Hello Martin,

I just tried the approach that you've suggested. And it seems that it works. I was able to query withing one resource by using query like this one:

CDOQuery cdoQuery = transaction.createQuery("hql", "from Product where resourceId=:id");
cdoQuery.setParameter("id", resourceCDOId);

However, what I've noticed is that for some EClasses from my ecore model corresponding tables in my MySQL database have null value in the resource_id column, but has some value in the container_id column, while for other EClasses, in the corresponding tables resource_id value is set correctly.
This happens for following situation.
For example, I have Class1 in the ecore model having an attribute A that is 0 or more references of Class2. Then in my MySQL database I have corresponding table for Class1 with resource_id values set correctly and nulls in container_id, and corresponding table for Class2 will nulls in the resource_id column and some values in the container_id

Using the query above, I can successfully query for the instances of Class1 for a given resource_id, but not for Class2. I assume I can probably use the container_id columns and perform a join to get all instances of Class2.

Is the join the only way?

Thank you.