Conditional replace in fetchxml

Hello Guys,

I have got a sql query which needs to be converted to fetchxml  scenerio is in a entity  got a field as

TXNTYP = 'AO'  when when AO is called it should be replaced by  'Activate Offer'  please find the below query

select @resp = CASE @type WHEN 'AO' THEN 'Activate Offer' WHEN 'NM' THEN 'New Member' WHEN 'RM' THEN 'Renewal Member'
WHEN 'CR' THEN 'Cash Redeem' WHEN 'SR' THEN 'Spend Redeem' WHEN 'RR' THEN 'Referral Redeem'
WHEN 'CP' THEN 'Change Profile' WHEN 'VR' THEN 'Voucher Redeem' WHEN 'OT' THEN 'Other Transaction' WHEN 'SP' THEN 'Spend Transactions' END