ถามเกี่ยวกับ dropdownlist 2 ตัว ต้องการเลือกให้เปลี่ยนตามข้อมูลที่มีแต่มีerrorครับ (query จาก database)

         Dbcon oCon = new Dbcon();
        oCon.OpenConnection();

        string strSql = "SELECT DISTINCT CONVERT(VARCHAR(10),pDate,103) AS pDate,pTime "  +
                          "FROM pRound T1 WHERE T1.pID=@ppID ";

        SqlCommand oCommandSql = new SqlCommand(strSql, oCon.DbConnect);
        oCommandSql.Parameters.Add("@ppID", SqlDbType.Int).Value = hdnpID.Value;
        SqlDataAdapter oAdapterSql = new SqlDataAdapter(oCommandSql);
        DataTable dtdropdown1 = new DataTable();
        oAdapterSql.Fill(dtdropdown1);
        oAdapterSql = null;
         //-----------------------------------------------------------------------------------------------------------------------------
        string sql = "SELECT DISTINCT CONVERT(VARCHAR(10),pDate,103) AS pDate,pTime "  +
                          "FROM pRound T1 WHERE T1.pID=@ppID and CONVERT(VARCHAR(10),pDate,103) = @ppDate";

        SqlCommand oSqlCommand = new SqlCommand(sql, oCon.DbConnect);
        oSqlCommand.Parameters.Add("@ppID", SqlDbType.Int).Value = hdnpID.Value;
        oSqlCommand.Parameters.Add("@ppDate", SqlDbType.VarChar).Value = hdndd1.Value;
        SqlDataAdapter osqlAdapter = new SqlDataAdapter(oSqlCommand);
        DataTable dtdropdown2 = new DataTable();
        osqlAdapter.Fill(dtdropdown2);
        osqlAdapter = null;
        oCon.Dispose();

        DataTable dtDdl1 = dtdropdown1.DefaultView.ToTable("dtDdl1", true, "pDate");
        DataTable dtDdl2 = dtdropdown2.DefaultView.ToTable("dtDdl2", true, "pTime");
        
        ddl1.Items.Clear();
        ddl1.DataSource = dtDdl1;
        ddl1.DataTextField = "pDate";
        ddl1.DataValueField = "pDate";
        ddl1.DataBind();
        
        ddl2.Items.Clear();
        ddl2.DataSource = dtDdl2;
        ddl2.DataTextField = "pTime";
        ddl2.DataValueField = "pTime";
        ddl2.DataBind();
        
        ddl1.SelectedValue = hdnddl1.Value; //hidden field
        ddl2.SelectedValue = hdnddl2.Value;

		'*** Default Value ***'
		myDDL2.SelectedIndex = myDDL2.Items.IndexOf(myDDL2.Items.FindByValue("W"))  '*** By DataValueField ***'
		'myDDL2.SelectedIndex = myDDL2.Items.IndexOf(myDDL2.Items.FindByText("Woman"))  '*** By DataTextField ***'