human
Schema:
Services (Service_ID, Service_Type_Code)
Participants (Participant_ID, Participant_Type_Code, Participant_Details)
Events (Event_ID, Service_ID, Event_Details)
Participants_in_Events (Event_ID, Participant_ID)
Please answer with SQL.
assistant
Sure, I understand.
human
What ids have more than one participant? | Which kind of ID do you mean? | Event ID and Service ID
assistant
SELECT T1.event_id , T1.service_id FROM EVENTS AS T1 JOIN Participants_in_Events AS T2 ON T1.Event_ID = T2.Event_ID GROUP BY T1.Event_ID HAVING COUNT( * ) > 1 ;