Symfony 2 doctrine persist doesn't work after updating Relationship Mapping - symfony

Question

I updated my entity file to include relationship mapping.
Persist worked before the update now it doesn't.
Maybe it's something I forgot to do.
namespace classes\classBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* advisersplans
*
* #ORM\Table()
* #ORM\Entity
*/
class advisersPlans
{
/**
*
* #ORM\ManyToOne(targetEntity="plans", inversedBy="adviserPlans")
* #ORM\JoinColumn(name="planid", referencedColumnName="id")
*/
public $plan;
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
public $id;
/**
* #var integer
*
* #ORM\Column(name="userid", type="integer")
*
*
*/
public $userid;
/**
* #var integer
*
* #ORM\Column(name="adviserid", type="integer")
*
*
*/
public $adviserid;
/**
* #var integer
*
* #ORM\Column(name="planid", type="integer")
*
*
*/
public $planid;
/**
* #var string
*
* #ORM\Column(name="participantLoginWebsiteAddress", type="string", length=255)
*/
public $participantLoginWebsiteAddress;
public function __construct()
{
$class_vars = get_class_vars(get_class($this));
foreach ($class_vars as $key => $value)
{
if ($key != "plan")
$this->$key = "";
}
}
}
Perist returns error saying planid is null. If I remove the following it works.
/**
*
* #ORM\ManyToOne(targetEntity="plans", inversedBy="adviserPlans")
* #ORM\JoinColumn(name="planid", referencedColumnName="id")
*/
Here is my code while persisting.
$adviserPlan = new advisersPlans();
$adviserPlan->planid = $planid;
$adviserPlan->userid = $this->userid();
$adviserPlan->adviserid = $session->get("editadviserid");
$em->persist($adviserPlan);
Am I supposed to populate the plan field and not the planid field or is my entity file coded wrong.

Answer 1

You shouldn't set ids. You should set entities:
$adviserPlan = new advisersPlans();
// You should retrieve the plan before doing this, of course.
$adviserPlan->setPlan($plan);
$plans->addAdviserPlan(§adviserPlan);
$em->persist($adviserPlan);
The methods for adding an entity to a collection should be generated by doctrine when you run:
php app/console doctrine:generate:entities YourBundle