How to join a List of string as comma separated characters and save in database in ASP.Net

Hi,

Please refer below Code,

C#

protected void Page_Load(object sender, EventArgs e)
{
    List<string> lista = new List<string>();
    lista.Add("1");
    lista.Add("2");
    lista.Add("3");
    Session["Canasta"] = lista;

    List<string> finalLista = (List<string>)Session["Canasta"];

    string allProductId = string.Join(",", finalLista);
    SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConString"].ConnectionString);
    SqlCommand cmd = new SqlCommand(string.Format("select * from products where productID in ({0})", allProductId), conn);
    conn.Open();
    SqlDataReader dr = cmd.ExecuteReader();
    gvProducts.DataSource = dr;
    gvProducts.DataBind();
    conn.Close();
}