Namespace (System.Data.OracleClient) ของ asp.net 4.0 Visual studio 2010 ใช้ไม่ได้ต้องเปิดอารายเพิ่มหรือเปล่า คับ

OleDbConnection cn = new OleDbConnection();
        OleDbCommand cm = new OleDbCommand();
        OleDbDataAdapter da = new OleDbDataAdapter();
        DataTable dt = new DataTable();
        DataSet ds = new DataSet();
        StringBuilder sb = new StringBuilder();
        string sql = "";

        protected void Page_Load(object sender, EventArgs e)
        {
            if (cn.State == System.Data.ConnectionState.Open) cn.Close();
            cn.ConnectionString = "Provider=MSDAORA;Data Source=XXXX;Password=XXXX;User ID=XXX;";
            cn.Open();

            sb.Remove(0, sb.Length);
            sb.Append("select * from customer ");
            sb.Append(" where customerid = '000005'");
            sql = sb.ToString();

            da = new OleDbDataAdapter(sql, cn);
            if (ds.Tables["aa"] != null)
            {
                ds.Tables["aa"].Clear();
            }
            da.Fill(ds, "aa");
            dt = ds.Tables["aa"];

            if (dt.Rows.Count != 0)
            {
                DetailsView1.DataSource = dt;
                DetailsView1.DataBind();
            }
                
        }