Cannot set mapped association Id during PrePersist event - php

Question

I have an article entity belongs to a category entity:
/**
* Article
*
* #ORM\Table(name="articles")
* #ORM\Entity(repositoryClass="App\Repository\ArticlesRepository")
* #ORM\HasLifecycleCallbacks
*/
class Article {
/**
* #ORM\Column(name="category_id", type="integer", nullable=true)
*/
private $categoryId;
/**
* #ORM\ManyToOne(targetEntity="App\Entity\Category", inversedBy="articles")
*/
private $category;
}
and I manually set category_id field in PrePersist event:
/** #ORM\PrePersist */
public function setProperPosition(\Doctrine\ORM\Event\LifecycleEventArgs $event){
$this->categoryId = 1;
}
But is does not work. The field (category_id) remains null on the database.

Answer 1

I'm not sure why you have two properties for the same column. You have $category and $categoryId, which basically reference the same value.
So basically you a declaring the same column twice. That's what's likely giving you trouble.
Anyway, try it this way:
/**
* #ORM\Table(name="articles")
* #ORM\Entity(repositoryClass="ArticlesRepository")
* #ORM\HasLifecycleCallbacks
*/
class Article
{
/**
* #ORM\ManyToOne(targetEntity="Category", inversedBy="articles")
*/
private $category;
/** #ORM\PrePersist */
public function setProperPosition(LifecycleEventArgs $event)
{
$this->category = $event
->getEntityManager()
->getReference(Category::class, 1);
}
}
I simplified all the required namespaces. Make sure you use them so the are imported and available in the file.
(To make it clear, remove the redundant $categoryId definition)