90 lines
2.5 KiB
ReStructuredText
90 lines
2.5 KiB
ReStructuredText
Override Field Association Mappings In Subclasses
|
|
-------------------------------------------------
|
|
|
|
Sometimes there is a need to persist entities but override all or part of the
|
|
mapping metadata. Sometimes also the mapping to override comes from entities
|
|
using traits where the traits have mapping metadata.
|
|
This tutorial explains how to override mapping metadata,
|
|
i.e. attributes and associations metadata in particular. The example here shows
|
|
the overriding of a class that uses a trait but is similar when extending a base
|
|
class as shown at the end of this tutorial.
|
|
|
|
Suppose we have a class ExampleEntityWithOverride. This class uses trait ExampleTrait:
|
|
|
|
.. code-block:: php
|
|
|
|
<?php
|
|
/**
|
|
* @Entity
|
|
*
|
|
* @AttributeOverrides({
|
|
* @AttributeOverride(name="foo",
|
|
* column=@Column(
|
|
* name = "foo_overridden",
|
|
* type = "integer",
|
|
* length = 140,
|
|
* nullable = false,
|
|
* unique = false
|
|
* )
|
|
* )
|
|
* })
|
|
*
|
|
* @AssociationOverrides({
|
|
* @AssociationOverride(name="bar",
|
|
* joinColumns=@JoinColumn(
|
|
* name="example_entity_overridden_bar_id", referencedColumnName="id"
|
|
* )
|
|
* )
|
|
* })
|
|
*/
|
|
class ExampleEntityWithOverride
|
|
{
|
|
use ExampleTrait;
|
|
}
|
|
|
|
/**
|
|
* @Entity
|
|
*/
|
|
class Bar
|
|
{
|
|
/** @Id @Column(type="string") */
|
|
private $id;
|
|
}
|
|
|
|
The docblock is showing metadata override of the attribute and association type. It
|
|
basically changes the names of the columns mapped for a property ``foo`` and for
|
|
the association ``bar`` which relates to Bar class shown above. Here is the trait
|
|
which has mapping metadata that is overridden by the annotation above:
|
|
|
|
.. code-block:: php
|
|
|
|
/**
|
|
* Trait class
|
|
*/
|
|
trait ExampleTrait
|
|
{
|
|
/** @Id @Column(type="string") */
|
|
private $id;
|
|
|
|
/**
|
|
* @Column(name="trait_foo", type="integer", length=100, nullable=true, unique=true)
|
|
*/
|
|
protected $foo;
|
|
|
|
/**
|
|
* @OneToOne(targetEntity="Bar", cascade={"persist", "merge"})
|
|
* @JoinColumn(name="example_trait_bar_id", referencedColumnName="id")
|
|
*/
|
|
protected $bar;
|
|
}
|
|
|
|
The case for just extending a class would be just the same but:
|
|
|
|
.. code-block:: php
|
|
|
|
class ExampleEntityWithOverride extends BaseEntityWithSomeMapping
|
|
{
|
|
// ...
|
|
}
|
|
|
|
Overriding is also supported via XML and YAML. |