题解 | #计算25岁以上和以下的用户数量#

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
    #按条件做分类
    group by age_cut;