How to get Doctrine2 entity identifier without knowing its name - entity

I am attempting to create an abstracted getId method on my base Entity class in Symfony2 using Doctrine2 for a database where primary keys are named inconsistently across tables.
When inspecting entity objects I see there is a private '_identifier' property that contains the information I am trying to retrieve but I am not sure how to properly access it.
I'm assuming there is some simple Doctrine magic similar to:
public function getId()
{
return $this->getIdentifier();
}
But I haven't managed to find it on the intertubes anywhere.

You can access this information via EntityManager#getClassMetadata(). An example would look like this:
// $em instanceof EntityManager
$meta = $em->getClassMetadata(get_class($entity));
$identifier = $meta->getSingleIdentifierFieldName();
If your entity has a composite primary key, you'll need to use $meta->getIdentifierFieldNames() instead. Of course, using this method, you'll need access to an instance of EntityManager, so this code is usually placed in a custom repository rather than in the entity itself.
Hope that helps.

Related

Sulu: Entity has no field or association error

I'm following Sulu example here: https://github.com/sulu/sulu-workshop/
trying to set translations for custom entity type.
My entity file has getter for field "home_team" defined like:
/**
* #Serializer\VirtualProperty(name="home_team")
*/
public function getHomeTeam(): ?string
{
$translation = $this->getTranslation($this->locale);
if (!$translation) {
return null;
}
return $translation->getHomeTeam();
}
So field is not actually part of that entity, but of it's translation entity since it suppose to be translatable.
When I try to create new object of that entity type it works well. I can see in database that field values are stored well and I don't get any error.
But on overview page instead of list of all objects I get error:
[Semantical Error] line 0, col 73 near 'home_team AS': Error: Class App\Entity\MatchEvent has no field or association named home_team
Any idea what could be wrong here?
If you wanna see the translation in the listView you have to create a real translationEntity, like in the workshop project. In this post it is already explained, how to translate a custom entity correctly.
If you have already created your translationEntity you have to configure the relation of the translation to your main entity via a join. Here is an example in the workshop for this configuration.
Sulu uses optimised queries to create the list-object directly from the database. So the entity itself does not get hydrated or serialised for performance reasons. Thus your virtualProperty is never executed.

executing a sql code for creating a table and database in zend framework

I wrote a sql script and in it I created a table ;
Now I need to know ,how I can execute this script? (with which codes?)
And I have another question : where? where I must write this codes?(which folder in zend project?)
if it is possible for you please explain with an example.thanks
Creating tables in the database
Zend Framework is not supposed to be the one creating the tables, thus, my suggestion is to run those scripts in other environment.
The fastest one is, probably, the very own SQL shell, but you can use another software such as MySQLWorkbench if you are using MySQL.
Once the tables are created, the access to the tables is made this way:
Introduction
When you are using Zend Framework, you are making use of the MVC pattern. I suggest you to read what is that: Wikipedia MVC
If you read the Wikipedia link, you probably know now that the acess to the database is going to be made by the model.
Thus, if you followed the recommended project structure that Zend provides you will have a models folder under your application folder. There, you are supposed to implement the classes that will make access to the DB.
But well... you now know where to locate those classes but you will ask me: how? It's easy if you know where to search. ZF provides an abstract class called Zend_Db_Table_Abstract that has all the methods that will make your life easier talking about interaction with your database's tables. This is the class that your classes should implement.
Example
Let's suppose you've got a page in your website in which you want to show to the user a list of products of your local store. You have a table in your database called "products" in which you have all the useful information such us name, price and availability.
You will have a controller with an action called indexAction() or listAction() this action is prepared to send the data to your view and will look like:
class Store_ProductsController extends Zend_Controller_Action {
public function indexAction(){
//TODO: Get data from the DataBase into $products variable
$this->view->products = $products;
}
}
And your view file will that that products variable and do sutff with it.
But now comes the magic, you will have a class that will access to the database as I've said, it'll be like:
class Model_Store_Products extends Zend_Db_Table_Abstract{
protected $_name = 'products';
public function getAllProducts(){
$select = $this->$select()
->from(array('P'=>$this->_name),
array('id', 'name', 'price', availability));
$productsArray = $this->fetchAll($select);
return $productsArray;
}
}
And ta-da, you have your array of products ready to be used by the controller:
class Store_ProductsController extends Zend_Controller_Action {
public function indexAction(){
$model = new Model_Store_Products();
$products = $model->getAllProducts();
$this->view->products = $products;
}
}
It can be said that, since fetchAll is public function, and our select does basically nothing but set which columns do we want (it doesn't even have a where clause), in this case, it would be easier to call the fetchAll directly from the controller with no where and it will recover the whole table (all columns):
class Store_ProductsController extends Zend_Controller_Action {
public function indexAction(){
$model = new Model_Store_Products();
$products = $model->fetchAll();
$this->view->products = $products;
}
}
Thus, our function in the model is not even needed.
This is the basic information of how to access to the database using Zend Framework. Further information of how to create the Zend_Db_Table_Select object can be found here.
I hope this helps.

