Symfony 2.0 Model relationships - php

Question

I am trying to model the following table structure in Symfony 2.0 using annotations.
State
PK Code
Name
County
PK State_Code -> FK State.Code
PK Code
Name
Muni
PK State_Code -> FK.State.Code
PK County_Code -> FK County.Code
PK Code
Name
Modeling the fields and the state - county relationship is simple enough, but I cannot determine how to define the relationship for the Muni table.
States have one or more counties.
Counties have one or more Munis.
Munis belong to one or more Counties.
The table structure is legacy and cannot be modified.

Answer 1

Here you go. Tested with 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;
}
Don't forget to generate getters/setters. All relationships are bi-directional.