<?php

class User {
  private $id;
  private $email;
  private $password;
  private $profile;
  
  public function __construct(string $email, string $password, UserProfile $profile) {
    $this->email = $email;
    $this->password = $password;
    $this->profile = $profile;
  }
}

class UserProfile {
  private $firstName;
  private $lastname;
  
  public function __construct(string $firstName, string $lastName) {
    $this->firstName = $firstName;
    $this->lastName = $lastName;
  }
}

/** Maps data to this table structure:
 * 
 * ------------------------------
 * id                 | int     |
 * email              | string  |
 * password           | string  |
 * profile_first_name | string  |
 * profile_last_name  | string  |
 */
 
 class DataMapper {
     private $db, $hidrator;
   
     public function save(User $user) {
       $attributes = $this->hidrator->dehydrate($user);
       if ($this-isNewRecord($user)) {
         $this->db->setIdentity($user); // selects next sequence value as ID (only postgresq, oracle, mssql)
         $this-db->insert($this->getTableName($user), $attributes);
       } else {
         $this->db->update($this->getTableName($user), $attributes, $this->getFindByIdentityCriteria($user));
       }
     }
     
     public function remove(User $user) {
       $this->db-delete($this->getTableName($user), $this->getIdentity($user));
     }
     
     // ...
 }