php mysql代码生成

<?php
class User {
    private $db;

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

    public function create($username, $email) {
        $stmt = $this->db->prepare("INSERT INTO users (username, email) VALUES (?, ?)");
        $stmt->execute([$username, $email]);
    }

    public function read($id) {
        $stmt = $this->db->prepare("SELECT * FROM users WHERE id = ?");
        $stmt->execute([$id]);
        return $stmt->fetch();
    }

    public function update($id, $username, $email) {
        $stmt = $this->db->prepare("UPDATE users SET username = ?, email = ? WHERE id = ?");
        $stmt->execute([$username, $email, $id]);
    }

    public function delete($id) {
        $stmt = $this->db->prepare("DELETE FROM users WHERE id = ?");
        $stmt->execute([$id]);
    }
}

// 使用示例
$db = new PDO('mysql:host=localhost;dbname=test', 'username', 'password');
$user = new User($db);

// 创建用户
$user->create('john_doe', 'john@example.com');

// 读取用户
$userData = $user->read(1);
print_r($userData);

// 更新用户
$user->update(1, 'john_updated', 'john_updated@example.com');

// 删除用户
$user->delete(1);
?>