In this query i can get the event_name which occurs with both types of worker role. But I want to have all of the rows showing and then some kind of tic column to show that the ones that match both conditions, ie in both types of worker roles.
select wv1.worker_role, wv1.event_name from event_worker_role_view wv1 where wv1.worker_role in('A31 Service Provider')
and wv1.event_name in (select wv2.event_name from event_worker_role_view wv2 where
wv2.worker_role = 'A29i Licensed Clinician')