Override Persister:loadAll in EntityRepository - php

Question

I have the need to display data from a table in a pager and at the same time get a count on records in a child table. There are too many child records to load into memory and count, so I want to modify how the query is built in my EntityRepository.
Ideally I don't want to re-implement the pager functionality, so I am looking to override findBy in my EntityRepository and add the count(), join and group by in my query?
How do I do this best? I'm using Symfony 2.8, Doctrine 2 and PagerFanta
I also found this http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/filters.html but it seems thin on documentation

Answer 1

I hope I can help you!
If I understand correctly, you want to load from the database for each instance of an object the number of child objects in addition to all the fields of this object - as an additional field. Right?
I don't know, how the parent entity and the child entity are named in your model. But I will give a working example for your tasks from my web application. You have only to rename the parent and child entity.
There are affiliate programs, each of which has a finite set of accounts in my application. So, I have a parent entity called 'AffiliateProgram' and I have a child entity called 'AffiliateProgramAccount'.
You should not override the standard method in the repository for class of your entity. You just have to add your method according to your needs.
First thing, create a repository for class of your parent entity (How to Create custom Repository Classes). I do it in the YAML file with a description as follows:
Analytics\TrafficStatisticsBundle\Entity\AffiliateProgram:
type: entity
table: affiliate_program
repositoryClass: Analytics\TrafficStatisticsBundle\Entity\AffiliateProgramRepository
Then you must create a repository class of your parent entity according to the path in the description for Doctrine. I keep the classes of repositories together with the model classes in the 'Entity' directory. Now you can create your custom methods in the created repository according to your individual needs.
I suggest to use Doctrine DBAL to solve your problem (How to use Doctrine DBAL). Here is an example of my query, absolutely identical to yours:
use Doctrine\ORM\EntityRepository;
class AffiliateProgramRepository extends EntityRepository {
/**
* #return array
* #throws \Doctrine\DBAL\DBALException
*/
public function findAllAffiliatePrograms() {
// $stmt = $this->getEntityManager()
// ->getConnection()
// ->prepare('
// SELECT COUNT(apa.id) AS Number_of_accounts, ap.*
// FROM affiliate_program AS ap
// LEFT JOIN affiliate_program_account AS apa ON apa.affiliate_program_id = ap.id
// GROUP BY ap.id');
// $stmt->execute();
// return $stmt->fetchAll();
$stmt = $this->getEntityManager()
->getConnection()
->prepare('
SELECT COUNT(apa.id) AS Number_of_accounts, ap.*
FROM affiliate_program AS ap,
affiliate_program_account AS apa
WHERE apa.affiliate_program_id = ap.id
GROUP BY ap.id');
$stmt->execute();
return $stmt->fetchAll();
}
}
Here notice that I don't use object names ('AnalyticsTrafficStatisticsBundle:AffiliateProgram' in my case) for operators FROM, [LEFT | RIGHT | INNER | OUTER] JOIN as it must be used in DQL, etc. Instead, I use the real table names.
Note: The query without using the JOIN operator executes faster. In my example I showed two ways - using the JOIN operator and the same with the using of WHERE operator. Proof:
and
Now you can get all the objects according to your query in the controller, simply by calling the newly created method:
<?php
namespace Testing\TestBundle\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Method;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Component\HttpFoundation\Request;
/**
* TestController
*
* #Route("/test")
*/
class TestController extends Controller {
/**
* #Route("/", name="test_index")
* #Method("GET")
*/
public function indexAction() {
$em = $this->getDoctrine()->getManager();
$affiliatePrograms = $em->getRepository('AnalyticsTrafficStatisticsBundle:AffiliateProgram')->findAllAffiliatePrograms();
return $this->render('TestingTestBundle:Test:test.html.twig', [
'result' => $affiliatePrograms
]);
}
}
And to make sure that everything works, you just write the following snippet in .twig file (for example):
{{ dump(result) }}
Materials also, see here:
How to use Raw SQL Queries in Symfony 2
Raw SQL Queries
Executing SQL directly in Symfony2 Doctrine
I hope that's all you need!