题解 | #计算25岁以上和以下的用户数量#
计算25岁以上和以下的用户数量
http://www.nowcoder.com/practice/30f9f470390a4a8a8dd3b8e1f8c7a9fa
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://www.nowcoder.com/questionTerminal/30f9f470390a4a8a8dd3b8e1f8c7a9fa
来源:牛客网
select (case when age>=25 then '25岁及以上' else '25岁以下' end) as age_cut,
count(device_id) as number
from user_profile
group by age_cut