不是唯一的表/别名（codeigniter）

Question

错误编号：1066

不是唯一的表/别名：'posts'

SELECT * FROM (SELECT id, title, keywords, 'posts' AS type FROM posts, postsUNION SELECT id, title, keywords, 'android' AS type FROM android, androidUNION SELECT id, title, keywords, 'mac' AS type FROM mac, mac)t WHERE t.title like '%yj% ' OR t.keywords LIKE '%yj%'

模型：

  $query = $this->input->GET('search', TRUE);

  $this->db->select("id, title, keywords, 'posts' AS type");

  $this->db->from("posts");

  $query1 = $this->db->get_compiled_select('posts');

  $this->db->select("id, title, keywords, 'android' AS type");

  $this->db->from("android");

  $query2 = $this->db->get_compiled_select('android');

  $this->db->select("id, title, keywords, 'mac' AS type");

  $this->db->from("mac");

  $query3 = $this->db->get_compiled_select('mac');

  $data = $this->db->query('SELECT * FROM (' . $query1 . ' UNION ' . $query2 . ' UNION ' . $query3 . ')' . "t WHERE t.title like '%$query%' OR t.keywords LIKE '%$query%'");

         return $data->result();

Answer 1

删除表的所有第二个名称并使用 UNION ALL 代替：SELECT * FROM (  SELECT id, title, keywords, 'posts' AS type FROM  posts   UNION ALL   SELECT id, title, keywords, 'android' AS type FROM android   UNION ALL   SELECT id, title, keywords, 'mac' AS type FROM mac)t WHERE t.title like '%yj%' OR t.keywords LIKE '%yj%'