DDC-3635: QueryBuilder - INSTANCE OF with parameter not working

[doctrinebot]

Jira issue originally created by user Wilt:

I use single table class inheritance.
When I write my *INSTANCE OF* clause in my QueryBuilder like this:

    $result = $this->createQueryBuilder('o')
        ->leftJoin('o.child', 'c')
        ->where('c INSTANCE OF :entity_class')
        ->setParameter('entity_class', 'My\Entity\Class')
        ->getQuery()
        ->getResult();

It does not work correctly. The problem seems to lie in the fact that the parameter is bound to the SQL query. So if I change the entity_class to the discriminator column name it works correctly.

So if the discriminator value for *My\Entity\Class* would be discriminator then this does work:

    $result = $this->createQueryBuilder('o')
        ->leftJoin('o.child', 'c')
        ->where('c INSTANCE OF :entity_class')
        ->setParameter('entity_class', 'discriminator')
        ->getQuery()
        ->getResult();

So the step for getting the discriminator column from the class name is missing and instead the class name is bound to the MySql query directly.

[doctrinebot]

Comment created by @guilhermeblanco:

INSTANCE OF expressions expect either their class names or their corresponding class metadata. This means the following examples are valid:

$qb->where('c INSTANCE OF My\Entity\Class');

// or

$qb
    ->where('c INSTANCE OF :param')
    ->setParameter('param', $em->getClassMetadata('My\Entity\Class'))
;

Assigning class name directly does not work.
Closing as invalid.

[doctrinebot]

Comment created by @Ocramius:

Re-opening. I think this is a documentation issue then, as http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/dql-doctrine-query-language.html#id2 says that the InstanceOfParameter accepts also an InputParameter

[doctrinebot]

Comment created by @guilhermeblanco:

[~ocramius] And it does. However, the bound parameter must be a ClassMetadata.

[jycamier]

It seams that there is a similar issue on the DoctrineORMAdapter object.

    $query = $this->createQueryBuilder('o')
        ->leftJoin('o.child', 'c')
        ->where('c INSTANCE OF :class')
        ->setParameter('class',  $em->getClassMetadata('My\Entity\Class'))
        ->getQuery();
    $adapter = new DoctrineORMAdapter($query);
    ...

This main query is okay : the mapping on the discriminator is done with the discriminator value. However, the subquery create to get the count isn't abble to do the job : the mapping is done with the string 'My\Entity\Class' and not the discriminator value.

[jarrettj]

Does not work for me @jycamier. I had to put the class name in the parameter. Tried $em->getClassMetadata() no luck. Then played around with it and it works on the class name without the namespace, which is weird. Hey it works :).

[smilesrg]

Issue from 24 Mar 2015, is it still relevant?

@guilhermeblanco maybe you know? :-)

[Ocramius]

@smilesrg would require a test - fairly sure it still doesn't work, since DQL was not refactored in that area.

[jarrettj]

Still does not work. :( Wasn't an issue as we simply had to do the instance check on the result set. Issue now is that the result set has become larger and there will be a performance issue. I had initially thought that the classname worked. But it did not.

Will do some more research and post findings.