mysql case when

select 
    a.*, 
    case
        when a.age = 1 then ‘一岁了‘
        when a.age = 2 then ‘二岁了‘
        when a.age >= 3 and a.age <= 8  then (
            case 
                when a.age = 3 then ‘三岁了‘
                when a.age = 4 then ‘四岁了‘
                when a.age = 5 then ‘五岁了‘
                when a.age = 6 then ‘六岁了‘
                when a.age = 7 then ‘七岁了‘
                when a.age = 8 then ‘八岁了‘
            end
        )
        when a.age > 8 then ‘超过8岁了‘
    end as agezh
from
    users a;