如评论中所述，我包括一个聚合函数，但没有“ group by”子句。
现在，这似乎可行（只需添加
GROUP BY一行即可）：
SELECt p.id, p.post_name, c.name, GROUP_CONCAt(t.`name`)FROM wp_posts pJOIN wp_term_relationships cr on (p.`id`=cr.`object_id`)JOIN wp_term_taxonomy ct on (ct.`term_taxonomy_id`=cr.`term_taxonomy_id` and ct.`taxonomy`='category')JOIN wp_terms c on (ct.`term_id`=c.`term_id`)JOIN wp_term_relationships tr on (p.`id`=tr.`object_id`)JOIN wp_term_taxonomy tt on (tt.`term_taxonomy_id`=tr.`term_taxonomy_id` and tt.`taxonomy`='post_tag')JOIN wp_terms t on (tt.`term_id`=t.`term_id`)GROUP BY p.id+---------------+----------+----------------+| post_id | category | tags||---------------+----------+----------------+| 213| news | tag1,tag2,tag3 |+---------------+----------+----------------+| 216| whatever | tag2,tag3 |+---------------+----------+----------------+
谢谢
