Doctrine2.1 load partial association - php

Say I have a an entity in Doctrine called Post and it has a bidirectional many-to-one relationship to another entity called Comment.
Say I have a function in Post that serializes the post to JSON and includes a portion of the comments:
public function serialize(){
return array(
... other data here ....
'comments' => $this->getSerializedComments(5),
'total_comments' => $this->getComments()->count()
);
}
I would like to also write a function getSerializedComments(limit) that only loads up to limit comments in the association (i.e. NOT all of the comments for the post, just 5). If I understand correctly, if I make the association EXTRA_LAZY, the count() will only run a count query, and not hydrate the whole association.
I would prefer to do all of this in my entity class, and not have to do it in a separate manager or repository function.
I know there's an #OrderBy annotation for To-Many relationships. Doesn't seem like there's an #Limit though.

You can simply use Doctrine\Common\Collections\Collection::slice(), which doesn't initialize the collection if it is marked as EXTRA_LAZY

Related

Symfony serialization with groups and relations

I am using Symfony's serializer to return a JSON response. I use groups to only return information that is relevant:
return new JsonResponse($this->serializer->serialize($userRepository->getActiveUser(), 'json', ['groups' => ['contact-information']]));
My User class has additional relationships I am not interested in for the above request, like paymentProfile. This property has a different group:
class User {
...
/**
* #ORM\ManyToOne(targetEntity=PaymentProfile::class)
* #Groups({"payment-information"})
*/
protected $paymentProfile;
}
The JSON returned does NOT include the paymentProfile property for Users (as expected), yet looking at the Symfony Profiler, I see that the request required 100s of individual paymentProfile queries (one for each users returned):
Repository:
public function getActiveUsers()
{
return $this->createQueryBuilder('u')
->andWhere('u.active= :active')
->setParameter('active', true)
->getQuery()->getResult()
;
}
Don't serialization groups prevent unnecessarily fetching data? If yes, what am I doing wrong? If not, how can I get rid of the extra queries?
EDIT:
Symfony\Component\Serializer\Normalizer\AbstractNormalizer::IGNORED_ATTRIBUTES is also not fixing the issue.
This is why:
There is a general performance consideration with Single Table Inheritance: If the target-entity of a many-to-one or one-to-one
association is an STI entity, it is preferable for performance reasons that it
be a leaf entity in the inheritance hierarchy, (ie. have no subclasses).
Otherwise Doctrine CANNOT create proxy instances of this entity and will ALWAYS load the entity eagerly. (https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/inheritance-mapping.html#performance-impact)
H/T https://stackoverflow.com/a/25754165/1550361

Does a one-to-one relationship in Laravel always need first()?

I have a one-to-one relationship between User and UserSettings models,
But (after $user = auth()->user()) when I try $user->settings()->something it throws an Undefined property error.
It's gone when I use $user->settings()->first()->something...
My question is, is this how it's supposed to work? or am I doing something wrong?
You cannot directly run $user->settings()->something.
Because when you call $user->settings(), it just return Illuminate\Database\Eloquent\Relations\HasOne object.
So it is not the model's object, you need to take the model's object and call its attribute like this.
$user->settings()->first()->something;
Dynamic Properties
Since you have one-to-one relationship between User and UserSettings.
If you have a one-to-one relationship in your User model:
public function settings()
{
return $this->hasOne('App\Models\UserSettings', 'user_id', 'id');
}
According to Laravel doc
Once the relationship is defined, we may retrieve the related record using Eloquent's dynamic properties. Dynamic properties allow you to access relationship methods as if they were properties defined on the model:
Eloquent will automatically load the relationship for you, and is even smart enough to know whether to call the get (for one-to-many relationships) or first (for one-to-one relationships) method. It will then be accessible via a dynamic property by the same name as the relation.
So you can use eloquent's dynamic properties like this:
$user->settings->something; // settings is the dynamic property of $user.
This code will give you a result of collection.
$user->settings;
So calling 'something' is not available or it will return you of null, unless you get the specific index of it.
$user->settings()->something
while this one works because you used first() to get the first data of collection and accessed the properties of it .
$user->settings()->first()->something
The first method returns the first element in the collection that passes a given truth test
see docs here laravel docs
If you want to get the user settings itself simply do this:
$user->settings
Then you can get the fields of the settings doing this:
$user->settings->something
When you do this $user->settings() you can chain query after that. E.g.
$user->settings()->where('something', 'hello')->first()
That's why the output of $user->settings and $user->settings()->first() are the same.
Auth only gives you user info;
Try the following code:
$user = User::find(auth()->user()->id);//and then
$user->settings->something;

