Editing Databases and Symfony (section)

== Entity classes ==

Entity classes define the basic mapping to a table in the database.

=== Configuring entity classes ===

Classes that represent table data go in the `Entity` directory inside of `AppBundle`.<ref>[http://symfony.com/doc/current/book/doctrine.html Doctrine Documentation], Symfony Documentation, "The Book"</ref>

Columns are represented by properties of the class. Typically these are `protected` and accessed with `public` "getter" and "setter" functions. 

<syntaxhighlight lang="php" highlight="6-8,10,15">
// src/AppBundle/Entity/Product.php
namespace AppBundle\Entity;

class Product
{
	protected $id;
	protected $name;
	protected $description;

	public function getId()
	{
		return ($this->id);
	}

	public function setID($id)
	{
		$this->id = $id;
	}

	/* etc... */ 
}
</syntaxhighlight>

The getter and setter routines can be generated with

<syntaxhighlight lang="bash">
$ php app/console doctrine:generate:entities AppBundle
</syntaxhighlight>

or 

<syntaxhighlight lang="bash">
$ php app/console doctrine:generate:entities AppBundle/Entity/Product
</syntaxhighlight>

To create an entity class solely from the command line:

<syntaxhighlight lang="bash">
$ php app/console doctrine:generate:entity \
    --entity="AppBundle:Category" \
    --fields="name:string(255)"
</syntaxhighlight>

=== Mapping information ===

Mapping metadata can be specified with YAML, XML, or directly in the entity class via annotations:<ref>[http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/basic-mapping.html#property-mapping Doctrine Property Mapping]</ref>,<ref>[http://symfony.com/doc/current/book/doctrine.html#book-doctrine-field-types Doctrine Field Types Reference]</ref><ref>[http://doctrine-orm.readthedocs.org/en/latest/reference/annotations-reference.html#annref-column Annotations Reference], Doctrine documentation</ref>

<syntaxhighlight lang="php" highlight="4,7-8,13-15,20">
// src/AppBundle/Entity/Product.php
namespace AppBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 * @ORM\Table(name="product")
 */
class Product
{
	/**
	 * @ORM\Column(type="integer")
	 * @ORM\Id
	 * @ORM\GeneratedValue(strategy="AUTO")
	 */
	protected $id;

	/**
	 * @ORM\Column(type="string")
	 */
	protected $name;

	/* etc... */
}
</syntaxhighlight>

=== Generating database tables and/or schema ===

Doctrine can create and update tables in the database using the entity classes as templates with:

<syntaxhighlight lang="bash">
$ php app/console doctrine:schema:update --force
</syntaxhighlight>

Changes to the properties and mapping of the entity class will cause updates that will attempt to preserve the existing data. 

The preferred way to generate changes that can be applied to a production environment is with [http://symfony.com/doc/current/bundles/DoctrineMigrationsBundle/index.html migrations] which generate SQL statements that are stored in migration classes.