Symfony2/Doctrine: How to re-save an entity with a OneToMany as a cascading new row

Question

Firstly, this question is similar to How to re-save the entity as another row in Doctrine 2 The difference is that I'm trying to save the data within an entity that has a OneToMany relationship. I'd like to re-save the entity as a new row in the parent entity (on the "one" side) and then as new rows in each subsequent child (on the "many" side). I've used a pretty simple example of a Classroom having many Pupils to keep it simple. So me might have ClassroomA with id=1 and it has 5 pupils (ids 1 through 5). I'd like to know how I could, within Doctrine2, take that Entity and re-save it to the database (after potential data changes) all with new IDs throughout and the original rows being untouched during the persist/flush. Lets first define our Doctrine Entities. The Classroom Entity: ``` namespace Acme\TestBundle\Entity; use Doctrine\ORM\Mapping as ORM; use Doctrine\Common\Collections\ArrayCollection; /** * @ORM\Entity * @ORM\Table(name="classroom") */ class Classroom { /** * @ORM\Id *…

Accepted Answer

The thing with `clone` is...

When an object is cloned, PHP 5 will perform a shallow copy of all of the object's properties. Any properties that are references to other variables, will remain references.

If you are using Doctrine >= 2.0.2, you can implement your own custom __clone() method:

```
public function __clone() {
    // Get current collection
    $pupils = $this->getPupils();

$this->pupils = new ArrayCollection();
    foreach ($pupils as $pupil) {
        $clonePupil = clone $pupil;
        $this->pupils->add($clonePupil);
        $clonePupil->setClassroom($this);
    }
}
```

NOTE: before Doctrine 2.0.2 you cannot implement a `__clone()` method in your entity as the generated proxy class implements its own `__clone()` which does not check for or call `parent::__clone()`. So you'll have to make a separate method for that like `clonePupils()` (in `Classroom`) instead and call that after you clone the entity. Either way, you can use the same code inside your `__clone()` or `clonePupils()` methods.

When you clone your parent class, this function will create a new collection full of child object clones as well.

```
$cloneClassroom = clone $classroom;
$cloneClassroom->clonePupils();

$em->persist($cloneClassroom);
$em->flush();
```

You'll probably want to cascade persist on your `$pupils` collection to make persisting easier, eg

```
/**
 * @ORM\OneToMany(targetEntity="Pupil", mappedBy="classroom", cascade={"persist"})
 */
protected $pupils;
```

Symfony2/Doctrine: How to re-save an entity with a OneToMany as a cascading new row

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