CodeIgniter框架Pokedex页面报错请求调试：变量未定义与类型错误

• PHP警告：未定义变量 $poke，文件views/pokeview.php行44
• TypeError异常：sizeof()参数#1必须为Countable|array类型，传入了null，文件views/pokeview.php行44

回溯路径：

文件: C:\xampp\htdocs\llames3\application\views\pokeview.php 行号: 44 函数: _error_handler
文件: C:\xampp\htdocs\llames3\application\controllers\Nav.php 行号: 13 函数: view
文件: C:\xampp\htdocs\llames3\index.php 行号: 315 函数: require_once

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Nav extends CI_Controller{

    public function __construct() {
        parent::__construct();
        $this->load->helper('url');
        $this->load->model('Pokemodel');
    }

    public function index(){
        $this->load->view('pokeview');
    }

    public function pokemonTable() {
        $pokemon = array(
        'poke' => $this->Pokemodel->poketable()
        );
        $this->load->view('pokeview', $pokemon);
    }
    

    public function insertPokemon(){
        $this->load->view('insert_form');
    }
    public function pokemonInsert() {
        $pokeName = $this->input->post('pokeName');
        $typeOne = $this->input->post('typeOne');
        $typeTwo = $this->input->post('typeTwo');
    
        $this->load->model('Pokemodel');
        $this->Pokemodel->pokeinsert($pokeName, $typeOne, $typeTwo);
    
        $data['poke'] = $this->Pokemodel->poketable();
        
        $this->load->view('pokeview', $data);
    }

    public function searchPokemon(){
        $searchTerm = $this->input->get('search');
        $this->load->model('Pokemodel');
        $data['poke'] = $this->Pokemodel->searchPokemon($searchTerm);
        $this->load->view('pokeview', $data);
    }
    
    public function viewPokemon($pokeName) {
        $data['pokemon'] = $this->Pokemodel->get_pokemon_by_name($pokeName);
        $this->load->view('view_pokemon', $data);
    }
    
    public function deletePokemon($pokeName) {
        $this->Pokemodel->delete_pokemon($pokeName);
        redirect('Nav/pokemonTable');
    }    
}
?>

<?php

class Pokemodel extends CI_Model{
    public function poketable(){
        $q = $this->db->query("SELECT * FROM pokedex ORDER BY pokeName ASC");
        return $q->result();
    }
            
 public function pokeinsert($pokeName, $typeOne, $typeTwo) {

    $d = array(
        'pokeName' => $pokeName,
        'typeOne' => $typeOne,
        'typeTwo' => $typeTwo
    );

     $this->db->insert('pokedex', $d);
 } 

 public function searchPokemon($searchTerm){
    if ($searchTerm !== null) {
        $this->db->like('pokeName', $searchTerm);
        $this->db->or_like('typeOne', $searchTerm);
        $this->db->or_like('typeTwo', $searchTerm);
    }

    $q = $this->db->get('pokedex');
    return $q->result();
}

public function get_pokemon_by_name($pokeName){
    $q = $this->db->get_where('pokedex', array('pokeName' => $pokeName));
    return $q->row();
}

public function delete_pokemon($pokeName){
    $this->db->where('pokeName', $pokeName);
    $this->db->delete('pokedex');
}
}
?>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV/Dwwykc2MPK8M2HN" crossorigin="anonymous">
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/js/bootstrap.bundle.min.js" integrity="sha384-C6RzsynM9kWDrMNeT87bh95OGNyZPhcTNXj1NW7RuBCsyN/o0jlpcV8Qyq46cDfL" crossorigin="anonymous"></script>
    <title>Pokemon</title>
    <nav class="navbar navbar-expand-lg bg-body-tertiary">
  <div class="container-fluid">
    <a class="navbar-brand" href="http://localhost/llames3/index.php/Nav/pokemonTable">Pokedex</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
      <ul class="navbar-nav me-auto mb-2 mb-lg-0">
        <li class="nav-item">
          <a class="nav-link active" aria-current="page" href="http://localhost/llames3/index.php/Nav/pokemonTable">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="http://localhost/llames3/index.php/Nav/insertPokemon">Insert</a>
        </li>
       
      </ul>
      <form class="d-flex" action="http://localhost/llames3/index.php/Nav/searchPokemon" method="get">
        <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search" name="search">
        <button class="btn btn-outline-success" type="submit">Search</button>
      </form>
    </div>
  </div>
</nav>
</head>
<body>
<div class="container">
<table class="table table-striped">
  <thead>
    <tr>
      <th scope="col">Pokemon Name</th>
      <th scope="col">Type One</th>
      <th scope="col">Type Two</th>
    </tr>
  </thead>
  <tbody>
      <?php for($i = 0; $i < sizeof($poke); $i++) {?>
                <tr>
                <th scope="row"><?php echo $poke[$i]->pokeName; ?></th>
                <td><?php echo $poke[$i]->typeOne; ?></td>
                <td><?php echo $poke[$i]->typeTwo; ?></td>
                <td>
                  <a href="<?= base_url('index.php/Nav/viewPokemon/' . $poke[$i]->pokeName) ?>" class="view-btn" >View</a>
                  <a href="<?= base_url('index.php/Nav/deletePokemon/' . $poke[$i]->pokeName) ?>" class="delete-btn">Delete</a>
                </td>
                </tr>
        <?php } ?>
  </tbody>
</table>
</div>
</body>
</html>

1. 修复控制器index方法未传数据问题 #

当前index方法直接加载视图，未传递$poke变量，导致视图报错。修改方式二选一：

// 方案1：重定向到已正确传参的pokemonTable方法
public function index(){
    redirect('Nav/pokemonTable');
}

// 方案2：直接获取数据并传递给视图
public function index(){
    $data['poke'] = $this->Pokemodel->poketable();
    $this->load->view('pokeview', $data);
}

2. 视图中增加变量安全检查 #

在视图的循环逻辑前，先确保$poke存在且为可计数类型，避免sizeof报错：

<tbody>
<?php 
// 初始化变量，避免未定义警告
$poke = isset($poke) ? $poke : [];
if(is_countable($poke) && sizeof($poke) > 0) {
    for($i = 0; $i < sizeof($poke); $i++) {?>
                <tr>
                <th scope="row"><?php echo $poke[$i]->pokeName; ?></th>
                <td><?php echo $poke[$i]->typeOne; ?></td>
                <td><?php echo $poke[$i]->typeTwo; ?></td>
                <td>
                  <a href="<?= base_url('index.php/Nav/viewPokemon/' . $poke[$i]->pokeName) ?>" class="view-btn" >View</a>
                  <a href="<?= base_url('index.php/Nav/deletePokemon/' . $poke[$i]->pokeName) ?>" class="delete-btn">Delete</a>
                </td>
                </tr>
        <?php } 
} else { ?>
    <tr><td colspan="4">暂无宝可梦数据</td></tr>
<?php } ?>
</tbody>

3. 验证数据库连接与查询结果 #

检查application/config/database.php中的数据库配置是否正确，可在模型poketable方法中添加调试代码确认查询状态：

public function poketable(){
    $q = $this->db->query("SELECT * FROM pokedex ORDER BY pokeName ASC");
    // 调试用：打印执行的SQL语句和结果行数
    // echo $this->db->last_query();
    // echo '<br>结果行数：'.$q->num_rows();
    return $q->result();
}

内容的提问来源于stack exchange，提问作者Kingsley Llames