//Ausgabe aller Kunden mit Kundendetails
        public Person[] getGesamt()
        {
            List <Person>   liste = new List <Person>();
            MySqlCommand    comm  = new MySqlCommand("select persnr, name, vorname, sprache, grad from person inner join sprachen using (persnr)", conn);
            MySqlDataReader msdr  = comm.ExecuteReader();

            while (msdr.Read())
            {
                Person suche = liste.Find(p => p.persNr == msdr["persnr"].ToString());
                if (suche != null)
                {
                    Sprachen s = new Sprachen();
                    s.sprache = msdr["sprache"].ToString();
                    s.grad    = Convert.ToInt32(msdr["grad"].ToString());
                    suche.sprachen.Add(s);
                }
                else
                {
                    suche          = new Person();
                    suche.name     = msdr["name"].ToString();
                    suche.vorname  = msdr["vorname"].ToString();
                    suche.persNr   = msdr["persnr"].ToString();
                    suche.sprachen = new List <Sprachen>();
                    Sprachen s = new Sprachen();
                    s.sprache = msdr["sprache"].ToString();
                    s.grad    = Convert.ToInt32(msdr["grad"].ToString());
                    suche.sprachen.Add(s);

                    liste.Add(suche);
                }
            }
            msdr.Close();
            return(liste.ToArray());
        }
        public List <Sprachen> getSprachen(String nummer)
        {
            List <Sprachen> liste = new List <Sprachen>();
            MySqlCommand    sec   = new MySqlCommand("select sprache, grad from sprachen where persnr = '" + nummer + "'", conn);
            MySqlDataReader data  = sec.ExecuteReader();

            while (data.Read())
            {
                Sprachen s = new Sprachen();
                s.sprache = data["sprache"].ToString();
                s.grad    = Convert.ToInt32(data["grad"].ToString());
                liste.Add(s);
            }

            data.Close();
            return(liste);
        }