What is the recommended doctrine relationship between these tables?

Question

I need to model the following tables in Doctrine2:

Table 1. Items (products)
Table 2. Categories
Table 3. ItemsToCategories (id, item_id, category_id)

An item can be in many categories. A category can have many items. Restructuring the data is (currently) not an option and I did not design the schema.

What is the recommended way to model this many-to-many association with a join table. The documentation does not seem to cover this exact case and I'm keen to hear from others who have done something similar with Doctrine2 and / or Symfony (2.4)

score 1 · Answer 1 · answered Feb 19 '14 at 12:36

Create two entities: Item and Category:

<?php

namespace YourApplication\Bundle\DatabaseBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 * @ORM\Table(name="Categories")
 */
class Category
{
    /**
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\ManyToMany(targetEntity="Item", inversedBy="categories")
     * @ORM\JoinTable(name="ItemsToCategories")
     */
    protected $items;

    public function __construct() {
        $this->categories = new \Doctrine\Common\Collections\ArrayCollection();
    }
}

<?php

namespace YourApplication\Bundle\DatabaseBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 * @ORM\Table(name="Items")
 */
class Item
{
    /**
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\ManyToMany(targetEntity="Category", mappedBy="items")
     */
    protected $items;

    public function __construct() {
        $this->items = new \Doctrine\Common\Collections\ArrayCollection();
    }
}

Since a category owns the items and the items are owned by the categories, Category will be the owning side and Item will be the inverse side of the relationship.

What is the recommended doctrine relationship between these tables?

1 Answers1