DML for Updating Receipt Routing from "Not Inspected" to "Direct"

UPDATE po.rcv_transactions 
SET    routing_header_id = 3 
WHERE  shipme nt_header_id IN 
       ( 
              SELECT shipment_header_id 
              FROM   rcv_shipment_headers 

              WHERE  receipt_num IN (<<MRN_NUMBER>>)

       );

Note: 

SELECT routing_name, 
       routing_header_id 
FROM   rcv_routing_headers;