Listing 18.8. Właściwość length w klasie River
class River
{
    ...

    /**
     * @var string $name
     *
     * @ORM\Column(name="name", type="string", length=255)
     */
    private $name;

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

    ...

}