Benefits of ADO.NET

ADO.NET provides three important benefits:

• A simple object model that provides strong support for disconnected data access

• Strong integration with XML, especially the DataSet object

• Performance advantages, including dedicated data providers, and objects dedicated to fast, efficient, streaming data access

• Automatic connection management, including pooling

The ADO.NET object model was designed with a focus on the developer, and the typical data access scenarios for which they code. Broadly speaking, data access falls into two areas: retrievals and updates.

Many Web applications are built solely around data retrievals, and provide few (if any) update screens. For this data access scenario, ADO.NET provides objects that support streaming data access, which is the fastest , most efficient way to retrieve data.

For Web applications that provide update capabilities, data access and synchronization has always been problematic . ADO.NET provides strong support for disconnected data access, including a specialized format called the DiffGram , which preserves a record of original and modified values in the same DataSet. Now, a Web application can deliver a disconnected DataSet to a client, which can in turn perform updates on the data. When the client is done, they can send the DataSet back to the Web server to have it synchronize the data changes. The DiffGram records error information for each row of data, which it can communicate back to the client in the event that the Web server encounters synchronization errors with the data updates.

Finally, ADO.NET provides strong integration with XML, particularly the DataSet object, which supports a range of methods for reading and writing XML and Extensible Schema Definition (XSD) schema information. The .NET Framework provides a number of classes for processing XML and XSD files, including reading documents, validating documents against schemas, and transforming XML using XSLT. Taken together, the System.Data namespace and the System.Xml namespace pack a powerful one-two punch that allows you to process XML data with a high level of sophistication. Some XML- related operations, such as generating XSD schemas and uploading XML documents to a DataSet, are a breeze to perform using the .NET Framework classes. Other operations, such as validating an XML document against multiple schema files, remain a difficult experience. But the functionality is there, and with perseverance your applications will be able to process XML in very sophisticated ways. This chapter pays particular attention to the strong integration of ADO.NET with XML.