Symfony2 - Entity and Relationship Annotation - sql

This is classic method for the entity relationship;
/**
* #ORM\OneToMany(targetEntity="Product", mappedBy="category")
*/
protected $products;
and other entity;
/**
* #ORM\ManyToOne(targetEntity="Category", inversedBy="products")
* #ORM\JoinColumn(name="category_id", referencedColumnName="id")
*/
protected $category;
But, when I use this method, I can't use limit function. All results are taken. But, I should use sql limit function. So, I use a repository class. I wrote all sql code again. I used join function again. Is the relationsip annotation necessary in this situation? Do I still need to add this annotation?

Unfortunately, there is no way of doing what are you asking. You are gonna have to write a custom DQL, preferably inside a custom repository in order to fetch exactly what you want. Of course you still need the annotation itself, as is required by Doctrine to do many things under the hood and, in general, to keep a good relationship model between your entities.
The most close annotation you have to control the way in which relationships are joined when using automatic method is the OrderBy one:
/*
* #OneToMany(...)
* #OrderBy({"name" = "ASC"})
*/
protected $relation;

Related

Using Doctrine and Symfony to create Polymorphic like associations

I'm attempting to have an Fileable trait that will give provide an Entity with methods to CRUD Files based on the File Entity mentioned below.
After reading the documentation on Doctrine and searching the internet, the best I could find is Inheritance Mapping but these all require the subclass to extend the superclass which is not ideal as the current Entities already extend other classes. I could have FileFoo entity and a FileBar entity but this gets too messy and requires an extra join (super -> sub -> entity).
Alternatively, I could have a File Entity which has many columns for Entities (so foo_id for the Foo object, bar_id for the bar object and so on) but this gets messy and would require a new column for every entity that I'd want to add the Fileable trait too.
So to the questions:
Am I thinking about how I want to hold data incorrectly?
Is there some features/functions in Doctrine/Symfony that I've missed?
Do you think I feature like this would be added if I were to fork Doctrine to add this feature, also where should I look?
<?php
/**
* File
*
* #ORM\Table()
* #ORM\Entity()
* #ORM\HasLifecycleCallbacks()
*/
class File
{
/**
* #var integer
*
* #ORM\Column(type="integer")
* #ORM\Id()
* #ORM\GeneratedValue()
*/
protected $id;
/**
* #var string
*
* #ORM\Column(type="string")
*/
protected $entityName;
/**
* #var string
*
* #ORM\Column(type="string")
*/
protected $entityId;
...
I accomplished a similar thing using Inheritance defined in traits, which alongside interfaces, basically gave me what a multiple extend would give.
Take a look at embeddables or you could use traits.

ArrayList or Aggregation with specified multiplicity

I am just starting with UML (StarUML 5) so please excuse this really basic question.
Let's say a Person has multiple Characteristics, each of which has a Name and a Value. (This is just to keep things simple.) Suppose I create the Characteristic class accordingly.
I want to generate Java class Person with a property something like ArrayList(Characteristic).
Should I add an attribute to the Person class like ArrayList(Characteristic), or should I just use an Aggregation relationship between Person and Characteristic and specify the multiplicity as 0..* ?
On the first (ArrayList) approach I don't even model the multiplicity. On the second (Aggregation) approach the Java code creates a property in Person of type Characteristic but not a "List-like" property, i.e. it ignores the multiplicity in the diagram.
Thank you.
I agree with Dave, this is a composition, a kind of UML association. Setting the composition as Ordered and not unique allows to generate the Java attribute as a List. It means you have a composition at the design level and a List at the implementation level. That's the code generator - or you if you don't use code generation - which correctly translates the UML diagram.
Here's what I would design in your case and the Java code I generated (feel free to fork):
public class Person
{
/**
* <!-- begin-user-doc -->
* <!-- end-user-doc -->
* #generated
* #ordered
*/
public List<Characteristic> characteristic;
/**
* <!-- begin-user-doc -->
* <!-- end-user-doc -->
* #generated
*/
public Person(){
super();
}
}
Notice you can import StarUML projects in GenMyModel if you'd like to quickly design generate online.
This sounds like a composition relationship to me. In my opinion you're better off with the second approach using Aggregation/Composition. Here is an interesting read on one take on Attribute vs Association. Regarding the failure of StarUML to implement the relationship correctly, you might be better off just implementing the List yourself.

Does CF ORM have an Active Record type Update()?

