我有一个自定义的帖子类型-case - 我正在为其构建一个归档页面。此类型有三种自定义分类法-micro_organisms, infection_types, 和antibiotic_types. 这些分类法是分级的，有各种各样的术语，最多有三个层次。对于给定的帖子类型，我想列出一些术语，比如antibiotic_types 分类法case 条目。
而在antibiotic_types 任何case 条目，我想显示指向所选术语的层次结构。
到目前为止，我已经完成了以下工作，这将导致一个只包含选定术语的平面列表，而不反映术语所处的层次结构。
// sourced from:
// http://wordpress.stackexchange.com/questions/66015/how-to-get-a-list-of-taxonomy-terms-which-are-being-used-only-within-certain-pos
function get_terms_by_post_type( $taxonomies, $post_types ) {
global $wpdb;
$query = $wpdb->get_results( "SELECT t.*, COUNT(*) AS count from $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id INNER JOIN $wpdb->term_relationships AS r ON r.term_taxonomy_id = tt.term_taxonomy_id INNER JOIN $wpdb->posts AS p ON p.ID = r.object_id WHERE p.post_type IN(\'" . join( "\', \'", $post_types ) . "\') AND tt.taxonomy IN(\'" . join( "\', \'", $taxonomies ) . "\') GROUP BY t.term_id");
return $query;
}
?>
...
<ul class="taxonomy-term-list">
<?php
$terms = get_terms_by_post_type(array($tax), array(\'case\'));
foreach ($terms as $term):
$termData = get_term_by(\'id\', $term->term_id, $tax);
$termName = $termData->name;
$termUrl = get_term_link($termData);
?>
<li class="taxonomy-term"><a href="<?php echo $termUrl; ?>?post_type=<?php echo $type; ?>"><?php echo $termName; ?> (<?php echo $term->count; ?>)</a></li>
<?php
endforeach;
?>
</ul>
输出类似于：
当所需输出为：
β-内酰胺类、头孢菌素类、头孢曲松类、青霉素类、青霉素g类、抗真菌类、两性霉素b类、5-氟胞嘧啶类等，我也尝试使用以下药物：
wp_list_categories(
array(
\'taxonomy\' => \'antibiotic_types\',
\'hierarchical\' => 1,
\'hide_empty\' => 1,
\'title_li\' => \'\'
)
);
它显示了给定分类法的所有术语，甚至那些没有被任何
case 条目。
浏览了函数引用后，它看起来并没有任何内置函数来完成我想要实现的功能，无论如何都不是直接实现的。到目前为止，我还没有对分类查询做太多的工作。有什么建议吗？
最合适的回答,由SO网友:gmazzap 整理而成
如果你看到wp_list_categories 在codex中，您将看到它接受include param，它应该包含一个以逗号分隔的类别ID列表。
所以如果你改变你的功能get_terms_by_post_type 创建函数get_terms_id_by_post_type 仅检索术语ID，如下所示：
function get_terms_id_by_post_type( $taxonomies, $post_types ) {
global $wpdb;
$query = $wpdb->get_col( "SELECT t.term_id from $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id INNER JOIN $wpdb->term_relationships AS r ON r.term_taxonomy_id = tt.term_taxonomy_id INNER JOIN $wpdb->posts AS p ON p.ID = r.object_id WHERE p.post_type IN(\'" . join( "\', \'", $post_types ) . "\') AND tt.taxonomy IN(\'" . join( "\', \'", $taxonomies ) . "\') GROUP BY t.term_id");
return $query;
}
然后您可以：
// retrieve the term ids used by post type
$terms = get_terms_id_by_post_type( array($tax), array(\'case\') );
// if that terms exist implode in a commasepared string
$term_list = ! empty($terms) ? implode(\',\', $terms) : false;
// use wp_list_categories with include param to included only used terms
if ( $term_list ) {
wp_list_categories(
array(
\'taxonomy\' => \'antibiotic_types\',
\'hierarchical\' => 1,
\'hide_empty\' => 1,
\'title_li\' => \'\',
\'include\' => $term_list
)
);
}
SO网友:natebeaty
为了防止其他人在google上搜索时只需要显示CPT帖子使用的一种分类法中的术语到另一种分类法，以下是我使用的代码，基于@gmazzap的回答：
// Get all story post IDs set to story_type of "rn"
$story_post_ids = get_posts([
\'numberposts\' => -1,
\'fields\' => \'ids\',
\'post_type\' => \'story\',
\'tax_query\' => [
[
\'taxonomy\' => \'story_type\',
\'field\' => \'slug\',
\'terms\' => [\'rn\'],
\'compare\' => \'IN\',
]
],
]);
// Find story topics in use by those post IDs
$story_topic_ids = $wpdb->get_col("
SELECT t.term_id FROM $wpdb->terms AS t
INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id
INNER JOIN $wpdb->term_relationships AS r ON r.term_taxonomy_id = tt.term_taxonomy_id
WHERE tt.taxonomy IN(\'story_topic\')
AND r.object_id IN (".implode(\',\', $story_post_ids).")
GROUP BY t.term_id
");
// Pull those topics
$story_topics = get_terms([
\'taxonomy\' => \'story_topic\',
\'include\' => $story_topic_ids,
]);
这将查找类型的所有术语
story_topic 由设置为术语的职位使用的
story_type “rn”的
