Динамическое создание полей 2

procedure TForm1.Button1Click(Sender: TObject);
var
  f: TField;
  i: integer;
begin
  Table1.Close;
  for i := 0 to Table1.FieldDefs.Count - 1 do
    Table1.FieldDefs.Items[i].CreateField(Table1);
  f := TStringField.Create(Table1);
  f.Name := 'Table1CalcField';
  f.FieldName := 'CalcField';
  f.DisplayLabel := 'CalcField';
  f.Calculated := True;
  f.DataSet := Table1;
  Table1.Open;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  f1, f2: TField;
begin
  Table1.Close;
  f1 := TStringField.Create(Table1);
  f1.Name := 'Table1CalcField';
  f1.FieldName := 'CalcField';
  f1.DisplayLabel := 'CalcField';
  f1.Calculated := True;
  f1.DataSet := Table1;
  f2 := TFloatField.Create(Table1);
  f2.Name := 'Table1Population';
  f2.FieldName := 'Population';
  f2.DisplayLabel := 'Population';
  f2.DataSet := Table1;
  Table1.Open;
end;