我正在尝试实现基于标记的搜索。当我指定某些标记时，将搜索标记的帖子，并显示与搜索条件匹配的帖子id。

目前它只适用于单个标记。

$query = "SELECT DISTINCT $wpdb->posts.ID FROM $wpdb->terms
    LEFT JOIN $wpdb->term_taxonomy ON ($wpdb->terms.term_id = $wpdb->term_taxonomy.term_id)
    LEFT JOIN $wpdb->term_relationships ON ($wpdb->terms.term_id = $wpdb->term_relationships.term_taxonomy_id)
    LEFT JOIN $wpdb->posts ON ($wpdb->term_relationships.object_id = $wpdb->posts.ID)
        WHERE $wpdb->term_taxonomy.taxonomy = \'post_tag\' " . $substring;

子字符串如下所示：

$substring = "AND $wpdb->terms.slug IN (\'tag1\',\'tag2\')"

这就是问题所在。它不寻找符合所有标准的单个帖子。相反，它“收集”所有帖子，并搜索所有标签。

例如：

// postid1 -> tag1
// postid2 -> tag2
// postid3 -> tag1, tag2

$substring = "AND $wpdb->terms.slug IN (\'tag1\')"
//Output: postid1, postid3 - - - CORRECT
$substring = "AND $wpdb->terms.slug IN (\'tag1\',\'tag2\')"
//Output: postid1, postid2, postid3 - - -WRONG!

//Expected: postid3

到目前为止，我不知道如何在一个mysql查询中解决它。也许我错过了什么。提前感谢您的帮助。

SELECT p.ID 
FROM wp_posts p 
INNER JOIN wp_term_relationships tr ON (p.ID = tr.object_id) 
INNER JOIN wp_term_taxonomy tt ON (tr.term_taxonomy_id = tt.term_taxonomy_id) 
INNER JOIN wp_terms t ON (tt.term_id = t.term_id) 
WHERE tt.taxonomy = \'post_tag\' 
AND t.slug IN (\'is\', \'filler\') 
GROUP BY p.ID HAVING count(p.ID) = 2