doctrine2/manual/docbook/doctrine.xml

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<book id="doctrinebook">

  <bookinfo>
    <title>Doctrine Documentation</title>
    <author>
      <firstname>Konsta</firstname>
      <surname>Vesterinen</surname>
    </author>
    <author>
      <firstname>Ian</firstname>
      <surname>Christian</surname>
      <email>pookey@pookey.co.uk</email>
    </author>
    <copyright>
      <holder>Doctrine Project</holder>
      <year>2007</year>
    </copyright>
    <legalnotice id="legalnotice">
      <para>
        The contents of this document are licensed under the Creative Commons
        <ulink url="http://creativecommons.org/licenses/by-sa/2.0/">Attribution-ShareAlike License</ulink>.
      </para>
    </legalnotice>

    <abstract>
      <para>
        Documentation for the PHP Doctrine project.
      </para>
      <para>
        This document was generated <?dbtimestamp format="Y-m-d H:M:S"?>.
      </para>
    </abstract>
  </bookinfo>

  <chapter id="introduction">
    <title>Introduction</title>
    <sect1 id="about-doctrine">
      <title>About Doctrine</title>
      <para>
        Doctrine is a Object Relational Mapping and database abstraction
        framework for PHP. The DBAL part of Doctrine derives from MDB2. The key
        idea was to provide very intuitive and easy-to-use persistency solution
        (eg. RoR ActiveRecord) with all the advanced features from the more
        heavy-weight solutions (eg. Hibernate).
      </para>
      <para>
        Doctrine Query Language implements EJB 3 OQL specificiation and expands
        it a bit further (it has special LIMIT and OFFSET clauses).
      </para>
    </sect1>

    <sect1 id="requirements">
      <title>Requirements</title>
      <para>
        Doctrine requires PHP >= 5.1, and it doesn't require any external libraries.
      </para>
      <para>
        For database abstraction Doctrine uses PDO which is bundled with php by
        default. Doctrine also requires a little adodb-hack for table creation,
        which comes with doctrine.
      </para>
    </sect1>

    <sect1 id="community">
      <title>Community</title>
      <para>
        Doctrine has 3 mailing lists, an IRC forum, and a wiki.
      </para>
      <sect2 id="community-mailinglist">
        <title>Mailing Lists</title>
        <para>
          The 'user' mailing list is for discussing the usage of doctrine.
          To subscribe to this list, send a blank email to
          <email>doctrine-user+subscribe@lists.pengus.net</email>
        </para>
        <para>
          The 'dev' mailing list is used for discussion of the development
          of doctrine.  To subscribe to this list, send a blank email to
          <email>doctrine-dev+subscribe@lists.pengus.net</email>
        </para>
        <para>
          The 'svn' mailing list is a read-only list, which users and developers
          can subscribe to to receive commit logs to the SVN repository.  This
          list is quite high traffic, as every commit to the repository results
          in an email containing the changelog entry and diffs of the changed
          files.
          To subscribe to this list, send a blank email to
          <email>doctrine-svn+subscribe@lists.pengus.net</email>
        </para>
      </sect2>
      <sect2 id="community-irc">
        <title>IRC</title>
        <para>
          The #doctrine IRC channel can be found on the freenode network.
        </para>
      </sect2>
    </sect1>

    <sect1 id="contributing">
      <title>Contributing</title>
      <para>
        Doctrine is constantly under development, and is always happy for new
        developers to contribute to the project.
      </para>
      <para>
        To get an account on trac to submit bugs and make suggestions, or to get
        access to commit to the SVN repository, please visit the IRC channel, or
        email the users mailing list.
      </para>
    </sect1>

    <sect1 id="installation">
      <title>Installation</title>
      <para>
        As of the time of writing, there is no stable release of doctrine.  That is not to say
        that it's unstable, but simply that the best way to install it is to aquire it from
        SVN.
      </para>
      <para>
        To get the latest copy, simple check out 'trunk' from SVN.  You will need subversion
        install to check out doctrine.  If you are unable to install subversion for whatever
        reason, see below for details on downloading a snapshot.
      </para>
      <screen>
        <prompt>bash $</prompt><command>svn checkout http://doctrine.pengus.net/svn/trunk</command>
      </screen>
      <para>
        Daily snapshots can be found at 
        <ulink url="http://doctrine.pengus.net/downloads/">http://doctrine.pengus.net/downloads/</ulink>
        and the latest daily snapshot can always be found at
        <ulink url="http://doctrine.pengus.net/downloads/latest-snapshot.tar.gz">http://doctrine.pengus.net/downloads/latest-snapshot.tar.gz</ulink>
      </para>
    </sect1>

