Doctrine2 - Sub query join without a relationship - symfony

Question

Ok so here's the issue.
I have a Entity named HelpDocuments and an Entity named LogEntry.
HelpDocuments can be dismissed by the user. When this happens I create a LogEntry with the following attributes:
event - eg: helpDocument.dismiss
entity_id - eg: 11
entityDiscriminator - eg: HelpDocument
There are no relationships created between HelpDocument and LogEntry as I'm implementing my own discriminator logic.
So what I'm trying to achieve is query for all HelpDocuments that have not been dismissed. I can do that with sql, left outer subquery join like so:
SELECT HelpDocument.*, temp.*
FROM HelpDocument
LEFT OUTER JOIN(
SELECT LogEntry.entity_id
FROM LogEntry
WHERE LogEntry.entityDiscriminator = 'HelpDocument'
AND LogEntry.event = 'helpDocument.dismiss'
AND LogEntry.entity_id = 11
) as temp ON HelpDocument.id = temp.entity_id
WHERE temp.entity_id IS NULL;
My issue is how do I turn this into DQL given that there is no relationship defined?
Updated Solution:
So the solution was to not use an LEFT OUTER JOIN because they don't exist / make sense in Doctrine2. In the end I had to do a subquery join:
/**
* Filter by User Dismissed
*
* #param $qb
* #param $route
* #return mixed
*/
public function filterQueryByUserDismissed(QueryBuilder $qb, $args)
{
$args = array_merge(array(
"user" => null,
"dismissed" => false
), $args);
/** #var $dismissedQB QueryBuilder */
$dismissedQB = $this->_em->createQueryBuilder();
/*
This line is important. We select an alternative attribute rather than
letting Doctrine select le.id
*/
$dismissedQB->select('le.entityId')
->from('\Mlf\AppBundle\Entity\UserEntityEventLog', 'le')
->where('le.entityDiscriminator = :entityDiscriminator')
->andWhere('le.event = :event')
->andWhere('le.user = :userId');
$function = (true === $args['dismissed']) ? "in" : "notIn";
$expr = $qb->expr()->$function($this->classAlias.'.id', $dismissedQB->getDQL());
/** #var $qb QueryBuilder */
$qb->andWhere($expr)
->setParameter("entityDiscriminator", HelpDocument::getDiscriminator())
->setParameter("event", HelpDocumentEvents::HELPDOCUMENT_DISMISS)
->setParameter("userId", $args["user"]);
// exit($result = $qb->getQuery()->getSQL());
return $qb;
}
This DQL query results in the following SQL:
SELECT h0_.id AS id0
FROM HelpDocument h0_
WHERE (
h0_.id NOT IN (
SELECT l1_.entity_id
FROM LogEntry l1_
WHERE l1_.entityDiscriminator = 'helpDocument'
AND l1_.event = 'helpDocument.dismiss'
AND l1_.user_id = 1
)
)
Yay!

Answer 1

I saw your solution and I have a minor change that will be a huge performance improvement. Especially if you have more then a couple of thousand rows.
public function filterQueryByUserDismissed(QueryBuilder $qb, $args)
{
$args = array_merge(array(
"user" => null,
"dismissed" => false
), $args);
/** #var $dismissedQB QueryBuilder */
$dismissedQB = $this->_em->createQueryBuilder();
/*
This line is important. We select an alternative attribute rather than
letting Doctrine select le.id
*/
$dismissedQB->select('le.entityId')
->from('\Mlf\AppBundle\Entity\UserEntityEventLog', 'le')
->where('le.entityDiscriminator = :entityDiscriminator')
->andWhere('le.event = :event')
->andWhere('le.user = :userId');
// ---- My changes below
// Get an array with the ids
$dismissedIdsMap = $dismissedQB->getQuery()->getResults();
$dismissedIds = array_map(
function($a){
return $a['entityId'];
},
$dismissedIdsMap);
$function = (true === $args['dismissed']) ? "in" : "notIn";
$expr = $qb->expr()->$function($this->classAlias.'.id', $dismissedIds);
// ---- My changes above
/** #var $qb QueryBuilder */
$qb->andWhere($expr)
->setParameter("entityDiscriminator", HelpDocument::getDiscriminator())
->setParameter("event", HelpDocumentEvents::HELPDOCUMENT_DISMISS)
->setParameter("userId", $args["user"]);
// exit($result = $qb->getQuery()->getSQL());
return $qb;
}
The code above is using two queries. If you are using one query, MySQL will create a temporary view from your subquery and then query the view with master query. It is a lot of overhead creating this view. With two queries you will be keeping the "view" in the PHP memory and this will reduce the overhead dramatically.