Think of this class:
class Person {
/**
* #var ArrayCollection
*
* #ORM\ManyToMany(targetEntity="Person", fetch="EXTRA_LAZY")
* #ORM\OrderBy({"name" = "ASC"})
*/
public $friends;
/**
*
* #var Person
* #ORM\ManyToOne(targetEntity="Person")
*/
public $bestFriend;
}
I have to iterate a lot over all Persons, so I'd like to fetch join them all at once.
To save memory, I have to do this partially.
So what I can do is:
$this->em->createQuery('SELECT partial p.{id, name, bestFriend} FROM Person p')->getResult();
This is cool, after this query, all persons are in the UoW, and I can traverse the graph via $aPersion->bestFriend->bestFriend without creating an additional query to the DB, since all Persons are in memory.
However, this does not work with the ToMany association. Adding friends to the partial select gives an error. If I want to iterate over all friends, this will first create a query to the join table...
How can I realise the full hydration of the friends-ToMany-assotiation with one query? Maybe a second query could help? Or a clever join clause?
Thanks in advance!
I would create a query in PersonRepository.php with a leftJoin and a addSelect like so:
$qb = $this->em->getRepository('App:Person')
->createQueryBuilder('p')
->leftJoin('p.friends', 'friends')
->select('partial p.{id, name, bestFriend}'}
->addSelect('partial friends.{id, name}') // Retrieve what you want here
->getQuery()->getResult();
return $qb;
I have not tested this, but believe it should work.
#DirkJFaber your answer was right,
in terms of DQL here is my solution:
$this->em->createQuery('
SELECT partial p.{id, name, bestFriend}, f FROM Person p JOIN f.friends f')->getResult();
Related
Have a problem with subquery with symfony.
What I try to do - I have a table with users and a table with posts.
Posts Users
id|author|content id|username
I want create subquery to get user name by id.
/**
* #return array
*/
public function findAll()
{
return $this->getEntityManager()->createQuery(
'SELECT a, (SELECT u.username
FROM BackendBundle:User u WHERE u.id = a.author) as authorName
FROM BackendBundle:Article a'
)->getResult();
}
Result:
What am I doing wrong? What is the best way to join column from other table by id? Maybe i can use annotations?
Thx for any help.
You don't need a subquery here, what you need is a simple (INNER) JOIN to join Users with their Articles.
$em->createQuery("SELECT a FROM Article JOIN a.author'");
You don't even need an on clause in your join, because Doctrine should already know (through annotations on your entities or a separate yaml file), that the article.author field relates to user.id.
Edit:
I assume you have a User entity that is One-To-Many related to the Article entity.
class User
{
// ...
/**
* #OneToMany(targetEntity="Article", mappedBy="author")
*/
private $articles;
// ...
}
class Article
{
// ...
/**
* #var User
* #ManyToOne(targetEntity="User", inversedBy="articles")
*/
private $author;
// ...
}
Please refer to doctrines association mapping documentation: http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/association-mapping.html
I have: two entities with undirectional M:M association.
class ShareInfo
{
// ...
/**
* #ORM\ManyToMany(targetEntity="Item")
* #ORM\JoinTable(name="share_info_items",
* joinColumns={#ORM\JoinColumn(name="share_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="item_id", referencedColumnName="id")})
*
* #var Item[]
*/
private $items;
}
class Item
{
// ...
// This entity has no association with ShareInfo,
// because M:M is undirectional and defined in ShareInfo entity
}
What I want:
Select data from items table (Item entity), where at least one M:M record between Item and ShareInfo exists.
My suggestion which doesn't work (I've got a semantic error):
$queryBuilder
->select('i')
->from(Item::class, 'i')
->innerJoin(ShareInfo::class, 'shareInfo', 'WITH', 'shareInfo.items = i');
In pure SQL I'd do something like this:
SELECT i.*
FROM items i
INNER JOIN share_info_items shareInfo
ON shareInfo.item_id = i.id
Can't believe there is no DQL analog for this. The only solution I can imagine is to split undirectional M:M association into bi-directional
P.S. This question has no duplicates, I checked well.
