SELECT t.*
FROM
  StateLogItem s NATURAL JOIN (
    SELECT
      task_id,
      MAX(
        COALESCE(updatedAt, createdAt)
      ) d,
      MAX(id) id
    FROM
      StateLogItem
    WHERE
      dtype = 'transitionlogitem'
    GROUP BY
      task_id
  ) m
  RIGHT JOIN Task t ON t.id = s.task_id
WHERE  s.toState = 'started';

'20', 1, NULL, 'just because', '2014-07-18 10:49:00', NULL

public function findByActionStatus($status){
    $sql = "SELECT t.id, t.description, t.created_by, t.updated_by, t.createdAt, t.updatedAt
            FROM StateLogItem s
                NATURAL JOIN (
                    SELECT task_id, MAX(COALESCE(updatedAt,createdAt)) d, MAX(id) id
                    FROM StateLogItem
                    WHERE dtype = 'transitionlogitem'
                    GROUP BY task_id
                ) m
                RIGHT JOIN Task t ON t.id=s.task_id
            WHERE s.toState = :status";

    $em = $this->getEntityManager();

    $rsm = new ResultSetMapping();
    $rsm->addEntityResult('ACCQueueBundle:Task', 't');
    $rsm->addFieldResult('t','t.id','id');
    $rsm->addFieldResult('t','t.created_by','createdBy');
    $rsm->addFieldResult('t','t.updated_by','updatedBy');
    $rsm->addFieldResult('t','t.description','description');
    $rsm->addFieldResult('t','t.createdAt','createdAt');
    $rsm->addFieldResult('t','t.updatedAt','updatedAt');

    $rsm->addJoinedEntityResult('ACCQueueBundle:TransitionLogItem','s','t','transitions'); //tried with and without


    $query = $em->createNativeQuery($sql,$rsm);
    $query->setParameter('status', $status);

    return $query->getResult();

}

namespace ACCQueueBundleEntity;

use DoctrineORMMapping as ORM;


use SymfonyComponentValidatorConstraints as Assert;
use DoctrineCommonCollectionsArrayCollection;
use ACCTraitsBlameableTrait;
use ACCMainBundleEntityTraitsHasDocumentsTrait;
use GedmoMappingAnnotation as Gedmo;
use GedmoTimestampableTraitsTimestampableEntity;


/**
 * Task
 * @ORMEntity(repositoryClass="ACCQueueBundleEntityTaskRepository")
 * @ORMHasLifecycleCallbacks()
 *
 */
class Task {

    use HasDocumentsTrait;
    use BlameableTrait;
    use TimestampableEntity;

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


    /**
     * @var Transition
     *
     * @ORMOneToMany(targetEntity = "TransitionLogItem", mappedBy = "task", orphanRemoval = true, cascade = {"persist"})
     * @ORMOrderBy({"createdAt" = "ASC"})
     */
    protected $transitions;

    /**
     * @var Pause
     *
     * @ORMOneToMany(targetEntity = "PauseLogItem", mappedBy = "task", orphanRemoval = true, cascade = {"persist"})
     * @ORMOrderBy({"createdAt" = "ASC"})
     */
    protected $pauses;


    /**
     * @var string
     *
     * @ORMColumn(name="description", type="text")
     */
    protected $description;

    /**
     * @ORMManyToMany(targetEntity = "ACCMainBundleEntityDocument", cascade={"persist","remove"})
     * @ORMJoinTable(name="Task_Document",
     *  joinColumns={@ORMJoinColumn(name="task_id", referencedColumnName="id")},
     *  inverseJoinColumns={@ORMJoinColumn(name="document_id", referencedColumnName="id", unique=true)})
     */
    protected $documents;

//etc.