select
    MEMBER_CODE as CODE
    , LAST_NAME as L_NAME
    , FIRST_NAME as F_NAME 
from
    member_mst 
where
    case 
        when substr(last_name, 2, 1) != '田' 
            then LAST_NAME = substr(last_name, 2, 1) 
        else true 
        end 
order by
    MEMBER_CODE desc