I am writing an SSIS package to run on SQL Server 2008. How do you do an UPSERT in SSIS?
IF KEY NOT EXISTS INSERT ELSE IF DATA CHANGED UPDATE ENDIF ENDI
See SQL Server 2008 - Using Merge From SSIS. I've implemented something like this, and it was very easy. Just using the BOL page Inserting, Updating, and Deleting Data using MERGE was enough to get me going.