Putting a limit on doctrine queries - php

I'm working on a site to make an inventory of series.
public function category(string $categoryName): Response
{
$categoryInfos = $this->getDoctrine()
->getRepository(Category::class)
->findOneByName($categoryName);
$programs = $this->getDoctrine()
->getRepository(Program::class)
->findByCategory($categoryInfos);
return $this->render('wild/category.html.twig', ['programs' => $programs, 'category' => $categoryInfos]);
}
This function allows me to retrieve all programs belonging to the specified category.
I would now like to limit the number of programs to 3 in my request.
$programs = $this->getDoctrine()
->getRepository(Program::class)
->findByCategory($categoryInfos)
->setMaxResults(3);
But this shows me the error:
-> Call to a member function setMaxResults() on array
What did I do wrong?
I get lost in the symfony doc, being new ^^

You are calling a method inside repository class that returns an array and you cannot execute setMaxResults() on arrays.
If you want to set the size of result you should set it inside findByCategory() method in ProgramRepository.php

Related

Laravel Eloquent - Relationships and methods. When to use ->users() vs ->users [duplicate]

There is some basic understanding/theory here that I am missing.I don't understand the difference between these function calls:
$distributors = $store->distributors();
$distributors = $store->distributors;
$distributors = $store->distributors()->get();
$distributors = $store->distributors->get();
What I am trying to accomplis here is to get a list of the distributors for a store (a many to many relationship), and they get each distributors list of beers into one giant list.
foreach ($distributors as $distributor)
{
$available_beers = array_merge($distributor->beers(), $available_beers);
}
I don't know if that is the best way to do this and I can't get it to work. Similar to the first list of methods, I don't know if I need ->$beers or ->$beers()
Update
Thanks to everyone who answered! This will be a good reference for me going forward. My biggest lesson was the difference between getting a collection back, vs getting the query builder/relationship object back. For future reference to those who find this question, here is what I set up in my controller:
$store = $this->store->find($id)->first();
$distributors = $store->distributors;
$beers = [];
foreach ($distributors as $distributor){
$beers = array_merge($distributor->beers->lists('name', 'id'), $beers);
}
Short answer
$model->relation() returns the relationship object
$model->relation returns the result of the relationship
Long answer
$model->relation() can be explained pretty simple. You're calling the actual function you defined your relation with. Yours for distributor probably looks somewhat like this:
public function distributors(){
return $this->hasMany('Distributor');
}
So when calling $store->distributors() you just get the return value of $this->hasMany('Distributor') which is an instance of Illuminate\Database\Eloquent\Relations\HasMany
When do you use it?
You usually would call the relationship function if you want to further specify the query before you run it. For example add a where statement:
$distributors = $store->distributors()->where('priority', '>', 4)->get();
Of course you can also just do this: $store->distributors()->get() but that has the same result as $store->distributors.
Which brings me to the explanation of the dynamic relationship property.
Laravel does some things under the hood to allow you to directly access the results of a relationship as property. Like: $model->relation.
Here's what happens in Illuminate\Database\Eloquent\Model
1) The properties don't actually exist. So if you access $store->distributors the call will be proxied to __get()
2) This method then calls getAttribute with the property name getAttribute('distributors')
public function __get($key)
{
return $this->getAttribute($key);
}
3) In getAttribute it checks if the relationship is already loaded (exists in relations). If not and if a relationship method exists it will load the relation (getRelationshipFromMethod)
public function getAttribute($key)
{
// code omitted for brevity
if (array_key_exists($key, $this->relations))
{
return $this->relations[$key];
}
$camelKey = camel_case($key);
if (method_exists($this, $camelKey))
{
return $this->getRelationshipFromMethod($key, $camelKey);
}
}
4) In the end Laravel calls getResults() on the relation which then results in a get() on the query builder instance. (And that gives the same result as $model->relation()->get().
The direct answer to your question:
$store->distributors() will return the actual relationship object (\Illuminate\Database\Eloquent\Relations\BelongsToMany).
$store->distributors will be a collection containing the results of the relationship query (\Illuminate\Database\Eloquent\Collection).
$store->distributors()->get() will be a collection containing the results of the relationship query (\Illuminate\Database\Eloquent\Collection).
