findBy() foreignKey is not working - symfony

Question

There is a relationship between the rubric and brand table (Many rubric to One brand).
Here is my code
$dbChoices = $this->getConfigurationPool()
->getContainer()
->get('Doctrine')
->getManager()
->getRepository('RibambelMainBundle:RubricMenu')
->findBy(array('brand_id' => 2));
Everytime this part is run, I got the following error:
Unrecognized field: brand_id
The brand_id column is found in the rubric table.
Anyone who can help me with this or show me another way of doing it?
class RubricMenu
{
/**
* #var int
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="Title", type="string", length=255)
*/
private $title;
/**
* #var int
*
* #ORM\Column(name="position", type="integer")
*/
private $position;
/**
* #ORM\ManyToOne(targetEntity="Brand")
* #ORM\JoinColumn(name="brand_id", nullable=false)
*/
private $brand;
/**
* Get id
*
* #return int
*/
public function getId()
{
return $this->id;
}
/**
* Set name
*
* #param string $title
*
* #return RubricMenu
*/
public function setTitle($title)
{
$this->title = $title;
return $this;
}
/**
* Get name
*
* #return string
*/
public function getTitle()
{
return $this->title;
}
/**
* Set position
*
* #param integer $position
*
* #return RubricMenu
*/
public function setPosition($position)
{
$this->position = $position;
return $this;
}
/**
* Get position
*
* #return int
*/
public function getPosition()
{
return $this->position;
}
/**
* Set brand
*
* #param \Ribambel\MainBundle\Entity\Brand $brand
*
* #return RubricMenu
*/
public function setBrand(\Ribambel\MainBundle\Entity\Brand $brand = null)
{
$this->brand = $brand;
return $this;
}
/**
* Get brand
*
* #return \Ribambel\MainBundle\Entity\Brand
*/
public function getBrand()
{
return $this->brand;
}
}

Answer 1

Searching by a foreign key simply does not make sense from an object point of view. brand_id is not a field of your RubricMenu entity, brand is.
If you have a Brand entity, then you can use findBy (or the magic method findByBrand) like this: (with $myBrand an instance of Brand)
$repository->findBy(['brand' => $myBrand]);
// OR
$repository->findByBrand($myBrand);
If you simply have the id of your target entity, you can use the IDENTITY DQL function but in that case you cannot use findBy directly as it expects a valid field name. Thus, you will need to add a method in your RubricMenu repository. Your method could look like this:
public function findByBrandId($brandId)
{
$qb = $this->createQueryBuilder('rm');
$qb->where('IDENTITY(rm.brand) = :brandId')
->setParameter('brandId', $brandId);
return $qb->getQuery()->getResult();
}
On a side note, as pointed out by #l.g.karolos's answer, doing
$repository->findBy(['brand' => $brandId]);
// OR
$repository->findByBrand($brandId);
will also work as the findBy method internals will be able to resolve that the given parameter is an ID of a Brand entity, thus it will produce the same query as if you had given the corresponding Brand instance.

Answer 2

Based on your entity you should do the following.
$dbChoices = $this->getConfigurationPool()
->getContainer()
->get('Doctrine')
->getManager()
->getRepository('RibambelMainBundle:RubricMenu')
->findBy(array('brand' => 2));

Answer 3

i thing you can do:
$dbChoices = $this->getConfigurationPool()
->getContainer()
->get('Doctrine')
->getManager()
->getRepository('RibambelMainBundle:RubricMenu')
->findBy(array('brand' => $brand));
if you have $brand object (...\Entity\Brand)
Example on https://www.wanadev.fr/56-comment-realiser-de-belles-requetes-sql-avec-doctrine/ :
$user = …;
$category = …;
$em = $this->container->get("doctrine.orm.default_entity_manager");
$entities = $em->getRepository(MyClass::class)->findBy([
"user" => $user,
"category" => $category,
]);