<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Inheritance Mapping — Doctrine MongoDB ODM 1.1.5 documentation</title> <link rel="stylesheet" href="../_static/bootstrap/css/bootstrap.min.css" type="text/css" /> <link rel="stylesheet" href="../_static/default.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <link rel="stylesheet" href="../_static/layout.css" type="text/css" /> <link rel="stylesheet" href="../_static/configurationblock.css" type="text/css" /> <script type="text/javascript"> var DOCUMENTATION_OPTIONS = { URL_ROOT: '../', VERSION: '1.1.5', COLLAPSE_MODINDEX: false, FILE_SUFFIX: '.html', HAS_SOURCE: true }; </script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/configurationblock.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/configurationblock.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/configurationblock.js"></script> <script src="../_static/bootstrap/js/bootstrap.min.js"></script> <script type="text/javascript"> <!-- $(document).ready(function() { $("#versions").change(function() { var docsUrl = $(this).val(); window.location.href = docsUrl; }); }); --> </script> <link rel="shortcut icon" href="../_static/doctrine.ico"/> <link rel="search" title="Search" href="../search.html" /> <link rel="top" title="Doctrine MongoDB ODM 1.1.5 documentation" href="../index.html" /> </head> <body> <div id="wrapper"> <div id="header"> <h1 id="h1title"></h1> <div id="logo"> <a href="http://www.doctrine-project.org/">Doctrine - PHP Database Libraries</a> </div> </div> <div id="nav" class="cls"> <div class="tl cls"> <ul> <li><a target="_top" href="http://www.doctrine-project.org/">Home</a></li> <li><a target="_top" href="http://www.doctrine-project.org/about.html">About</a></li> <li><a target="_top" href="http://www.doctrine-project.org/projects.html">Projects</a></li> <li><a target="_top" href="http://www.doctrine-project.org/contribute.html">Contribute</a></li> <li><a target="_top" href="http://www.doctrine-project.org/community.html">Community</a></li> <li><a target="_top" href="http://www.doctrine-project.org/archive.html">Blog</a></li> <li><a target="_top" href="http://www.doctrine-project.org/jira">Development</a></li> </ul> </div> </div> <div id="content" class="cls"> <div class="related"> <h3>Navigation</h3> <ul> <li><a href="/">Doctrine Homepage</a> »</li> <li><a href="../index.html">Doctrine MongoDB ODM 1.1.5 documentation</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" > <div class="section" id="inheritance-mapping"> <span id="id1"></span><h1>Inheritance Mapping<a class="headerlink" href="#inheritance-mapping" title="Permalink to this headline">¶</a></h1> <p>Doctrine currently offers two supported methods of inheritance: <a class="reference internal" href="#single-collection-inheritance"><span class="std std-ref">single collection</span></a> and <a class="reference internal" href="#collection-per-class-inheritance"><span class="std std-ref">collection per class</span></a> inheritance.</p> <div class="section" id="mapped-superclasses"> <h2>Mapped Superclasses<a class="headerlink" href="#mapped-superclasses" title="Permalink to this headline">¶</a></h2> <p>A mapped superclass is an abstract or concrete class that provides mapping information for its subclasses, but is not itself a document. Typically, the purpose of such a mapped superclass is to define state and mapping information that is common to multiple document classes.</p> <p>Just like non-mapped classes, mapped superclasses may appear in the middle of an otherwise mapped inheritance hierarchy (through <a class="reference internal" href="#single-collection-inheritance"><span class="std std-ref">single collection</span></a> or <a class="reference internal" href="#collection-per-class-inheritance"><span class="std std-ref">collection per class</span></a>) inheritance.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">A mapped superclass cannot be a document and is not queryable.</p> </div> <p>Example:</p> <div class="configuration-block"> <ul class="simple"> <li><em>PHP</em><div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span> <span class="k">namespace</span> <span class="nx">Documents</span><span class="p">;</span> <span class="sd">/** @MappedSuperclass */</span> <span class="k">abstract</span> <span class="k">class</span> <span class="nc">BaseDocument</span> <span class="p">{</span> <span class="p">}</span> </pre></div> </div> </li> <li><em>XML</em><div class="highlight-xml"><div class="highlight"><pre><span class="cp"><?xml version="1.0" encoding="UTF-8"?></span> <span class="nt"><doctrine-mongo-mapping</span> <span class="na">xmlns=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"</span> <span class="na">xmlns:xsi=</span><span class="s">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="na">xsi:schemaLocation=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping</span> <span class="s"> http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd"</span><span class="nt">></span> <span class="nt"><mapped-superclass</span> <span class="na">name=</span><span class="s">"Documents\BaseDocument"</span><span class="nt">></span> <span class="nt"></mapped-superclass></span> <span class="nt"></doctrine-mongo-mapping></span> </pre></div> </div> </li> <li><em>YAML</em><div class="highlight-yaml"><div class="highlight"><pre><span class="l l-Scalar l-Scalar-Plain">Documents\BaseDocument</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">type</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">mappedSuperclass</span> </pre></div> </div> </li> </ul> </div> </div> <div class="section" id="single-collection-inheritance"> <span id="id2"></span><h2>Single Collection Inheritance<a class="headerlink" href="#single-collection-inheritance" title="Permalink to this headline">¶</a></h2> <p>In single collection inheritance, each document is stored in a single collection and a discriminator field is used to distinguish one document type from another.