Symfony2 get object from inverted entity with ManyToMany relation

As follows from doctrine documentation:

mappedBy: This option specifies the property name on the targetEntity that is the owning side of this relation. Its a required attribute for the inverse side of a relationship.

inversedBy: The inversedBy attribute designates the field in the entity that is the inverse side of the relationship.

So, try to change inversedBy="Article" to inversedBy="articles" in Article class and mappedBy="Category" to mappedBy="categories" in Category class.

Also see this Many-To-Many bidirectional example.

Hope this helps.

All right then, I followed your advice and changed Article with articles, and Category by categories. I also changed my mapping for the master side, Articles, like that :

/** * @ORM\ManyToMany( *    targetEntity="Alpha\BlogBundle\Entity\Category", *    cascade={"persist"}, *    inversedBy="articles" * ) * @ORM\JoinTable(name="article_category", *      joinColumns={@ORM\JoinColumn(name="article_id", referencedColumnName="id")}, *      inverseJoinColumns={ *          @ORM\JoinColumn(name="category_id", referencedColumnName="id") *      } * ) */

It works like a charm. I don't exactly understand but I'm gonna study that :)