The way to achieve this is through a subquery:
$em=$this->getDoctrine()->getManager();
$queryBuilder1=$em->createQueryBuilder();
$queryBuilder1->select(array('DISTINCT i.id'))
->from('AppBundle:ShareInfo', 'share_info')
->innerJoin('share_info.items', 'i');
$queryBuilder=$em->createQueryBuilder();
$queryBuilder->select('i')
->from('AppBundle:items', 'i')
->where($queryBuilder->expr()
->in('i.id',$queryBuilder1->getDql()));
I have an Alert Class with some data in it. I then have an Availability class. In my Availability class I have
/**
* #var \Nick\AlertBundle\Entity\Alert
*
* #ORM\ManyToOne(targetEntity="Nick\AlertBundle\Entity\Alert")
* #ORM\JoinColumns({
* #ORM\JoinColumn(name="availability_alert_id", referencedColumnName="id")
* })
*/
private $availabilityAlert;
So this is a foreign key back to my Alert class, linked to my Alerts class id.
I am now doing some work on the Availability data, so I have the DQL query
public function getAlertAvailability($id)
{
return $this->getEntityManager()
->createQuery(
'SELECT a.id, a.classLetter, a.flightNumber, a.alertPseudo, a.availability, a.lastUpdated
FROM NickAlertBundle:Availability a
WHERE a.availabilityAlert = :id
ORDER by a.classLetter, a.lastUpdated'
)
->setParameter('id', $id)
->getResult();
}
The way I call that is like this
public function getAvailabilityData(){
$alerts = $this->em->getRepository('NickAlertBundle:Alert')->getActiveAlertIds();
if (!$alerts) {
echo "No Availability";
}
foreach($alerts as $alert){
$alertId = (int)$alert['id'];
$allAvailability = $this->em->getRepository('NickAlertBundle:Availability')->getAlertAvailability($alertId);
}
}
So I essentially get all my active Alerts Ids, and then pass this to get my Availability for these individual Alerts.
Now I have a couple of problems.
Firstly, in the DQL query I make, I need to also get something from my Alert table (a field called command). How would I do a join in this query to get this piece of data?
Secondly, with the data that is returned, how do I access availabilityAlert in my Twig file?
UPDATE
Attempt at join
public function getAlertAvailability()
{
return $this->getEntityManager()
->createQuery(
'SELECT a.id, a.classLetter, a.flightNumber, a.alertPseudo, a.availability, a.lastUpdated, u.searchCommand
FROM NickAlertBundle:Availability a
JOIN a.availabilityAlert u
ORDER BY a.classLetter, a.lastUpdated'
)
->getResult();
}
Doctrine will load that entity as a proxy (for lazy loading) when the Availability entity is loaded.
You can access these via a normal getter / property access, but they will typically be lazy loaded by Doctrine. You can have them joined via a DQL query and the property will be hydrated with all the linked entities already loaded, see Improving Performance with a Join.
You can then access those associated entities in Twig as any other property.
I have two entities:
class User extends BaseEntity {
/**
* #ORM\OneToOne(targetEntity="Profile", mappedBy="user", cascade={"persist", "remove"})
* #var Profile
*/
protected $profile;
}
class Profile extends BaseEntity {
/**
* #ORM\OneToOne(targetEntity="User", inversedBy="profile", cascade={"persist"})
* #ORM\JoinColumn(name="user_id", referencedColumnName="id", onDelete="CASCADE")
* #var User
*/
protected $user;
}
What I'm trying to do is to SELECT only users who don't have any profile (so there's no profile row with user_id=:user_id in profiles table). However, I have no idea how to make my QueryBuilder.
First, I tried something simple like
//u as user
$query = $this->er->createQueryBuilder('u');
$query
->join('u.profile', 'p')
->where('u.profile = 1');
But that returns A single-valued association path expression to an inverse side is not supported in DQL queries. Use an explicit join instead. so I suppose there's something wrong with my relationship? I tried to switch join() for leftJoin() but it didn't help either...
