Chapter 10. ADO.NET and XML

IN THIS CHAPTER

• Basic Reading and Writing of XML

• Creating an XmlReader from a Command Object

• The XmlDataDocument Object

Setting aside the marketing hype, XML does address a lot of real development and business problems. That's especially true as the integration of diverse systems and platforms, both within a company and between companies, is becoming increasingly important. One of the fundamental design goals for Visual Studio.NET was to offer extensive support for XML from the ground up.

XML is the persistence and transmission format for the DataSet. That is, when a DataSet is saved to disk, the format that it's saved in is XML, rather than some proprietary and/or binary format. Also, when a DataSet is passed from one computer or process to another, it is passed as an XML stream.

In earlier chapters, we showed that the DataSet doesn't know or care about the source of the data that it contains. As far as it is concerned, data is data, regardless of where it comes from. The same is true when the data source is XML. The DataSet offers flexible support for reading and writing XML data and/or schema information. This support goes well beyond the simple support that was patched onto previous versions of ADO. Moreover, together with the XmlDataDocument, an application can both view and manipulate data in a DataSet by using relational tools, XML tools, or both, depending on the particular situation.

Using XML, along with its related technologies and tools, is a very broad topic, most of which is beyond the scope of this book. In Chapter 9 we presented the basics of the extensive XML support provided by the .NET Framework. In this chapter we present the basics of integration between ADO.NET and XML. Further information on these topics can be found in the help files for VS.NET and the .NET Framework and at the MSDN Web site, http://msdn.microsoft.com.