select
    BD.ID, BD.OWNER,
    CC.EXPMONTH, CC.EXPYEAR, CC.CARDNUMBER,
    BA.ACCOUNT, BA.BANKNAME, BA.SWIFT,
    case
        when CC.CREDITCARD_ID is not null then 1
        when BA.ID is not null then 2
        when BD.ID is not null then 0
    end
from
    BILLINGDETAILS BD
    left outer join CREDITCARD CC on BD.ID=CC.CREDITCARD_ID
    left outer join BANKACCOUNT BA on BD.ID=BA.ID