使用PDO时出错：致命错误：调用成员函数prepare（）null

Question

我正在学习PDO，并且我一直在收到此错误，我做了一些搜索，没有任何结果解决问题。这里是我使用的代码：

的index.php :::

require_once 'database/Connection.php'; 
require 'Task.php'; 
$pdo = Connection::make(); 

$statement = $pdo->prepare("select * from todos"); 
$statement->execute(); 
$tasks= $statement->fetchAll(PDO::FETCH_CLASS, 'Task'); 

<ul> 
     <?php foreach ($tasks as $task) : ?> 
      <li><?= $task->description; ?></li> 
     <?php endforeach; ?> 
    </ul> 

Connection.php :::

class Connection { 

    public static function make() { 
     try { 
       $pdo = new PDO('mysql:host=127.0.0.1;dbname=mytodo', 'root', 'mysql'); 
      } catch(PDOException $e) { 
       die($e->getMessage().' DB Could not find'); 
      } 
    } 

} 

Answer 1

使用return关键字为：

class Connection { 

    public static function make() { 
     try { 
       return $pdo = new PDO('mysql:host=127.0.0.1;dbname=mytodo', 'root', 'mysql'); 
      } catch(PDOException $e) { 
       die($e->getMessage().' DB Could not find'); 
      } 
    } 

}