Android sqlite get data from a table and then show all the data from one of the column in spinner

      dbconnection = new SQLControlerSubject(this);
      dbconnection.openDatabase();
      spinnerM = (Spinner)findViewById(R.id.spinnerMark);
      Cursor cursor = dbconnection.readSubjectMark();

      String[] from = new String[] {
            DBhelperSubject.SUBJECT_ID,
            DBhelperSubject.SUBJECT_NAME
      };
      int[] to = new int[] {
            R.id.subject_id,
            R.id.spinnerMark
      };

      SimpleCursorAdapter adapterMark = new SimpleCursorAdapter
            (MarkActivity.this, R.layout.support_simple_spinner_dropdown_item, cursor, from, to);
      adapterMark.notifyDataSetChanged();
      spinnerM.setAdapter(adapterMark);

readSubjectMark(){}

    public Cursor readSubjectMark(){
    String[] subjectNameOnly = new String[]{
      DBhelperSubject.SUBJECT_ID,
      DBhelperSubject.SUBJECT_NAME
    };

    Cursor c = database.query(DBhelperSubject.TABLE_SUBJECT,subjectNameOnly,null,null,null,null,null);
    if (c !=null){
        c.moveToFirst();
    }
    return  c;
}

Why the spinner inside show nothing ?

It run without error but data won't go to the spinner itself.