php/mysql试图在codeigniter中输出单个结果？

我是codeigniter的新手，尝试将百分比结果输出到我的项目的codeigniter视图中。一旦我解决了这个问题，事情就会顺利得多。 他是模型函数：

<?php

public function _construct()
{
    $this->load->database();
}

public function percent_specilation1($numstudent)
{
    $query = $this->db->query("SELECT * FROM Student WHERE Student.JRNOption ='1'");

    $numstudent = $query->num_rows()/25; 

    if($query->num_rows() > 0){
        return $numstudent;
    }
    return null; 
}

?>

---

试试这段代码，我已经更新了控制器和模型的一些代码，并在模型查询中为
学生id
使用
学生
表的主键

更新型号：

<?php

public function _construct()
{
    $this->load->database();
}

public function percent_specilation1()
{
    $query = $this->db->query("SELECT (SELECT COUNT(s2.student_id) 
            FROM Student s2
            WHERE s2.JRNOption='1')*100/COUNT(s1.student_id) AS percentage
            FROM Student s1");

    $result = $query->row_array(); 

    return $result['percentage']; 
}

?>

<?php
class Statscontroller extends CI_Controller {
    public function _contruct(){
        parent::_construct();
        $this->load->model('Stats_model');
    }
    public function index(){

        //echo "Various stats for the Journalism department:";
        $data['Test'] = $this->Stats_model->percent_specilation1();
        $this->load->view('templates/header',$data);
        $this->load->view('Statscontroller/index',$data);
        $this->load->view('templates/header');
    }


}
?>



更新控制器：

<?php

public function _construct()
{
    $this->load->database();
}

public function percent_specilation1()
{
    $query = $this->db->query("SELECT (SELECT COUNT(s2.student_id) 
            FROM Student s2
            WHERE s2.JRNOption='1')*100/COUNT(s1.student_id) AS percentage
            FROM Student s1");

    $result = $query->row_array(); 

    return $result['percentage']; 
}

?>

<?php
class Statscontroller extends CI_Controller {
    public function _contruct(){
        parent::_construct();
        $this->load->model('Stats_model');
    }
    public function index(){

        //echo "Various stats for the Journalism department:";
        $data['Test'] = $this->Stats_model->percent_specilation1();
        $this->load->view('templates/header',$data);
        $this->load->view('Statscontroller/index',$data);
        $this->load->view('templates/header');
    }


}
?>



希望这将对您有所帮助。
试试这段代码，我已经更新了控制器和模型的一些代码，并在模型查询中为
学生id
使用
学生
表的主键

更新型号：

<?php

public function _construct()
{
    $this->load->database();
}

public function percent_specilation1()
{
    $query = $this->db->query("SELECT (SELECT COUNT(s2.student_id) 
            FROM Student s2
            WHERE s2.JRNOption='1')*100/COUNT(s1.student_id) AS percentage
            FROM Student s1");

    $result = $query->row_array(); 

    return $result['percentage']; 
}

?>

<?php
class Statscontroller extends CI_Controller {
    public function _contruct(){
        parent::_construct();
        $this->load->model('Stats_model');
    }
    public function index(){

        //echo "Various stats for the Journalism department:";
        $data['Test'] = $this->Stats_model->percent_specilation1();
        $this->load->view('templates/header',$data);
        $this->load->view('Statscontroller/index',$data);
        $this->load->view('templates/header');
    }


}
?>



更新控制器：

<?php

public function _construct()
{
    $this->load->database();
}

public function percent_specilation1()
{
    $query = $this->db->query("SELECT (SELECT COUNT(s2.student_id) 
            FROM Student s2
            WHERE s2.JRNOption='1')*100/COUNT(s1.student_id) AS percentage
            FROM Student s1");

    $result = $query->row_array(); 

    return $result['percentage']; 
}

?>

<?php
class Statscontroller extends CI_Controller {
    public function _contruct(){
        parent::_construct();
        $this->load->model('Stats_model');
    }
    public function index(){

        //echo "Various stats for the Journalism department:";
        $data['Test'] = $this->Stats_model->percent_specilation1();
        $this->load->view('templates/header',$data);
        $this->load->view('Statscontroller/index',$data);
        $this->load->view('templates/header');
    }


}
?>



希望这能对您有所帮助。
问题可能在您的索引中，然后添加$this->view（），以显示您创建的视图。模型看起来根本不像CI。您可能误解了框架。请仔细阅读文档。问题可能在您的索引中，然后添加$this->view（），以显示您创建的视图。模型看起来根本不像CI。您可能误解了框架。请看一下文件。