Где я допустил ошибку .

в SQL - select r4 from main group by r4


procedure TForm10.SpeedButton1Click(Sender: TObject);
Var Kol:Integer;
Text:String;
begin
Text:='';
Memo1.Text:='';

Query1.Close;
Query1.Open;
Query1.First;
For Kol:=1 to Query1.RecordCount do
Begin
Query2.Close;
Query2.Sql.Clear;
Query2.Sql.add('select * from main where r4=:Par1');
Query2.ParamByName('Par1').AsString:=Query1.FieldByName('r4').AsString;
Query2.open;
If (Query2.RecordCount>1) and (Kol<Query1.RecordCount) Then
Begin
Text:=Text+Query1.FieldByName('r4').AsString+',';
End;
If (Query2.RecordCount>=1) and (Kol=Query1.RecordCount) Then
Begin
Text:=Text+')';
End;
Query1.Next;
End;
If Text<>'' Then
Begin
kOL:=Pos(')',Text);
Delete(Text,Kol-1,2);
Memo1.Text:=Text;
Query2.Close;
Query2.Sql.Clear;
Query2.Sql.add('c');
Query2.open;
End;
Query1.Close;

end;

end.