调用未定义的方法Product_filter_model :: fetch_data（）| 500内部服务器错误| Codeigninter

Question

我是CodeIgniter的新手，在过去3个小时中，我一直在努力解决此错误。

在以下代码中调用未定义的方法Product_filter_model :: fetch_data（）错误。

您可以在以下链接的“检查”>“网络”选项卡中查看错误： http://admin.millionkidstoschool.org/index.php/product_filter

我已经确认了型号，控制器和功能的名称。我也试过把$ this-> load-> model（'product_filter_model'）;在函数fetch_data（）中，它没有帮助。

控制器

class Product_filter extends CI_Controller{
public function __construct()
{

    parent::__construct();
    $this->load->model('product_filter_model');
    $this->load->helper('url');
}


 function fetch_data(){


    $minimum_price = $this->input->post('minimum_price');
    $maximum_price = $this->input->post('maximum_price');
    $brand = $this->input->post('brand');
    $ram = $this->input->post('ram');
    $storage = $this->input->post('storage');
    $output = array(
        /*'pagination_link' => $this->pagination->create_links(),*/
        'product_list'    => $this->product_filter_model->fetch_data($minimum_price, $maximum_price, $brand, $ram, $storage)
        );
    echo json_encode($output);
 }

查看

    $(document).ready(function(){

    filter_data();

       function filter_data(){
           $('#filter_data').html("<div id='loading'></div>");
           var action = 'fetch_data';
           var minimum_price = $('#hidden_minimum_price').val();
           var maximum_price = $('#hidden_maximum_price').val();
           var brand = get_filter('brand');
           var ram = get_filter('ram');
           var storage = get_filter('storage');
           $.ajax({
               url:"<?php echo base_url(); ?>index.php/product_filter/fetch_data",
               method:"POST",
               dataType:"JSON",
               data:{action:action, minimum_price:minimum_price,maximum_price:maximum_price, brand:brand, ram:ram, storage:storage},
               success:function(data){
                   $('.filter_data').html(data.product_list);
                   /*$('#pagination_link').html(data.pagination_link);*/
               }
           })
       }

}

型号

function fetch_data($minimum_price, $maximum_price, $brand, $ram, $storage)
{
    $query = $this->make_query($minimum_price, $maximum_price, $brand, $ram, $storage);

    /*$query .= ' LIMIT '.$start.', ' . $limit;*/

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

    $output = '';
    if($data->num_rows() > 0)
    {
        foreach($data->result_array() as $row)
        {
            $output .= '
            some data
            ';
        }
    }
    else
    {
        $output = '<h3>No Data Found</h3>';
    }
    return $output;
}

谢谢您的时间。

更新：

我在发布ajax请求的控制器函数中复制了两个模型方法的代码。有效。但是我无法理解为什么控制器功能无法访问模型方法？

public function fetch_data(){
    $this->load->model('product_filter_model');
    $minimum_price = $this->input->post('minimum_price');
    $maximum_price = $this->input->post('maximum_price');
    $brand = $this->input->post('brand');
    $ram = $this->input->post('ram');
    $storage = $this->input->post('storage');

    //$output = array(
        /*'pagination_link' => $this->pagination->create_links(),*/
       // 'product_list'    => $this->product_filter_model->fetch_data//($minimum_price, $maximum_price, $brand, $ram, $storage)
        //);

    /*$query = $this->product_filter_model->make_query($minimum_price, $maximum_price, $brand, $ram, $storage);*/

        /*$query .= ' LIMIT '.$start.', ' . $limit;*/

    $query = "
        SELECT * FROM product
        WHERE product_status = '1'
        ";

        if(isset($minimum_price, $maximum_price) && !empty($minimum_price) && !empty($maximum_price))
        {
            $query .= "
            AND product_price BETWEEN '".$minimum_price."' AND '".$maximum_price."'
            ";
        }

        if(isset($brand)){
            $brand_filter = implode("','", $brand);
            $query .="
            AND product_brand IN('".$brand_filter."')
            ";
        }

        if(isset($ram)){
            $ram_filter = implode("','", $ram);
            $query .="
            AND product_ram IN('".$ram_filter."')
            ";
        }

        if(isset($storage)){
            $storage_filter = implode("','", $storage);
            $query .="
            AND product_storage IN('".$storage_filter."')
            ";
        }
        /*
        return $query;*/

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

        $result = '';
        if($data->num_rows() > 0)
        {
            foreach($data->result_array() as $row)
            {
                $result .= '
                <div class="col-sm-4 col-lg-3 col-md-3">
                 <div style="border:1px solid #ccc; border-radius:5px; padding:16px; margin-bottom:16px; height:450px;">
                  <img src="'.base_url().'images/'. $row['product_image'] .'" alt="" class="img-responsive" >
                  <p align="center"><strong><a href="#">'. $row['product_name'] .'</a></strong></p>
                  <h4 style="text-align:center;" class="text-danger" >'. $row['product_price'] .'</h4>
                  <p>Camera : '. $row['product_camera'].' MP<br />
                  Brand : '. $row['product_brand'] .' <br />
                  RAM : '. $row['product_ram'] .' GB<br />
                  Storage : '. $row['product_storage'] .' GB </p>
                 </div>
                </div>
                ';
            }
            $output = array('product_list' => $result);
        }
        else
        {
            $result = '<h3>No Data Found</h3>';
        }



    echo json_encode($output);