So what's up with this error and how to make proper condition with where() to tell Doctrine I want only users where there's no profile?
Here is how I was able to do it. Basically I had Domain & Hosting entities and I wanted to select Domains that had no Hosting attached to them in a one to one relationship.
$er->createQueryBuilder('d')
->leftJoin('d.hosting', 'h')
->where('h.id is NULL');
Credits for this solution goes to this Answer
Hope it works for you since our situations are almost identical.
Just check for null as value of profile
//u as user
$query = $this->er->createQueryBuilder('u');
$query
->where('u.profile is NULL');
Try to use repositories, example for UserRepository:
$qb = $this->createQueryBuilder('u');
$e = $qb->expr();
$qb->leftJoin('u.profile', 'p')
->where($e->isNull('p.id'))
Raw query will look like this:
SELECT * FROM users AS u LEFT JOIN u.profile AS p WHERE p.id IS NULL;
I have a Car entity with a many-to-one relationship with an entity Owner. If I select all cars, Doctrine does one query on the Car table, and subsequently one query on the Owner table for each car. So fetching N cars becomes N+1 queries instead of a single JOIN query between the Car and Owner tables.
My entities are as follows:
/** #Entity */
class Car {
/** #Id #Column(type="smallint") */
private $id;
/** #ManyToOne(targetEntity="Owner", fetch="EAGER")
#JoinColumn(name="owner", referencedColumnName="id") */
private $owner;
public function getId() { return $this->id; }
public function getOwner() { return $this->owner; }
}
/** #Entity */
class Owner {
/** #Id #Column(type="smallint") */
private $id;
/** #Column(type="string") */
private $name;
public function getName() { return $this->name; }
}
If I want to list the cars with their owners, I do:
$repo = $em->getRepository('Car');
$cars = $repo->findAll();
foreach($cars as $car)
echo 'Car no. ' . $car->getId() .
' owned by ' . $car->getOwner()->getName() . '\n';
Now this all works very well, apart from the fact that Doctrine issues a query for each car.
SELECT * FROM Car;
SELECT * FROM Owner WHERE id = 1;
SELECT * FROM Owner WHERE id = 2;
SELECT * FROM Owner WHERE id = 3;
....
Of course I'd want my query log to look like this:
SELECT * FROM Car JOIN Owner ON Car.owner = Owner.id;
Whether I have fetch="EAGER" or fetch="LAZY" doesn't matter, and even if I make a custom DQL query with JOIN between the two entities, $car->getOwner() still causes Doctrine to query the database (unless I use EAGER, in which case $repo->findAll() causes all of them).
Am I just too tired here, and this is the way it is supposed to work - or is there a clever way to force Doctrine to do the JOIN query instead?
At least in 1.x Doctrine if you wanted to query for the related objects, you had to use DQL. For your case, the DQL query would look something like this:
//Assuming $em is EntityManager
$query = $em->createQuery('SELECT c, o FROM Car c JOIN c.owner o');
$cars = $query->execute();
Run first a DQL query where you select all the cars joined (DQL JOIN) with the owner. Put the owner in the select().
// preload cars
$qb = $em->createQueryBuilder()
->select('car, owner')
->from('\Entity\Car', 'car')
->leftJoin('c.owner', 'owner');
$query = $qb->getQuery();
// the following seems not needed, but I think it depends on the conf
$query->setFetchMode("\Entity\Car", "owner", "EAGER");
$query->execute(); //you don't have to use this result here, Doctrine will keep it
Doctrine 2 will then perform a JOIN (normally faster as it requires less db queries depending on the number of records).
Now launch your foreach, Doctrine will find the entities internally and it won't run single queries when you need the owner.
Monitor the number of queries first/after each change (eg. mysql general log)
Your query...
$car->getOwner() // "go and fetch this car's owner"
... is in a foreach loop so it will certainly issue the query several times.
If you're writing custom DQL to deal with this, $car->getOwner() shouldn't feature in this at all. This is a function of the Car class. The custom DQL you would write would mimick the exact SQL query you point out and get your join done efficiently.