是因为版本不对吗，怎么实际查出来不是这个效果
1.select   * from eb_user a left join eb_user_behaviour b on a.uid=b.uid  where b.active_time=(select MAX(c.active_time)  from eb_user_behaviour c where c.uid=a.uid)  用时0.4s不到
2.select   a.*,b.active_time from eb_user a left join eb_user_behaviour b on a.uid=b.uid  left join eb_user_behaviour c on c.uid=b.uid  group by a.uid,b.date,b.active_time having b.active_time=MAX(c.active_time);  用时接近10s