public ArrayList<Integer> rechenArt()
    {
        ArrayList<Integer> list = new ArrayList<>();
        int a = 0, s = 0, m = 0, d = 0, p = 0, w = 0;
        try
        {
            ResultSet set = read("SELECT RECHENART FROM OPERATION");
            while(set.next())
            {
               switch(set.getString("RECHENART"))
               {
                   case "Addition":
                       a += 1;
                       break;
                   case "Subtraktion":
                       s += 1;
                       break;
                   case "Multiplikation":
                       m += 1;
                       break;
                   case "Division":
                       d += 1;
                       break;
                   case "Potenz":
                       p += 1;
                       break;
                   case "Wurzel":
                       w += 1;
                       break;
                   default:
                       break;
               }
            }
            list.add(a);
            list.add(s);
            list.add(m);
            list.add(d);
            list.add(p);
            list.add(w);
            set.close();
        }
        catch(SQLException e)
        {
            System.out.println("SQL Fehler");
        }
        return list;
    }