-- https://school.programmers.co.kr/learn/courses/30/lessons/164671
SELECT concat('/home/grep/src','/',f.board_id,'/',f.file_id,f.file_name,f.file_ext) file_path
from used_goods_board b
join used_goods_file f
on b.board_id=f.board_id
where b.views= (select max(views)
from used_goods_board)
order by f.file_id desc