Typecho 调取随机文章

function getRandomPosts($limit = 10){    
    $db = Typecho_Db::get();
    $result = $db->fetchAll($db->select()->from('table.contents')
        ->where('status = ?','publish')
        ->where('type = ?', 'post')
        ->where('created <= unix_timestamp(now())', 'post')
        ->limit($limit)
        ->order('RAND()')
    );
    if($result){
        $i=1;
        foreach($result as $val){
            if($i<=3){
                $var = ' class="red"';
            }else{
                $var = '';
            }
            $val = Typecho_Widget::widget('Widget_Abstract_Contents')->push($val);
            $post_title = htmlspecialchars($val['title']);
            $permalink = $val['permalink'];
            echo '<li><i'.$var.'>'. '</i><a href="'.$permalink.'" title="'.$post_title.'" target="_blank">'.$post_title.'</a></li></br>';
            $i++;
        }
    }
}

<?php getRandomPosts('10');?>

...
    </br>
    <h2> 推荐阅读 </h2>
    </br>
    <?php getRandomPosts('5');?
...