</p> <p>Simple example:</p> <div class="configuration-block"> <ul class="simple"> <li><em>PHP</em><div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span> <span class="k">namespace</span> <span class="nx">Documents</span><span class="p">;</span> <span class="sd">/**</span> <span class="sd"> * @Document</span> <span class="sd"> * @InheritanceType("SINGLE_COLLECTION")</span> <span class="sd"> * @DiscriminatorField("type")</span> <span class="sd"> * @DiscriminatorMap({"person"="Person", "employee"="Employee"})</span> <span class="sd"> */</span> <span class="k">class</span> <span class="nc">Person</span> <span class="p">{</span> <span class="c1">// ...</span> <span class="p">}</span> <span class="sd">/**</span> <span class="sd"> * @Document</span> <span class="sd"> */</span> <span class="k">class</span> <span class="nc">Employee</span> <span class="k">extends</span> <span class="nx">Person</span> <span class="p">{</span> <span class="c1">// ...</span> <span class="p">}</span> </pre></div> </div> </li> <li><em>XML</em><div class="highlight-xml"><div class="highlight"><pre><span class="cp"><?xml version="1.0" encoding="UTF-8"?></span> <span class="nt"><doctrine-mongo-mapping</span> <span class="na">xmlns=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"</span> <span class="na">xmlns:xsi=</span><span class="s">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="na">xsi:schemaLocation=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping</span> <span class="s"> http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd"</span><span class="nt">></span> <span class="nt"><document</span> <span class="na">name=</span><span class="s">"Documents\Person"</span> <span class="na">inheritance-type=</span><span class="s">"SINGLE_COLLECTION"</span><span class="nt">></span> <span class="nt"><discriminator-field</span> <span class="na">name=</span><span class="s">"type"</span> <span class="nt">/></span> <span class="nt"><discriminator-map></span> <span class="nt"><discriminator-mapping</span> <span class="na">value=</span><span class="s">"person"</span> <span class="na">class=</span><span class="s">"Person"</span> <span class="nt">/></span> <span class="nt"><discriminator-mapping</span> <span class="na">value=</span><span class="s">"employee"</span> <span class="na">class=</span><span class="s">"Employee"</span> <span class="nt">/></span> <span class="nt"></discriminator-map></span> <span class="nt"></document></span> <span class="nt"></doctrine-mongo-mapping></span> <span class="cp"><?xml version="1.0" encoding="UTF-8"?></span> <span class="nt"><doctrine-mongo-mapping</span> <span class="na">xmlns=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"</span> <span class="na">xmlns:xsi=</span><span class="s">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="na">xsi:schemaLocation=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping</span> <span class="s"> http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd"</span><span class="nt">></span> <span class="nt"><document</span> <span class="na">name=</span><span class="s">"Documents\Employee"</span><span class="nt">></span> <span class="nt"></document></span> <span class="nt"></doctrine-mongo-mapping></span> </pre></div> </div> </li> <li><em>YAML</em><div class="highlight-yaml"><div class="highlight"><pre><span class="l l-Scalar l-Scalar-Plain">Documents\Person</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">type</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">document</span> <span class="l l-Scalar l-Scalar-Plain">inheritanceType</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">SINGLE_COLLECTION</span> <span class="l l-Scalar l-Scalar-Plain">discriminatorField</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">type</span> <span class="l l-Scalar l-Scalar-Plain">discriminatorMap</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">person</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">Person</span> <span class="l l-Scalar l-Scalar-Plain">employee</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">Employee</span> </pre></div> </div> </li> </ul> </div> <p>The discriminator value allows Doctrine to infer the class name to instantiate when hydrating a document. If a discriminator map is used, the discriminator value will be used to look up the class name in the map.</p> <p>Now, if we query for a Person and its discriminator value is <code class="docutils literal"><span class="pre">employee</span></code>, we would get an Employee instance back:</p> <div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span> <span class="nv">$employee</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">Employee</span><span class="p">();</span> <span class="c1">// ...