error loadind data from sqlite to spinner

Question

While loading data from SQLite to spinner the data are repeated several times, values "Traditionnel" and "fast food" are repeated several times

    @Override
    protected void onCreate(Bundle savedInstanceState) {


               ContentValues values = new ContentValues();
               values.put(COLUMN_CATEGORIENAME , "fast food");
               db.insert(TABLE_CATEGORIE, null, values);
               values.put(COLUMN_CATEGORIENAME , "Traditionnel");
               db.insert(TABLE_CATEGORIE, null, values);

               db.insert(TABLE_CATEGORIE, null, values);
               Cursor c = db.query(TABLE_CATEGORIE,  new String[] { COLUMN_IDCATEGORIE, COLUMN_CATEGORIENAME}   , null,null,null,null,null);


            int col=c.getCount();   


                    if (col == 0) {
                        Toast.makeText(MainActivity.this, "Pas de donnees ", Toast.LENGTH_LONG).show();
                        // effacer le contenue champ login et mot de passe

                        }
                    else {
                        // col =1  il ya un utilisateur qui verifie la condition
                        c.moveToFirst();
                           while (c.isAfterLast() == false) {
                               // conversion int to string casting 
                               String ch1=""+c.getInt(0);
                                String ch2=c.getString(1);
                               adapter.add(ch2);
                                c.moveToNext();
                            }
                    }   
                    c.close();  


                     Spinner s = (Spinner) findViewById(R.id.spinner1);
                    s.setAdapter(adapter);