如何将单个 MySql 连接与多个 PHP 对象一起使用。

Question

我已经阅读了很多这方面的例子，但是我读的越多，我就越感到困惑（对不起！）。我的首要任务是保持简单和高效。生成单个 MySql 连接并与多个 PHP 对象共享。

// open a db connection 
$dbc = new PDO(.......);

// allow multiple objects to use the same connection

$object_1 = new class_1($dbc);
$object_2 = new class_2($dbc);
$object_3 = new class_3($dbc);

// or should it be passed this way?

$object_1->connection($dbc);
$object_2->connection($dbc);
$object_3->connection($dbc);

// or should each of the classes be getting the connection
// from a singleton type db object? 

// should each object be an extesion of a db class?

// or is there something else I need to consider?

Answer 1

// allow multiple objects to use the same connection

$object_1 = new class_1($dbc);
$object_2 = new class_2($dbc);
$object_3 = new class_3($dbc);

// or should it be passed this way?

$object_1->connection($dbc);
$object_2->connection($dbc);
$object_3->connection($dbc);

这两个都是正确的，尽管如果一个对象需要数据库连接才能工作，那么将它传递给构造函数是首选方式。

有关此主题的更多信息，请查看有关依赖注入的文章。

例如：http://martinfowler.com/articles/injection.html

Answer 2

我更喜欢将连接类设为 Singlton：

class DBConnection {
    // Store the single instance of DBConnection 
    private static $m_pInstance;

    private function __construct() { ... }

    public static function getInstance()
    {
        if (!self::$m_pInstance)
        {
            self::$m_pInstance = new DBConnection();
        }

        return self::$m_pInstance;
    }
}