帖子ID并不意味着是连续的。要按顺序对帖子编号，必须使用元字段。回到这个问题上，有人对此进行了讨论：

Change Permalinks Structure to a Sequential Number for Each Post?

对于您想要做的事情，最好的答案似乎是发布在支持论坛上的一段代码：

http://wordpress.org/support/topic/display-sequential-post-numbercount-not-post-id

function updateNumbers() {
    /* numbering the published posts, starting with 1 for oldest;
    / creates and updates custom field \'incr_number\';
    / to show in post (within the loop) use <?php echo get_post_meta($post->ID,\'incr_number\',true); ?>
    / alchymyth 2010 */
    global $wpdb;
    $querystr = "SELECT $wpdb->posts.* FROM $wpdb->posts 
                 WHERE $wpdb->posts.post_status = \'publish\' 
                 AND $wpdb->posts.post_type = \'post\' 
                 ORDER BY $wpdb->posts.post_date ASC";
    $pageposts = $wpdb->get_results($querystr, OBJECT);
    $counts = 0 ;
    if ($pageposts):
    foreach ($pageposts as $post):
        $counts++;
        add_post_meta($post->ID, \'incr_number\', $counts, true);
        update_post_meta($post->ID, \'incr_number\', $counts);
    endforeach;
endif;
}  

add_action ( \'publish_post\', \'updateNumbers\', 11 );
add_action ( \'deleted_post\', \'updateNumbers\' );
add_action ( \'edit_post\', \'updateNumbers\' );

（我对其进行了非常轻微的修改，以按发布日期排序，而不是像最初的代码那样仅按ID排序。）

它将连接到所有帖子操作（保存/发布/删除），并更新所有帖子的“incr\\u number”自定义字段。因此，当数据库中有大量帖子时，保存帖子时会出现性能滞后，但一旦帖子被保存，显示数字就非常简单

echo get_post_meta( $post->ID, \'incr_number\', true );