Proper way to check if many-to-many relation exists - Symfony2/Doctrine

Question

Let's suppose I have two entities User and Product related by a Many-to-Many relationship with Doctrine.

I would like to know the best way to handle a $user->hasProduct($product) method for my User entity that returns true is relation exists or false if not.

I'm currently doing this :

public function hasProduct($id)
{
    foreach($this->getProducts() as $product) {
        if($product->getId() == $id) {
            return true;
        }
    }

    return false;
}

But i'm not sure it's the best way, especially if there is many relations in the loop.

If someone has something better, let me know :)

Pierrickouw · Accepted Answer · 2013-01-24T14:40:15.350

61

Your function getProducts gives you an ArrayCollection.

Just do

if($user->getProducts()->contains($product)) //the real product object not the id
       //your stuff

Edit :

For twig template :

{% if product in user.products %}
    //your stuff
{% endif %}

edited Jan 24 '13 at 14:40

answered Jan 24 '13 at 14:33

Pierrickouw

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29

Sounds good ! I will use that. Is there a way to perform this in twig templates ? – Thomas Piard Jan 24 '13 at 14:38
And what if I want to check e.g. if product with a given name exits? – Abdel5 Jul 04 '15 at 15:28
You have to manually loop through the products or use a custom `DQL` query – Pierrickouw Jul 06 '15 at 08:23
1

Note: You don't actually need to fetch the object prior to using `contains()`. A lazy reference is good enough, which you can obtain with `$product = $em->getReference('MyBundle:MyProduct', $id)`. This will not cause an DB query. – jlh Nov 23 '17 at 09:18
How do you check the opposite in twig? if it’s not in user.product? – Miles M. Oct 19 '18 at 10:30
1

@MilesM. That would be {% if product not in user.products %} //your stuff {% endif %} – Motxila dev Dec 02 '20 at 22:48

score 4 · Answer 2 · answered Jan 18 '18 at 06:51

I was struggling with the same problem, and came across this blog entry which solved this problem by making use of Doctrine Filters.

If I understand your problem correctly and you have three tables (user, user_product and product) you should be able to rewrite your hasProduct($id) function like this:

use Doctrine\Common\Collections\Criteria;

public function hasProduct(int $productId): bool {

  $criteria = Criteria::create();
  $criteria->where(Criteria::expr()->eq('id', $productId));

  if(count($this->products->matching($criteria)) > 0) {
    return true;
  }

  return false;
}

When running this code, Doctrine does not load all the Products linked to the User. It in fact only queries the cross reference table (user_product).

Proper way to check if many-to-many relation exists - Symfony2/Doctrine

2 Answers2