wordpress:从特定类别的文章中生成标签数组

我不确定你能用WordPress提供的功能完成你想要的。下面是一个SQL查询,它似乎可以满足您的需要:

SELECT tag_terms.name, COUNT(wp_posts.ID) FROM wp_posts 

INNER JOIN wp_term_relationships AS cat_term_relationships ON wp_posts.ID= cat_term_relationships.object_ID 
INNER JOIN wp_term_taxonomy AS cat_term_taxonomy ON cat_term_relationships.term_taxonomy_id= cat_term_taxonomy.term_taxonomy_id 
INNER JOIN wp_terms AS cat_terms ON cat_term_taxonomy.term_id= cat_terms.term_id 

INNER JOIN wp_term_relationships AS tag_term_relationships ON wp_posts.ID= tag_term_relationships.object_ID 
INNER JOIN wp_term_taxonomy AS tag_term_taxonomy ON tag_term_relationships.term_taxonomy_id= tag_term_taxonomy.term_taxonomy_id 
INNER JOIN wp_terms AS tag_terms ON tag_term_taxonomy.term_id= tag_terms.term_id 

WHERE cat_term_taxonomy.taxonomy='category' AND cat_terms.name='apple' AND tag_term_taxonomy.taxonomy='post_tag'
GROUP BY tag_terms.name

其要点是,您将wp_posts表与分类表连接几次,以获取所需类别中的post id,然后再将这些id与分类表连接几次,以获取相关的标记。

下面是如何使用WordPress函数完成这一任务

<?php
$tags = array();

$posts = get_posts('category_name=new-cat&numberposts=-1'); //get all posts in category

foreach ($posts as $post){
    $posttags = get_the_tags($post->ID); //check for tags
    if ($posttags){
        foreach ($posttags as $posttag){
            $tags[$posttag->term_id] = $posttag->name; // add to array of tag ids => names
        }
    }
}
print_r($tags);
?>

这可能比原始SQL查询更可取,因为当WordPress更新其数据库模式时,这些查询常常会中断。