Identify the duplicates in MySQL

To identify the duplicate entries in MySQL, use below query.

                     SELECT COUNT(*) as repetitions, group_concat(id, ' (', startTime, ', ', endTime, ') ' SEPARATOR ' | ') as row_data FROM GROUP BY startTime, endTime HAVING repetitions > 1

FYI,

1. id, startTime and endTime columns should be changed based on your table schema.
2. you can change the output format here like alias and the separator.