php - codeigniter，如何获取多个查询并从模型中对其进行计数

Question

我是 Codeigniter 的新手。我正在尝试让我的模型返回两个查询，一个是针对数据本身(表中的一些注释)，另一个是计算字段。并返回表单的输出(非常好、好和坏)。在他与 officer_name 相关的投票中。问题是当我从三个不同的查询中使用 count(*) 时，结果仅为空。

这是来 self 的模型的查询。

$this->db->select('a.id_poll')
                ->select('a.poll')
                ->select('a.date')
                ->select('a.id_officer')
                ->select('b.officer_name')
                ->select('c.id_service')
                ->select('c.service_name')
                ->select('count(a.poll) as verygood')
                ->where('b.officer_name', $officer['officer_name'])
                ->where('a.poll','verygood')
                ->select('count(a.poll) as good')
                ->where('b.officer_name', $officer['officer_name'])
                ->where('a.poll','good');
                ->select('count(a.poll) as bad')
                ->where('b.officer_name', $officer['officer_name'])
                ->where('a.poll','bad');
$this->db->from('tbl_poll as a');
$this->db->join('tbl_officer as b', 'a.id_officer = b.id_officer');
$this->db->join('tbl_service as c', 'b.id_service = c.id_service');
return $this->db->get()->result_array();

这是我想要的输出:

Officer_name | Service |        Polls          |
             |         | Verygood | Good | Bad |
Bella        | Payments|    3     |  2   |  1  |
Christy      |   CS    |    5     |  3   |  0  |
ETC.         |   etc   |    3     |  3   |  3  |

有人可以帮助我以及如何做到这一点，或者修复我当前的代码吗？

提前致谢!

抱歉我的英语太差了

这是 sqlfiddle

Answer 1

试试这个，可能会有帮助。

$this->db->select('a.id_poll,a.poll,a.date,a.id_officer,b.officer_name,c.id_service,c.service_name,count(a.poll) as verygood,count(a.poll) as good,count(a.poll) as bad');
$this->db->from('tbl_poll as a');

$this->db->join('tbl_officer as b', 'a.id_officer = b.id_officer');
$this->db->join('tbl_service as c', 'b.id_service = c.id_service');

$this->db->where('b.officer_name', $officer['officer_name'])
$this->db->where('a.poll','verygood')

$this->db->where('b.officer_name', $officer['officer_name'])
$this->db->where('a.poll','good');

$this->db->where('b.officer_name', $officer['officer_name'])
$this->db->where('a.poll','bad');

$query = $this->db->get();

$result = $query->result_array();

//To check the resutl for test purpose only

echo "<pre>";  print_r($this->db->last_query()); echo "</pre>";  // To check the query
echo "<pre>";  print_r($result); echo "</pre>";