Data Processing Extensions
Data processing extensions process query requests from the Report Processor component by performing the following tasks:
- Open a connection to a data source.
- Analyze a query and return a list of field names.
- Run a query against the data source and return a rowset.
- Pass parameters to a query, if required.
- Iterate through the rowset and retrieve data.
While all data processing extensions perform the tasks listed earlier, some extensions can also perform the following tasks:
- Analyze a query and return a list of parameter names used in the query.
- Analyze a query and return the list of fields used for grouping.
- Analyze a query and return the list of fields used for sorting.
- Provide a user name and password to connect to the data source.
- Pass parameters with multiple values to a query.
- Iterate through rows and retrieve auxiliary meta data.
Each data processing extension is specific to a particular type of data source. Reporting Services includes four data processing extensions: SQL Server, Oracle, ODBC, and OLE DB. Reporting Services can also use any ADO.NET data provider. Developers can use the extensibility model for Reporting Services to create additional data processing extensions. The following sections describe the data processing extensions that are provided with Reporting Services.
SQL Server Data Processing Extension
The SQL Server data processing extension uses the .NET Framework Data Provider for SQL Server to connect to and retrieve data from the SQL Server database engine. This extension can connect to SQL Server 7.0 or later. For SQL Server 6.5 and earlier, use the OLE DB data processing extension.
OLE DB Data Processing Extension
The OLE DB data processing extension uses the .NET Framework Data Provider for OLE DB . Using this extension, the report server can query any data source that has an OLE DB provider.
To retrieve Analysis Services data, use the OLE DB Provider for OLAP Services 8.0. Queries against Analysis Services are written using Multidimensional Expressions (MDX).
Oracle Data Processing Extension
The OLE DB data processing extension uses the Microsoft .NET Framework Data Provider for Oracle. This provider connects to and retrieves data from Oracle using the Oracle Call Interface (OCI) as provided by Oracle Client software. Oracle 8i Release 3 (8.1.7) Client or later must be installed on the report server for this provider to function.
ODBC Data Processing Extension
The OLE DB data processing extension uses the .NET Framework Data Provider for ODBC. This provider provides access to native ODBC drivers the same way the OLE DB .NET Data Provider provides access to native OLE DB providers.
Additional Data Processing Extensions
For information about creating and implementing additional extensions, see Extending Reporting Services.