$store->distributors->get() should return an error since you're calling get() on a Collection object and the first parameter is not optional. If not an error, it should at least return null.
More information:
Given the following model:
class Store extends Eloquent {
public function distributors() {
return $this->belongsToMany('Distributor');
}
}
Calling the relationship method ($store->distributors()) will return to you the relationship (\Illuminate\Database\Eloquent\Relations\BelongsToMany) object. This is basically a query object which you can continue to modify, but you still need to call some type of method to get the results (e.g. get(), first(), etc).
However, accessing the relationship attribute ($store->distributors) will return to you a collection (\Illuminate\Database\Eloquent\Collection) object containing the results from executing the relationship query.
By default, the relationship attribute is created and assigned a value the first time it is accessed (known as "lazy loading"). So, the first time you access $store->distributors, behind the scenes it is executing the relationship query, storing the results in the $store->distributors attribute, and then returning those results. However, it only does this once. The next time you access $store->distributors, the attribute already contains the data, so that is what you are accessing.
To illustrate this:
// the following two statements will run the query twice
$r1 = $store->distributors()->get();
$r2 = $store->distributors()->get();
// the following two statements will run the query once.
// the first statement runs the query, populates $store->distributors, and assigns the variable
// the second statement just accesses the data now stored in $store->distributors
$r3 = $store->distributors;
$r4 = $store->distributors;
// at the end, $r1 == $r2 == $r3 == $r4
Relationships can also be "eager" loaded, using the with() method on the query. This is done to alleviate all of the extra queries that may be needed for lazy loading (known as the n+1 problem). You can read more about that here.
When you work with relationships with Eloquent the property is a collection (Illuminate\Database\Eloquent\Collection) of your relation white the method is a start of a new query.
Say your model looks like this:
class User extends Eloquent {
public function roles()
{
return $this->belongsToMany('Role');
}
}
If you try to access $user->roles, Eloquent will run the query and fetch all roles related to that user thanks to magic methods and returns an instance of Illuminate\Database\Eloquent\Collection. That class has a method called get, that's why $user->roles->get() works for you.
If you try to access the method, $user->roles(), you will instead get a query builder object so you can fine tune your query.
$user->roles()->whereIn('role_id', [1, 3, 4])->get();
That would only return roles where role_id is 1, 3 or 4.
So, the property returns a complete query and it results (Illuminate\Database\Eloquent\Collection) while the method lets you customize your query.
$distributors = $store->distributors();
Result of a method (function)
$distributors = $store->distributors;
Value of property (variable)
$distributors = $store->distributors()->get();
Take the first one, where it's the result of a method, if the method returns an object, this is a method in that object that was returned.
$distributors = $store->distributors->get();
If the property is an object, then it's calling a method in that property that's an object.
Re ->$beers vs ->$beers() that's a dynamic name of a property/method depending on what you're for. Just make a really rough guess at what you're doing, in your class you're going to have
$this->beers = array('bud','miller','sam');
and in your code using the $store object, you're actually going to go something like
$drink_type = 'beers';
$drink_list = $store->$drink_type;
And that will return $this->beers from $store, the same as writing $store->beers;
Imagine that the store class looks like this:
<?php
class Store {
public $distributors;
function __construct($distributors = array()) {
$this->distributors = $distributors;
}
public function distributors() {
return $this->distributors;
}
}
So the difference is:
$store = new Store(array('some guy', 'some other guy'));
$guys = $store->distributors; # accesing the $distributors property
$more = $store->distributors(); # calling the distributors() method.
The main difference is:
$distributors = $store->distributors() return instance of the relationship object like Illuminate\Database\Eloquent\Relations\BelongsToMany. You can use other conditions such as where after call this.
$store->distributors return instance of the collection Illuminate/Database/Eloquent/Collection. Laravel call the magic method __get under the hood. It will return a result of query relationship.
Maybe this will be usefull.
Access to method:
$object->method();
Access to property:
$object->property;

