(doctrine2 + symfony2) cascading remove : integrity constraint violation 1451

So, thanks to this French forum, I fixed the problem.

I needed to add nullable=true & onDelete="SET NULL" in @ORM\JoinColumn

Here is the workable configuration, maybe it will help someone :

#User.    /**     * @ORM\OneToMany(targetEntity="\sfCommands\ContentBundle\Entity\Application", mappedBy="user", cascade={"remove"}, orphanRemoval=true)     * @ORM\OrderBy({"name" = "ASC"})     */    protected $applications;    /**     * @ORM\OneToOne(targetEntity="\sfCommands\ContentBundle\Entity\Entity")     * @ORM\JoinColumn(name="entity1_id", referencedColumnName="id", nullable=true, onDelete="SET NULL")     */    private $entity1;    /**     * @ORM\OneToOne(targetEntity="\sfCommands\ContentBundle\Entity\Entity")     * @ORM\JoinColumn(name="entity2_id", referencedColumnName="id", nullable=true, onDelete="SET NULL")     */    private $entity2;#Application.    /**     * @ORM\OneToMany(targetEntity="\sfCommands\ContentBundle\Entity\Bundle", mappedBy="application", cascade={"remove"}, orphanRemoval=true)     * @ORM\OrderBy({"name" = "ASC"})     */    protected $bundles;    /**     * @ORM\ManyToOne(targetEntity="\sfCommands\UserBundle\Entity\User", inversedBy="applications", cascade={"persist"})     * @ORM\JoinColumn(name="user_id", referencedColumnName="id", nullable=true, onDelete="SET NULL")     */    protected $user;#Bundle.    /**     * @ORM\ManyToOne(targetEntity="\sfCommands\ContentBundle\Entity\Application", inversedBy="bundles", cascade={"persist"})     * @ORM\JoinColumn(name="application_id", referencedColumnName="id", nullable=true, onDelete="SET NULL")     */    protected $application;    /**     * @ORM\OneToMany(targetEntity="\sfCommands\ContentBundle\Entity\Entity", mappedBy="bundle", cascade={"remove"}, orphanRemoval=true)     * @ORM\OrderBy({"name" = "ASC"})     */    protected $entitys;#Entity.    /**     * @ORM\ManyToOne(targetEntity="\sfCommands\ContentBundle\Entity\Bundle", inversedBy="entitys", cascade={"persist"})     * @ORM\JoinColumn(name="bundle_id", referencedColumnName="id", nullable=true, onDelete="SET NULL")     */    protected $bundle;

Use onDelete="CASCADE" if you are using annotation

/** * @ORM\ManyToOne(targetEntity="Report", inversedBy="responses") * @ORM\JoinColumn(name="reportId", referencedColumnName="id",onDelete="CASCADE") */

Use onDelete: CASCADE if you are using yml

joinColumn:      name: pid      referencedColumnName: id      onDelete: CASCADE

onDelete="CASCADE" also works fine. But don't forget to run app/console doctrine:schema:update --force before DB level changes will take an effect.