php - 从公共(public)范围获取变量以连接数据库第 2 部分

Question

$hostname['application'] = '127.0.0.1';
$username['application'] = 'root';
$password['application'] = 'root';
$database['application'] = 'band';
$dbdriver['application'] = 'mysql';

class database
{
    private $hostname;
    private $username;
    private $password;
    protected $database;
    private $dbdriver;

    function __construct( $database )
    {

    }
}

$db = new database( 'application' );

仍然是与以前相同的问题，但我仍然想了解如何制作一个简单的 pdo 包装器。 我们可以通过仅知道 $x['database'] 来获取 $hostname['application'] 等吗？我的意思是我想做的是把 getting a variable from a public scope to connect database 。但我正在尝试解决不同的问题。

感谢您的关注。

Answer 1

尝试依赖注入(inject):

$hostname['application'] = '127.0.0.1';
$username['application'] = 'root';
$password['application'] = 'root';
$database['application'] = 'band';
$dbdriver['application'] = 'mysql';

class database {
    private $hostname;
    private $username;
    private $password;
    protected $database;
    private $dbdriver;

    function __construct( $hostname, $username, $password, $database, $driver = 'mysql' ) {
        $this->hostname = $hostname;
        $this->username = $username;
        $this->password = $password;
        $this->database = $database;
        $this->driver = $driver;
    }
}

$dbInstance = new database( $hostname['application'], $username['application'], $password['application'], $database['application'] );

作为一般规则，您不应该使用全局变量。如果您在函数或类方法中的某个位置需要变量，您应该显式地将它们作为参数“注入(inject)”到您的函数/方法中。