Multiple JoinColumns in Symfony2 using Doctrine annotations?

Question

Here is the problem:

Class Routing with attributes objectId and objectType. objectId is an int, and objectT

Answer 1

After further researching I found a man (Dirk Olbertz) in the know who had the same problem.

Information can be found at: Google Groups: Multiple JoinColumns?

I have now implemented this and I will explain how I did it incase it might help anyone else.

The answer to my problem was the use of single table inheritance.

The first thing I needed to do was update the routing entity to use single table inheritance:

../Entity/Routing.php

/**
 * @ORM\Entity
 * @ORM\InheritanceType("SINGLE_TABLE")
 * @ORM\DiscriminatorColumn(name="object_type", type="string")
 * @ORM\DiscriminatorMap({"product" = "ProductRouting", "department" = "DepartmentRouting", "brand" = "BrandRouting"})
 * @ORM\Table(name="routing")
 */
class Routing
{
    /**
     * @ORM\Id
     * @ORM\Column(name="id", type="integer", length=11)
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;
...

The DiscriminatorColumn allowed me to specify what column would be used to link, which in this case was the object_type field.

The DiscriminatorMap allowed me to specify what object_type will link with what entities.

These entities then had to be created that extended the Routing entity.

../Entity/ProductRouting.php

/**
 * @ORM\Entity
 */
class ProductRouting extends Routing
{
    /**
     * @ORM\ManyToOne(targetEntity="Product")
     * @ORM\JoinColumn(name="object_id", referencedColumnName="id")
     */
    protected $product;
...

../Entity/DepartmentRouting.php

/**
 * @ORM\Entity
 */
class DepartmentRouting extends Routing
{
    /**
     * @ORM\ManyToOne(targetEntity="Department")
     * @ORM\JoinColumn(name="object_id", referencedColumnName="id")
     */
    protected $department;
...

../Entity/BrandRouting.php

/**
 * @ORM\Entity
 */
class BrandRouting extends Routing
{
    /**
     * @ORM\ManyToOne(targetEntity="Brand")
     * @ORM\JoinColumn(name="object_id", referencedColumnName="id")
     */
    protected $brand;
...

Then in each of the Product, Department and Brand entities I needed to add the new $routings.

../Entity/Product.php

...
class Product
{
    ...
    /**
     * @ORM\OneToMany(targetEntity="ProductRouting", mappedBy="product", cascade={"all"})
     */
    private $routings;
...

../Entity/Department.php

...
class Department
{
    ...
    /**
     * @ORM\OneToMany(targetEntity="DepartmentRouting", mappedBy="department", cascade={"all"})
     */
    private $routings;
...

../Entity/Brand.php

...
class Brand
{
    ...
    /**
     * @ORM\OneToMany(targetEntity="BrandRouting", mappedBy="brand", cascade={"all"})
     */
    private $routings;
...

Hope that helps...