Symfony queryBuilder: too many queries

6
votes

I have an entity with a ManyToMany relationship with the User table:

/**
 * @ORM\ManyToMany(targetEntity="User")
 * @ORM\JoinTable(
 *  name="offer_allowedusers",
 *  joinColumns={
 *      @ORM\JoinColumn(name="offer_id", referencedColumnName="id", onDelete="CASCADE")
 *  },
 *  inverseJoinColumns={
 *      @ORM\JoinColumn(name="user_id", referencedColumnName="id", onDelete="CASCADE")
 *  }
 * )
 */
private $allowedUsers;

And, in the form, I want to display a dropdown (using select2) to select which users are allowed:

enter image description here

To do that, I made, in the Form building:

->add('allowedUsers', EntityType::class, [
        'class' => 'AppBundle\Entity\User',
        'query_builder' => function (EntityRepository $er) {
            return $er->createQueryBuilder('u')
            ->orderBy('u.username', 'ASC');
        },
        'label' => 'Allowed users',
        'required' => false,
        'multiple' => true
    ])

The problem is that it makes a query for each user, to get the username... So if I have 500 users, it makes 500 queries...

enter image description here

How can optimize and do a single query to fetch all the records?

2
phpsymfonysymfony-3.3
Have you implemented the __toString() method in your User class ? this method would return the user name – Mz1907
I have, that returns $this->username. Without that it wouldn't display the usernames in the dropdown – the_nuts
Lookup how to create a custom dql query. That will allows you to load the related users in one gulp. And read up a bit on lazy loading vs eager loading. Won't get very far with the orm unless you understand these key concepts. – Cerad
Doctrine always retrieves OneToOne relations no matter what. You can't put a LAZY or EXTRA_LAZY setting to change that. But, you can join them as well in your QueryBuilder. see my answer for what should work. – Jason Roman
@the_nuts then adds the userProfile join statement to the query builder. – yceruto

2 Answers

9
votes

Explicitly create the join in your QueryBuilder, and select both the user and allowed users.

UPDATE

You must also join and select your user profile and user settings OneToOne relations because Doctrine automatically retrieves OneToOne relations them any time you fetch the User entity.

The Doctrine documentation talks about why it has to perform an extra query when fetching the inverse side of a one-to-one relation.

->add('allowedUsers', EntityType::class, [
    'class' => 'AppBundle\Entity\User',
    'query_builder' => function (EntityRepository $er) {
        return $er->createQueryBuilder('u')
            ->select('u, au, up, us')
            ->join('u.allowedUsers', 'au')
            ->join('u.userProfile', 'up')
            ->join('u.userSettings', 'us')
            ->orderBy('u.username', 'ASC')
        ;
    },
    'label' => 'Allowed users',
    'required' => false,
    'multiple' => true
])
1
votes

If you don't have queries to your "entity" that don't need to fetch allowedUsers the simplest way would be to explicitly define fetch mode as EAGER in the field's annotations:

/**
 * @ORM\ManyToMany(targetEntity="User", fetch="EAGER")
 * @ORM\JoinTable(
 *  name="offer_allowedusers",
 *  joinColumns={
 *      @ORM\JoinColumn(name="offer_id", referencedColumnName="id", onDelete="CASCADE")
 *  },
 *  inverseJoinColumns={
 *      @ORM\JoinColumn(name="user_id", referencedColumnName="id", onDelete="CASCADE")
 *  }
 * )
 */
private $allowedUsers;