访问数据库不会更新asp.net

Question

我有表，在我编辑和删除按钮的操作列上。 编辑按钮打开模型。在模态中，我有一个更新按钮，这是代码，但我的数据库不会更新。

protected void Btnupdate_Click(object sender, EventArgs e)
    {
        foreach (RepeaterItem RI in rptEdit.Items)
        {
            Label id = RI.FindControl("Pid") as Label;
            TextBox prdname = RI.FindControl("prdname") as TextBox;
            TextBox prdprice = RI.FindControl("prdprice") as TextBox;
            TextBox prdshortdesc = RI.FindControl("prdshortdesc") as TextBox;
            TextBox prdtype = RI.FindControl("prdtype") as TextBox;
            TextBox prdbrand = RI.FindControl("prdbrand") as TextBox;

            string ConnString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\Table.accdb";
            string SqlString = "UPDATE ProductList SET Pname = ?";

            using (OleDbConnection conn = new OleDbConnection(ConnString))
            {
                using (OleDbCommand cmd = new OleDbCommand(SqlString, conn))
                {
                    cmd.CommandType = CommandType.Text;
                    cmd.Parameters.AddWithValue("FirstName", prdname.Text);
                    conn.Open();
                    cmd.ExecuteNonQuery();
                }
            }
        }
    }