symfony2: How to remove related entity with doctrine / restrict annotation? - symfony

Question

I have some bit of troubles with delete constraint in an entity.
I have an entity merchandise and an entity vehicle with a relation many to one in merchandise, so a merchandise only could be in one vehicle, and a vehicle could have many merchandise. So I have:
class Merchandise{
/**
* #ORM\ManyToOne(targetEntity="Vehicle",inversedBy="merchandise")
* #ORM\JoinColumn(name="vehicle", referencedColumnName="id")
*/
private $vehicle;
}
class Vehicle{
/**
* #ORM\OneToMany(targetEntity="Merchandise",mappedBy="vehicle")
*/
private $merchandise;
}
What I want to get is that when I try to delete a Merchandise which have a vehicle, the Merchandise couldn't be deleted.
But I don't know how can I put an ORM Level restrict constraint. I tried restrict={"remove"} but it doesn't exist in #ORM\OneToMany.
I also try to put a preRemove function which return false, but it doesn't work :(
Any idea?
Thanks!!!

Answer 1

ManyToOne / inversedBy is the OWNING side of the bidirectional relation from doctrine's point of view - which can lead to confusion.
To resolve your issue add cascade operation to your merchandise entity. example:
/**
* #ORM\ManyToOne(targetEntity="Vehicle",mappedBy="merchandise", cascade={"all"})
*/
cascade can be set to a combination of :
persist
remove
merge
detach
all
Improve further by adding cascade ( ORM-level ) to your Vehicle entity aswell. example:
/**
* #ORM\OneToMany(targetEntity="Merchandise", mappedBy="vehicle", cascade={"persist","remove"})
*/
... or use onDelete ( database-level ) with one of
SET NULL
CASCADE
... like this
/**
* #ORM\OneToMany(targetEntity="Merchandise", inversedBy="vehicle", onDelete="CASCADE")
*/
Now if you remove a Vehicle - the related Merchandise entities will be removed. Added Merchandises will automatically be saved.
... finally update your schema and drop -> re-create your database if constraints have not been updated and errors occur. Make sure both sides use the cascade option.
Read more in the documentation chapter Transitive persistence / Cascade Operations.