Nested Table Access Violation or wrong data (depends on Unicode)

Discussion of open issues, suggestions and bugs regarding ODAC (Oracle Data Access Components) for Delphi, C++Builder, Lazarus (and FPC)
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jdorlon
Posts: 172
Joined: Fri 05 Jan 2007 22:07

Nested Table Access Violation or wrong data (depends on Unicode)

Post by jdorlon » Thu 10 Jun 2021 13:40

Dear ODAC,

Note: The problem does not occur with all nested tables. I have only observed it when the nested table column is a table of VARCHAR2 fields.

Using this table...

Code: Select all

create or replace type varchar32_table as table of varchar2(32 char);

drop table odac_nestedtable2 purge;

create table ODAC_NESTEDTABLE2
(  code integer generated always as identity,
   CONTENT varchar32_table)
nested table content
  store as CONTENT_nt;

insert into ODAC_NESTEDTABLE2(CONTENT)
     values (varchar32_table('123456', 'abcdef'));

commit;
There are 2 bugs, depending on unicode settings.

1) if OraCall.OCIUnicode is false, and Session.UnicodeEnvironment = false, and Session.UseUnicode=False, then I get access violations as soon as I try to set the TOraNestedTable.DataSetField property.

2) If the above-named properties are all TRUE, there is no access violation, but the first character of each row in the nested table is missing. So instead of seeing "123456", and "abcdef", I see "23456" and "bcdef"

I am using Delphi version 10.1, compiled in 32 bit, using Oracle 19c database and 12.1.0.2 client (but I believe it happens with other client/server versions)

Demo app below. Just create the table above, then run the app and click either of the buttons.

Unit2.pas

Code: Select all

  
unit Unit2;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Data.DB, Vcl.Grids, Vcl.DBGrids, OraCall, DBAccess, Ora, OraSmart, MemDS,
  Vcl.ExtCtrls, Vcl.StdCtrls;

type
  TForm2 = class(TForm)
    NestedTable: TOraNestedTable;
    SmartQuery: TSmartQuery;
    dsMaster: TDataSource;
    Session: TOraSession;
    DBGrid1: TDBGrid;
    Splitter1: TSplitter;
    DataSource1: TDataSource;
    DBGrid2: TDBGrid;
    Panel1: TPanel;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.Button1Click(Sender: TObject);
begin
  // restart the app to try the other button
  Button1.Enabled := False;
  Button2.Enabled := False;

  OraCall.OCIUnicode := True;
  Session.Options.UnicodeEnvironment := True;
  Session.Options.UseUnicode := True;

  session.username := 'JDORLON';
  session.password := 'jdorlon';
  session.server := 'AZURE_19c_PLUG';
  session.Connected := True;

  SmartQuery.sql.add('select * from ODAC_NESTEDTABLE2');
  SmartQuery.Open;

  NestedTable.DataSetField := TDataSetField(SmartQuery.FieldByName('CONTENT'));
end;

procedure TForm2.Button2Click(Sender: TObject);
begin
  // restart the app to try the other button
  Button1.Enabled := False;
  Button2.Enabled := False;

  OraCall.OCIUnicode := False;
  Session.Options.UnicodeEnvironment := False;
  Session.Options.UseUnicode := False;

  session.username := 'JDORLON';
  session.password := 'jdorlon';
  session.server := 'AZURE_19c_PLUG';
  session.Connected := True;

  SmartQuery.sql.add('select * from ODAC_NESTEDTABLE2');
  SmartQuery.Open;

  NestedTable.DataSetField := TDataSetField(SmartQuery.FieldByName('CONTENT'));

end;

end.
Unit2.dfm

Code: Select all

object Form2: TForm2
  Left = 0
  Top = 0
  Caption = 'Form2'
  ClientHeight = 435
  ClientWidth = 577
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object Splitter1: TSplitter
    Left = 0
    Top = 205
    Width = 577
    Height = 6
    Cursor = crVSplit
    Align = alTop
    ExplicitTop = 120
  end
  object DBGrid1: TDBGrid
    Left = 0
    Top = 41
    Width = 577
    Height = 164
    Align = alTop
    DataSource = dsMaster
    TabOrder = 0
    TitleFont.Charset = DEFAULT_CHARSET
    TitleFont.Color = clWindowText
    TitleFont.Height = -11
    TitleFont.Name = 'Tahoma'
    TitleFont.Style = []
  end
  object DBGrid2: TDBGrid
    Left = 0
    Top = 211
    Width = 577
    Height = 224
    Align = alClient
    DataSource = DataSource1
    TabOrder = 1
    TitleFont.Charset = DEFAULT_CHARSET
    TitleFont.Color = clWindowText
    TitleFont.Height = -11
    TitleFont.Name = 'Tahoma'
    TitleFont.Style = []
  end
  object Panel1: TPanel
    Left = 0
    Top = 0
    Width = 577
    Height = 41
    Align = alTop
    TabOrder = 2
    object Button1: TButton
      Left = 0
      Top = 10
      Width = 265
      Height = 25
      Caption = 'Unicode - wrong data'
      TabOrder = 0
      OnClick = Button1Click
    end
    object Button2: TButton
      Left = 289
      Top = 10
      Width = 272
      Height = 25
      Caption = 'No Unicode - access violation'
      TabOrder = 1
      OnClick = Button2Click
    end
  end
  object NestedTable: TOraNestedTable
    Left = 163
    Top = 53
  end
  object SmartQuery: TSmartQuery
    Session = Session
    ObjectView = True
    Left = 118
    Top = 55
  end
  object dsMaster: TDataSource
    DataSet = SmartQuery
    Left = 128
    Top = 105
  end
  object Session: TOraSession
    Options.UseUnicode = True
    Options.UnicodeEnvironment = True
    LoginPrompt = False
    Left = 61
    Top = 47
  end
  object DataSource1: TDataSource
    DataSet = NestedTable
    Left = 188
    Top = 105
  end
end
Prooject1.dpr

Code: Select all

program Project2;

uses
  Vcl.Forms,
  Unit2 in 'Unit2.pas' {Form2};

{$R *.res}

begin
  Application.Initialize;
  Application.MainFormOnTaskbar := True;
  Application.CreateForm(TForm2, Form2);
  Application.Run;
end.

Thanks,
John Dorlon

MaximG
Devart Team
Posts: 1669
Joined: Mon 06 Jul 2015 11:34

Re: Nested Table Access Violation or wrong data (depends on Unicode)

Post by MaximG » Fri 18 Jun 2021 11:21

Thank you for the information. We will investigate the described issue and let you know the results shortly.

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