ADO.NET 1.x was the successor to ActiveX Data Objects 2.6 (ADO). The main goal of ADO.NET 1.x was to enable developers to easily create distributed, data-sharing applications in the .NET Framework. The main goals of ADO.NET today are to improve the performance of existing features in ADO.NET 1.x, to provide easier use and to add new features without breaking backward compatibility.
Throughout this chapter, when ADO.NET is mentioned without a version number after it (that is, 1.x, 2.0, or 3.5), the statement applies to all versions of ADO.NET.
ADO.NET 1.x was built upon industry standards such as XML, and it provided a data-access interface to communicate with data sources such as SQL Server and Oracle. ADO.NET 3.5 builds upon these concepts, while increasing performance. Applications can use ADO.NET to connect to these data sources and retrieve, manipulate, and update data. ADO.NET 3.5 does not break any compatibility with ADO.NET 2.0 or 1.x; it only adds to the stack of functionality.
In solutions that require disconnected or remote access to data, ADO.NET 3.5 uses XML to exchange data between programs or with Web pages. Any component that can read XML can make use of ADO.NET components. A receiving component does not even have to be an ADO.NET component if a transmitting ADO.NET component packages and delivers a data set in an XML format. Transmitting information in XML-formatted data sets enables programmers to easily separate the data-processing ...