ADO.NET

ActiveX Data Objects .NET

ADO.NET provides consistent access to data sources such as SQL Server and XML, and to data sources exposed through OLE DB and ODBC. Applications use ADO.NET to connect to these data sources and retrieve, handle, and update the data that they contain.

ADO.NET Components

The two main components of ADO.NET for accessing and manipulating data are the .NET Framework data providers and the DataSet.

.NET Framework Data Providers

The .NET Framework Data Providers are components that have been explicitly designed for data manipulation and fast, forward-only, read-only access to data.

• The Connection object provides connectivity to a data source.

• The Command object enables access to database commands to return data, modify data, run stored procedures, and send or retrieve parameter information.

• The DataReader provides a high-performance stream of data from the data source.

• Finally, the DataAdapter provides the bridge between the DataSet object and the data source. The DataAdapter uses Command objects to execute SQL commands at the data source to both load the DataSet with data and reconcile changes that were made to the data in the DataSet back to the data source.

DataSet

The ADO.NET DataSet is explicitly designed for data access independent of any data source. As a result, it can be used with multiple and differing data sources, used with XML data, or used to manage data local to the application.

The DataSet contains a collection of one or more DataTable objects consisting of rows and columns of data, and also primary key, foreign key, constraint, and relation information about the data in the DataTable objects.