我有下面的查询,我很难找出在数据库表中添加的最佳方法。我想把表forum_categories
加进去然后从中选择id
。我不确定如何在查询中拥有两个相同的列名,但这是我需要从该表中获得的唯一字段。
如何添加forum_categories
到这个查询.
$query2 = mysqli_query($con,"SELECT * FROM forum_topics ORDER BY topic_reply_date DESC LIMIT 3")
然后只从它获取id,并能够输出它具有相同的列名?
<?php
$con = mysqli_connect("localhost", "", "", "");
$query2 = mysqli_query($con,"SELECT * FROM forum_topics ORDER BY topic_reply_date DESC LIMIT 3")
or die ("Query2 failed: %s'n".($query2->error));
$numrows2 = mysqli_num_rows($query2);
if($numrows2 > 0){
$topics .= "<table width='100%' style='border-collapse: collapse;'>";
//Change link once discussion page is made
$topics .= "<tr style='background-color: #dddddd;'><td>Topic Title</td><td width='65' align='center'>Replies</td><td width='65'
align='center'>Views</td></tr>";
$topics .= "<tr><td colspan='3'><hr /></td></tr>";
while($row2 = mysqli_fetch_assoc($query2)){
$tid = $row2['id'];
$title = $row2['topic_title'];
$views = $row2['topic_views'];
$date = $row2['topic_date'];
$creator = $row2['topic_creator'];
$topics .= "<tr><td><a href='forum_view_topic.php?tid=".$tid."'>".$title."</a><br /><span class='post_info'>Posted
by: ".$creator." on ".$date."</span></td><td align='cener'>0</td><td align='center'>".$views."</td></tr>";
$topics .= "<tr><td colspan='3'><hr /></td></tr>";
}
$topics .="</table>";
echo $topics;
} else {
echo "<p>There are no topics in this category yet.</p>";
}
?>
更正后的SQL查询:
SELECT t.*, c.id AS cid FROM forum_topics AS t, forum_categories AS c ORDER BY t.topic_reply_date DESC LIMIT 3