ASP.NET ExecuteReader

The ExecuteReader() in SqlCommand Object sends the SQL statements to the Connection Object and populate a SqlDataReader Object based on the SQL statement. When the ExecuteReader method in SqlCommand Object execute , it will instantiate a SqlClient.SqlDataReader Object.

Dim reader As SqlDataReader = cmd.ExecuteReader
SqlDataReader reader = cmd.ExecuteReader();

The SqlDataReader Object is a stream-based , forward-only, read-only retrieval of query results from the Data Source, which do not update the data it contains. The SqlDataReader cannot be created directly from code, they can created only by calling the ExecuteReader method of a Command Object.

The following ASP.NET program execute sql statement and using ExecuteReader mthod.


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ""> <html xmlns=""> <head id="Head1" runat="server"> <title>Untitled Page</title> </head> <body> <form id="form1" runat="server"> <div> <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" /> <br /> <asp:ListBox ID="ListBox1" runat="server"></asp:ListBox> <br /> <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> </div> </form> </body> </html>
Full Source | C#
using System; using System.Data ; using System.Data.SqlClient ; using System.Configuration; public partial class _Default : System.Web.UI.Page { protected void Button1_Click(object sender, EventArgs e) { string connectionString = ConfigurationManager.ConnectionStrings["SQLDbConnection"].ToString(); SqlConnection connection = new SqlConnection(connectionString); string sql = "select au_lname,au_fname from authors"; try { connection.Open(); SqlCommand cmd = new SqlCommand(sql, connection); SqlDataReader reader = cmd.ExecuteReader(); while (reader.Read()) { ListBox1.Items.Add(reader.GetValue(0) + " " + reader.GetValue(1)); } connection.Close(); } catch (Exception ex) { Label1.Text = "Error in ExecuteReader " + ex.ToString(); } } }
Full Source | VB.NET
Imports System.Data Imports System.Data.SqlClient Imports System.Configuration Partial Class _Default Inherits System.Web.UI.Page Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click Dim connectionString As String Dim connection As SqlConnection connectionString = ConfigurationManager.ConnectionStrings("SQLDbConnection").ToString connection = New SqlConnection(connectionString) Dim sql As String = "select au_lname,au_fname from authors" Try connection.Open() Dim cmd As New SqlCommand(sql, connection) Dim reader As SqlDataReader = cmd.ExecuteReader While reader.Read() ListBox1.Items.Add(reader.Item(0) & " " & reader.Item(1)) End While connection.Close() Catch ex As Exception Label1.Text = "Error in ExecuteReader " & ex.ToString End Try End Sub End Class

Click the following links to see full source code

C# Source Code
VB.NET Source Code