在CodeIgniter中调用未定义的方法CI_DB_mysqli_result :: where（）

Question

我正在尝试设置一条路线，CodeIgniter按键'系列'和'id'拉动照片。它会遵循这个逻辑：

photos /：返回数据库中的所有表'照片'。照片/系列：返回所有符合特定系列的照片。 'photos / nature'将返回所有带有'系列'等于'nature'的照片。 photos / series / id：返回单张照片。 'photos / nature / 1'会返回一张照片，其中'系列'等于'自然'，'id'等于'1'

调用'http://localhost/public_html/photos/nature/1'我收到以下错误：

A php Error was encountered
Severity: Error
Message: Call to undefined method CI_DB_mysqli_result::where()
Filename: models/Photos_model.php
Line Number: 14
Backtrace:

我的'照片'表结构：

CREATE TABLE `photos` (
  `filename` varchar(45) NOT NULL,
  `series` varchar(45) NOT NULL,
  `id` int(11) NOT NULL,
  `caption` varchar(45) NOT NULL,
  `description` varchar(45) NOT NULL,
  PRIMARY KEY (`filename`))

'照片'表的价值：

INSERT INTO `photos` VALUES 
  ('file00053809264.jpg','nature',1,'waterfall','description of waterfall'),
  ('file000267747089.jpg','nature',2,'forest','description of burning forest'),
  ('file000325161223.jpg','cloudburst',1,'sky','description of sky'),
  ('file000267804564.jpg','cloudburst',2,'bursting abstract','description bursting abstract'),
  ('file000132701536.jpg','landmarks',1,'taj mahal','description taj mahal');

CodeIgniter中的我的照片控制器：

<?php
    class Photos extends CI_Controller {
        public function __construct() {
            parent::__construct();
            $this->load->model('photos_model');
            $this->load->helper('url_helper');
            $this->load->helper('html'); // needed for header
            $this->load->helper('url'); // needed for footer
        }
        public function view($series = NULL, $id = NULL) {
            $data['photos'] = $this->photos_model->get_photos($series, $id)->result_array();
            if (empty($data['photos'])){
                show_404();
            }
            $data['title'] = 'Photos';
            $this->load->view('templates/header', $data);
            $this->load->view('photos/view', $data);
            $this->load->view('templates/footer');
        }
        public function index() {
            $data['photos'] = $this->photos_model->get_photos();
            $data['title'] = 'Photos';
            $this->load->view('templates/header', $data);
            $this->load->view('photos/index', $data);
            $this->load->view('templates/footer');
        }
    }

我的照片模型：

<?php
    class Photos_model extends CI_Model {
        public function __construct() {
            $this->load->database();
        }        
        public function get_photos($series = FALSE, $id = FALSE) {
            if ($series === FALSE && $id === FALSE) {
                $query = $this->db->get('photos');
            } else if ($id === FALSE) {
                $query = $this->db->get_where('photos', array('series' => $series));        
            } else {
                $query = $this->db->get('photos')->where('series', $series)->where('id', $id);    
            }
            return $query->result_array();
        }
    }

我的'photos / view.php'视图：

<?php
echo $photos['photos'];

我的路线配置：

$route['photos/'] = 'photos/view';
$route['photos/(:any)'] = 'photos/view/$1';
$route['photos/(:any)/(:num)'] = 'photos/view/$1/$2';

如果你能告诉我我在哪里以及如何滑倒，你可以向我解释一下吗？谢谢。