IF OBJECT_ID('tempdb..#TestMerge') IS NOT NULL
DROP TABLE #TestMerge;
GO

CREATE TABLE #TestMerge
(
ID INT NOT NULL,
K INT NOT NULL,
T VARCHAR(40) NOT NULL
);

;WITH X AS
(
SELECT n FROM (VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) v(n)
)
INSERT INTO #TestMerge(ID, K, T)
SELECT TOP 30 RN, RN % 4, RIGHT(CONCAT('0000', RN % 17), 3) FROM
(
SELECT
-1 + ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS RN
FROM X AS X1, X AS X2
) XX
ORDER BY RN ;

SELECT * FROM #TestMerge
ORDER BY K, T;

IF OBJECT_ID('tempdb..#IDS') IS NOT NULL
DROP TABLE #IDS;

CREATE TABLE #IDS(KK INT NOT NULL);
INSERT INTO #IDS(KK) VALUES(0), (1)

;



WITH t AS (
SELECT t.* FROM #TestMerge t
INNER JOIN #IDS I ON I.KK = t.K
)
MERGE t AS target
USING (
SELECT ID, K, T + T AS T FROM #TestMerge WHERE K IN (1, 0) AND ID <= 20
UNION ALL
SELECT 9999, 0, '999999'
UNION ALL
SELECT 8888, 1, '888888'
) AS source
ON source.ID = target.ID AND
source.K = target.K
WHEN MATCHED AND (
source.T <> target.T
)
THEN UPDATE SET
T = source.T
WHEN NOT MATCHED BY TARGET THEN
INSERT (ID, K, T)
VALUES (
ID, K, T
)
WHEN NOT MATCHED BY SOURCE
THEN
DELETE
;

SELECT * FROM #TestMerge
ORDER BY K, T;