SO-38572618

CREATE TABLE #t (
  Id INT,
  v1 INT,
  v2 INT,
  v3 INT
);

INSERT INTO #t
        (Id, v1, v2, v3)
VALUES
	(1,1,1,1),
	(2,2,2,2),
	(3,3,3,3),
	(4,4,4,4);

SELECT * FROM #t;

MERGE INTO #t AS TGT
USING ( VALUES
    (1,1,2,1),
    (5,5,5,5) ) AS SRC (Id, v1, v2, v3)
ON TGT.Id = SRC.Id
WHEN MATCHED THEN
    UPDATE SET TGT.v1 = SRC.v1,
               TGT.v2 = SRC.v2,
               TGT.v3 = SRC.v3
WHEN NOT MATCHED BY TARGET THEN
    INSERT (Id, v1, v2, v3)
    VALUES (SRC.Id,
            SRC.v1,
            SRC.v2,
            SRC.v3);

SELECT * FROM #t;