sql中取一行最大值或者最小值

原始資料和目标資料

實作SQL語句(最大)

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

實作SQL語句(最小)

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