introduction.rst

Introduction

Welcome

Doctrine 2 is an object-relational mapper (ORM) for PHP 5.3.0+ that provides transparent persistence for PHP objects. It sits on top of a powerful database abstraction layer (DBAL). Object-Relational Mappers primary task is the transparent translation between (PHP) objects and relational database rows.

One of Doctrines key features is the option to write database queries in a proprietary object oriented SQL dialect called Doctrine Query Language (DQL), inspired by Hibernates HQL. Besides DQLs slight differences to SQL it abstracts the mapping between database rows and objects considerably, allowing developers to write powerful queries in a simple and flexible fashion.

Disclaimer

This is the Doctrine 2 reference documentation. Introductory guides and tutorials that you can follow along from start to finish, like the "Guide to Doctrine" book known from the Doctrine 1.x series, will be available at a later date.

Using an Object-Relational Mapper

As the term ORM already hints at, Doctrine 2 aims to simplify the translation between database rows and the PHP object model. The primary use case for Doctrine are therefore applications that utilize the Object-Oriented Programming Paradigm. For applications that not primarily work with objects Doctrine 2 is not suited very well.

Requirements

Doctrine 2 requires a minimum of PHP 5.3.0. For greatly improved performance it is also recommended that you use APC with PHP.

Doctrine 2 Packages

Doctrine 2 is divided into three main packages.

• Common
• DBAL (includes Common)
• ORM (includes DBAL+Common)

This manual mainly covers the ORM package, sometimes touching parts of the underlying DBAL and Common packages. The Doctrine code base is split in to these packages for a few reasons and they are to...

• ...make things more maintainable and decoupled
• ...allow you to use the code in Doctrine Common without the ORM or DBAL
• ...allow you to use the DBAL without the ORM

The Common Package

The Common package contains highly reusable components that have no dependencies beyond the package itself (and PHP, of course). The root namespace of the Common package is Doctrine\Common.

The DBAL Package

The DBAL package contains an enhanced database abstraction layer on top of PDO but is not strongly bound to PDO. The purpose of this layer is to provide a single API that bridges most of the differences between the different RDBMS vendors. The root namespace of the DBAL package is Doctrine\DBAL.

The ORM Package

The ORM package contains the object-relational mapping toolkit that provides transparent relational persistence for plain PHP objects. The root namespace of the ORM package is Doctrine\ORM.

Installing

Doctrine can be installed many different ways. We will describe all the different ways and you can choose which one suits you best.

PEAR

You can easily install any of the three Doctrine packages from the PEAR command line installation utility.

To install just the Common package you can run the following command:

$ sudo pear install pear.doctrine-project.org/DoctrineCommon-<version>

If you want to use the Doctrine Database Abstraction Layer you can install it with the following command.

$ sudo pear install pear.doctrine-project.org/DoctrineDBAL-<version>

Or, if you want to get the works and go for the ORM you can install it with the following command.

$ sudo pear install pear.doctrine-project.org/DoctrineORM-<version>

Note

The <version> tag above represents the version you want to install. For example if the current version at the time of writing this is 2.0.7 for the ORM, so you could install it like the following:

$ sudo pear install pear.doctrine-project.org/DoctrineORM-2.0.7

When you have a package installed via PEAR you can require and load the ClassLoader with the following code.

<?php
require 'Doctrine/ORM/Tools/Setup.php';

Doctrine\ORM\Tools\Setup\registerAutoloadPEAR();

The packages are installed in to your shared PEAR PHP code folder in a folder named Doctrine. You also get a nice command line utility installed and made available on your system. Now when you run the doctrine command you will see what you can do with it.

$ doctrine
Doctrine Command Line Interface version 2.0.0BETA3-DEV

Usage:
  [options] command [arguments]

Options:
  --help           -h Display this help message.
  --quiet          -q Do not output any message.
  --verbose        -v Increase verbosity of messages.
  --version        -V Display this program version.
  --color          -c Force ANSI color output.
  --no-interaction -n Do not ask any interactive question.

Available commands:
  help                         Displays help for a command (?)
  list                         Lists commands
dbal
  :import                      Import SQL file(s) directly to Database.
  :run-sql                     Executes arbitrary SQL directly from the command line.
orm
  :convert-d1-schema           Converts Doctrine 1.X schema into a Doctrine 2.X schema.
  :convert-mapping             Convert mapping information between supported formats.
  :ensure-production-settings  Verify that Doctrine is properly configured for a production environment.
  :generate-entities           Generate entity classes and method stubs from your mapping information.
  :generate-proxies            Generates proxy classes for entity classes.
  :generate-repositories       Generate repository classes from your mapping information.
  :run-dql                     Executes arbitrary DQL directly from the command line.
  :validate-schema             Validate that the mapping files.
orm:clear-cache
  :metadata                    Clear all metadata cache of the various cache drivers.
  :query                       Clear all query cache of the various cache drivers.
  :result                      Clear result cache of the various cache drivers.
orm:schema-tool
  :create                      Processes the schema and either create it directly on EntityManager Storage Connection or generate the SQL output.
  :drop                        Processes the schema and either drop the database schema of EntityManager Storage Connection or generate the SQL output.
  :update                      Processes the schema and either update the database schema of EntityManager Storage Connection or generate the SQL output.