    <sect1 id="include-and-autoload">
      <title>Include and autoload</title>
      <para>
        In order to use Doctrine in your project it must first be included.
      </para>
      <programlisting role="php"><![CDATA[
<?php
  require_once('path-to-doctrine/lib/Doctrine.php');
?>]]></programlisting>
      <para>
        Doctrine support <ulink
        url="http://www.php.net/autoload">Autoloading</ulink> for including
        files so that you do not have to include anything more then the base
        file. There are two different strategies that can be used to do this:
      </para>

      <para>
        If you do use the <emphasis>__autoload</emphasis> function for your own
        logic you can use it.
      </para>
      <programlisting role="php"><![CDATA[
<?php
  function __autoload($class) {
    Doctrine::autoload($class);
  }
?>]]></programlisting>
    
      <para>
        If your project uses autoload and/or you have other libraries that use
        it you could use <ulink
        url="http://www.php.net/manual/en/function.spl-autoload-register.php">spl_autoload_register</ulink>
        to register more then one autoloading function.
      </para>

      <programlisting role="php"><![CDATA[
<?php
  spl_autoload_register(array('Doctrine', 'autoload'));
?>]]></programlisting>
    </sect1>

    <sect1 id="compiling">
      <title>Compiling</title>
      <para>
        Compiling is a method for making a single file of most used doctrine
        runtime components including the compiled file instead of multiple files
        (in worst cases dozens of files) can improve performance by an order of
        magnitude. In cases where this might fail, a Doctrine_Exception is throw
        detailing the error.
      </para>
      <programlisting role="php"><![CDATA[
<?php
  Doctrine::compile();

  // on some other script:
  require_once('path_to_doctrine/Doctrine.compiled.php');
?>]]></programlisting>
    </sect1>

    <sect1 id="new-project">
      <title>Starting a new project</title>
      <para>
        Doctrine_Record is the basic component of every doctrine-based project.
        There should be atleast one Doctrine_Record for each of your database
        tables.  Doctrine_Record follows the <ulink
        url="http://www.martinfowler.com/eaaCatalog/activeRecord.html">Active
        Record pattern</ulink>
      </para>
    </sect1>
  </chapter>

  <chapter id="connection-management">
  <title>Connection Management</title>
  </chapter>

  <chapter id="object-relational-mapping">
  <title>Object Relational Mapping</title>
  </chapter>

  <chapter id="working-with-objects">
  <title>Working With Objects</title>
  </chapter>

  <chapter id="configuration">
  <title>Configuration</title>
  </chapter>

  <chapter id="advanced-components">
  <title>Advanced Components</title>
  </chapter>

  <chapter id="dql">
  <title>DQL (Doctrine Query Lanaguage)</title>
  <sect1 id="dql-intro">
    <title>Introduction</title>
    <para>
    Doctrine Query Language(DQL) is an Object Query Language created for helping users in complex object retrieval.
    </para>
    <para>
    You should always consider using DQL(or raw SQL) when retrieving relational data efficiently (eg. when fetching users and their phonenumbers).
    </para>
    <para>
    When compared to using raw SQL, DQL has several benefits:
    </para>

    <itemizedlist>
      <listitem><para>From the start it has been designed to retrieve records(objects) not result set rows.</para></listitem>
      <listitem><para>DQL understands relations so you don't have to type manually sql joins and join conditions.</para></listitem>
      <listitem><para>DQL is portable on different databases</para></listitem>
      <listitem><para>DQL has some very complex built-in algorithms like (the record limit algorithm) which can help developer to efficiently retrieve objects.</para></listitem>
      <listitem><para>It supports some functions that can save time when dealing with one-to-many, many-to-many relational data with conditional fetching.</para></listitem>
    </itemizedlist>

    <para>
      If the power of DQL isn't enough, you should consider using the rawSql API for object population.
    </para>

    <programlisting role="php"><![CDATA[
<?php 
  // DO NOT USE THE FOLLOWING CODE 
  // (using many sql queries for object population):

  $users = $conn->getTable('User')->findAll();
  foreach($users as $user) {
    print $user->name."\n";
    foreach($user->Phonenumber as $phonenumber) {
        print $phonenumber."\n";
    }
  }

  // same thing implemented much more efficiently: 
  // (using only one sql query for object population)

  $users = $conn->query("FROM User.Phonenumber");
  foreach($users as $user) {
    print $user->name."\n";
    foreach($user->Phonenumber as $phonenumber) {
        print $phonenumber."\n";
    }
  }
?>]]></programlisting>
  </sect1>

  </chapter>

  <chapter id="native-sql">
  <title>Native SQL</title>
  </chapter>

  <chapter id="transactions">
  <title>Transactions</title>
  </chapter>

  <chapter id="caching">
  <title>Caching</title>
  </chapter>

  <chapter id="database-abstraction">
  <title>Database Abstraction</title>
  </chapter>

  <chapter id="technology">
  <title>Technology</title>
  </chapter>

  <chapter id="real-world-examples">
  <title>Real World Examples</title>
  </chapter>

  <chapter id="coding-standards">
  <title>Coding Standards</title>
  </chapter>

</book>