Currently I am working partly with cfwheels and its Active Record ORM (which is great), and partly raw cfml with its Hibernate ORM (which is also great).
Both work well for applicable situations, but the thing I do miss most when using CF ORM is the model.update() method that is available in cfwheels, where you can just pass a form struct to the method, and it will map up the struct elements with the model properties and update the records.. really good for updating and maintaining large tables. In CF ORM, it seems the only way to to update a record is to set each column individually, then do a save. Is this the case?
Does cf9 ORM have an Active Record type update() (or equivalent) method which can just receive a struct with values to update and update the object without having to specify each one?
For example, instead of current:
member = entityLoadByPK('member',arguments.id);
member.setName(arguments.name);
member.setEmail(arguments.email);
is there a way to do something like this in CF ORM?
member = entityLoadByPK('member',arguments.id);
member.update(arguments);
Many thanks in advance
In my apps I usually create two helper functions for models which handle the task:
/*
* Get properties as key-value structure
* #limit Limit output to listed properties
*/
public struct function getMemento(string limit = "") {
local.props = {};
for (local.key in variables) {
if (isSimpleValue(variables[local.key]) AND (arguments.limit EQ "" OR ListFind(arguments.limit, local.key))) {
local.props[local.key] = variables[local.key];
}
}
return local.props;
}
/*
* Populate the model with given properties collection
* #props Properties collection
*/
public void function setMemento(required struct props) {
for (local.key in arguments.props) {
variables[local.key] = arguments.props[local.key];
}
}
For better security of setMemento it is possible to check existence of local.key in variables scope, but this will skip nullable properties.
So you can make myObject.setMemento(dataAsStruct); and then save it.
There's not a method exactly like the one you want, but EntityNew() does take an optional struct as a second argument, which will set the object's properties, although depending on how your code currently works, it may be clunky to use this method and I don;t know whether it'll have any bearing on whether a create/update is executed when you flush the ORM session.
If your ORM entities inherit form a master CFC, then you could add a method there. Alternatively, you could write one as a function and mix it into your objects.
I'm sure you're aware, but that update() feature can be a source of security problems (known as the mass assignment problem) if used with unsanitized user input (such as the raw FORM scope).

Aren't entity definitions for ORM error prone?

I'm using Doctrine ORM in a project that I am working on. Although the idea of providing an object interface to the db is nice, I have a question about the implementation of the entity classes.
Let's consider this example of a User entity:
<?php
/**
* #Entity #Table(name="users")
**/
class User
{
/**
* #Id #GeneratedValue #Column(type="integer")
* #var int
**/
protected $id;
/**
* #Column(type="string")
* #var string
**/
protected $name;
/**
* #OneToMany(targetEntity="Bug", mappedBy="reporter")
* #var Bug[]
**/
protected $reportedBugs = null;
/**
* #OneToMany(targetEntity="Bug", mappedBy="engineer")
* #var Bug[]
**/
protected $assignedBugs = null;
// .. (other code)
}
Now, its all fine and dandy, but I was wondering what would happen if I make a spelling mistake in one of the comments e.g. I write:
#Table(name="users)
instead of
#Table(name="users")
the IDE will not complain since its a comment, and I'll only get an error when I run the "generate entities" command (that does the magic in the background of generating code, creating tables, columns and relationships).
So my question is: Aren't entity definitions for ORM error prone? since there really is no check on the syntax if its valid, and errors are generated only at 'generate' time. Is there a way to automate / check for mistakes earlier on while development?
Thanks!
IMO, The issue that you highlighted can be compared to using wrong variables in PHP ($var1 instead of $var2). For that matter, in all dynamic languages.
But you can avoid the problem highlighted by you, if you write unit tests.

How to manage deserialized entities with entity manager?

I am using JMSSerializerBundle to serialize my entities to json and deserialize json into entities, but I think this question applies for any deserialization techniques.
For example, this schema:
class Order
{
private $id;
/**
* #Serializer\Type("ArrayCollection<MyBundle\Entity\Order\Item>")
* #ORM\OneToMany(targetEntity="\MyBundle\Entity\Order\Item", mappedBy="order", cascade={"persist"})
*/
private $items;
}
class Item
{
private $id;
/**
* #ORM\ManyToOne(targetEntity="\MyBundle\Entity\Order", inversedBy="items")
*/
private $order;
/**
* #var integer $amount
* #Serializer\Type("integer")
* #ORM\Column(name="amount", type="integer")
*/
private $amount;
}
Maps to this json: {"id":1,"items":[{"id":1,"amount":100}, {"id":2,"amount":200}]} and the same json is properly deserialized into an object of type MyBundle:Order that has a colletion of two MyBundle:Order/Item objects.
The problem is that when I try to persist this object, new entries are created in the database, rather than updating existing, ignoring the ids. How do I tell entity manager that theses objects should be updated, rather that created?
Update. Generally EntityManager::merge solution (as suggested by DaveM) is fine. But you must only merge existing objects. For example, if you have a json that represents a new Order entity that is connected to existing Order\Item entities
{"id":null,"items":[{"id":1,"amount":100}, {"id":2,"amount":200}]}
In this case you cannot just merge an Order object like this:
$em->merge($order), because order is a new entity and entity manager will attempt to find an Order object with id = null and you will end up with a new Order and empty items array. So the solution is to loop the Order::$items array and merge each item individually. Then a new order will be created and connected with existing items.
You need to use the merge() method on the EntityManager as merging entities refers to the merging of entities into the context of an EntityManager so that they can become managed again. In order to merge the state of an entity into an EntityManager use the EntityManager#merge($entity) method. The state of the passed entity will be merged into a managed copy of this entity and this copy will subsequently be returned.
$detachedEntity = unserialize($serializedEntity);
$entity = $em->merge($detachedEntity);
Also be sure to note when you want to serialize/unserialize entities you have to make all entity properties protected, never private. The reason for this is, if you serialize a class that was a proxy instance before, the private variables won’t be serialized and a PHP Notice is thrown.
More information can be found in the doctrine documentation here:
http://doctrine-orm.readthedocs.org/en/2.0.x/reference/working-with-objects.html#merging-entities
I know this question is three years old, but it mislead me to think the only answer was using the merge operation. I'd like to add my two cents:
The JMSSerializerBundle includes an object constructor for Doctrine entities. When you enable this constructor, the deserialized entities are managed entities that can be persisted(with $em->persist($entity)).
Please check this comment to understand other benefits from this.
And here is how you can enable it.