Error in SQL Server Merge Statement: The column prefix 'Updated' does not match with a table name or alias name used in the query

Question

I have the following SQL statement and I get the error:

MERGE Target_Table AS Tg
USING #Temp_SourceTable AS So
ON (Tg.COl1 = So.COL1 AND 
    Tg.COL2 = So.COL2AND 
    Tg.COL3= So.COL3)
WHEN MATCHED THEN 
    Update set Tg.COl4= Tg.COL4 + So.COL4,
           Tg.COL5= '2014-01-03'
OUTPUT $action, Updated.*;

Error: The column prefix 'Updated' does not match with a table name or alias name used in the query

Any thoughts on what I am missing here??

Answer 1

Updated just does not exist. There are just INSERTED and DELETED. For updates, both are filled. Use INSERTED to get the new values.