Entity Framework 4.1 Dynamically retrieve mapped column name

I am trying to construct an SQL statement dynamically.
My context is created dynamically, using reflection finding classes deriving from EntityTypeConfiguration and adding them to DbModelBuilder.Configuration.
My EntityTypeConfiguration classes specify HasColumnName to map the Entity property name to db table column name, which I need to construct my SQL statement.
namespace MyDomain {
public class TestEntityConfig : EntityTypeConfiguration<TestEntity>{
Property("Name").HasColumnName("dbName");
}
}
From What I have researched, it seems I can get access to this information through MetadataWorkspace, which I can get to through ObjectContext.
I have managed to retrieve the the entity I am interested in with MetadataWorkspace.GetItem("MyDomain.TestEntity",DataSpace.OSpace), which gives me access to Properties, but none of the properties, of Properties, give me the name of the mapped db column, as specified with HasColumnName.
Also I am not clear what DataSpace.OSpace is and why my model is constructed in this space.
If Anyone can shed some light on this I would be grateful
UPDATE
Further to #Ladislav's comments. I discovered I can get the information as follows
For the class properties
ctx.MetadataWorkspace.GetItem<ClrEntityType>("MyDomain.TestEntity", DataSpace.OSpace)).Members
For the table properties
ctx.MetadataWorkspace.GetItem<EntityType>("CodeFirstDatabaseSchema.TestEntity",SSpace).Members
So given that I only know the type MyDomain.TestEntity and Memeber "Name". How would I go about to get "dbName". Can I always assume that my mapped class will be created in CodeFirstDatabaseSchema, om order to dynamically construct the identity to retrieve it from SSpace and how would I get to the correct Member in SSpace. Can I do something like
var memIndex = ctx.MetadataWorkspace.GetItem<ClrEntityType>("MyDomain.TestEntity", DataSpace.OSpace)).Members["Name"].Index;
var dbName = ctx.MetadataWorkspace.GetItem<EntityType>("CodeFirstDatabaseSchema.TestEntity",SSpace).Members[memIndex];
MetadataWorkspace contanis several containers specified by DataSpace. Interesting for you are:
CSpace - description of conceptual model (this should contain properties)
CSSpace - mapping of conceptual model to storage model (this should contain how classes / properties are mapped to tables / columns)

NHibernate: How to get mapped values?

Suppose I have a class Customer that is mapped to the database and everything is a-ok.
Now suppose that I want to retrieve - in my application - the column name that NH knows Customer.FirstName maps to.
How would I do this?
You can access the database field name through NHibernate.Cfg.Configuration:
// cfg is NHibernate.Cfg.Configuration
// You will have to provide the complete namespace for Customer
var persistentClass = cfg.GetClassMapping(typeof(Customer));
var property = persistentClass.GetProperty("FirstName");
var columnIterator = property.ColumnIterator;
The ColumnIterator property returns IEnumerable<NHibernate.Mapping.ISelectable>. In almost all cases properties are mapped to a single column so the column name can be found using property.ColumnInterator.ElementAt(0).Text.
I'm not aware that that's doable.
I believe your best bet would be to use .xml files to do the mapping, package them together with the application and read the contents at runtime. I am not aware of an API which allows you to query hibernate annotations (pardon the Java lingo) at runtime, and that's what you would need.
Update:
Judging by Jamie's solution, NHibernate and Hibernate have different APIs, because the Hibernate org.hibernate.Hibernate class provides no way to access a "configuration" property.

NHibernate DTO Parent child relation

I have som entities and now want to make some DTO´s based on there entities using nhibernate.
I have a Service - Allocation -Ressource where allocation describes how the ressource is allocated for the service.
I want a DTO like
ServiceDTO
-Name
-RessourceDTO
where RessourceDTO also has a name.
In the examples I have see for NHibernate projection/DTO you either use properties or constructor. If I use The Constructor approach I would have something like
ServiceDTO(Name, List
But I can't figure out how to make this work.
Another approach is to extract all the services and then loop through them and hit the database each time, or extract a larger result and then make the DTO's
What is the best approach? I going to hide all of this inside a repository.
How about
public ServiceDTO GetDTOFor(int Id);
{
var service = Session.CreateCriteria<Service>()
.Add(Restrictions.Eq("Id", id)
.SetFetchMode("Resources", fetchmode.eager) // eager load resources
.uniqueResult<Service>();
return new ServiceDTO(service.Name, service.Resources.ToList()) // Copy the Resources
}