我正在玩一个留言簿/聊天室的想法，并且有一个包含三列的MySQL表设置：

1-id-主键自动递增

2-名称-字符串

3-注释-字符串

我对PHP的经验很少，但这是我为该操作汇总的内容：

$result = mysql_query("SELECT * FROM guestbook");
$i = 0;
while($row = mysql_fetch_array($result))
  {
      //add the row to the $chat array at specific index of $i
      $chat[$i] = $row;
      $i += 1;
  }

$encode = json_encode($chat);
echo "$encode";

但是，此输出看起来很糟糕：

[{"0":"1","id":"1","1":"Justin ","name":"Justin ","2":"Comment 1","comment":"Comment 1"},
{"0":"2","id":"2","1":"Justin ","name":"Justin ","2":"Another comment","comment":"Another comment"},
{"0":"3","id":"3","1":"Justin ","name":"Justin ","2":"Look at this comment!","comment":"Look at this comment!"},
{"0":"4","id":"4","1":"Justin ","name":"Justin ","2":"Ok I'm done talking","comment":"Ok I'm done talking"}]

我希望获得三个字段：ID，名称和注释，但看起来好像翻了一番。有人可以帮忙吗？

谢谢！