Book Image

Persistence in PHP with Doctrine ORM

By : Kevin Dunglas
Book Image

Persistence in PHP with Doctrine ORM

By: Kevin Dunglas

Overview of this book

Doctrine 2 has become the most popular modern persistence system for PHP. It can either be used as a standalone system or can be distributed with Symfony 2, and it also integrates very well with popular frameworks. It allows you to easily retrieve PHP object graphs, provides a powerful object-oriented query language called DQL, a database schema generator tool, and supports database migration. It is efficient, abstracts popular DBMS, and supports PHP 5.3 features. Doctrine is a must-have for modern PHP applications. Persistence in PHP with Doctrine ORM is a practical, hands-on guide that describes the full creation process of a web application powered by Doctrine. Core features of the ORM are explained in depth and illustrated by useful, explicit, and reusable code samples. Persistence in PHP with Doctrine ORM explains everything you need to know to get started with Doctrine in a clear and detailed manner. From installing the ORM through Composer to mastering advanced features such as native queries, this book is a full overview of the power of Doctrine. You will also learn a bunch of mapping annotations, create associations, and generate database schemas from PHP classes. You will also see how to write data fixtures, create custom entity repositories, and issue advanced DQL queries. Finally it will teach you to play with inheritance, write native queries, and use built-in lifecycle events. If you want to use a powerful persistence system for your PHP application, Persistence in PHP with Doctrine ORM is the book you.
Table of Contents (12 chapters)

Bootstrapping the app


The following steps need to be performed for bootstrapping the app:

  1. Create a new file called config/config.php that will contain configuration parameters of our app as shown in the following code:

      <?php
    
      // App configuration
      $dbParams = [
        'driver' => 'pdo_sqlite',
        'path' => __DIR__.'/../data/blog.db'
      ];
    
      // Dev mode?
      $dev = true;

    The Doctrine configuration parameters are stored in the $dbParams array. We will use a SQLite Database called blog.db stored in the data/ directory. If you want to use MySQL or any other DBMS, it's here that you will configure the driver to use, the database name, and the access credentials.

    Note

    The following is a sample configuration to use MySQL instead of SQLite:

    $dbParams = [
        'driver' => 'pdo_mysql',
        'host' => '127.0.0.1',
        'dbname' => 'blog',
        'user' => 'root',
        'password' => ''
    ];

    Config keys are self-explanatory.

    If the $dev variable is true, some optimizations will be disabled to ease debugging. Disabling the dev mode allows Doctrine to put a lot of data such as metadata in powerful caches to increase overall performances of the app.

    Note

    It requires cache driver installation and extra configuration, which is available at http://docs.doctrine-project.org/en/latest/reference/caching.html.

  2. Next, we need a way to bootstrap our app. Create a file called bootstrap.php in the src/ directory. This file will load everything we need as given in the following code:

      <?php
    
      require_once __DIR__.'/../vendor/autoload.php';
      require_once __DIR__.'/../config/config.php';

    The first line requires the Composer autoloader. It allows you to automatically load the Doctrine's classes, the project's classes (that will be in the src/ directory), and any class of a library installed with Composer.

    The second line imports the configuration file of the app. The project structure is created and the initialization process of the app is done. We are ready to start using Doctrine.