ID相同，A表修改与B表的其他列

CREATE TABLE #TA
(
ID    int,
UName VARCHAR(10)
)
GO
INSERT INTO #TA
SELECT 1,'A'
UNION ALL
SELECT 2,'A'
UNION ALL
SELECT 3,'B'
UNION ALL
SELECT 4,'B'
UNION ALL
SELECT 5,'C'
UNION ALL
SELECT 6,'C'
UNION ALL
SELECT 7,'C'

GO

CREATE TABLE #TB
(
ID    int,
UName VARCHAR(10)
)
GO
INSERT INTO #TB
SELECT 1,'1'
UNION ALL
SELECT 2,'2'
UNION ALL
SELECT 3,'3'
UNION ALL
SELECT 4,'4'
UNION ALL
SELECT 5,'5'
UNION ALL
SELECT 6,'6'
UNION ALL
SELECT 7,'7'

update B
set B.UName=A.UName
from #TA AS A
inner join #TB AS B
on B.ID =  A.ID

SELECT * FROM #TA
SELECT * FROM #TB

DROP TABLE  #TA
DROP TABLE  #TB