Delete an item from oneToMany relationship. Null value instead of removing - php

Question

I have these entity
class Centro {
/* ... */
/**
* #ORM\OneToMany(targetEntity=NivelesEscolares::class, mappedBy="centro", cascade={"persist", "remove"}, orphanRemoval=true)
*/
private $nivelesEscolares;
/* ... */
}
Center is linked to a OneToMany relationship with a NivelesEscolares entity. Here is the statement
class NivelesEscolares
{
/*...*/
/**
* #ORM\ManyToOne(targetEntity=App\Entity\Centro::class, inversedBy="nivelesEscolares")
*/
private $centro;
}
When I remove a center, the school level should be removed, but it becomes null instead. I already tried with orphanRemoval but it still doesn't remove anything. Also try with onDelete = "CASCADE" but it doesn't delete anything. I need help with OneToMany relationships.

Answer 1

Well orphanRemoval and onDelete have a little differences as follow:
1. orphanRemoval="true"
the entity on the inverse side is deleted when the owning side entity is AND it is not connected to any other owning side entity anymore. Not exactly, this makes doctrine behave like it is not owned by an other entity, and thus remove it.
implementation in the ORM
2. onDelete="CASCADE"
this will add On Delete Cascade to the foreign key column IN THE DATABASE
This strategy is a bit tricky to get right but can be very powerful and fast. (this is a quote from doctrine official tutorial... but haven't seen much more explaination)
ORM has to do less work (compared to the two previous way of doing) and therefore should have better performance.
if you want to delete the NivelesEscolares when you delete Centro well just use onDelete not orphanRemoval like this:
the Centro should looks like this:
class Centro {
/* ... */
/**
* #ORM\OneToMany(targetEntity=NivelesEscolares::class, mappedBy="centro", cascade={"persist", "remove"})
*/
private $nivelesEscolares;
/* ... */
}
and also use onDelete for NivelesEscolares with #ORM\JoinColumn like this:
class NivelesEscolares
{
/*...*/
/**
* #ORM\ManyToOne(targetEntity=App\Entity\Centro::class, inversedBy="nivelesEscolares")
* #ORM\JoinColumn(onDelete="CASCADE")
*/
private $centro;
}
This will force doctrine to remove the 'school levels' as you said, Enjoy! 🙂