第三题我自己的想法……但是完全没通过不知道哪里错了 select s2.match_rank,round(avg(s2.match_time),4),max(s2.match_time) from ( select s.old_rank match_rank,strftime('%s',s.matcht)-strftime('%s',s.startt) match_time from (select t.t_when,max(t.tole_id) role_id,max(t.old_rank) old_rank,max(t1.t_when) matcht,max(t2.t_when) startt from (select t_when,tole_id,old_rank from battle_result) t join success_match t1 on t.tole_id=t1.role_id and t1.t_when<t.t_when join start_match t2 on t.tole_id=t2.role_id and t2.t_when<t.t_when group by t.t_when) s) s2 group by s2.match_rank