Microsoft SQL Server MERGE Merge using EXCEPT
Example
Use EXCEPT to prevent updates to unchanged records
MERGE TargetTable targ
USING SourceTable AS src
ON src.id = targ.id
WHEN MATCHED
AND EXISTS (
SELECT src.field
EXCEPT
SELECT targ.field
)
THEN
UPDATE
SET field = src.field
WHEN NOT MATCHED BY TARGET
THEN
INSERT (
id
,field
)
VALUES (
src.id
,src.field
)
WHEN NOT MATCHED BY SOURCE
THEN
DELETE;
