbestInventarisatie.AgendaItem as aItemVerlof on aItemVerlof/AsbestInventarisatie.AgendaItem_Category/AsbestInventarisatie.Category/Verlof = 'true' group by ac/ID It's validated by the modeler but when executing I get the following error: group by ac/ID, DATEPART(YEAR, alleItems/DatumUitvoeringStart) at x.a(SourceFile:57) Caused by: java.util.ConcurrentModificationException at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372) at java.util.AbstractList$Itr.next(AbstractList.java:343) It has something to do with the on constraint of the left join. It seems that references can not be used in on joins. Rephrasing it to a WHERE clause is not an option because it's a left join and aItemVerlof can be null. Any idea's?
1 answers

I have seen more OQL parsing OK and giving errors.

I always end up rewriting the OQL with for example a sub-select in the from clause or EXISTS sub-queries.