如何将以下查询转换为 codeigniter [重复]

Question

SELECT r.report_id,
       a.advertisement_title,
       COUNT(r.advertisement_id) AS total
FROM report r
JOIN advertisement a ON a.advertisement_id = r.advertisement_id
GROUP BY r.advertisement_id

Answer 1

$this->db->query('
SELECT r.report_id,
   a.advertisement_title,
   COUNT(r.advertisement_id) AS total
 FROM report r
JOIN advertisement a ON a.advertisement_id = r.advertisement_id
GROUP BY r.advertisement_id')

Answer 2

下面是如何做到的

$this->db->select('r.report_id,
       a.advertisement_title,
       COUNT(r.advertisement_id) AS total');
$this->db->from('report r');
$this->db->join('advertisement a','a.advertisement_id = r.advertisement_id');
$this->db->group_by('r.advertisement_id');