php - CodeIgniter 错误为 foreach() 提供的参数无效

Question

我正在尝试从数据库中选择数据，但出现此错误:

  A PHP Error was encountered        
    Severity: Warning
    Message: Invalid argument supplied for foreach()
    Filename: controllers/hello.php
    Line Number: 24

Controller :

<?php
    // system/application/controllers/hello.php

    class Hello extends CI_Controller {

       public function __construct()
       {
            parent::__construct();
       }

       function show_data() {

            $query = $this->load->model('user');
            foreach ($query->result() as $value) {
                echo $value -> username;
                echo $value -> password;
                echo $value -> first_name;
                echo $value -> last_name;
            }
       }
    }
?>

型号:

class User extends CI_Model {

    function __construct()
    {
        // Call the Model constructor
        parent::__construct();
    }

    function show()
    {
        $query = $this->db->get('user', 10);
        return $query->result();
    }
}

我正在查看本教程:https://www.codeigniter.com/user_guide/database/results.html

错误是什么意思？

Answer 1

你的 Controller 函数应该是这样的，

function show_data() {
    $this->load->model('user');
    $query = $this->user->show();
    foreach($query as $value) {
        echo $value->username;
        echo $value->password;
        echo $value->first_name;
        echo $value->last_name;
    }
}

检查 here关于如何加载模型。