题解 | #查看不同年龄段的用户明细#

# select
#     device_id,
#     gender,
#     case
#         when age < 20 then "20岁以下"
#         when age >= 20
#         and age <= 24 then "20-24岁"
#         when age >= 25 then "25岁及以上"
#         else "其他"
#     end age_cut
# from
#     user_profile

select 
    device_id,
    gender,
    if(age<20,"20岁以下",
        if(age>=20 and age<=24,"20-24岁",
            if(
                age>=25,
                "25岁及以上",
                "其他"
                ))) 
    as age_cut
from user_profile