Doctrine Entity findBy Many to Many - symfony1

Question

I have a many to many relationship between products and colours.
What I am trying to do is find products by their colours.
eg)
$colours = $em->getRepository('Xxxxx\XxxxxBundle\Entity\Colour')->findBy(array('name'=>'red');
$products = $em->getRepository('Xxxxx\XxxxxBundle\Entity\Product')->findBy(array('colours'=>$colours));
This is my Yaml config:
Xxxxx\XxxxxBundle\Entity\Product:
type: entity
manyToMany:
colours:
targetEntity: Colour
joinTable:
name: Product_Colour
joinColumns:
product_id:
referencedColumnName: id
inverseJoinColumns:
colour_id:
referencedColumnName: id
.
Xxxxx\XxxxxBundle\Entity\Colour:
type: entity
id:
id:
type: integer
generator:
strategy: AUTO
fields:
hex:
type: string
length: 320
name:
type: string
length: 320
The error message I am getting is:
Notice: Undefined index: joinColumns in /home/xxx/public_html/products/vendor/doctrine/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php line 1217
Would someone be able to shine some light on why this is not working.

Answer 1

I know this is an old question, but if anyone else arrives here via Google (like I did), I had to eschew the findBy and use DQL in the repository:
$products = $em->getRepository('Vendor\Bundle\Entity\Product')->findByColours($colours);
And in the repository:
public function findByColours($colours)
{
$qb = $this->getEntityManager()->createQueryBuilder();
$qb ->select(array('p'))
->from('VendorBundle:Product', 'p')
->join('p.colours', 'c', 'WITH', $qb->expr()->in('c.id', $colours));
$result = $qb->getQuery()->execute();
return $result;
}
You may need to change the join based on what $colours is. This is assuming it's an array of colour IDs. If it's a string you can forgo the in() or if it's an array of strings you'll need to bind the strings as parameters (see the following link). Clarification on expr() and such is in the Doctrine docs
I don't know why Undefined index: joinColumns occurs, but this is a method to side-step it altogether. Hopefully someone can clarify as to the error, as my solution adds extra work to the Many to Many relationship.