mysql - SQL 查询和 php 出现问题

Question

我正处于刚刚开始了解 PHP 和 MySQL 的阶段，但我陷入了困境。我一直在研究developphp.com的一个教程，其中Shawn的WI正在构建一个消息系统

https://www.youtube.com/playlist?list=PLgsYR-L3Uwbps9E-xIQPajQOiZVbOo6lr

我正在尝试重新设计教程，使其适合我的需求。我已经构建了一个名为 pm_inbox.php 的邮件页面，该页面工作正常，它为我提供了按 DESC 顺序发送给我的邮件。

pm_inbox.php

$sql = "SELECT pm.*, u.avatar, u.country 
FROM pm AS pm
LEFT JOIN users AS u ON u.username = pm.sender
WHERE (pm.receiver='$u' AND pm.parent='x' AND pm.rdelete='0')
OR (pm.sender='$u' AND pm.sdelete='0' AND pm.parent='x' AND pm.hasreplies='1')
ORDER BY senttime DESC";
$query = mysqli_query($db_conx, $sql);
$statusnumrows = mysqli_num_rows($query);
// Gather data about parent pm's
if($statusnumrows > 0){
    while ($row = mysqli_fetch_array($query, MYSQLI_ASSOC)) {
        $pmid = $row["id"];
        //div naming
        $pmid2 = 'pm_'.$pmid;
        $wrap1 = 'pm_message_wrap_'.$pmid;
        //button naming
        $btid2 = 'bt_'.$pmid;
        //textarea naming
        $rt = 'replytext_'.$pmid;
        //button naming
        $rb = 'replyBtn_'.$pmid;
        $receiver = $row["receiver"];
        $sender = $row["sender"];
        $subject = $row["subject"];
        $message = $row["message"];
        $time = $row["senttime"];
        $rread = $row["rread"];
        $sread = $row["sread"];
        $avatar = $row["avatar"];
        $country = $row["country"];

        // Start to build our list of parent pm's
        $mail .= '<div id="'.$wrap1.'" class="pm_message_wrap">';
        $mail .= '<table id="inboxMailMessages" width="100%" align="center" cellpadding="2">
  <tr>
    <td width="6%"><input name="toggleAll" id="toggleAll" type="checkbox"/></td>
    <td width="19%"><a href="user.php?u='.$sender.'" title="'.$sender.'"><img src="user/'.$sender.'/'.$avatar.'"width=100" height="100" border="0" /></a></td>
    <td width="75%">
    <div class="inboxmailRollover">
    <p class="mailboxp">Subject: ' .$subject. '<br></p>
    <p class="mailboxp"><a href="user.php?u=' . $sender . '">From:'.$sender. '</a><br></p>
    <p class="mailboxp"><a href="inboxMain.php?u=' . $u . '">' .$country. '</a><br></p>
    <p class="mailboxp">' .$message. '</p>
    </div>
    </td>
  </tr>
</table>';
        $mail .= '<hr>';
        $mail .= '</div>';

我想做的是，当有人单击 pm_inbox.php 上的国家/地区链接时，它将带他们进入另一个名为 inboxMain.php 的页面，其中它将显示已发送邮件的容器中的人员详细信息，如下所示发件人、主题和国家/地区。

我在 pm_inbox.php 上有 4 封人们发给我的邮件。当我按下国家/地区链接时，它会带我进入 inboxMain.php，但不是只显示向我发送邮件的人员详细信息，而是显示 4 个单独容器中的所有 4 个人的详细信息。我知道这是 inboxMain.php 上的 sql 查询问题，但无法解决。我想知道是否有人可以帮助我。

inboxMain.php

$sql = "SELECT pm., u.avatar, u.country 
FROM pm AS pm
LEFT JOIN users AS u ON u.username = pm.sender
WHERE pm.id='$pmid' AND pm.sender='$u' AND pm.sdelete='0' AND pm.parent='x'";
$query = mysqli_query($db_conx, $sql);
$statusnumrows = mysqli_num_rows($query);
// Gather data about parent pm's
if($statusnumrows > 0){
    while ($row = mysqli_fetch_array($query, MYSQLI_ASSOC)) {
        $pmid = $row["id"];
        //div naming
        $pmid2 = 'pm_'.$pmid;
        $wrap2 = 'reply_profile_wrap'.$pmid;
        //button naming
        $btid2 = 'bt_'.$pmid;
        //textarea naming
        $rt = 'replytext_'.$pmid;
        //button naming
        $rb = 'replyBtn_'.$pmid;
        $receiver = $row["receiver"];
        $sender = $row["sender"];
        $subject = $row["subject"];
        $message = $row["message"];
        $time = $row["senttime"];
        $rread = $row["rread"];
        $sread = $row["sread"];
        $avatar = $row["avatar"];
        $country = $row["country"];

        // Start to build our list of parent pm's
        $reply_profile .= '<div id="'.$wrap2.'" class="reply_profile_wrap">';
        $reply_profile .= '<table id="replyProfile" width="100%" border="0">
  <tr>
    <td width="19%"><a href="user.php?u='.$sender.'" title="'.$sender.'"><img src="user/'.$sender.'/'.$avatar.'"width=75" height="75" border="0" /></a></td>
    <td>    
    <p class="replyProfilep">Subject: ' .$subject. '<br></p>
    <p class="replyProfilep"><a href="user.php?u=' . $sender . '">From:'.$sender. '</a><br></p>
    <p class="replyProfilep">Country: ' .$country. '</p>
    </td>
  </tr>
</table>';

        $reply_profile .= '</div>';

Answer 1

放置一个链接，获取全国各地的特定 pm.id。

<p class="replyProfilep"><a href="mail.php?id=' . $pmid . '">Country: ' .$country. '</a></p>

然后在 mail.php 中您可以使用如下查询:

$pmid = $_GET['id'];
$sql = "SELECT pm.*, u.avatar, u.country 
    FROM pm AS pm
    LEFT JOIN users AS u ON u.username = pm.sender
    WHERE pm.id = $pmid";