The DataView provides different views of the data stored in aDataTable. DataView can be used to sort, filter, and search in a DataTable , additionally we can add new rows and modify the content in a DataTable. DataViews can be created and configured both design time and run time . Changes made to a DataView affect the underlying DataTable automatically, and changes made to the underlying DataTable automatically affect any DataView objects that are viewing the DataTable.

We can create DataView in two different ways. We can use theDataView constructor, or you can create a reference to the DefaultView property of the DataTable. The DataView constructor can be empty, or it can take either a DataTable as a single argument, or a DataTable along with filter criteria, sort criteria, and a row state filter.

dataView = dataSet.Tables(0).DefaultView

The following source code shows how to create a DataView in VB.NET. Create a new VB.NET project and drag a DataGridView and a Button on default Form Form1 , and copy and paste the following Source Codeon button click event.

Imports System.Data.SqlClient Public Class Form1     Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click         Dim connetionString As String         Dim connection As SqlConnection         Dim command As SqlCommand         Dim adapter As New SqlDataAdapter         Dim ds As New DataSet         Dim dv As DataView         Dim sql As String   connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password"         sql = "Select  * from product"         connection = New SqlConnection(connetionString)         Try             connection.Open()             command = New SqlCommand(sql, connection)             adapter.SelectCommand = command             adapter.Fill(ds, "Create DataView")             adapter.Dispose()             command.Dispose()             connection.Close()              dv = ds.Tables(0).DefaultView             DataGridView1.DataSource = dv          Catch ex As Exception             MsgBox(ex.ToString)         End Try     End Sub End Class  

ADO stands for ActiveX Data Objects and it relies on COM whereas ADO.NET relies on managed providers defined by the .NET CLR (Common Language Runtime). ADO.NET provides consistent access todata sources such as SQL Server, as well as data sources exposed through OLE DB and XML. While there are similarities between ADO and ADO.NET, the way they operate and their foundations are quite different. The following are some Advantages of ADO.Net over ADO in basic level.

A major difference in creating connections with ADO and ADO.NET is that ADO fits all connections to all types of data sources into a single Connection object. ADO.NET can have separate Objects that represent connections to different data sources. In ADO.NET you can create multiple data provider namespaces to connect specifically with a particular data source, making access faster and more efficient and allowing each namespace to exploit the features of its targeted data provider.

  Dim connection As SqlConnection 
  connection = New SqlConnection("connetionString")

  Dim connection As OleDbConnection 
  connection = New OleDbConnection("connetionString")

ADO allows you to create client side cursors only whereas ADO.NET gives you the choice of either using client side or server side cursors.

ADO.NET introduces a new way of getting a single value from a query's results when you expect only one row and one column to return. The ADO.NET command object has an ExecuteScalar method which returns the first row and column's value from its associated query.

ADO.Net dataset represents in memory representation of a database. ADO recordsets is merely a set of rows retrieved from a data source.

ADO recordsets can hold data from one data source at a time. ADO.Net datasets can hold data from various sources and integrate the data and write it back to one or several data sources.

The ADO.NET Framework supports two models of Data Access Architecture, Connection Oriented Data Access Architecture and Disconnected Data Access Architecture.

In the case of Data Communication , ADO objects communicate in binary mode while ADO.NET uses XML for passing the data.

You can find more information on ADO to ADO.NET from the following link :

http://msdn.microsoft.com/en-us/magazine/cc163954.aspx

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. You can see from the following links how these Data Providers making connection to the specified data Sources.

SQL Server Connection

OLEDB Connection

ODBC Connection

The four Objects from the .Net Framework provide the functionality of Data Providers in ADO.NET. They are Connection Object, Command Object , DataReader Object and DataAdapter Object. The following link shows in details about these Objects.

Connection

Command

DataReader

DataAdapter

Connection String is a normal String representation which contains Database connection information to establish the connection between Datbase and the Application. The Connection String includes parameters such as the name of the driver, Server name and Database name , as well as security information such as user name and password. Data providers use a connection string containing a collection of parameters to establish the connection with the database.

The .NET Framework provides mainly three data providers: MicrosoftSQL Server, OLEDB and ODBC. Here you can see how to make connection string to these ADO.NET Data Providers.

Microsoft SQL Server Connection String

connetionString ="Data Source = ServerName; Initial Catalog = Databasename; User ID = UserName; Password=Password"

OLEDB Data Provider Connection String

connetionString = "Provider = Microsoft.Jet.OLEDB.4.0; Data Source = yourdatabasename.mdb;"

ODBC Connection String

connetionString = "Driver = {Microsoft Access Driver (*.mdb)}; DBQ = yourdatabasename.mdb;"

Note : You have to provide the necessary informations to the Connection String attributes.

In the following section you can see how to these ADO.NET Data Providers establish connection to the Databse in detail.

SQL Server Connection

OLEDB Connection

ODBC Connection