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php 实现 model层

2026-02-16 01:01:27PHP

在 PHP 中实现 Model 层通常遵循 MVC（Model-View-Controller）架构模式，Model 层负责处理数据逻辑、数据库交互等核心业务。以下是几种常见实现方式：

基础实现（原生 PHP）

使用原生 PHP 实现 Model 层可以通过封装数据库操作完成：

class UserModel {
    private $db;

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

    public function getUsers() {
        $query = "SELECT * FROM users";
        $stmt = $this->db->prepare($query);
        $stmt->execute();
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }

    public function createUser($data) {
        $query = "INSERT INTO users (name, email) VALUES (:name, :email)";
        $stmt = $this->db->prepare($query);
        $stmt->bindParam(':name', $data['name']);
        $stmt->bindParam(':email', $data['email']);
        return $stmt->execute();
    }
}

使用 ORM 框架（Eloquent）

Laravel 的 Eloquent ORM 提供了简洁的 Model 层实现：

use Illuminate\Database\Eloquent\Model;

class User extends Model {
    protected $table = 'users';
    protected $fillable = ['name', 'email'];
}

// 使用示例
$user = new User();
$user->name = 'John';
$user->email = 'john@example.com';
$user->save();

抽象基类封装

创建基础 Model 类减少重复代码：

abstract class BaseModel {
    protected $table;
    protected $db;

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

    public function find($id) {
        $query = "SELECT * FROM {$this->table} WHERE id = :id";
        $stmt = $this->db->prepare($query);
        $stmt->bindParam(':id', $id);
        $stmt->execute();
        return $stmt->fetch(PDO::FETCH_ASSOC);
    }
}

class ProductModel extends BaseModel {
    protected $table = 'products';
}

实现 ActiveRecord 模式

结合数据库操作的 Model 实现：

class ActiveRecordModel {
    private static $db;
    protected static $table;

    public static function setDb($db) {
        self::$db = $db;
    }

    public static function all() {
        $query = "SELECT * FROM " . static::$table;
        $stmt = self::$db->prepare($query);
        $stmt->execute();
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }
}

class Post extends ActiveRecordModel {
    protected static $table = 'posts';
}

数据映射模式

分离数据库操作与业务逻辑：

class UserDataMapper {
    private $db;

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

    public function mapToObject(array $data) {
        $user = new User();
        $user->setId($data['id']);
        $user->setName($data['name']);
        return $user;
    }

    public function fetchById($id) {
        $query = "SELECT * FROM users WHERE id = :id";
        $stmt = $this->db->prepare($query);
        $stmt->bindParam(':id', $id);
        $stmt->execute();
        return $this->mapToObject($stmt->fetch(PDO::FETCH_ASSOC));
    }
}

选择实现方式时应考虑项目规模：

php 实现 model层