Package Download

You can also use Doctrine 2 by downloading the latest release package from the download page.

See the configuration section on how to configure and bootstrap a downloaded version of Doctrine.

GitHub

Alternatively you can clone the latest version of Doctrine 2 via GitHub.com:

$ git clone git://github.com/doctrine/doctrine2.git doctrine

This downloads all the sources of the ORM package. You need to initialize the Github submodules for the Common and DBAL package dependencies:

$ git submodule init
$ git submodule update

This updates your Git checkout to use the Doctrine and Doctrine package versions that are recommended for the cloned Master version of Doctrine 2.

See the configuration chapter on how to configure a Github installation of Doctrine with regards to autoloading.

NOTE

You should not combine the Doctrine-Common, Doctrine-DBAL and Doctrine-ORM master commits with each other in combination. The ORM may not work with the current Common or DBAL master versions. Instead the ORM ships with the Git Submodules that are required.

Subversion

NOTE

Using the SVN Mirror is not recommended. It only allows access to the latest master commit and does not automatically fetch the submodules.

If you prefer subversion you can also checkout the code from GitHub.com through the subversion protocol:

$ svn co http://svn.github.com/doctrine/doctrine2.git doctrine2

However this only allows you to check out the current master of Doctrine 2, without the Common and DBAL dependencies. You have to grab them yourself, but might run into version incompatibilities between the different master branches of Common, DBAL and ORM.

Sandbox Quickstart

NOTE The sandbox is only available via the Doctrine2 Github Repository or soon as a separate download on the downloads page. You will find it in the $root/tools/sandbox folder.

The sandbox is a pre-configured environment for evaluating and playing with Doctrine 2.

Overview

After navigating to the sandbox directory, you should see the following structure:

sandbox/
    Entities/
        Address.php
        User.php
    xml/
        Entities.Address.dcm.xml
        Entities.User.dcm.xml
    yaml/
        Entities.Address.dcm.yml
        Entities.User.dcm.yml
    cli-config.php
    doctrine
    doctrine.php
    index.php

Here is a short overview of the purpose of these folders and files:

• The Entities folder is where any model classes are created. Two example entities are already there.
• The xml folder is where any XML mapping files are created (if you want to use XML mapping). Two example mapping documents for the 2 example entities are already there.
• The yaml folder is where any YAML mapping files are created (if you want to use YAML mapping). Two example mapping documents for the 2 example entities are already there.
• The cli-config.php contains bootstrap code for a configuration that is used by the Console tool doctrine whenever you execute a task.
• doctrine/doctrine.php is a command-line tool.
• index.php is a basic classical bootstrap file of a php application that uses Doctrine 2.

Mini-tutorial

1. From within the tools/sandbox folder, run the following command and you should see the same output.

   $ php doctrine orm:schema-tool:create Creating database schema... Database schema created successfully!

2. Take another look into the tools/sandbox folder. A SQLite database should have been created with the name database.sqlite.
3. Open index.php and at the bottom edit it so it looks like the following:

<?php
//... bootstrap stuff

## PUT YOUR TEST CODE BELOW

$user = new \Entities\User;
$user->setName('Garfield');
$em->persist($user);
$em->flush();

echo "User saved!";

Open index.php in your browser or execute it on the command line. You should see the output "User saved!".

4. Inspect the SQLite database. Again from within the tools/sandbox folder, execute the following command:

   $ php doctrine dbal:run-sql "select * from users"

You should get the following output:

array(1) {
  [0]=>
  array(2) {
    ["id"]=>
    string(1) "1"
    ["name"]=>
    string(8) "Garfield"
  }
}

You just saved your first entity with a generated ID in an SQLite database.

5. Replace the contents of index.php with the following:

<?php
//... bootstrap stuff

## PUT YOUR TEST CODE BELOW

$q = $em->createQuery('select u from Entities\User u where u.name = ?1');
$q->setParameter(1, 'Garfield');
$garfield = $q->getSingleResult();

echo "Hello " . $garfield->getName() . "!";

You just created your first DQL query to retrieve the user with the name 'Garfield' from an SQLite database (Yes, there is an easier way to do it, but we wanted to introduce you to DQL at this point. Can you find the easier way?).

TIP When you create new model classes or alter existing ones you can recreate the database schema with the command doctrine orm:schema-tool --drop followed by doctrine orm:schema-tool --create.

6. Explore Doctrine 2!

Instead of reading through the reference manual we also recommend to look at the tutorials:

Getting Started Tutorial <../tutorials/getting-started-xml-edition>