Distributed Queries on Multiple Instances of SQL Server
Specifying an instance of SQL Server 2005 on a server running multiple instances of SQL Server 2005 requires no syntax changes to the Transact-SQL elements that are used in distributed queries. Instances can be specified in distributed queries by using one of the following methods:
- Specify a server name by using the syntax 'server_name\instance_name' in the @datasrc parameter of sp_addlinkedserver.
- Specify 'server=server_name\instance_name' in a connection string.
If an instance is not specified, the distributed query connects to the default instance of SQL Server 2005 on the specified server.
The following examples show specifying a specific instance named Payroll on a server named London.
-- Define a linked server on an instance of SQL Server by using @datasrc.
sp_addlinkedserver
@server = 'LondonPayroll1',
@srvproduct = ' ',
@provider = 'SQLNCLI',
@datasrc = 'London\Payroll'
-- Define a linked server on an instance of SQL Server by using
-- server_name\instance_name in a provider string.
sp_addlinkedserver
@server = 'LondonPayroll2',
@srvproduct = ' ',
@provider = 'SQLNCLI',
@provstr = 'Server=London\Payroll'
-- Specify an instance of SQL Server in OPENDATASOURCE
-- by using a provider string.
SELECT *
FROM OPENDATASOURCE('SQLNCLI',
'Data Source=London\Payroll;Integrated Security=SSPI')
.AdventureWorks.HumanResources.Employee
-- Specify an instance of SQL Server in OPENROWSET
-- by using a provider string.
SELECT a.*
FROM OPENROWSET(
'SQLNCLI',
'Server=London\Payroll;Trusted_Connection=yes',
AdventureWorks.HumanResources.Employee) AS a
See Also
Concepts
Distributed Queries
SQL Native Client OLE DB Provider
Other Resources
sp_addlinkedserver (Transact-SQL)