How to Show All Tags in a Category

In WordPress  you can create your own function for your own purpose. Anyways if you want to wordPress tags such as a tag cloud using only tags found in a specific category and also tag and category intersection. Maybe you are finding helping from using tags in category, please looking help bellow:

In your theme’s functions.php insert the following function:
function get_category_tags($args) { global $wpdb; $tags = $wpdb->get_results (" SELECT DISTINCT terms2.term_id as tag_id, terms2.name as tag_name, null as tag_link FROM wp_posts as p1 LEFT JOIN wp_term_relationships as r1 ON p1.ID = r1.object_ID LEFT JOIN wp_term_taxonomy as t1 ON r1.term_taxonomy_id = t1.term_taxonomy_id LEFT JOIN wp_terms as terms1 ON t1.term_id = terms1.term_id, wp_posts as p2 LEFT JOIN wp_term_relationships as r2 ON p2.ID = r2.object_ID LEFT JOIN wp_term_taxonomy as t2 ON r2.term_taxonomy_id = t2.term_taxonomy_id LEFT JOIN wp_terms as terms2 ON t2.term_id = terms2.term_id WHERE t1.taxonomy = 'category' AND p1.post_status = 'publish' AND terms1.term_id IN (".$args['categories'].") AND t2.taxonomy = 'post_tag' AND p2.post_status = 'publish' AND p1.ID = p2.ID ORDER by tag_name "); $count = 0; foreach ($tags as $tag) { $tags[$count]->tag_link = get_tag_link($tag->tag_id); $count++; } return $tags; }

In your theme document(archive.php) insert the following code:

Note: change category id (12,13,14) to your id category you want to show tags

$args = array( 'categories' => '12,13,14' ); $tags = get_category_tags($args);
$content .= "<ul>"; foreach ($tags as $tag) { $content .= "<li><a href=\"$tag->tag_link\">$tag->tag_name</a></li>"; } $content .= "</ul>"; echo $content;