OpenDataSource Usage

Posted 2020-06-11

OpenDataSource 使用ad hoc 链接信息链接到Remote Data Source，而不是使用Linked Server，而OpenDataSource Row Set函数的作用是在使用 four-part object name 定位一个object时，提供ServerName\InstanceName。SQL Server 任何一个Object完全指定的命名结构依次是:Server Name，Instance Name，Database name，Schema Name，Object name。

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

Openquery 函数是不确定性的函数，就是说，对于相同的输入值，不保证每次返回的值都是相同的。

All rowset functions are nondeterministic. This means these functions do not always return the same results every time they are called, even with the same set of input values.

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 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 Server 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.

 

Example

SELECT *
FROM OPENDATASOURCE(‘SQLNCLI‘,
    ‘Data Source=London\Payroll;Integrated Security=SSPI‘)
    .AdventureWorks2012.HumanResources.Employee


SELECT * FROM OPENDATASOURCE(‘Microsoft.Jet.OLEDB.4.0‘,
‘Data Source=C:\DataFolder\Documents\TestExcel.xls;Extended Properties=EXCEL 5.0‘)...[Sheet1$] ;

引用文档：MSDN OPENDATASOURCE (Transact-SQL)