Integrity constraint violation 1451 between entities - symfony

Question

I've got these entities (relevant part for the problem) :
/**
* Criterion
*
* #ORM\Table(name="innova_stepcondition_criterion")
* #ORM\Entity(repositoryClass="Innova\PathBundle\Repository\CriterionRepository")
*/
class Criterion implements \JsonSerializable
{
/**
* Criteriagroup
* #var \Innova\PathBundle\Entity\Criteriagroup
*
* #ORM\ManyToOne(targetEntity="Innova\PathBundle\Entity\Criteriagroup", inversedBy="criteria", cascade={"all"})
* #ORM\JoinColumns({
* #ORM\JoinColumn(onDelete="SET NULL")
* })
*/
protected $criteriagroup;
}
and
/**
* Criteriagroup
*
* #ORM\Table(name="innova_stepcondition_criteriagroup")
* #ORM\Entity(repositoryClass="Innova\PathBundle\Repository\CriteriagroupRepository")
*/
class Criteriagroup implements \JsonSerializable
{
/**
* Criteria linked to the criteriagroup
* #var \Doctrine\Common\Collections\ArrayCollection
*
* #ORM\OneToMany(targetEntity="Innova\PathBundle\Entity\Criterion", mappedBy="criteriagroup", indexBy="id", cascade={"persist", "remove"})
*/
protected $criteria;
}
When i try to delete a criteriagroup, i want to delete the attached criterion. I've got this error :
An exception occurred while executing 'DELETE FROM innova_stepcondition_criteriagroup WHERE id = ?' with params [1]: SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`claroline_path`.`innova_stepcondition_criteriagroup`, CONSTRAINT `FK_F33A94EA727ACA70` FOREIGN KEY (`parent_id`) REFERENCES `innova_stepcondition_criteriagroup` (`id`))
So i've read some post like this our this one and the suggested solution is the solution is to use a onDelete="SET NULL" on the joinColumn in the ManyToOne side, which i did. But i still get this error.
What could be wrong ?
Thank you
EDIT :
#RaulFerriz : Thank you for the answer. If i try your modifications : with cascade={"persist"} instead of cascade={"all"} in Criterion, i still have the same error.
But if i remove entirely the cascade in Criterion, i have :
A new entity was found through the relationship \u0027Innova\\PathBundle\\Entity\\Criterion#criteriagroup\u0027 that was not configured to cascade persist operations for entity: Innova\\PathBundle\\Entity\\Criteriagroup#0000000034dfa7b200000000f76198d8. To solve this issue: Either explicitly call EntityManager#persist() on this unknown entity or configure cascade persist this association in the mapping for example #ManyToOne(..,cascade={\u0022persist\u0022}). If you cannot find out which entity causes the problem implement \u0027Innova\\PathBundle\\Entity\\Criteriagroup#__toString()\u0027 to get a clue`
that seems to mean the cascade={"persist"} is needed.
I don't knwon what to try next.
I do a doctrine:schema:update after each modification.

Answer 1

Your problem is not in your relation Criteriagroup and Criteria.
If you check the SQL error, the constraint that failed is for the field parent_id. Which is part of your Criteriagroup / Criteriagroup relation.
I put here the definition of your buggy relation, if someone else need this :
/**
* Parent criteriagroup
* #var \Innova\PathBundle\Entity\Criteriagroup
*
* #ORM\ManyToOne(targetEntity="Criteriagroup", inversedBy="children", cascade={"all"})
* #ORM\JoinColumn(name="parent_id", referencedColumnName="id")
*/
protected $parent;
/**
* Children criteriagroup
* #var \Doctrine\Common\Collections\ArrayCollection
*
* #ORM\OneToMany(targetEntity="Criteriagroup", mappedBy="parent", indexBy="id", cascade={"persist", "remove"})
* #ORM\OrderBy({"order" = "ASC"})
*/
protected $children;
In order to make this work, you need to replace :
#ORM\JoinColumn(name="parent_id", referencedColumnName="id")
by
#ORM\JoinColumn(name="parent_id", referencedColumnName="id", onDelete="CASCADE")
By adding this, when you will delete a CriteriaGroup, all children CriteriaGroup will be deleted. If you don't want to delete children, just add onDelete="SET NULL".
Hope it helps.

Answer 2

As you have defined the entities, when you try to remove a "Criterion" the entity Criteriongroup will also be deleted. That is not what you are attempting to achieve.
Try with this
/**
* Criterion
*
* #ORM\Table(name="innova_stepcondition_criterion")
* #ORM\Entity(repositoryClass="Innova\PathBundle\Repository\CriterionRepository")
*/
class Criterion implements \JsonSerializable
{
/**
* Criteriagroup
* #var \Innova\PathBundle\Entity\Criteriagroup
*
* #ORM\ManyToOne(targetEntity="Innova\PathBundle\Entity\Criteriagroup", inversedBy="criteria")
* #ORM\JoinColum(referencedColumnName="id")
*/
protected $criteriagroup;
}
And this
/**
* Criteriagroup
*
* #ORM\Table(name="innova_stepcondition_criteriagroup")
* #ORM\Entity(repositoryClass="Innova\PathBundle\Repository\CriteriagroupRepository")
*/
class Criteriagroup implements \JsonSerializable
{
/**
* Criteria linked to the criteriagroup
* #var \Doctrine\Common\Collections\ArrayCollection
*
* #ORM\OneToMany(targetEntity="Innova\PathBundle\Entity\Criterion", mappedBy="criteriagroup", indexBy="id", cascade={"persist", "remove"})
*/
protected $criteria;
}
Basically, clean up Criterion entity from cascading all, at most I suppose you will need {cascade="persist"} at this entity that means: when Criterion is persisted, persist also Criteriagroup linked with it.