php - Select 语句没有回显数据库中的所有行

Question

我有两个数据库表。我的 comments 表如下所示:

comid | comuserid
  10      7    
  20      7    
  30      9  

我的 replies 表如下所示:

repid | repcomid | repfromuser | reptouser
  1       10          22             7   
  2       10          22             7   

这是我的 index.php 页面目前的样子:

comid10 (commented by comuserid1)
    [repid1] repfromuser22 to comuserid1

comid10 (commented by comuserid1)
    [repid2] repfromuser22 to comuserid1

我的问题是我的代码仅回显包含回复者的 comments 行，但完全跳过不包含回复者的 comments 行。但我希望我所有的 comments 行都被回显，即使它们不包含回复者。我还希望我的回复者根据他们评论过的评论者分组在一起。这是我想要实现的真实结果:

comid10 (commented by comuserid1)
    [repid1] repfromuser22 to comuserid1
    [repid2] repfromuser22 to comuserid1

comid20 (commented by comuserid1)

comid30 (commented by comuserid2)

我如何用我当前的代码实现它？请帮助:

<?php
$rqid = (int)$_GET['rqid'];
$query = $conn->query("
    SELECT comments.*, replies.*, users.username
    FROM comments
    INNER JOIN replies
    ON comments.comid = replies.repcomid
    INNER JOIN users
    ON comments.comid = users.userid
    WHERE comments.comrqid = {$rqid}
");
$comreps = [];
while($row = $query->fetch_object()) {
  $comreps[] = $row;
}
?>

<?php foreach($comreps as $comrep): ?>
    <div class="rqdivc">
        <?php echo $comrep->username; ?>
    </div>
    <div class="fxrp">
        <div>
            <?php echo $comrep->repfromuser; ?> -->
            <?php echo $comrep->reptouser; ?>
        </div>
    </div>
<?php endforeach; ?>

Answer 1

Strawberry 建议 - 使用 LEFT JOIN - 解决了我的问题。谢谢你!