预装主义ODM参考文档

Question

I'm using Doctrine ODM (MongoDB) and I have something like the following

• Attendee document
• Answer document
• each Answer references one Attendee . (one-to-many relation)

I do something like the following

attendees = attendeeRepo.findby(whatever)

foreach(attendees as attendee)
    answers = attendee.getAnswers()

The problem here is that on each attendee.getAnswers() Doctrine ODM executes a query like that:

db.TicketAnswer.find({ 
    "attendee.$id": ObjectId("50ae80608ead0ea71e00008b") 
})

if I have 100 atendees, 100 queries like this one will get executed, so I was trying to preload all Answers before the loop. but it didn't work as I expected.

I guess it didn't work as I was expecting as this is a one-to-many relation and I asked the one side of the relation ( Attendee ) to load the many ( Answer ). in other cases when I'm doing the opposite, preloading works as expected.

I'm not sure what's the best solution for a case like that. wish if anyone has ideas that can help.

Answer 1

Check this article out: http://docs.doctrine-project.org/projects/doctrine-mongodb-odm/en/latest/reference/priming-references.html

To quote:

/** @Document */
class User
{
    /** @ReferenceMany(targetDocument="Account") */
    private $accounts;
}

-

$qb = $dm->createQueryBuilder('User')
    ->field('accounts')->prime(true)
    ->limit(100);
$query = $qb->getQuery();
$users = $query->execute();