Saving ADO Recordsets in XML Format

January 2000

By Kamaljit Bath and Dax Hawkins

Summary: Microsoft® ActiveX® Data Objects (ADO) 2.0 allowed you to persist Recordset objects both to and from files in ADTG (Advanced Data Table Gram) format. Using this feature, you could save a Recordset to a disk file and later reopen it from the file. ADO 2.1 extended Recordset persistence by allowing you to persist Recordset objects in XML format, albeit with limited support for XML. ADO 2.1 did not support persistence of hierarchical Recordset objects or persistence of Recordset objects with pending changes.

For ADO versions 2.5 and later, some of these restrictions on XML support have been removed. Furthermore, ADO now allows persistence of both the XML and ADTG formats to any object that supports the COM IStream interface, such as the ADO Stream object, the IIS 5.0 Response object, and the XML DOM Document object. Additionally, this release provides built-in integration between ADO and Active Server Pages (ASP) in Internet Information Server (IIS) 5.0, and between Remote Data Service (RDS) and ASP.

This paper includes the following sections:

• ADO Recordset Persistence   Describes the feature in brief and how you can take advantage of it to write scalable distributed applications. Includes some code examples.
• XML Persistence Format   Describes the XML format generated by ADO in detail to help developers understand the format so that they can transform it using XSL/DOM or other techniques.
• Integration with ASP   Describes how ADO can be used with ASP to generate XML directly from the server.
• XSL Transformations   Describes how XSL can be applied to generated XML.
• Integration with DOM   Describes how the XML document object model can be used to manipulate the generated XML.
• Security Considerations   Describes security issues that affect the behavior of a Recordset used in a control in an Internet zone.
• Appendix   Contains troubleshooting information and the definition of urn:schemas-microsoft-com:rowset.

The paper assumes that you are familiar with Microsoft Visual C++®, Microsoft Visual Basic®, ADO, OLE DB, COM, and XML.