In this article I will explain with an example, how to use ExecuteReader method of SQLCommand in ASP.Net using C# and VB.Net.
 
 
Database
Here I am making use of Microsoft’s Northwind Database. You can download it from here.
Download and install Northwind Database
 
 
HTML Markup
The following HTML Markup consists of:
GridView – For displaying data.
Columns
The GridView consists of three BoundField columns.
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField ItemStyle-Width="150px" DataField="CustomerID" HeaderText="CustomerID" />
        <asp:BoundField ItemStyle-Width="150px" DataField="ContactName" HeaderText="Contact Name" />
        <asp:BoundField ItemStyle-Width="150px" DataField="City" HeaderText="City" />
    </Columns>
</asp:GridView>
 
 
Namespaces
You will need to import the following namespaces
C#
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
 
VB.Net
Imports System.Data
Imports System.Configuration
Imports System.Data.SqlClient
 
 
Fetching Data using ExecuteReader in ASP.Net
Inside the Page Load event handler, the BindGrid method is called.
BindGrid
Inside the BindGrid method, the connection string is fetched from the Web.Config file and object of SqlConnection class is created using it.
Note: For more details on how to read Connection String from Web.Config file, please refer my article Read (Get) Connection String from Web.Config file in ASP.Net using C# and VB.Net.
 
Then, an object of SqlCommand class is created and the INSERT query is passed to it as parameter.
And the connection is opened and the ExecuteReader method is executed and fetched data is assigned to the DataSource property of the GridView.
Finally, the GridView is populated.
C#
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}
 
private void BindGrid()
{
    string query = "SELECT TOP 10 * FROM Customers";
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand(query))
        {
            cmd.Connection = con;
            con.Open();
            gvCustomers.DataSource = cmd.ExecuteReader();
            gvCustomers.DataBind();
            con.Close();
        }
    }
}
 
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
        Me.BindGrid()
    End If
End Sub
 
Private Sub BindGrid()
    Dim query As String = "SELECT TOP 10 * FROM Customers"
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand(query)
            cmd.Connection = con
            con.Open()
            gvCustomers.DataSource = cmd.ExecuteReader()
            gvCustomers.DataBind()
            con.Close()
        End Using
    End Using
End Sub
 
 
Screenshot
Using SQLCommand ExecuteReader Example in ASP.Net with C# and VB.Net
 
 
Downloads
Download Code