$getPost = MysqL_query('SELECT
  p.*,r.reply_id,r.username r_username,r.reply_content,r.timestamp r_timestamp
  From post p
    left join reply r
  ORDER BY p.post_id DESC'
);

$posts = array();
$last_id = 0;
while($row = MysqL_fetch_array($getPost)) 
{ 
  if ($last_id != $row['post_id']) {
    $posts[] = array(
      'post_id' => $row['post_id'],'user_id' => $row['user_id'],'username' => $row['username'],'content' => $row['content'],'timestamp' => $row['timestamp'],'comments' => array()
    );
  }

  $posts[sizeof($posts) - 1]['comments'][] = array(
    'reply_id' => $row['reply_id'],'username' => $row['r_username'],'reply_content' => $row['reply_content'],'timestamp' = $row['r_timestamp']
  );
}

否则,将其分成两个查询,如下所示：

$getPost = MysqL_query('SELECT
  p.*,FROM post p
  ORDER BY p.post_id DESC'
);

$rows = array();
$ids = array();
$index = array();
while($row = MysqL_fetch_assoc($getPost)) {
  $row['comments'] = array();
  $rows[] = $row;
  $ids[] = $row['post_id'];
  $index[$row['post_id']] = sizeof($rows) - 1;
}

$getComments = MysqL_query('select r.* from replies r where r.post_id in ("'
  . join('","',$ids)
  . '")');
while ($row = mysq_fetch_assoc($getComments)) {
  $rows[$index[$row['post_id']]]['comments'][] = $row;
}

… 或类似的东西.任何一个选项都允许您使用WHERE子句乱丢您的第一个查询,等等.第二种方法的优点是您不会为每条评论重新传输原始帖子数据！