# 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&quo...