CREATE TABLE participants (Participant_ID VARCHAR(255), participant_details VARCHAR(255)); CREATE TABLE Participants_in_Events (Participant_ID VARCHAR(255))
How many events had participants whose details had the substring 'Dr.'
    
SQL: SELECT COUNT(*) FROM participants AS T1 JOIN Participants_in_Events AS T2 ON T1.Participant_ID = T2.Participant_ID WHERE T1.participant_details LIKE '%Dr.%'