PHP OOP實踐

Question

我想下面給出的代碼可以正常工作（我正忙於學習OOP PHP，但尚未測試這些代碼），如果我想檢索單個記錄。 如果我要循環播放記錄怎么辦？ 怎么做 ？ 我可以使用單一類檢索單一和循環記錄嗎？ 如果是，怎么辦？

include('class.database.php');
class News 
{
    protected $id;
    protected $title;
    protected $detail;
    protected $updatedon;
    protected $views;
    protected $pic;
    protected $cat;
    protected $reporter;

    function __construct ($id);
        $newsdb = new Database; 
        $Query = "SELECT * FROM news WHERE nws_sn =".$id;
        $db->query($Query);
        $db->singleRecord();
        $this->id = $newsdb->Record['nws_sn'];
        $this->title = $newsdb->Record['nws_title'];
        $this->detail = $newsdb->Record['nws_detail'];
        $this->updatedon = $newsdb->Record['nws_time'];
        $this->views = $newsdb->Record['nws_view'];
        $this->pic = $newsdb->Record['nws_pic'];
        $this->cat = $newsdb->Record['nws_cat_id'];
        $this->reporter = $newsdb->Record['nws_rptr_id']
    }
    function getId () {
        return $this->id;
    }
    function getTitle () {
        return $this->title;
    }
    function getDetail () {
        return $this->detail;
    }
    function getViews () {
        return $this->views;
    }
    function getImage () {
        return $this->pic;
    }
    function getTime () {
        return $this->updatedon;
    }
}   

Answer 1

您想使用構造函數來初始化對象的內部狀態。 在您的情況下，您在構造函數中做了太多事情，這也違反了“單一責任原則”。 似乎“新聞”只是一個實體或數據傳輸對象，因此您必須從外部對其進行初始化。

首先，我將保留新聞只是為了存儲從數據庫接收到的信息。

其次，我將在News類中創建一個靜態工廠方法，以便它創建一個實際的News對象，並使用從外部傳遞給該方法的數據填充該對象。 另外，您可以創建一個工廠對象來創建您的實體，但是由於構造邏輯非常簡單，因此我認為將其保留在單個方法中是有意義的。

考慮下面的代碼：

class News 
{
    protected $id;
    protected $title;
    protected $detail;
    protected $updatedon;
    protected $views;
    protected $pic;
    protected $cat;
    protected $reporter;

    public static createFromRecord($record)
    {
        $obj = new self();

        $obj->setId($record->Record['nws_sn']);
        $obj->setTitle($record->Record['nws_title']);
        $obj->setDetail($record->Record['nws_detail']);
        $obj->setUpdateon($record->Record['nws_time']);
        $obj->setViews($record->Record['nws_view']);
        $obj->setPic($record->Record['nws_pic']);
        $obj->setCat($record->Record['nws_cat_id']);
        $obj->setReporter($record->Record['nws_rptr_id']);

        return $obj;
    }

    function getId () {
        return $this->id;
    }

    function getTitle () {
        return $this->title;
    }
    function getDetail () {
        return $this->detail;
    }
    function getViews () {
        return $this->views;
    }
    function getImage () {
        return $this->pic;
    }
    function getTime () {
        return $this->updatedon;
    }

    // ... add public setters for the properties
}   

...

$newsdb = new Database; 
$Query = "SELECT * FROM news WHERE nws_sn =".$id;
$db->query($Query);
$record = $db->singleRecord();

$newsObject = News::createFromRecord($record);