Get Url from database and redirect on Button click in ASP.Net

You want to get the URL based on selected value of Second DropDownList.

If you need to get the Url from the database and redirect to the Selected brand Page please refer this code.

C#

protected void Redirect(object sender, EventArgs e)
{
    if (ddlbrands.Enabled)
    {
        string constr = ConfigurationManager.ConnectionStrings["conString2"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("SELECT Url FROM BrandsTable WHERE BrandName = @BrandName", con))
            {
                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    cmd.Parameters.AddWithValue("@BrandName", this.ddlbrands.SelectedItem.Text);
                    con.Open();
                    object url = cmd.ExecuteScalar();
                    con.Close();
                    if (url != null)
                    {
                        Response.Redirect(url.ToString());
                    }
                }
            }
        }
    }
}