我有一个自定义帖子类型查询：

$paged = ( get_query_var( \'paged\' ) ) ? get_query_var( \'paged\' ) : 1;
$args = array(
    \'paged\'     => $paged,
    \'post_type\' => \'my_custom_post_type\',
    \'orderby\'   => \'meta_key\',
// Here I am filtering posts further
    \'meta_query\'=> array(
        array(
            \'key\'   => \'_assignment_type\',
            \'value\' => \'sales_assignment\',
            \'compare\' => \'LIKE\',
        ),
    ),
// This is the part that isn\'t working at all:
    \'meta_key\'  => \'_homepage_publish_date\',
    \'meta_type\' => \'datetime\',
    \'order\'     => \'DESC\',
    \'posts_per_page\' => 30,
);
query_posts($args);

homepage\\u publish\\u date上的值如下：2019-06-05 18:29:32.000

每当我尝试使用此顺序时，查询都会按照创建帖子的顺序返回帖子。

这里会出什么问题？

\'orderby\'   => \'meta_key\'

\'orderby\'   => \'meta_value\'