return yearMonth.get(DateTimeFieldType.year()) +"-"+ yearMonth.get(DateTimeFieldType.monthOfYear());
return String.format("%d-%02d", yearMonth.get(DateTimeFieldType.year()), yearMonth.get(DateTimeFieldType.monthOfYear()));
    public Object javaToSql(Object object) {        if (object != null) {            Partial yearMonth = (Partial) object;            return yearMonth.get(DateTimeFieldType.year()) +"-"+ yearMonth.get(DateTimeFieldType.monthOfYear());        }        return null;    }