Select Duplicate rows ( select duplicate in in_s_no)

SELECT `booking_no`, COUNT(*) c FROM booking_main_list  GROUP BY `booking_no` HAVING c > 1;


Remove duplicate rows(remove duplicates in booking_no using unique 'id')

DELETE FROM booking_main_list
    WHERE id NOT IN (select minid from (SELECT MIN(id) as minid FROM booking_main_list GROUP BY booking_no) e) 