ADO.NET is a data access technology from Microsoft .Net Framework , which provides communication between relational and non-relational systems through a common set of components . ADO.NET consist of a set of Objects that expose data access services to the .NET environment. ADO.NET is built for disconnected architecture , so it enables truly disconnected Data Access and Data Manipulation through its Dataset Object, which is completely independent from the Data Source.
The two key components of ADO.NET are Data Providers and DataSet . The .Net Framework includes mainly three Data Providers for ADO.NET. They are the Microsoft SQL Server Data Provider, OLEDB Data Provider and ODBC Data Provider. SQL Server uses the SqlConnection object , OLEDB uses the OleDbConnection Object and ODBC uses OdbcConnection Object respectively.
The four Objects from the .Net Framework provide the functionality of Data Providers in the ADO.NET. They are Connection Object, Command Object , DataReader Object and DataAdapter Object. The Connection Object provides physical connection to the Data Source. The Command Object uses to perform SQL statement or stored procedure to be executed at the Data Source. The DataReader Object is a stream-based , forward-only, read-only retrieval of query results from the Data Source, which do not update the data. Finally the DataAdapter Object , which populate a Dataset Object with results from a Data Source .
DataSet provides a disconnected representation of result sets from the Data Source, and it is completely independent from the Data Source. DataSet provides much greater flexibility when dealing with related Result Sets. DataSet consists of a collection of DataTable objects that you can relate to each other with DataRelation objects. The DataTable contains a collection of DataRow and DataCoulumn Object which contains Data. The DataAdapter Object provides a bridge between the DataSet and the Data Source.
In the following section you can see each of the ADO.NET components in details with vb.net source code.