我想得到所有的帖子类型st_tours 与分类法关联st_tour_type, 在仪表板中浏览旅游类别时，我有以下链接：

taxonomy=st_tour_type&post_type=st_tours

所以我写了这个查询：

   $args = array(
        \'post_type\'     => \'st_tours\',
        \'post_status\'   => \'publish\',
        \'tax_query\'     => array(
            \'taxonomy\'  => \'st_tour_type\'
        ),
        \'order\'         => \'DESC\'
    );

    $query = new WP_Query($args);
    var_dump($wpdb->found_posts);
    var_dump($wpdb->last_query);

但这只返回了一篇帖子，而执行的查询实际上是不正确的，因为我有：

 SELECT post_id, meta_key, meta_value FROM wp_postmeta WHERE post_id IN (6565) ORDER BY meta_id ASC

我做错了什么？

UPDATE

$args = array(
    \'post_type\'     => \'st_tours\',
    \'post_status\'   => \'publish\',
    \'tax_query\'     => array(
        array(
            \'taxonomy\'  => \'st_tour_type\'
        )
    ),
    \'order\'         => \'DESC\'
);

$query = new WP_Query($args);

if ($query->have_posts()) : ?>
    <?php the_title(); ?>

    <?php echo \'test\' ?>

<?php endif;

未打印任何内容

\'tax_query\'     => array(
    \'taxonomy\'  => \'st_tour_type\'
),

\'tax_query\'     => array(
    array (
        \'taxonomy\'  => \'st_tour_type\',
        \'operator\' => \'EXISTS\'
    )
),