tag直接关联文章副表里面的tag，然后找到文章表对应id，然后调出缩略图

效果：

<?php
$sql=$empire->query("select * from {$dbtbpre}enewstags where cid = 1 order by isgood desc limit 15");
while($r=$empire->fetch($sql))
{
$r2=$empire->fetch1("select id from {$dbtbpre}ecms_news_data_1 where infotags like '%".$r['tagname']."%' ORDER BY `{$dbtbpre}ecms_news_data_1`.`id` DESC limit 1");
$r3=$empire->fetch1("select titlepic from {$dbtbpre}ecms_news where id = ".$r2['id']." and titlepic != '' ORDER BY `{$dbtbpre}ecms_news`.`newstime` desc limit 1");

if($r3['titlepic']==null){
$r3['titlepic']= 'http://bz.xiazaii.com/e/data/images/notimg.gif';
}
?>
<a href="/tag/<?=$r['tagid']?>.html" target="_blank">
<div class="photo-l">
<img src="<?=$r3['titlepic']?>">
</div>
<div class="text-r">
<p class="tit"><?=$r['tagname']?></p>
<p class="picnum">图片数：<?=$r['num']?>组</p>
</div>
</a>
<?php
}
?>

前提是要将tag手动设置好分类。