Вот, пожалуйста.Протестировано с Symfony 2.0.5 (Doctrine 2.1):
State.php
namespace Acme\WhateverBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* State
*
* @ORM\Entity
*/
class State
{
/**
* @ORM\Id()
* @ORM\GeneratedValue(strategy="NONE")
* @ORM\Column(name="Code", type="integer")
*/
private $code;
/**
* @ORM\Column(name="Name", type="string")
*/
private $name;
/**
* @ORM\OneToMany(targetEntity="County", mappedBy="state_code")
*/
private $counties;
/**
* @ORM\OneToMany(targetEntity="Muni", mappedBy="state_code")
*/
private $munis;
}
County.php
namespace Acme\WhateverBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* County
*
* @ORM\Entity()
*/
class County
{
/**
* @ORM\Id
* @ORM\GeneratedValue(strategy="NONE")
* @ORM\Column(name="Code", type="integer")
*/
private $code;
/**
* @ORM\Column(name="Name", type="string")
*/
private $name;
/**
* @ORM\Id
* @ORM\GeneratedValue(strategy="NONE")
* @ORM\ManyToOne(targetEntity="State", inversedBy="counties")
* @ORM\JoinColumn(name="State_Code", referencedColumnName="Code")
*/
private $state_code;
/**
* @ORM\OneToMany(targetEntity="Muni", mappedBy="county_code")
*/
private $munis;
}
Muni.php
namespace Acme\WhateverBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* Muni
*
* @ORM\Entity
*/
class Muni
{
/**
* @ORM\Id
* @ORM\GeneratedValue(strategy="NONE")
* @ORM\Column(name="Code", type="integer")
*/
private $code;
/**
* @ORM\Column(name="Name", type="string")
*/
private $name;
/**
* @ORM\Id
* @ORM\GeneratedValue(strategy="NONE")
* @ORM\ManyToOne(targetEntity="County", inversedBy="munis")
* @ORM\JoinColumn(name="County_Code", referencedColumnName="Code")
*/
private $county_code;
/**
* @ORM\Id
* @ORM\GeneratedValue(strategy="NONE")
* @ORM\ManyToOne(targetEntity="State", inversedBy="munis")
* @ORM\JoinColumn(name="State_Code", referencedColumnName="Code")
*/
private $state_code;
}
Не забудьте создать методы получения / установки.Все отношения двунаправлены.