我不知道为什么我的脚本的子类别“论坛”没有被摸索到相应的类别。相反,子类别强制脚本重复类别代码。
如下图所示,有一个类别测试,在该类别中有测试和错误。但是,Bugs 滑入了第二个表,它不应该是因为两个测试类别都是一个,而是看起来像数据库中有两个类别,称为测试。我的代码中有什么问题是错误被推入复制类别“测试”而不是在测试下 - 只是一个简单的测试论坛?
这是代码。
<?php
include 'connect.php';
include 'header.php';
$sql = "SELECT
categories.cat_id,
categories.cat_name,
forums.forum_id,
forums.forum_cat,
forums.forum_name,
forums.forum_desc,
COUNT(forums.forum_id) AS forums
FROM
categories
LEFT JOIN
forums
ON
forums.forum_cat = categories.cat_id
GROUP BY
forums.forum_name, forums.forum_desc, forums.forum_id
ORDER BY
categories.cat_id ASC
";
$result = mysql_query($sql);
if(!$result)
{
echo 'The categories could not be displayed, please try again later.';
}
else
{
if(mysql_num_rows($result) == 0)
{
echo 'No categories defined yet.';
}
else
{
//prepare the table
while($row = mysql_fetch_assoc($result))
{
echo '<table border="1">
<tr>
<th>' . $row['cat_name'] . '</th><th></th>
</tr>';
echo '<tr>';
echo '<td class="leftpart">';
echo '<h3><a href="viewforum.php?id=' . $row['forum_id'] . '">' . $row['forum_name'] . '</a></h3>' . $row['forum_desc'];
echo '</td>';
echo '<td class="rightpart">';
//fetch last topic for each cat
$topicsql = "SELECT
topic_id,
topic_subject,
topic_date,
topic_cat
FROM
topics
WHERE
topic_cat = " . $row['forum_id'] . "
ORDER BY
topic_date
DESC
LIMIT
1";
$topicsresult = mysql_query($topicsql);
if(!$topicsresult)
{
echo 'Last topic could not be displayed.';
}
else
{
if(mysql_num_rows($topicsresult) == 0)
{
echo 'no topics';
}
else
{
while($topicrow = mysql_fetch_array($topicsresult))
echo '<a href="viewtopic.php?id=' . $topicrow['topic_id'] . '">' . $topicrow['topic_subject'] . '</a> at ' . date('d-m-Y', strtotime($topicrow['topic_date']));
}
}
echo '</td>';
echo '</tr>';
echo '</br>';
}
}
}
include 'footer.php';
?>
表结构
类别
cat_id | int(8) | primary | auto incr
cat_name | var(255)
|2|Damm
|3|Hmm
|1|Test
论坛
forum_id | int(8) | primary | auto_incr
forum_cat | int(8) <-- forum cat "category" is just ID of category it belongs to
forum_name | var(255)
forum_desc | var(255)
|1|1|Test|Just a simple forum test
|2|3|Lol
|3|1|Bugs|Bugs and related go here
话题
topic_id | int(8) | primary | auto_incr
topic_subject | var(255)
topic_date | datetime
topic_cat | int(8)
topic_by | int(8)
|1|Test|2012-07-31 23:12:47|1|1
我个人尝试了不同的事情,但仍然无法弄清楚为什么会这样。