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php orm 实现

2026-02-28 11:48:36PHP

PHP ORM 实现方法

PHP 中实现 ORM（对象关系映射）可以通过多种方式，包括使用现成的 ORM 框架或自行实现简单的 ORM 功能。以下是几种常见的实现方法：

使用现有 ORM 框架

1. Doctrine ORM
Doctrine 是 PHP 中最流行的 ORM 框架之一，功能强大且文档完善。
安装 Doctrine ORM：

composer require doctrine/orm

基本配置示例：

use Doctrine\ORM\Tools\Setup;
use Doctrine\ORM\EntityManager;

$paths = [__DIR__ . "/src/Entity"];
$isDevMode = true;
$dbParams = [
    'driver'   => 'pdo_mysql',
    'user'     => 'root',
    'password' => '',
    'dbname'   => 'test_db',
];

$config = Setup::createAnnotationMetadataConfiguration($paths, $isDevMode);
$entityManager = EntityManager::create($dbParams, $config);

定义实体类：

php orm 实现

use Doctrine\ORM\Mapping as ORM;

/
 * @ORM\Entity
 * @ORM\Table(name="users")
 */
class User {
    /
     * @ORM\Id
     * @ORM\GeneratedValue
     * @ORM\Column(type="integer")
     */
    private $id;

    /
     * @ORM\Column(type="string")
     */
    private $name;
}

2. Eloquent ORM
Eloquent 是 Laravel 框架内置的 ORM，也可以独立使用。
安装 Eloquent：

composer require illuminate/database

基本配置示例：

php orm 实现

use Illuminate\Database\Capsule\Manager as Capsule;

$capsule = new Capsule;
$capsule->addConnection([
    'driver'    => 'mysql',
    'host'      => 'localhost',
    'database'  => 'test_db',
    'username'  => 'root',
    'password'  => '',
    'charset'   => 'utf8',
    'collation' => 'utf8_unicode_ci',
]);
$capsule->bootEloquent();

定义模型类：

use Illuminate\Database\Eloquent\Model;

class User extends Model {
    protected $table = 'users';
}

自行实现简单 ORM

1. 基础 ORM 实现
以下是一个简单的 ORM 实现示例，包含基本的 CRUD 操作：

class Database {
    private $pdo;

    public function __construct($dsn, $username, $password) {
        $this->pdo = new PDO($dsn, $username, $password);
    }

    public function query($sql, $params = []) {
        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($params);
        return $stmt;
    }
}

class Model {
    protected $table;
    protected $db;

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

    public function find($id) {
        $sql = "SELECT * FROM {$this->table} WHERE id = ?";
        return $this->db->query($sql, [$id])->fetch(PDO::FETCH_OBJ);
    }

    public function save($data) {
        $fields = implode(', ', array_keys($data));
        $placeholders = implode(', ', array_fill(0, count($data), '?'));
        $sql = "INSERT INTO {$this->table} ($fields) VALUES ($placeholders)";
        $this->db->query($sql, array_values($data));
        return $this->db->lastInsertId();
    }
}

2. 使用反射实现动态属性映射
通过反射机制动态映射数据库字段到模型属性：

class Model {
    protected $table;
    protected $attributes = [];

    public function __set($name, $value) {
        $this->attributes[$name] = $value;
    }

    public function __get($name) {
        return $this->attributes[$name] ?? null;
    }

    public function save() {
        $fields = implode(', ', array_keys($this->attributes));
        $placeholders = implode(', ', array_fill(0, count($this->attributes), '?'));
        $sql = "INSERT INTO {$this->table} ($fields) VALUES ($placeholders)";
        // 执行 SQL
    }
}