/*
 * @ORMMappedSuperClass
 * @JMSExclusionPolicy("all")
 */

abstract class BaseEntity {

/**
 * @var string $createdBy
 *
 * @GedmoBlameable(on="create")
 * @ORMColumn(name="created_by", type="string", nullable=true)
 */
protected $createdBy;

/**
 * @var DateTime $created
 *
 * @GedmoTimestampable(on="create")
 * @ORMColumn(name="created_at", type="datetime", nullable=true)
 */
protected $createdAt;

/**
  * Survey
  *
  * @ORMTable(name="answers")
       *@ORMEntity(repositoryClass="AcmeSomeBundleRepositoryAnswerAnswerRepository")
  */
 class Answer extends BaseEntity {

/**
 * @var integer
 *
 * @ORMColumn(name="id", type="integer")
 * @ORMId
 * @ORMGeneratedValue(strategy="AUTO")
 */
protected $id;

$data = $em->merge($datas);
    $em->persist($data);
    $em->flush();