Thank´s to Remy, the code bellow works for my case.

  _Stream := _Qry.CreateBlobStream(_Qry.FieldByName('Script'), bmRead);
  _StrStream := TStringStream.Create;
  try
    _StrStream.LoadFromStream(_Stream);
    Query.Sql.LoadFromStream(_StrStream, TEncoding.Unicode);
  finally
    _Stream.Free;
    _StrStream.Free;
  end;