Future<List<List<Widget>>> getList(List<int> list, String column) async {
    List<Widget> list1 = List();
    List<Widget> list2 = List();
    List<Widget> list3 = List();
    List<List<Widget>> listFromDB = [list1, list2, list3];
    var databasesPath = await getDatabasesPath();
    String path = join(databasesPath, 'books.db');
    Database database = await openDatabase(path, version: 1);
    for (int i = 0; i < list.length; i++) {
      var result = await database
          .rawQuery('SELECT DISTINCT $column FROM $booksTable WHERE $colId= ${list[i]}');

      debugPrint('List: ' +list[i].toString());
      if (list[i] < 18) list1.add(_item(result[0][column].toString()));
      if (list[i] > 17 && list[i] < 50)
        list2.add(_item(result[0][column].toString()));
      if (list[i] > 49) list3.add(_item(result[0][column].toString()));
    }

   // await database.close();
    return listFromDB;
  }

bool _summary = false;

  _getAnswer() async{
    SharedPreferences pref = await SharedPreferences.getInstance();
    List<String> listString = pref.getStringList('Answers') ?? List();

    if(listString.isNotEmpty){
      List<int> listInt = listString.map(int.parse).toList();
      listInt.sort();
      _list = await DB().getList(listInt, _summary ? 'Detail' : 'Output'); //colums from db.

      setState((){});
    }
  }