我有一个自定义帖子类型（Books），它与第二个自定义帖子类型（People）相连接。图书CPT有一个额外的作者元框，如果选中，它应该出现在额外的人物CPT上。

然而，即使检查并指定了第二位作者，这本书CPT也不会出现在第二个人CPT的页面上。我的页面代码如下：

<?php
    $author_id = get_the_ID();
    $single_books_query = new WP_Query(array(
        \'post_type\' => \'post\',
        \'category_name\' => \'books\',
        \'meta_query\' => array(                  
           array(
             \'key\' => \'ecpt_pub_author\',                  
             \'value\' => $author_id,               
             \'type\' => \'NUMERIC\',                 
             \'compare\' => \'=\'                 
           ),
          \'posts_per_page\' => \'-1\'
    ))); 


    if ( $single_books_query->have_posts() ) : while ($single_books_query->have_posts()) : $single_books_query->the_post(); ?>      
            <a href="<?php the_permalink(); ?>">
                <?php if ( has_post_thumbnail()) {  the_post_thumbnail(\'directory\', array(\'class\'   => "floatleft"));  } ?>
                <h5><?php the_title();?></h5>
                <h6><?php if ( get_post_meta($post->ID, \'ecpt_pub_date\', true) ) : echo get_post_meta($post->ID, \'ecpt_pub_date\', true);  endif; ?><?php if ( get_post_meta($post->ID, \'ecpt_publisher\', true) ) :?>, <?php echo get_post_meta($post->ID, \'ecpt_publisher\', true);  endif; ?></h6>
        <p><b>Role:&nbsp;<span style="text-transform:capitalize;"><?php echo get_post_meta($post->ID, \'ecpt_pub_role\', true); ?></span>

     //This is the line that isn\'t working:
        <?php if (get_post_meta($post->ID, \'ecpt_author_cond\', true) == \'on\') { $faculty_post_id2 = get_post_meta($post->ID, \'ecpt_pub_author2\', true); ?><br>
           <?php echo get_the_title($faculty_post_id2); ?>,&nbsp;<?php echo get_post_meta($post->ID, \'ecpt_pub_role2\', true); ?>
        <?php } ?>

        </b></p>
        </a>
        <hr>
    <?php endwhile; endif; ?>

是否需要建立另一个循环来查询ecpt_pub_author2?

UPDATE

我在查询中添加了一个关系键，如果选中，它将显示第二本关于适当人员的书。但如果未选中条件，它也默认为第一个人CPT。为什么会这样？我的更新查询：

$author_id = get_the_ID();
$single_books_query = new WP_Query(array(
    \'post_type\' => \'post\',
    \'category_name\' => \'books\',
    \'meta_query\' => array(   
    \'relation\'=> \'AND\',               
       array(
         \'key\' => \'ecpt_pub_author\',                  
         \'value\' => $author_id,               
         \'type\' => \'NUMERIC\',                 
         \'compare\' => \'=\'                 
       ),
       array(
        \'key\'=>\'ecpt_pub_author2\',
        \'value\' => $author_id,               
         \'type\' => \'NUMERIC\',                 
         \'compare\' => \'=\'       
        ),
      \'posts_per_page\' => \'-1\'
)));