PHP DataMapper模式：我的类需要一个PDO的实例，我想把它包装在一个Db类中 [英] PHP DataMapper pattern: My class needs an instance of PDO, I want to wrap it inside a Db class

问题描述

这是我有的：

  class Entry 
 {
 public $ id; 
 public $ name; 
 public $ seoName; 
 public $ timeCreated; 
 
 public function someFunction（）
 {
 
} 
 
} 
 
 class EntryMapper 
 {
 protected $ db; 
 
 public function __construct（PDO $ db）
 {
 $ this-> db = $ db; 
} 
 
 public function saveEntry（Entry& $ entry）
 {
 if（$ entry-> id）{
 $ sql = ; 
} 
 else {
 $ sql =INSERT INTO tbl_entry（name，seo_name，time_created）VALUES（：name，：seo_name，，time_created）; 
 $ stmt = $ this-> db-> prepare（$ sql）; 
 $ stmt-> bindParam（name，$ entry-> name）; 
 $ stmt-> bindParam（seo_name，$ entry-> seoName）; 
 $ stmt-> bindParam（time_created，$ entry-> timeCreated）; 
 $ stmt-> execute（）; 
 $ entry-> id = $ this-> db-> lastInsertId（）; 
} 
} 
 
} 
  

这里是我在我的视图文件中使用它（目前只是测试插入命令）：

  $ entry = new Entry（）; 
 
 $ entry-> name =KartonažaadGradačac; 
 $ entry-> seoName =kartonaza-ad-gradacac; 
 $ entry-> timeCreated = date（Y-m-d H：i：s）; 
 
 $ entryMapper = new EntryMapper（new PDO（mysql：host = .....））; 
 $ entryMapper-> saveEntry（$ entry）; 
  

我想要这样的$ entryMapper行：

  $ entryMapper = new EntryMapper（new Database（））; 
  

意思是我应该有一个单独的类Database.php，在那里我将建立连接。

我尝试过，但是由于我的类EntryMapper.php需要直接的PDO实例，所以我收到一个错误。我试过数据库从PDO扩展，但也引起错误，表示PDO构造函数未在EntryMapper中调用

任何想法？

$ b $编辑：如果你看到任何代码耦合或类似的迹象，让我知道，因为我想学习正确编码。非常感谢！

解决方案

这是我终于解决了（如果一个更好的实现出现，我会确定重新编码） 。这是在这里接受的答案下的解决方案的实现：数据库连接的全局或单例？ / a>

我的ConnFactory.php

  include（'config /config.php'）; 
 
 class ConnFactory 
 {
 private static $ factory; 
 
 public static function getFactory（）
 {
 if（！self :: $ factory）{
 self :: $ factory = new ConnFactory（）; 
 return self :: $ factory; 
} 
 
} 
 
 private $ db; 
 
 public function pdo（）
 {
 if（！$ this-> db）{
 $ options = array（
 PDO :: ATTR_PERSISTENT => true，
 PDO :: ATTR_ERRMODE => PDO :: ERRMODE_EXCEPTION，
 PDO :: ATTR_EMULATE_PREPARES => false，
 PDO :: MYSQL_ATTR_INIT_COMMAND =>SET NAMES utf8 
）; 
 $ this-> db = new PDO（mysql：host =。DB_HOST。; port =DB_PORT; dbname =DB_SCHEMA，DB_USER，DB_PASS，$ options）; 
} 
 return $ this-> db; 
} 
 
} 
  

我的视图/ html文件中的用法（只是插入功能的测试）：

  $ entry = new Entry（）; 
 $ entry-> name =KartonažaadGradačac; 
 $ entry-> seoName =kartonaza-ad-gradacac; 
 $ entry-> timeCreated = date（Y-m-d H：i：s）; 
 
 $ entryMapper = new EntryMapper（ConnFactory :: getFactory（） - > pdo（））; 
 $ entryMapper-> saveEntry（$ entry）; 
  

here's what I have:

class Entry
{
    public $id;
    public $name;
    public $seoName;
    public $timeCreated;

    public function someFunction()
    {

    }

}

class EntryMapper
{
    protected $db;

    public function __construct(PDO $db)
    {
        $this->db = $db;
    }

    public function saveEntry(Entry &$entry)
    {
        if($entry->id){
            $sql = "";
    }
    else {
        $sql = "INSERT INTO tbl_entry (name, seo_name, time_created) VALUES (:name, :seo_name, :time_created)";
        $stmt = $this->db->prepare($sql);
        $stmt->bindParam("name", $entry->name);
        $stmt->bindParam("seo_name", $entry->seoName);
        $stmt->bindParam("time_created", $entry->timeCreated);
        $stmt->execute();
        $entry->id = $this->db->lastInsertId();
        }
    }

}

Now, here's how I use it in my view file (currently just testing insert command):

$entry = new Entry();

$entry->name = "Kartonaža ad Gradačac";
$entry->seoName = "kartonaza-ad-gradacac";
$entry->timeCreated = date("Y-m-d H:i:s");

$entryMapper = new EntryMapper(new PDO("mysql:host=....."));
$entryMapper->saveEntry($entry);

I want to have the $entryMapper line like this:

$entryMapper = new EntryMapper(new Database());

meaning I should have a separate class Database.php where I would establish the connection.

I tried that, but since my class EntryMapper.php needs an instance of PDO directly, i'm getting an error. I have tried Database extend from PDO but that also raises error saying that PDO constructor was not called in EntryMapper

Any thoughts?

EDIT: if you see any signs of code coupling or similar, let me know because I want to learn to code properly. Thank you very much!

解决方案

This is how I finally solved it (if a better implementation arises, I will for sure recode). It is an implementation of solution under the accepted answer here: Global or Singleton for database connection?

My ConnFactory.php

include('config/config.php');

class ConnFactory
{
    private static $factory;

    public static function getFactory()
    {
        if(!self::$factory){
            self::$factory = new ConnFactory();
            return self::$factory;
        }

    }

    private $db;

public function pdo()
{
    if(!$this->db){
        $options = array(
            PDO::ATTR_PERSISTENT => true,
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_EMULATE_PREPARES => false,
            PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"
        );
        $this->db = new PDO("mysql:host=".DB_HOST.";port=".DB_PORT.";dbname=".DB_SCHEMA."", DB_USER, DB_PASS, $options);
    }
    return $this->db;
    }

}

Usage in my view/html file (just a test of insert functionalty):

$entry = new Entry();
$entry->name = "Kartonaža ad Gradačac";
$entry->seoName = "kartonaza-ad-gradacac";
$entry->timeCreated = date("Y-m-d H:i:s");

$entryMapper = new EntryMapper(ConnFactory::getFactory()->pdo());
$entryMapper->saveEntry($entry);

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