Please refer this code
HTML
<span>Roll No</span>
<asp:TextBox ID="txtRollNumber" runat="server" />
<asp:Button ID="btnDeleteStudent" Text="Delete" OnClick="DeleteStudent" runat="server" />
<hr />
<asp:GridView ID="gvStudents" HeaderStyle-BackColor="#3AC0F2" HeaderStyle-ForeColor="White"
runat="server" AutoGenerateColumns="false">
<Columns>
<asp:BoundField DataField="RollNumber" HeaderText="Roll Number" ItemStyle-Width="150" />
<asp:BoundField DataField="StudentName" HeaderText="Student Name" ItemStyle-Width="150" />
</Columns>
</asp:GridView>
Namespace
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
C#
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
this.PopulateStudents();
}
}
private void PopulateStudents()
{
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand("SELECT RollNumber, StudentName FROM Students", con))
{
con.Open();
this.gvStudents.DataSource = cmd.ExecuteReader();
this.gvStudents.DataBind();
con.Close();
}
}
}
protected void DeleteStudent(object sender, EventArgs e)
{
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand("DELETE FROM Students WHERE RollNumber = @RollNumber", con))
{
cmd.Parameters.AddWithValue("@RollNumber", Convert.ToInt32(this.txtRollNumber.Text.Trim()));
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
}
Response.Redirect(Request.Url.AbsoluteUri);
}
Screenshot