我正在尝试按类别获取woocommerce产品。。当我使用wpdb进行查询时，它会正确地获取存在于后端产品列表中的产品。但是，当我使用query\\u posts进行查询时，它会得到另一组未在后端列出的产品。

为什么会出现这种差异？

     global $post, $wpdb;                   


    $query = "SELECT $wpdb->posts.* FROM $wpdb->posts
    LEFT JOIN $wpdb->term_relationships ON
    ($wpdb->posts.ID = $wpdb->term_relationships.object_id)
    LEFT JOIN $wpdb->term_taxonomy ON
    ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id)
    WHERE $wpdb->posts.post_status = \'publish\'
    AND $wpdb->term_taxonomy.taxonomy = \'product_cat\'
    AND $wpdb->term_taxonomy.term_id = 1
    $childcond
    ORDER BY post_date DESC"; 

    if ($wpdb->num_rows > 0) {
        foreach ($postresults as $post) { 
              //process product item
        }
    }

 query_posts(\'cat=1&showposts=-1\');