查一下链接服务器
或者是这种方式
select *
from (SELECT *
FROM OpenDataSource('sqloledb', 'Data Source= "127.0.0.1";User ID=sa;Password=123').[DEVTEST].[dbo].[Person]) A,
(SELECT *
FROM OpenDataSource('sqloledb', 'Data Source= "127.0.0.1";User ID=sa;Password=1123').[MyTestDataBase].[dbo].[Person1]) B
where A.id = B.id