save a belongsTo relationship

I have a classic one-to-many relationships, and I am trying to save the model of the belongsTo side.
The 2 models have these relationships:
// Model myModel
function domicile()
{
return $this->belongsTo('App\Address', 'domicile_id');
}
// Model Address
function myModels()
{
return $this->hasMany('App\MyModel', 'domicile_id');
}
This is what I am tryng to do to save it:
$myModel->domicile()->save($my_array);
With this code I get the error:
Call to undefined method Illuminate\Database\Eloquent\Relations\BelongsTo::save()
if I use this code (without the brackets):
$myModel->domicile->save($my_array);
I do not get any error but the model is not saved.
I know there is the method associate, but I need to update an existent record, not to save a new one.
Because $myModel->domicile()->save($my_array); is totally different to $myModel->domicile->save($my_array); :
$myModel->domicile() will produce a BelongsTo object, doesn't support the save because save is a method of HasMany instances, instead for BelongsTo instances you should use associate(YourModel)
$myModel->domicile will produce a Model object of the associated element, which support the save(array) method, but that array is a options array, as api says https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Model.html#method_save
So in other words, if you have a one (address) to many (domicile) relation, if you want to associate to the address one or many domiciles, you have to use save or saveMany (https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Relations/HasMany.html#method_save), instead if you want to associate to a domicile a address, you should use associate (https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Relations/BelongsTo.html#method_associate)... keep in mind that if you want to do this, you should call the properties with the brackets, in order to have back a HasMany object or a BelongsTo object, and not a Model or a Collection (which you will get if you call the properties without the brackets)
Instead of using the save function, in order to save a belongsTo relationships you have to use the fill function.
In this way:
$myModel->domicile->fill($my_array);
$myModel->domicile->save();
You must use associate() + save() in order to store a BelongsTo relationship:
$myModel->domicile()->associate($domicile);
$myModel->save();
See Laravel Docs

laravel Eloquent one to many two relationship. OpenCart table style

How to implement information and information_description tables in laravel Eloquent Model ? Some how it need to set language, because a title should be a one record.
$information = App\Information::find(1);
$information->title
tables structure
You can review how to do this, and plenty more, by reading the documents by Laravel. They are a great help and this particular question has an example and everything. Having said that, I'll help with getting you started.
Define a relationship in either model, information or information_description, or both. For brevity, I'll use information only.
Pass the foreign_key and local_key in the hasMany() relationship since it differs from Laravel's default behavior.
So we have a model that now looks like:
class Information extends Model
{
/**
* Get the descriptions for the Information model.
* Note the 2nd and 3rd arguments in the method
* which define foreign_key and local_key.
*/
public function description()
{
return $this->hasMany('App\InformationDescription', 'information_id', 'information_id');
}
}
Now that you have the relationship defined, you can perform your query.
// Get the description for the information
$information = App\Information::find(1)->description;
// Iterate over the results
foreach ($information as $description) {
$description->title;
}
The table naming convention used is a little odd, but if I understand it correctly, this will work. Hope it helps.

How to retrieve an entity with all of its associations using EntityManager in Doctrine2?

