database Codeigniter 未定义属性： xxxx_model::$db 仅来自模型

Codeigniter Undefined property: xxxx_model::$db only from Model

提问by Stephane Grenier

First the Model class:

首先是模型类：

    class Xxxx_model extends Model
    {
      function XxxxModel()
      {
        parent::Model();
        $this->load->database();
      }

      function isInDatabase()
      {
        // Please ignore the sql query, it's just to show some random sql code with results
11.      $result = $this->db->query('SELECT * FROM someTable WHERE ...');
        $numberOfRows = $result->num_rows();
        ... 
        return $test;
      }
    }

Now the controller:

现在控制器：

function someLogic()
{
  $this->load->model('xxxx_Model', 'xxxxModel'); // not necessary to specify
  $this->xxxxModel->isInDatabase();
}

When I run this I get the error:

当我运行它时，我收到错误：

Severity: Notice  --> Undefined property: Xxxx_model::$db .../xxxx_model.php line 11

I have no idea why this is. If I put the db code in the controller it seems to work, it's only with this setup in the model that it fails. I can't for the life of me figure out where the code is astray...

我不知道这是为什么。如果我将 db 代码放在控制器中，它似乎可以工作，只有模型中的此设置才会失败。我一生都无法弄清楚代码在哪里误入歧途......

采纳答案by Wesley Murch

To add to atno's answer:

添加到 atno 的答案：

class Xxxx_model extends Model
{
  function XxxxModel() //<--- does not match model name Xxxx_model
  {
    parent::Model();
    $this->load->database();
  }

Basically, you are not constructing the class orthe parent class Model. If you are on PHP5, you may use __construct(), otherwise you must match the class name exactly, regardless of what alias you load it with in your controller. Example:

基本上，您不是在构建类或父类Model。如果您使用的是 PHP5，则可以使用__construct()，否则您必须完全匹配类名，无论您在控制器中使用什么别名加载它。例子：

class Xxxx_model extends Model
{
  function __construct()
  {
    parent::__construct(); // construct the Model class
  }
}

I may be mistaken (haven't used 1.x in a while), but if you construct the Model class, there's no need to load the database if you are using the default connection settings in config/database.php, it should already be loaded for you.

我可能弄错了（有一段时间没有使用 1.x），但是如果您构建 Model 类，如果您使用的是 中的默认连接设置config/database.php，则不需要加载数据库，它应该已经为您加载了。

回答by uwublogs

You have to load the db library first. In autoload.phpadd below code,

您必须先加载 db 库。在autoload.php添加下面的代码，

$autoload[‘libraries'] = array(‘database');

回答by Tonci14

add library 'datatabase' to autoload.

将库“数据库”添加到自动加载。

/application/config/autoload.php

/application/config/autoload.php

$autoload['libraries'] = array( 'database' );

$autoload['libraries'] = array( 'database' );

Propably you're started new project, like me ;-)

可能你和我一样开始了新项目;-)

回答by afarazit

If function XxxxModel()isn't your constructor, you're not loading the database by calling $this->xxxxModel->isInDatabase();

如果function XxxxModel()不是您的构造函数，则不会通过调用加载数据库$this->xxxxModel->isInDatabase();

Try autoloading the database library from within autoload.php, or create a proper constructor in your model.

尝试从 内部自动加载数据库库autoload.php，或在您的模型中创建适当的构造函数。