-- 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 |
-- -- List the type of the services in alphabetical order.

SELECT service_type_code FROM services ORDER BY service_type_code;