您可以在wp query中使用元查询来获取所需的帖子

  $args = array(
   \'meta_query\' => array(
     \'relation\' => \'OR\',
      array(
        \'key\' => \'city\',
        \'value\' => \'Melbourne\',
        \'compare\' => \'NOT LIKE\'
      ),
      array(
        \'key\' => \'city\',
        \'value\' => \'Melbourne\',
        \'compare\' => \'NOT EXISTS\'
      )
   )
  );
  $query = new WP_Query( $args );

我想用city = Melbourne 然后对照你试图在页面上显示的所有帖子检查所有这些内容是错误的。

为什么不使用你应该已经拥有的单圈，并放置类似的东西来检查城市是否是墨尔本？

 <?php
    //check custom field \'city\'
    $custom_field = get_post_custom();              
    if(isset($custom_field["city"][0]) && $custom_field["city"][0] != \'Melbourne\')
    {
        //output
    }
    else
    { 
        //do something else?
    }
 ?>