mysql分组后只取每组的第一条

SELECT * FROM
(SELECT bs_file_resource_t.*
FROM

bs_file_resource_t 
Join bs_apply_car_t
on bs_file_resource_t.source_id = bs_apply_car_t.car_id

WHERE car_status=1 AND source_type=1 AND res_type = 1
ORDER BY write_date DESC,res_kind LIMIT 10000) t 
GROUP BY source_id,res_kind

通过source_id分组后，又分为三组，每组取一条数据