ORMLite中 DAO.queryRaw方法的用法

有时候，我们的SQL语句可能会比较复杂，用DAO的query方法可能不能满足需要，就需要调用queryRaw方法来查询原生的SQL语句。 下例中，ShortMessage是Mode类

    try {
            GenericRawResults results = messageDao
                    .queryRaw(
                            "select id,_to,_from,message,MAX(date),username,_type,read from message group by username order by date desc;",
                            new RawRowMapper() {
                                @Override
                                public ShortMessage mapRow(
                                        String[] columnNames,
                                        String[] resultColumns)
                                        throws SQLException {
                                    // TODO Auto-generated method stub
                                    ShortMessage message = new ShortMessage();
                                    message.setId(Integer
                                            .parseInt(resultColumns[0]));
                                    message.setTo(resultColumns[1]);
                                    message.setFrom(resultColumns[2]);
                                    message.setMessage(resultColumns[3]);
                                    String dateStr = resultColumns[4];// 存储格式为2012-12-05
                                                                        // 14:46:23.000927
                                    SimpleDateFormat sdf = new SimpleDateFormat(
                                            "yyyy-MM-dd HH:mm:ss");
                                    try {
                                        message.setDate(sdf.parse(dateStr));
                                    } catch (ParseException e) {
                                        // TODO Auto-generated catch block
                                        e.printStackTrace();
                                    }
                                    message.setUsername(resultColumns[5]);
                                    message.setType(Integer
                                            .parseInt(resultColumns[6]));
                                    int readed = Integer
                                            .parseInt(resultColumns[7]);
                                    if (readed == 0) {
                                        message.setRead(false);
                                    } else {
                                        message.setRead(true);
                                    }
                                    return message;
                                }
                            });

            Iterator iterator = results.iterator();
            List messageList = new ArrayList();
            while (iterator.hasNext()) {
                ShortMessage message = iterator.next();
                messageList.add(message);
            }