What are event details associated with the event of this type code?
select t1.event_details from events as t1 join services as t2 on t1.service_id = t2.service_id where t2.service_type_code = 'Marriage'
How many among them are with "success"?
select count ( * ) from events as t1 join services as t2 on t1.service_id = t2.service_id where t2.service_type_code = 'Marriage' and event_details = 'Success'