Hi nedash,

Use FileUpload control to select the file.

Check this example. Now please take its reference and correct your code.

HTML

<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button Text="Restore" runat="server" OnClick="OnRestore" />

Namespaces

C#

using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.IO;

VB.Net

Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient
Imports System.IO

Code

C#

protected void Restore(object sender, EventArgs e)
{
    if (FileUpload1.HasFile)
    {
        FileUpload1.SaveAs(Server.MapPath("~/") + Path.GetFileName(FileUpload1.PostedFile.FileName));
        string data = System.IO.File.ReadAllText(Server.MapPath("~/") + Path.GetFileName(FileUpload1.PostedFile.FileName));
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString);
        SqlCommand cmd = new SqlCommand(data, con);
        cmd.CommandType = CommandType.Text;
        cmd.Connection = con;
        con.Open();
        cmd.ExecuteNonQuery();
        con.Close();
        File.Delete(Server.MapPath("~/") + Path.GetFileName(FileUpload1.PostedFile.FileName));
    }
}

VB.Net

Protected Sub Restore(ByVal sender As Object, ByVal e As EventArgs)
    If FileUpload1.HasFile Then
        FileUpload1.SaveAs(Server.MapPath("~/") & Path.GetFileName(FileUpload1.PostedFile.FileName))
        Dim data As String = System.IO.File.ReadAllText(Server.MapPath("~/") & Path.GetFileName(FileUpload1.PostedFile.FileName))
        Dim con As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("constr").ConnectionString)
        Dim cmd As SqlCommand = New SqlCommand(data, con)
        cmd.CommandType = CommandType.Text
        cmd.Connection = con
        con.Open()
        cmd.ExecuteNonQuery()
        con.Close()
        File.Delete(Server.MapPath("~/") & Path.GetFileName(FileUpload1.PostedFile.FileName))
    End If
End Sub