如何使用自定义分类法查询自定义帖子类型？

出于某种原因，我发现使用自定义分类法来获取任何帖子都非常困难……有人可以揭开我的愚蠢之谜吗？

 $args = array(
    'post_type' => 'adverts',
    'advert_tag' => 'politics' // Doesn't seem to work.
  );

query_posts($args); 

while ( have_posts() ) : the_post();
 //Show Posts
endwhile;

分类声明：

add_action( 'init', 'add_custom_taxonomy', 0 );
function add_custom_taxonomy() {
register_taxonomy('advert_tag', 'Adverts', array(
  'hierarchical' => true,
  'labels' => array(
    'name' => _x( 'Advert Tags', 'taxonomy general name' ),
    'singular_name' => _x( 'Advert Tag', 'taxonomy singular name' ),
    'search_items' =>  __( 'Search Advert Tags' ),
    'all_items' => __( 'All Advert Tags' ),
    'parent_item' => __( 'Parent Advert Tag' ),
    'parent_item_colon' => __( 'Parent Advert Tag:' ),
    'edit_item' => __( 'Edit Advert Tag' ),
    'update_item' => __( 'Update Advert Tag' ),
    'add_new_item' => __( 'Add New Advert Tag' ),
    'new_item_name' => __( 'New Advert Tag Name' ),
    'menu_name' => __( 'Advert Tags' ),
  ),
  'rewrite' => array(
    'slug' => 'advert-tags',
    'with_front' => false,
    'hierarchical' => true
  ),
));
  }

自定义帖子类型声明：

  add_action( 'init', 'create_post_type' );
  function create_post_type() {
    register_post_type( 'Adverts',
    array(
        'labels' => array(
            'name' => __( 'Adverts' ),
            'singular_name' => __( 'Advert'),
            'add_new' => __( 'Add New' ),
            'add_new_item' => __( 'Add a New Advert' ),
            'edit' => __( 'Edit' ),
            'edit_item' => __( 'Edit Advert' ),
            'new_item' => __( 'New Advert' ),
            'view' => __( 'View' ),
            'view_item' => __( 'View Advert' ),
            'search_items' => __( 'Search Adverts' ),
            'not_found' => __( 'No Adverts found' ),
            'not_found_in_trash' => __( 'No Adverts found in Trash' ),
            ),
        'supports' => array(
                'title',
                'thumbnail',
            ),
        'has_archive' => true,
        'menu_position' => 10,
        'public' => true,
        'rewrite' => array( 'slug' => 'adverts' ),
        'taxonomies' => array('advert_tag')
    )
);

}

所有的杉杉没有使用query_posts()过，阅读更多关于它在这里：当你应该使用WP_Query VS query_posts（）VS get_posts（）？。

您必须使用WP_Query获取所需的信息。阅读文档。在您的情况下，查询可能是这样的：

$the_query = new WP_Query( array(
    'post_type' => 'Adverts',
    'tax_query' => array(
        array (
            'taxonomy' => 'advert_tag',
            'field' => 'slug',
            'terms' => 'politics',
        )
    ),
) );

while ( $the_query->have_posts() ) :
    $the_query->the_post();
    // Show Posts ...
endwhile;

/* Restore original Post Data 
 * NB: Because we are using new WP_Query we aren't stomping on the 
 * original $wp_query and it does not need to be reset.
*/
wp_reset_postdata();

我正在使用此查询来获取具有其自定义分类法（faq_category）的自定义帖子（FAQ帖子）。由于自v.3.1起不推荐使用WP_Query args中的{taxonomy}参数，并引入了{tax_query}。以下是完美运行的代码。

$query = new WP_Query( array(
    'post_type' => 'faqs',          // name of post type.
    'tax_query' => array(
        array(
            'taxonomy' => 'faq_category',   // taxonomy name
            'field' => 'term_id',           // term_id, slug or name
            'terms' => 48,                  // term id, term slug or term name
        )
    )
) );

while ( $query->have_posts() ) : $query->the_post();
    // do stuff here....
endwhile;

/**
 * reset the orignal query
 * we should use this to reset wp_query
 */
wp_reset_query();

由于wordpress更改了其分类参数信息，因此该答案现在不再有效。请使用这种方式。它将起作用。这个对我有用。“ tax_query”替换为“ tax”。希望它能工作。

$the_query = new WP_Query( array(
    'post_type' => 'Adverts',
    'tax' => array(
        array (
            'taxonomy' => 'advert_tag',
            'field' => 'slug',
            'terms' => 'politics',
        )
    ),
) );

while ( $the_query->have_posts() ) :
    $the_query->the_post();
    // Show Posts ...
endwhile;

/* Restore original Post Data 
 * NB: Because we are using new WP_Query we aren't stomping on the 
 * original $wp_query and it does not need to be reset.
*/
wp_reset_postdata();