2.4. Data Mapper¶

 1<?php
 2
 3class User
 4{
 5    private int $id;
 6    private string $name;
 7    private string $email;
 8
 9    public function __construct(int $id, string $name, string $email)
10    {
11        $this->id = $id;
12        $this->name = $name;
13        $this->email = $email;
14    }
15
16    public function getId(): int
17    {
18        return $this->id;
19    }
20
21    public function getName(): string
22    {
23        return $this->name;
24    }
25
26    public function getEmail(): string
27    {
28        return $this->email;
29    }
30
31    public function setId(int $id): void
32    {
33        $this->id = $id;
34    }
35}

 1<?php
 2
 3class UserMapper
 4{
 5    private PDO $db;
 6
 7    public function __construct($db)
 8    {
 9        $this->db = $db;
10    }
11
12    public function getById($id): ?User
13    {
14        $stmt = $this->db->prepare('SELECT * FROM users WHERE id = :id');
15        $stmt->bindParam(':id', $id);
16        $stmt->execute();
17        $result = $stmt->fetch(PDO::FETCH_ASSOC);
18
19        if (!$result) {
20            return null;
21        }
22
23        return new User($result['id'], $result['name'], $result['email']);
24    }
25
26    public function save(User $user): void
27    {
28        $stmt = $this->db->prepare('INSERT INTO users (name, email) VALUES (:name, :email)');
29        $name = $user->getName();
30        $stmt->bindParam(':name', $name);
31        $email = $user->getEmail();
32        $stmt->bindParam(':email', $email);
33        $stmt->execute();
34        $user->setId($this->db->lastInsertId());
35    }
36}

 1<?php
 2
 3$db = new PDO('mysql:host=localhost;dbname=mydb', 'username', 'password');
 4
 5$userMapper = new UserMapper($db);
 6$user = $userMapper->getById(1);
 7echo $user->getName(); // Outputs the user's name
 8
 9$newUser = new User(null, 'John Doe', 'john@example.com');
10$userMapper->save($newUser);
11echo $newUser->getId(); // Outputs the new user's ID