Call to a member function getNbr() on array

i want to select all users in the database that have the role ROLE_USER only but i get this problm when i call the function they say "Call to a member function getNbr() on null" i think bcoz i use Findby() , bcoz i use the same function in another call and it works great look at the code :
public function indexAction(Request $request)
{
$us = $this->getDoctrine()->getManager();
$locationus = $us->getRepository('AppBundle:Usr')->findBy(
[ 'roles' => ["ROLE_USER"] ]);
echo $nb_us = $locationus->getNbr();
if($authChecker->isGranted(['ROLE_ADMIN']))
{
return $this->render('settingAdmin/profiladmin.html.twig' , array(
'nb_us' => $nb_us,
));
}
and this is the other function in the UserRepository:
class UserRepository extends \Doctrine\ORM\EntityRepository
{
public function getNbr() {
return $this->createQueryBuilder('l')
->select('COUNT(l)')
->getQuery()
->getSingleScalarResult();
}
}
getNbr is method of UserRepository class, so it can be called only for this UserRepository class instance. This method returns total users count.
findBy returns array of entities (in you case all users with role ROLE_USER), not UserRepository class instance, so you can't use getNbr in context of this variable
If you want to get the length of array of entities (in you case all users with role ROLE_USER), just use count function:
echo $nb_us = count($locationus);
if($authChecker->isGranted(['ROLE_ADMIN']))
{
return $this->render('settingAdmin/profiladmin.html.twig' , array(
'nb_us' => $nb_us, 'locationus' => $locationus
));
}
There looks to be quite many things going on in the code there:
1) $us->getRepository('AppBundle:Usr') is probably typoed and should be $us->getRepository('AppBundle:User') instead (?) In general it would be safer to use $us->getRepository(AppBundle\User::class) so that syntax errors can be caught easier/earlier.
2) You are trying to invoke repository method on array with $locationus->getNbr() which is incorrect on multiple accounts (you cannot invoke functions on arrays - and repository methods cannot be invoked from entities either).
3) why is the code using echo?
4) as an additional note (assuming that this is roughly the full intended code), it would make sense to move all the getters & handling inside the if section so that the code will perform better (it doesn't do unnecessary database queries etc when the user doesn't have enough rights to access the view/information).
If I understood the intention correctly, in this case, the second repository function getNbr is superfluous here. If that is intending to just calculate the number of instances returned by the first find:
$locationus = $us->getRepository('AppBundle:User')->findBy(['roles' => ["ROLE_USER"] ]);
$nb_us = count($locationus);
Or alternatively (if you want to use and fix the getNbr repository function) then you don't need the first repository getter. This will require some rewriting of the repository function as well though:
$nb_us = $us->getRepository('AppBundle:User')->getNbr("ROLE_USER");

Laravel dynamic queries on array of Eloquent models

I am currently trying to make a function that calls different scopeQueries such as scopeByLocation() or scopeByPublished() on models defined in an array. I've got the basics working through [this link][1]. However, when trying to access custom made query scopes that are defined in the corresponding model, I get the following error: "Call to undefined method Illuminate\Database\Query\Builder::ForLocation($location)->get()".
What I want to achieve is a single method which loops through every model in the array of models and retrieves & calls the right scopeQuery on the model, something like this:
$modelElements = $model::{$queryScope}();
Where for example $model = 'Modules\News\Models\Article'
And $queryScope is a defined queryScope in the model itself. E.g. scopeForLocation($location).
I've tested $queryScope = 'all' and I get a result just fine, however when I try to access a custom queryScope ($queryScope = 'ForLocation($location)->get') that exists within for example the Location model, I get the following error: "Call to undefined method Illuminate\Database\Query\Builder::ForLocation($location)->get()".
So this all happens in a foreach-loop where every model in my models-array gets called and then the corresponding queryScope gets called on the model.
Why does the $queryScope = 'all' method works on my dynamic models, but other scopes throw an error? I really hope someone could help me get into the right direction with this issue.
Thanks in advance,
J. Doe.
Okay, I've finally solved it the following way:
//array of models
public function models()
{
return [
'Modules\Website\Models\Article',
...
];
}
//function that retrieves all elements for a model
public function getAllElementsForModel($model, $param)
{
//instantiate model
$model = new $model;
//call queryScope
//'queryScope' could be any queryScope that is defined within your model(s),
//the parameters are needed for the associated queryScope
$query = call_user_func_array([$model, 'queryScope'], [$param1, $param2]);
$result = $query->get();
//do stuff with your $result
}
//retrieves all
public function all($param)
{
//loop through the array of models
foreach($this->models() as $model){
$this->getAllElementsForModel($model, $param);
//do stuff here...
}
}
Sharing is caring!

