UPDATE FROM

DECLARE @TEMP1 TABLE(ID INT,Name NVARCHAR(30),Ex INT)
DECLARE @TEMP2 TABLE(ID INT,Name NVARCHAR(30),Ex INT)

INSERT INTO @TEMP1(ID,Name,Ex)
SELECT 1,'1',0 UNION ALL
SELECT 2,'2',0 UNION ALL
SELECT 3,'3',0 UNION ALL
SELECT 4,'4',0 UNION ALL
SELECT 5,'5',0 UNION ALL
SELECT 6,'6',0 UNION ALL
SELECT 7,'7',0 

INSERT INTO @TEMP2(ID,Name,Ex)
SELECT 1,'1',0 UNION ALL
SELECT 2,'2',0 UNION ALL
SELECT 3,'3',0 UNION ALL
SELECT 4,'4',0 UNION ALL
SELECT 5,'5',0 UNION ALL
SELECT 6,'6',0 UNION ALL
SELECT 7,'7',0 

UPDATE @TEMP1 SET Name = 2 FROM @TEMP1 AS T1 LEFT JOIN @TEMP2 AS T2 ON T1.ID = T2.ID
SELECT * FROM @TEMP1