-- Database schema
| Services : Service_ID [ INT ] primary_key , Service_Type_Code [ TEXT ] | Participants : Participant_ID [ INT ] primary_key , Participant_Type_Code [ TEXT ] , Participant_Details [ TEXT ] | Events : Event_ID [ INT ] primary_key , Service_ID [ INT ] Events.Service_ID = Services.Service_ID , Event_Details [ TEXT ] | Participants_in_Events : Event_ID [ INT ] primary_key Participants_in_Events.Event_ID = Events.Event_ID , Participant_ID [ INT ] Participants_in_Events.Participant_ID = Participants.Participant_ID |
-- -- Which service id and type has the least number of participants?

SELECT T3.service_id ,  T4.Service_Type_Code FROM participants AS T1 JOIN Participants_in_Events AS T2 ON T1.Participant_ID  =  T2.Participant_ID JOIN EVENTS AS T3 ON T2.Event_ID   =  T3.Event_ID JOIN services AS T4 ON T3.service_id  =  T4.service_id GROUP BY T3.service_id ORDER BY count(*) ASC LIMIT 1;