mysql group by 得到的最大值和最小值怎么去判断

SELECT sno,MAX(degree),MIN(degree) FROM score
GROUP BY sno;
得到
101 99 77
102 87 65
103 88 72
104 75 81
我要怎么得到sno 最大值小于90 最小值大于70的？求帮忙解答

SELECT sno,MAX(degree) as m1,MIN(degree) as m2 FROM score
GROUP BY sno
where m1 < 90 and m2 > 70

select * from ( select xx,max(ff) m1 ,min(ff) m2 from score group by ff) t where m1 70;