Difference between method calls $model->relation(); and $model->relation;

There is some basic understanding/theory here that I am missing.I don't understand the difference between these function calls:
$distributors = $store->distributors();
$distributors = $store->distributors;
$distributors = $store->distributors()->get();
$distributors = $store->distributors->get();
What I am trying to accomplis here is to get a list of the distributors for a store (a many to many relationship), and they get each distributors list of beers into one giant list.
foreach ($distributors as $distributor)
{
$available_beers = array_merge($distributor->beers(), $available_beers);
}
I don't know if that is the best way to do this and I can't get it to work. Similar to the first list of methods, I don't know if I need ->$beers or ->$beers()
Update
Thanks to everyone who answered! This will be a good reference for me going forward. My biggest lesson was the difference between getting a collection back, vs getting the query builder/relationship object back. For future reference to those who find this question, here is what I set up in my controller:
$store = $this->store->find($id)->first();
$distributors = $store->distributors;
$beers = [];
foreach ($distributors as $distributor){
$beers = array_merge($distributor->beers->lists('name', 'id'), $beers);
}
Short answer
$model->relation() returns the relationship object
$model->relation returns the result of the relationship
Long answer
$model->relation() can be explained pretty simple. You're calling the actual function you defined your relation with. Yours for distributor probably looks somewhat like this:
public function distributors(){
return $this->hasMany('Distributor');
}
So when calling $store->distributors() you just get the return value of $this->hasMany('Distributor') which is an instance of Illuminate\Database\Eloquent\Relations\HasMany
When do you use it?
You usually would call the relationship function if you want to further specify the query before you run it. For example add a where statement:
$distributors = $store->distributors()->where('priority', '>', 4)->get();
Of course you can also just do this: $store->distributors()->get() but that has the same result as $store->distributors.
Which brings me to the explanation of the dynamic relationship property.
Laravel does some things under the hood to allow you to directly access the results of a relationship as property. Like: $model->relation.
Here's what happens in Illuminate\Database\Eloquent\Model
1) The properties don't actually exist. So if you access $store->distributors the call will be proxied to __get()
2) This method then calls getAttribute with the property name getAttribute('distributors')
public function __get($key)
{
return $this->getAttribute($key);
}
3) In getAttribute it checks if the relationship is already loaded (exists in relations). If not and if a relationship method exists it will load the relation (getRelationshipFromMethod)
public function getAttribute($key)
{
// code omitted for brevity
if (array_key_exists($key, $this->relations))
{
return $this->relations[$key];
}
$camelKey = camel_case($key);
if (method_exists($this, $camelKey))
{
return $this->getRelationshipFromMethod($key, $camelKey);
}
}
4) In the end Laravel calls getResults() on the relation which then results in a get() on the query builder instance. (And that gives the same result as $model->relation()->get().
The direct answer to your question:
$store->distributors() will return the actual relationship object (\Illuminate\Database\Eloquent\Relations\BelongsToMany).
$store->distributors will be a collection containing the results of the relationship query (\Illuminate\Database\Eloquent\Collection).
$store->distributors()->get() will be a collection containing the results of the relationship query (\Illuminate\Database\Eloquent\Collection).
$store->distributors->get() should return an error since you're calling get() on a Collection object and the first parameter is not optional. If not an error, it should at least return null.
More information:
Given the following model:
class Store extends Eloquent {
public function distributors() {
return $this->belongsToMany('Distributor');
}
}
Calling the relationship method ($store->distributors()) will return to you the relationship (\Illuminate\Database\Eloquent\Relations\BelongsToMany) object. This is basically a query object which you can continue to modify, but you still need to call some type of method to get the results (e.g. get(), first(), etc).
However, accessing the relationship attribute ($store->distributors) will return to you a collection (\Illuminate\Database\Eloquent\Collection) object containing the results from executing the relationship query.
By default, the relationship attribute is created and assigned a value the first time it is accessed (known as "lazy loading"). So, the first time you access $store->distributors, behind the scenes it is executing the relationship query, storing the results in the $store->distributors attribute, and then returning those results. However, it only does this once. The next time you access $store->distributors, the attribute already contains the data, so that is what you are accessing.
To illustrate this:
// the following two statements will run the query twice
$r1 = $store->distributors()->get();
$r2 = $store->distributors()->get();
// the following two statements will run the query once.
// the first statement runs the query, populates $store->distributors, and assigns the variable
// the second statement just accesses the data now stored in $store->distributors
$r3 = $store->distributors;
$r4 = $store->distributors;
// at the end, $r1 == $r2 == $r3 == $r4
Relationships can also be "eager" loaded, using the with() method on the query. This is done to alleviate all of the extra queries that may be needed for lazy loading (known as the n+1 problem). You can read more about that here.
When you work with relationships with Eloquent the property is a collection (Illuminate\Database\Eloquent\Collection) of your relation white the method is a start of a new query.
Say your model looks like this:
class User extends Eloquent {
public function roles()
{
return $this->belongsToMany('Role');
}
}
If you try to access $user->roles, Eloquent will run the query and fetch all roles related to that user thanks to magic methods and returns an instance of Illuminate\Database\Eloquent\Collection. That class has a method called get, that's why $user->roles->get() works for you.
If you try to access the method, $user->roles(), you will instead get a query builder object so you can fine tune your query.
$user->roles()->whereIn('role_id', [1, 3, 4])->get();
That would only return roles where role_id is 1, 3 or 4.
So, the property returns a complete query and it results (Illuminate\Database\Eloquent\Collection) while the method lets you customize your query.
$distributors = $store->distributors();
Result of a method (function)
$distributors = $store->distributors;
Value of property (variable)
$distributors = $store->distributors()->get();
Take the first one, where it's the result of a method, if the method returns an object, this is a method in that object that was returned.
$distributors = $store->distributors->get();
If the property is an object, then it's calling a method in that property that's an object.
Re ->$beers vs ->$beers() that's a dynamic name of a property/method depending on what you're for. Just make a really rough guess at what you're doing, in your class you're going to have
$this->beers = array('bud','miller','sam');
and in your code using the $store object, you're actually going to go something like
$drink_type = 'beers';
$drink_list = $store->$drink_type;
And that will return $this->beers from $store, the same as writing $store->beers;
Imagine that the store class looks like this:
<?php
class Store {
public $distributors;
function __construct($distributors = array()) {
$this->distributors = $distributors;
}
public function distributors() {
return $this->distributors;
}
}
So the difference is:
$store = new Store(array('some guy', 'some other guy'));
$guys = $store->distributors; # accesing the $distributors property
$more = $store->distributors(); # calling the distributors() method.
The main difference is:
$distributors = $store->distributors() return instance of the relationship object like Illuminate\Database\Eloquent\Relations\BelongsToMany. You can use other conditions such as where after call this.
$store->distributors return instance of the collection Illuminate/Database/Eloquent/Collection. Laravel call the magic method __get under the hood. It will return a result of query relationship.
Maybe this will be usefull.
Access to method:
$object->method();
Access to property:
$object->property;

