第2个回答 2018-08-02
select
*
from(
select a.workid,b.username,a.stime,row_number over (partition by b.id,b.ares order by a.stime desc ) rank1 from worktable a,usertable b
where a.userid=b.userid group by b.id,b.ares order by a.stime desc)
where a.rank=1
将用户id和时间建索引本回答被网友采纳