投稿を日付順に並べようとしていますが、そうしようとすると常に次のエラーが発生します。
警告: mysql_num_rows() は、パラメーター 1 がリソースであると想定し、ブール値は C:\localhost\bootstrap\category.php 行 58 で指定されます
データベース構造: http://puu.sh/1630b
<?php
//category.php
include 'connect.php';
//first select the category based on $_GET['cat_id']
$sql = "SELECT
cat_id,
cat_name,
cat_description
FROM
categories
WHERE
cat_id = " . mysql_real_escape_string($_GET['id']);
$result = mysql_query($sql);
if(!$result)
{
echo 'The category could not be displayed, please try again later.' . mysql_error();
}
else
{
if(mysql_num_rows($result) == 0)
{
echo 'This category does not exist.';
}
else
{
//display category data
while($row = mysql_fetch_assoc($result))
{
echo '<h2>Topics in ′' . $row['cat_name'] . '′ category</h2><br />';
$title = $row['cat_name'];
include 'header.php';
}
//do a query for the topics
$sql = "SELECT
topic_id,
topic_subject,
topic_date,
topic_cat
FROM
topics
ORDER BY
topic_date DESC
WHERE
topic_cat = " . mysql_real_escape_string($_GET['id']);
$result = mysql_query($sql);
// if(!$result)
// {
// echo 'The topics could not be displayed, please try again later.';
// }
// else
// {
if(mysql_num_rows($result) == 0)
{
echo 'There are no topics in this category yet.';
}
else
{
//prepare the table
echo '<table border="1" class="table table-bordered table-striped" style="float: right; width: 990px;">
<tr>
<th>Topic</th>
<th>Created at</th>
</tr>';
while($row = mysql_fetch_assoc($result))
{
echo '<tr>';
echo '<td class="leftpart">';
echo '<h3><a href="topic.php?id=' . $row['topic_id'] . '">' . $row['topic_subject'] . '</a><br /><h3>';
echo '</td>';
echo '<td class="rightpart">';
echo date('d-m-Y', strtotime($row['topic_date']));
echo '</td>';
echo '</tr>';
echo '';
echo '';
}
echo '</table>';
echo '</div>';
}
// }
}
}
include('footer.php');
?>