WordPress 多站点建站教程（三）：主站如何调用子站的文章内容、SQL语句如何写？

<?php
function wpmu_recent_posts_mu($how_many=10, $how_long=0, $titleOnly=true, $begin_wrap="\n<li>", $end_wrap="</li>")
{
    global $wpdb;
    global $table_prefix; $counter = 0; //首先通过判断是否显示时间区间来分别使用不同的SQl语句
    if ($how_long > 0)
    {
        $blogs = $wpdb->get_col("SELECT blog_id FROM $wpdb->blogs WHERE public = '1' AND archived = '0' AND mature = '0' AND spam = '0' AND deleted = '0' AND last_updated >= DATE_SUB(CURRENT_DATE(), INTERVAL $how_long DAY) ORDER BY last_updated DESC"); } else { $blogs = $wpdb->get_col("SELECT blog_id FROM $wpdb->blogs WHERE public = '1' AND archived = '0' AND mature = '0' AND spam = '0' AND deleted = '0' ORDER BY last_updated DESC"); }
        
        //如果存在多站点ID
        if ($blogs) { 
            echo "<ul>";
            foreach ($blogs as $blog) { // 下面是需要使用的数据表
                $blogOptionsTable = $wpdb->base_prefix.$blog."_options"; $blogPostsTable = $wpdb->base_prefix.$blog."_posts"; $options = $wpdb->get_results("SELECT option_value FROM $blogOptionsTable WHERE option_name IN ('siteurl','blogname') ORDER BY option_name DESC"); // 为最新文章获取标题和ID号
                if ($how_long > 0) 
                 $thispost = $wpdb->get_results("SELECT ID, post_title FROM $blogPostsTable WHERE post_status = 'publish' AND ID > 1 AND post_type = 'post' AND post_date >= DATE_SUB(CURRENT_DATE(), INTERVAL $how_long DAY) ORDER BY id DESC LIMIT 0,1"); } else { $thispost = $wpdb->get_results("SELECT ID, post_title FROM $blogPostsTable WHERE post_status = 'publish' AND ID > 1 AND post_type = 'post' ORDER BY id DESC LIMIT 0,1"); 
                 } // 如果存在将输入内容
                 if($thispost) 
                 {
                 // 获取子站点文章链接
                 $thispermalink = get_blog_permalink($blog, $thispost[0]->ID); if ($titleOnly == false) { echo $begin_wrap.'<a href="' .$thispermalink.'">'.$thispost[0]->post_title.'</a> <br/> by <a href="' .$options[0]->option_value.'">' .$options[1]->option_value.'</a>'.$end_wrap; $counter++; } else { echo $begin_wrap.'<a href="'.$thispermalink .'">'.$thispost[0]->post_title.'</a>'.$end_wrap; $counter++; } } // 对文章数量进行判断。
                 if($counter >= $how_many) { break; } 
        } echo "</ul>"; 
    } 
}

?>

<?php wpmu_recent_posts_mu(10, 0, true, '<li>', '</li>'); ?>

<?php
function lei_multsite_recent_post($showpost) {
    global $wpdb, $post, $table_prefix; //首先将所有的子站点ID号显示出来
        $most_post = $wpdb->get_col("SELECT blog_id FROM $wpdb->blogs WHERE public = '1' AND archived = '0' AND mature = '0' AND spam = '0' AND deleted = '0' ORDER BY last_updated DESC");
        foreach ($most_post as $key => $v) 
        {
            if($v !=1 ) //除主站点ID
            { $b_id[$key] = $v; } 
        }
        $newid = array_flip($b_id); //php数组函数对换键值
        $new_post_id = array_rand($newid,2); //php数组函数随机显示2条，这里的数值不能大于你创建子站点的个数。
        foreach ( $new_post_id as $k => $vol )
        {
            $blogPostsTable = $wpdb->base_prefix.$vol."_posts"; $recent_post = $wpdb->get_results("SELECT * from $blogPostsTable where post_status = 'publish' and post_type = 'post' ORDER BY post_date desc LIMIT 0,$showpost");
            foreach ($recent_post as $ks => $vs)
            {
                $thispermalink = get_blog_permalink($vol, $vs->ID);
                $count1 += 1;
                echo '<li><a href="'.$thispermalink.'">'.$vs->post_title.'</a></li>'; 
            } 
    }
}
?>

<?php lei_multsite_recent_post(1); ?>