The query will check for occurrence with an active status where the occurrence has no client enrolments with an active status.
Once this list is generated you can also update these statuses in bulk by clicking the Action button and choosing Update enrolment status. This will allow you to update the status of the occurrence for all occurrences that show up in this list.
You can download this query file here: Active Occurrences with No Active Enrolments.vtdq