Two entities

Address.php

<?php

namespace myProject\Entity;

Class Address {
    /**
     * @ORM\Id
     */
    protected $id;

    /**
     * @ORM\Column(type="string")
     */
    protected $postalCode;
    
    
    public function getPostalCode() 
    {
        return $this->postalCode;
    }


    public function setPostalCode($postalCode)
    {
        $this->postalCode= $postalCode;
    }

}

User.php

<?php

namespace myProject\Entity;

use myProject\Entity\Address;

Class User {
    /**
     * @ORM\Id
     */
    protected $id;

    /**
     * @ORM\Column(type="string")
     */
    protected $name;
    
    /**
     * @ORM\OneToOne(targetEntity="Address")
     * @ORM\JoinColumn(name="id", referencedColumnName="id")
     */
    protected $address;
    

    public function getName() 
    {
        return $this->name;
    }


    public function setName($name)
    {
        $this->name = $name;
    }

    public function getAddress()
    {
        return $this->address;
    }

    public function setAddress(Address $address)
    {
        $this->address = $address;
    }

}