Doctrine cascade removing fails with OneToMany and

Question

I've been struggling for the past few days on a simple case of cascade removing using Doctrine. Doctrine and Symfony are up to date. I have two entities Serie and Asset that are linked to each other by two relationships OneToOne and OneToMany.

The schema is exactly like this :

A Serie has many Assets. (content).

A Serie can have an Asset. (a preview, this field is nullable).

However, no matter how I try to write and rewrite the annotations, I ALWAYS end up with this error:

An exception occurred while executing 'DELETE FROM serie WHERE id = ?' with params [1]:

SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (galanthis.asset, CONSTRAINT FK_2AF5A5CAA3A9334 FOREIGN KEY (serie) REFERENCES serie (id))

Of course, the problem disappear if I delete the "preview" field and its annotations in the following code:

/**
 * Serie
 *
 * @ORM\Table(name="serie")
 * @ORM\Entity(repositoryClass="Gedmo\Sortable\Entity\Repository\SortableRepository")
 * @ORM\HasLifecycleCallbacks
 */
class Serie
{
/**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer")
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="AUTO")
 */
private $id;

/**
 * @var string
 *
 * @ORM\Column(name="title", type="string", length=96)
 */
private $title;

/**
 * @var integer
 *
 * @Gedmo\SortablePosition
 * @ORM\Column(name="position", type="integer", nullable=true)
 */
private $position;

/**
 * @var \Portfolio
 *
 * @ORM\ManyToOne(targetEntity="Portfolio", inversedBy="series")
 * @ORM\JoinColumns({
 *   @ORM\JoinColumn(name="portfolio", referencedColumnName="id")
 * })
 */
private $portfolio;


/**
 * @var \Asset
 *
 * @ORM\OneToOne(targetEntity="Asset")
 * @ORM\JoinColumns({
 *   @ORM\JoinColumn(name="preview", referencedColumnName="id", nullable=true, onDelete="SET NULL")
 * })
 */
private $preview;

/**
 * @var \Doctrine\Common\Collections\Collection
 *
 * @ORM\OneToMany(targetEntity="Asset", mappedBy="serie", cascade={"remove"})
 **/
private $assets;

Here's the code for the Asset entity:

/**
 * Asset
 *
 * @ORM\Table(name="asset")
 * @ORM\Entity(repositoryClass="Gedmo\Sortable\Entity\Repository\SortableRepository")
 * @ORM\HasLifecycleCallbacks
 * @ORM\InheritanceType("SINGLE_TABLE")
 * @ORM\DiscriminatorColumn(name="asset", type="string")
 * @ORM\DiscriminatorMap({"asset" = "Asset", "video" = "Video","image" = "Image"})
 *
 */
class Asset
{
/**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer")
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="AUTO")
 */
protected $id;

/**
 * @var string
 *
 * @ORM\Column(name="path", type="string", length=128)
 */
protected $path;

/**
 * @var string
 *
 * @ORM\Column(name="filename", type="string", length=64)
 */
protected $filename;

/**
 * @var integer
 *
 * @ORM\Column(name="position", type="integer", nullable=true)
 * @Gedmo\SortablePosition
 */
protected $position;

/**
 * @var string
 *
 * @ORM\Column(name="description", type="string", length=255, nullable=true)
 */
protected $description;

/**
 * @var string
 *
 * @ORM\Column(name="mime", type="string", length=16, nullable=true)
 */
protected $mime;

/**
 * @var \Serie
 *
 * @ORM\ManyToOne(targetEntity="Serie", inversedBy="assets")
 * @ORM\JoinColumns({
 *   @ORM\JoinColumn(name="serie", referencedColumnName="id")
 * })
 */
protected $serie;

/**
 * @var UploadedFile
 */
protected $file;

/**
 * @var string
 */
protected $extension;

It's driving me crazy, it's just some simple relationships... Is there a mistake I'm not seeing anymore, or do i need to use a workaround?

Answer 1

My guess is to set the cascade={"remove"} on the ManyToOne relationship in the Asset entity and not the other way around. That way, it tells Doctrine what to do when you delete a serie that is linked to many assets.