gistfile1.txt

class Tile extends Entity {

    /**
     * @ORM\OneToOne(
     *  targetEntity="Domino\Entity\Tile",
     *  mappedBy="tileLeft",
     *  cascade={"persist", "merge"}
     * )
     * @var Tile
     */
    protected $tileRight;

    /**
     * @ORM\OneToOne(
     *  targetEntity="Domino\Entity\Tile",
     *  inversedBy="tileRight"
     * )
     * @ORM\JoinColumn(
     *  name="tile_left_id",
     *  referencedColumnName="id",
     *  onDelete="CASCADE"
     * )
     * @var Tile
     */
    protected $tileLeft;

}