SUBSTRING_INDEX(GROUP_CONCAT(DISTINCT use_end_time ORDER BY use_end_time DESC),',',1) use_end_time,
SUBSTRING_INDEX(GROUP_CONCAT(DISTINCT add_time ORDER BY add_time DESC),',',1) add_time
FROM (
SELECT use_start_time,use_end_time,use_type,universities_colleges_id FROM universities_colleges_jurisdiction_experimental_system WHERE use_type != 0
SELECT use_start_time,use_end_time,use_type,universities_colleges_id,add_time FROM universities_colleges_jurisdiction_experimental_system WHERE use_type != 0
UNION ALL
SELECT use_start_time,use_end_time,use_type,universities_colleges_id FROM universities_colleges_jurisdiction_curriculum_resources WHERE use_type != 0
SELECT use_start_time,use_end_time,use_type,universities_colleges_id,add_time FROM universities_colleges_jurisdiction_curriculum_resources WHERE use_type != 0
)t
GROUP BY universities_colleges_id
)a ON a.universities_colleges_id = t.universities_colleges_id