example.php

<?php

// "NativeQuery" like http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/native-sql.html

$nativeQuery = 'SELECT user.id AS id, user.name AS name, address.id AS address_id, address.street AS street, address.city AS city ' .
               'FROM user INNER JOIN address ON address.id = user.address_id ' .
               'WHERE user.name = :name';

$atlas
    ->nativeQuery($nativeQuery)
    ->bindValue('name', 'romanb')
    ->addMapper(UserMapper::class, 'user', ['id', 'name'])
    ->addMapper(AddressMapper::class, 'address', ['address_id' => 'id', 'street', 'city'])
    ->fetchAll();