Update randomly certain number of rows - symfony

Question

I'm trying to update a certain number of rows of my entity "Vehicule". I have no idea how could it work.
I'm actually trying to modify only two rows where direction= 5.This is the function I used in order to update.
public function ValidAction(\OC\UserBundle\Entity\User $direction) {
$qb = $this->getDoctrine()
->getRepository('CarPfeBundle:Vehicule')
->createQueryBuilder('v');
$q = $qb->update ('CarPfeBundle:vehicule v')
->set('v.direction', '?1')
->where('v.direction = ?2')
->setParameter(1, $direction)
->setParameter(2, 5)
->getQuery();
$p = $q->execute();
return $this->redirect($this->generateUrl('demandeveh_afficher'));
}
But the above code update all rows of my database. I need to update only two rows. Any help please?

Answer 1

Try to do this ;
public function ValidAction(\OC\UserBundle\Entity\User $direction) {
$qb = $this->getDoctrine()
->getRepository('CarPfeBundle:Vehicule')
->createQueryBuilder('v');
// $ids an array that contains all ids with your condition
$ids = $qb->select('v.id')
->where('v.direction = :direction')
->setParameter(
array(
'direction' => $direction
)
)
->getQuery()
->getResult();
$id1 = $ids[array_rand($ids)];
$id2 = $ids[array_rand($ids)];
//To be sure that $id1 is different from id2
while ($id1 == $id2) {
$id2 = $ids[array_rand($ids)];
}
$q = $qb->update ('CarPfeBundle:vehicule v')
->set('v.direction', ':val1')
->where('v.direction = :val2')
->andWhere('v.id IN (:id1, :id2)')
->setParameter(
array(
'val1' => $direction ,
'val2' => 5 ,
'id1' => $id1,
'id2' => $id2,
)
)
->getQuery();
$p = $q->execute();
return $this->redirect($this->generateUrl('demandeveh_afficher'));
}
With the above code I hope you can update only two rows and randomly.
Good luck !

Answer 2

While a solution like Houssem Zitoun suggested may work, why not use a subquery?
If you get the (like I did, if not, just skip the middle SELECT)
Error: #1235 - This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'
go with this answer and something like (doc): - untested
UPDATE CarPfeBundle:Vehicule v
SET v.direction = ?1
WHERE v.direction IN
(SELECT * FROM (
SELECT v.direction
FROM CarPfeBundle:Vehicule v2
WHERE v.direction = ?2 LIMIT 2
)) AS sq