Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE participants_in_events ( event_id number, participant_id number )
TABLE: CREATE TABLE participants ( participant_id number, participant_type_code text, participant_details text )
TABLE: CREATE TABLE events ( event_id number, service_id number, event_details text )
TABLE: CREATE TABLE services ( service_id number, service_type_code text )

### Question ###
How many events had participants whose details had the substring 'Dr.

### Accurate 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.%'