База DBF и Query

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ADODB, DB, Grids, DBGrids, StdCtrls;
 
type
  TForm1 = class(TForm)
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    ADOConnection1: TADOConnection;
    ADOTable1: TADOTable;
    ADOQuery1: TADOQuery;
    ListBox1: TListBox;
    ComboBox1: TComboBox;
    Label1: TLabel;
    Button1: TButton;
    procedure ListBox1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
  AppFolderPath: String;
 
 
implementation
 
{$R *.dfm}
 
 
procedure TForm1.FormCreate(Sender: TObject);
 var fs:TSearchRec;
 begin
  Label1.Caption:='Aua?aou aaco';
  AppFolderPath:=copy(ExtractFilePath(Application.ExeName),1,length(ExtractFilePath(Application.ExeName)))+'BD';
//  ComboBox1.ItemIndex:=0;
  if FindFirst(AppFolderPath+'\*.dbf', faAnyFile, fs)=0 then
  repeat
     ListBox1.AddItem(fs.Name,nil);
  until FindNext(fs)<>0;
  FindClose(fs);
end;
 
procedure TForm1.ListBox1Click(Sender: TObject);
var
i: Integer;
begin
ADOTable1.Active:= false;
ADOConnection1.Connected:=false;
ADOConnection1.ConnectionString:='Provider=Microsoft.Jet.OLEDB.4.0;Data Source="' +AppFolderPath + '";Extended Properties="DBASE IV;";"';
    ADOConnection1.LoginPrompt:=False;
    ADOConnection1.Mode:=cmRead;
    ADOConnection1.Connected:=True;
    DataSource1.DataSet:=ADOTable1;
    ComboBox1.Items.Clear;
  ADOConnection1.Connected:=True;
    ADOTable1.TableName:=ListBox1.Items[ListBox1.ItemIndex];
    ADOTable1.Active:=True;
   ComboBox1.ItemIndex:=ADOTable1.FieldCount;
    for i:= 1 to (ADOTable1.FieldCount - 1) do
    //While not IntToStr(ADOTable1.FieldCount) do
    begin
       ComboBox1.Items.Add(ADOTable1.Fields[i].FieldName);
    //   ADOQuery1.Next;
    end;
    DBGrid1.DataSource:=DataSource1;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
begin
  ADOTable1.Active:=False;
  ADOQuery1.SQL.Text:= 'Select RFA From KADRY_,DBF Where R069 is null';
  ADOQuery1.Active:= True;
end;
 
end.

ADOConnection1.ConnectionString:='Provider=MSDASQL.1;Persist Security Info=False;Data Source=dBASE Files;Mode=Read;Extended Properties="DSN=dBASE Files;DefaultDir=X:\Projects\Delphi7\FreeWork\Kadry;DriverId=533;MaxBufferSize=2048;PageTimeout=5;"';
 
...
 
 
 ADOQuery1.SQL.Text:= 'Select RFA From KADRY_.DBF Where R069 is null';  //должна быть точка перед DBF

procedure TForm1.ListBox1Click(Sender: TObject);
var
  i: Integer;
begin
  ADOTable1.Active:= false;
  ADOConnection1.Connected:=false;
  //ADOConnection1.ConnectionString:=