Databases and Symfony

Overview

Notes on how to access data in a Symfony project.

Entity classes

Configuring entity classes

Classes that represent table data go in the Entity directory inside of AppBundle.

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

// 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... */ 
}

The getter and setter routines can be generated with

$ php app/console doctrine:generate:entities AppBundle/Entity/Product

Mapping information

Mapping metadata can be specified with YAML, XML, or directly in the entity class via annotations:,

// 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... */
}

Generating database tables and/or schema

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

$ php app/console doctrine:schema:update --force

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 migrations which generate SQL statements that are stored in migration classes.

Committing object data to a database

The logic to commit object data to a database is place in a controller:

// src/AppBundle/Controller/DefaultController.php

// ...
use AppBundle\Entity\Product;
use Symfony\Component\HttpFoundation\Response;

// ...
public function createAction()
{
    $product = new Product();
    $product->setName('A Foo Bar');
    $product->setPrice(19.95);
    $product->setDescription('Lorem ipsum dolor');

    $em = $this->getDoctrine()->getManager();

    $em->persist($product);
    $em->flush();

    return new Response('Created product id '.$product->getId());
}