ExecuteReader in Asp.Net with Example

ExecuteReader is forward only retrieval of records and it is used to read the table values from first to last. It sends the CommandText to the Connection and builds a SqlDataReader.

Example :

Consider you have a " Employees " table in your database.

Now , you want to fetch all the record from your Employee table and show them in a GridView.

Add this code to youe aspx Page(Here i am using a GridView control to show Employee records).

<form id="form1" runat="server">
<asp:GridView ID="EmployeesList" runat="server">
</asp:GridView>
</form>

Write this code in your code behind file(Name.aspx.cs) :

//Add Following NameSpaces

using System;
using System.Data.SqlClient;
using System.Data;

//Add some code to your Page_Load Event

protected void Page_Load(object sender, EventArgs e)
{
if (! IsPostBack) //When you are posting the page for the first time then IsPostBack is false and !IsPostBack it becomes true
{
BindGridview();
}
}

// This method is used to bind gridview from database
protected void BindGridview()
{
using (SqlConnection connection = new SqlConnection("Write Your Connection string here.."))
{
connection.Open();
SqlCommand cmd = new SqlCommand("Select FirstName,LastName FROM Employees", connection);

SqlDataReader reader = cmd.ExecuteReader();
EmployeesList.DataSource = reader; //Adding datasource to our GridView
Employees.DataBind();  //Binding data to GridView
connection.Close();
}
}

In this way you can fetch(retrieve) records from your DataBase table using ExecuteReader  

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