if与 case when ... end 都可以用来做判断 select if(age>=25,'25岁及以上','25岁以下' ) as age_cut, count(device_id) as number from user_profile group by age_cut select age_cut,count(device_id)as number from(Select if(age>=25,'25岁及以上','25岁以下' )as age_cut,device_id From user_profile)u2 Group by age_cut 链接:https...