Symfony - Building query for table created by many to many relation - php

Question

I have 2 entities connected with many to many relation into a 3th table, and I want to get every color for an id of product:
/**
* #var ArrayCollection
*
* #ORM\ManyToMany(targetEntity="AppBundle\Entity\Color", inversedBy="products")
* #ORM\JoinTable(name="products_colors",
* joinColumns={#ORM\JoinColumn(name="product_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="color_id", referencedColumnName="id")}
* )
*/
private $colors;
And in my second entity:
/**
* #var ArrayCollection
*
* #ORM\ManyToMany(targetEntity="AppBundle\Entity\Product", mappedBy="colors")
*/
private $products;
This is my query: (I was trying to make some joins but cant make it work)
class ProductRepository extends \Doctrine\ORM\EntityRepository
{
public function getColors($id)
{
$query = $this->createQueryBuilder('p')
->join('AppBundle\Entity\Color', 'c')
->where('c.product_id = :id')
->setParameter('id', $id)
->getQuery()
->getResult();
return $query;
}
}
I got this error:
[Semantical Error] line 0, col 85 near 'product_id =': Error: Class
AppBundle\Entity\Color has no field or association named product_id
which I understand, but can't think of a way to make this work.

Answer 1

Symfony expects you to reference the entity (not id) of an object when mapped by ManyToMany relationship. Try:
class ProductRepository extends \Doctrine\ORM\EntityRepository
{
public function getColors(Product $product)
{
$query = $this->createQueryBuilder('p')
->join('AppBundle\Entity\Color', 'c')
->where('c.product = :product')
->setParameter('product', $product)
->getQuery()
->getResult();
return $query;
}
}
Of course you'll have to modify your call to this function accordingly.
You can also skip the query creation altogether with the getter function in your entity; symfony automagically will do the query for you.
// class Product
private $colors; // as you have it set up already
/**
* #return ArrayCollection|Color[]
*/
public function getColors()
{
return $this->colors;
}