I have a simple entity with many-to-many and one-to-many associations. I'm aware of 'Joins' for fetching related associations which is a manual solution for my problem.
How can I fetch an entity with all of its associations using EntityManager in Doctrine2? e.g.:
$this->em
->getRepository('Entities\Patientprofile')
->findOneByuserid('555555557')
->fetchAllAssociations();
from http://doctrine-orm.readthedocs.org/en/latest/reference/dql-doctrine-query-language.html#temporarily-change-fetch-mode-in-dql
you can set eager fetch mode temporarily:
$query = $em->createQuery("SELECT u FROM MyProject\User u");
$query->setFetchMode("MyProject\User", "address", "EAGER");
$query->execute();
If you want do load dynamically all associations with this fetch mode, you can use the getAssociationMappings() method of the Doctrine\ORM\Mapping\ClassMetadataInfo, passing your entity name as parameter to the constructor of ClassMetadataInfo and then iterate over the returned array as $assoc and call:
$query->setFetchMode("MyProject\User", $assoc, "EAGER");
Doc: ClassMetadataInfo#getAssociationMappings()
Doctrine2 setFetchMode not working with "EAGER"
I tried also to fetch the associating entities "eagerly" using setFetchMode in my query, but the following didn't seem to work:
$query->setFetchMode("MyProject\User", "address", "EAGER");
When I jumped into the files I found out that the third parameter $fetchMode should be an integer. The constants are defined in Doctrine\ORM\Mapping:ClassMetadataInfo. When passing a string it will default to Mapping\ClassMetadata::FETCH_LAZY because of this if clause.
/**
* Specifies that an association is to be fetched when it is first accessed.
*/
const FETCH_LAZY = 2;
/**
* Specifies that an association is to be fetched when the owner of the
* association is fetched.
*/
const FETCH_EAGER = 3;
/**
* Specifies that an association is to be fetched lazy (on first access) and that
* commands such as Collection#count, Collection#slice are issued directly against
* the database if the collection is not yet initialized.
*/
const FETCH_EXTRA_LAZY = 4;
So setting the corresponding integer solved the problem:
$query->setFetchMode("MyProject\User", "address", 3);
Or declare the class use Doctrine\ORM\Mapping\ClassMetadata at the top and then use the constant:
$query->setFetchMode("MyProject\User", "address", ClassMetadata::FETCH_EAGER);
EDIT:
Since there seems to be a lot of confusion here on how to fetch associations the right way I will edit my answer and add some additional information on how you can fetch join using your repository.
According to the Doctrine documentation there are 2 types of joins:
Regular Joins: Used to limit the results and/or compute aggregate values.
Fetch Joins: In addition to the uses of regular joins: Used to fetch related entities and include them in the hydrated result of a
query.
So to get an entity including its associations you will need to "fetch-join" all these associations to make sure they are loaded eagerly.
I usually don't use DQL queries for getting entities and solving my fetch joins, instead I add a custom method to a repository where I use a query builder. This is more flexible and much more readable then using DQL. The correct DQL query will be created by the query builder when we call the createQuery method. You can check the created DQL query of course for debug purposes.
An example for such a custom method inside the Patientprofile entity repository from the question above:
public function findPatientByIdWithAssociations($id)(
// create a query builder for patient with alias 'p'
$qb = $this->createQueryBuilder('p')
->where('p.id = :patient_id')
->addSelect('pd')
->leftJoin('p.documentation', 'pd')
->addSelect('pa')
->leftJoin('p.address', 'pa')
->setParameter('patient_id', $id);
$query = $queryBuilder->getQuery();
return $query->getSingleResult();
}
And now you can use your custom repository method to get the patient by id (for example '555555557') including associations to the patient documentation and address:
$repository = $this->em->getRepository('Entities\Patientprofile');
$patient = $repository->findPatientByIdWithAssociations('555555557');
Make sure you use both addSelect and leftJoin to do eager loading.
Doctrine 2 uses Proxy classes for lazy loading, so you don't actually need to have the associations' data fetched until you use the objects. Since the Proxy classes inherit from your association classes, you're able to use the proxies exactly as you would use the fretch association classes.
but, if you really need to fetch the actual association classes, you need to tell the query to set the fetch mode to Doctrine\ORM\Mapping\ClassMetadata::FETCH_EAGER. If you're using the annotations, you can achieve this with:
e.g.
/**
* #ManyToMany(targetEntity="Item", fetch="EAGER")
*/
private $items;
You can use a DQL query:
$query = $em->createQuery("SELECT p, f FROM Entities\\Patientprofile p JOIN p.Foo f WHERE p.id = ?1");
$query->setParameter(1, 321);
$patient = $query->getSingleResult();
Faced the same problem.
It was necessary to pull out all chain of parents of an element.
$query->setFetchMode(EntityClass, "alias_in_entity", 3) gets only 1 lvl deep, other parents are just proxy.
This can be fixed by changed in entity class fetch mode to eager. But if it`s not if this is not possible for some reason (performance etc), this can be made as #wormhit mentioned by changing entity metadata "on fly"
Example:
$query = $this->entityManager->createQueryBuilder()->select('fields')
->from(FormField::class, 'fields');
$metadata = $this->entityManager->getClassMetadata(FormField::class);
$metadata->setAssociationOverride('parent', ['fetch' => \Doctrine\ORM\Mapping\ClassMetadata::FETCH_EAGER]);
return $query->getOneOrNullResult();

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