select
t.periodth,max(t.current),min(t.current),max(t.voltage),min(t.voltage),avg(t.voltage)
from motorpam t
group by t.periodth
t.periodth,max(t.current),min(t.current),max(t.voltage),min(t.voltage),avg(t.voltage)
from motorpam t
group by t.periodth
ls够快...
ps:尽是近视进士
不是求所有参数的平均,只求最大两个数的平均!