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OPENDATASOURCE (Transact-SQL)

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Provides ad hoc connection information as part of a four-part object name without using a linked server name.

Topic link iconTransact-SQL Syntax Conventions

Syntax

OPENDATASOURCE ( provider_name, init_string )

Arguments

  • provider_name
    Is the name registered as the PROGID of the OLE DB provider used to access the data source. provider_name is a char data type, with no default value.

  • init_string
    Is the connection string passed to the IDataInitialize interface of the destination provider. The provider string syntax is based on keyword-value pairs separated by semicolons, such as: 'keyword1=value;keyword2=value'.

    For specific keyword-value pairs supported on the provider, see the Microsoft Data Access SDK. This documentation defines the basic syntax. The following table lists the most frequently used keywords in the init_string argument.

    Keyword OLE DB property Valid values and description

    Data Source

    DBPROP_INIT_DATASOURCE

    Name of the data source to connect to. Different providers interpret this in different ways. For SQL Native Client OLE DB provider, this indicates the name of the server. For Jet OLE DB provider, this indicates the full path of the .mdb file or .xls file.

    Location

    DBPROP_INIT_LOCATION

    Location of the database to connect to.

    Extended Properties

    DBPROP_INIT_PROVIDERSTRING

    The provider-specific connect-string.

    Connect timeout

    DBPROP_INIT_TIMEOUT

    Time-out value after which the connection try fails.

    User ID

    DBPROP_AUTH_USERID

    User ID to be used for the connection.

    Password

    DBPROP_AUTH_PASSWORD

    Password to be used for the connection.

    Catalog

    DBPROP_INIT_CATALOG

    The name of the initial or default catalog when connecting to the data source.

    Integrated Security

    DBPROP_AUTH_INTEGRATED

    SSPI, to specify Windows authentication

Remarks

OPENDATASOURCE can be used to access remote data from OLE DB data sources only when the DisallowAdhocAccess registry option is explicitly set to 0 for the specified provider, and the Ad Hoc Distributed Queries advanced configuration option is enabled. When these options are not set, the default behavior does not allow for ad hoc access.

The OPENDATASOURCE function can be used in the same Transact-SQL syntax locations as a linked-server name. Therefore, OPENDATASOURCE can be used as the first part of a four-part name that refers to a table or view name in a SELECT, INSERT, UPDATE, or DELETE statement, or to a remote stored procedure in an EXECUTE statement. When executing remote stored procedures, OPENDATASOURCE should refer to another instance of SQL Server. OPENDATASOURCE does not accept variables for its arguments.

Like the OPENROWSET function, OPENDATASOURCE should only reference OLE DB data sources that are accessed infrequently. Define a linked server for any data sources accessed more than several times. Neither OPENDATASOURCE nor OPENROWSET provide all the functionality of linked-server definitions, such as security management and the ability to query catalog information. All connection information, including passwords, must be provided every time that OPENDATASOURCE is called.

Important

Windows Authentication is much more secure than SQL Server Authentication. You should use Windows Authentication whenever possible. OPENDATASOURCE should not be used with explicit passwords in the connection string.

Permissions

Any user can execute OPENDATASOURCE. The permissions that are used to connect to the remote server are determined from the connection string.

Examples

The following example creates an ad hoc connection to the Payroll instance of SQL Server on server London, and queries the AdventureWorks.HumanResources.Employee table.

SELECT *
FROM OPENDATASOURCE('SQLNCLI',
    'Data Source=London\Payroll;Integrated Security=SSPI')
    .AdventureWorks.HumanResources.Employee

See Also

Reference

OPENROWSET (Transact-SQL)
sp_addlinkedserver (Transact-SQL)

Other Resources

Distributed Queries
Identifying a Data Source by Using an Ad Hoc Name

Help and Information

Getting SQL Server 2005 Assistance

Change History

Release History

14 April 2006
New content:
  • Added the example.