Showing custom SQL results

What do I want to do
I want to list data that is pulled from the database with a certain condition.
What do I have and what does it do
I have a function that calls the data. When I print_r the data, it throws the correct stuff, so the query is executing directly. However, the display isn't working. It shows all the data in the database.
Here is my function:
public function myfunction() {
$adminExtensions = $this->AdminExtension->find('all',
array(
'conditions' => array('location_id'=>'3')
)
);
//print_r($adminExtensions);
$this->set('adminExtensions', $this->paginate());
}
What is the problem
The problem, as stated, is that it doesn't list just the records with location_id == 3. It lists everything.
I have narrowed it down to the last line of the function, but I can't seem to get the right code in there.
My display file (myfunction.ctp) is a basic baked cakePHP index file.
What am I doing wrong?
The code you currently have calls two different find operations. $this->AdminExtension->find() will return an array with all the AdminExtensions with a location_id of 3. The second $this->paginate() call just returns all possible results suitable for pagination in the view.
If you want to filter the paginated results you have to either configure the $paginate variable in the Controller or do it directly before you call $this->paginate.
class PostsController extends AppController {
public $paginate = array(
'conditions' => array('location_id'=>'3')
);
}
This will adjust pagination for all $this->paginate calls in the controller.
To do it for only one paginate call:
public function your_view() {
$this->set('adminExtensions', $this->paginate('AdminExtension', array('location_id' => '3')));
);

Categories