unit TEST_U1;
// Thomas Wassermann
// Nur ein kleines Beispiel
//!!! Threadproperties nur im OnThreadTerm verwenden nicht abgesichert
interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, ADODB, StdCtrls, Grids, DBGrids;

type


  TMyThread=Class(TThread)
    private
      FAC:TAdoConnection;
      FADS:TadoDataset;
      FConnectionString :String;
      FSQL:String;
      FErrorString: String;
      FStream: TStringStream;
    public
    Constructor Create(Const ConnectionString,SQL:String;TermProc:TNotifyEvent);overload;
    Destructor Destroy;override;
    Procedure Execute;override;
    Property Dataset:TAdodataset read Fads;
    Property ErrorString:String read FErrorString ;
    Property ResultStream:TStringStream read FStream;
  End;




  TForm3 = class(TForm)
    Button1: TButton;
    ADS: TADODataSet;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    ADOConnection1: TADOConnection;
    procedure Button1Click(Sender: TObject);
  private
    procedure OnThreadTerm(Sender: TObject);
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form3: TForm3;

implementation
uses ActiveX,ComObj,ADOInt;
{$R *.dfm}


procedure TForm3.OnThreadTerm(Sender: TObject);
var
    Stream: TStringStream;
    RS:Variant;
begin
    if TMyThread(Sender).Dataset.Active then
        begin
          RS := CreateOleObject('ADODB.Recordset');
          RS.Open(TStreamAdapter.Create(TMyThread(Sender).ResultStream) as IUnknown);
          Ads.Recordset := IUnknown(RS) as _Recordset;
        end

    else Showmessage(TMyThread(Sender).ErrorString);
end;

procedure TForm3.Button1Click(Sender: TObject);
begin
   TMyThread.Create('Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=TP2003;Data Source=DEVTESTSERV\SQL2005'
                    ,'Select * from Abfragen'
                    ,OnThreadTerm);
end;

{ TMyThread }

constructor TMyThread.Create(const ConnectionString, SQL: String; TermProc: TNotifyEvent);
begin
   inherited Create(false);
   FreeOnTerminate := true;
   OnTerminate := TermProc;

   FConnectionString := ConnectionString;
   FSQL := SQL;
end;

destructor TMyThread.Destroy;
begin
  FAC.Free;
  FADS.Free;
  Fstream.free;
  Couninitialize;
  inherited;

end;

procedure TMyThread.Execute;
begin
   Coinitialize(nil);
   FAC:=TAdoConnection.Create(Application);
   FAC.LoginPrompt := false;
   FAC.ConnectionString := FConnectionString;
   FADS:=TadoDataset.Create(nil);
   FAds.Connection := FAC;
   FADS.CommandText := FSQL;
   FStream := TStringStream.Create('');
   try
   FAds.Open;
   FAds.Recordset.Save(TStreamAdapter.Create(Fstream) as IUnknown,adPersistXML);
   FStream.Position := 0;
   except
     on E:Exception do FErrorString := E.Message;
   end;

end;



end.