1. max 사이즈 조회SELECT @@group_concat_max_len 2. max 사이즈 변경SET @@group_concat_max_len = 1000000; 예) SELECT a.vehicle_seq, a.license_plate, GROUP_CONCAT(a.start_date ORDER BY a.start_date) start_date, GROUP_CONCAT(a.result_value ORDER BY a.start_date) result_value, LENGTH(GROUP_CONCAT(a.start_date ORDER BY a.start_date)) start_date_length, LENGTH(GROUP_CONCAT(a.result_value ORDER BY a.start_date)) r..
