GP SQL Trigger SOP Transactions

I need to add an update trigger on the SOP10100.ReqShipDate field My question here is how do I specify the SOPNUMBE and SOPTYPE fields coming down from SOP10100?

UPDATE SOP20100.ReqShipDate = SOP10100.ReqShipDate Where 'Put Parameters Here'

We need to have the ship date field on the lines always updated to the ship dates field on the header whenever the header ship date field is changed.