sql中取一行最大值或者最小值

原始数据和目标数据

实现SQL语句(最大)

select
shop,
month,
greatest(dz,fz,sp) as max
from
tablename;
           

实现SQL语句(最小)

select
shop,
month,
least (dz,fz,sp) as min
from
tablename;