</span> <span class="nv">$dm</span><span class="o">-></span><span class="na">persist</span><span class="p">(</span><span class="nv">$employee</span><span class="p">);</span> <span class="nv">$dm</span><span class="o">-></span><span class="na">flush</span><span class="p">();</span> <span class="nv">$employee</span> <span class="o">=</span> <span class="nv">$dm</span><span class="o">-></span><span class="na">find</span><span class="p">(</span><span class="s1">'Person'</span><span class="p">,</span> <span class="nv">$employee</span><span class="o">-></span><span class="na">getId</span><span class="p">());</span> <span class="c1">// instanceof Employee</span> </pre></div> </div> <p>Even though we queried for a Person, Doctrine will know to return an Employee instance because of the discriminator map!</p> <p>If your document structure has changed and you've added discriminators after already having a bunch of documents, you can specify a default value for the discriminator field:</p> <div class="configuration-block"> <ul class="simple"> <li><em>PHP</em><div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span> <span class="k">namespace</span> <span class="nx">Documents</span><span class="p">;</span> <span class="sd">/**</span> <span class="sd"> * @Document</span> <span class="sd"> * @InheritanceType("SINGLE_COLLECTION")</span> <span class="sd"> * @DiscriminatorField("type")</span> <span class="sd"> * @DiscriminatorMap({"person"="Person", "employee"="Employee"})</span> <span class="sd"> * @DefaultDiscriminatorValue("person")</span> <span class="sd"> */</span> <span class="k">class</span> <span class="nc">Person</span> <span class="p">{</span> <span class="c1">// ...</span> <span class="p">}</span> <span class="sd">/**</span> <span class="sd"> * @Document</span> <span class="sd"> */</span> <span class="k">class</span> <span class="nc">Employee</span> <span class="k">extends</span> <span class="nx">Person</span> <span class="p">{</span> <span class="c1">// ...</span> <span class="p">}</span> </pre></div> </div> </li> <li><em>XML</em><div class="highlight-xml"><div class="highlight"><pre><span class="cp"><?xml version="1.0" encoding="UTF-8"?></span> <span class="nt"><doctrine-mongo-mapping</span> <span class="na">xmlns=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"</span> <span class="na">xmlns:xsi=</span><span class="s">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="na">xsi:schemaLocation=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping</span> <span class="s"> http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd"</span><span class="nt">></span> <span class="nt"><document</span> <span class="na">name=</span><span class="s">"Documents\Person"</span> <span class="na">inheritance-type=</span><span class="s">"SINGLE_COLLECTION"</span><span class="nt">></span> <span class="nt"><discriminator-field</span> <span class="na">name=</span><span class="s">"type"</span> <span class="nt">/></span> <span class="nt"><discriminator-map></span> <span class="nt"><discriminator-mapping</span> <span class="na">value=</span><span class="s">"person"</span> <span class="na">class=</span><span class="s">"Person"</span> <span class="nt">/></span> <span class="nt"><discriminator-mapping</span> <span class="na">value=</span><span class="s">"employee"</span> <span class="na">class=</span><span class="s">"Employee"</span> <span class="nt">/></span> <span class="nt"></discriminator-map></span> <span class="nt"><default-discriminator-value</span> <span class="na">value=</span><span class="s">"person"</span> <span class="nt">/></span> <span class="nt"></document></span> <span class="nt"></doctrine-mongo-mapping></span> <span class="cp"><?xml version="1.0" encoding="UTF-8"?></span> <span class="nt"><doctrine-mongo-mapping</span> <span class="na">xmlns=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"</span> <span class="na">xmlns:xsi=</span><span class="s">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="na">xsi:schemaLocation=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping</span> <span class="s"> http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd"</span><span class="nt">></span> <span class="nt"><document</span> <span class="na">name=</span><span class="s">"Documents\Employee"</span><span class="nt">></span> <span class="nt"></document></span> <span class="nt"></doctrine-mongo-mapping></span> </pre></div> </div> </li> <li><em>YAML</em><div class="highlight-yaml"><div class="highlight"><pre><span class="l l-Scalar l-Scalar-Plain">Documents\Person</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">type</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">document</span> <span class="l l-Scalar l-Scalar-Plain">inheritanceType</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">SINGLE_COLLECTION</span> <span class="l l-Scalar l-Scalar-Plain">discriminatorField</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">type</span> <span class="l l-Scalar l-Scalar-Plain">defaultDiscriminatorValue</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">person</span> <span class="l l-Scalar l-Scalar-Plain">discriminatorMap</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">person</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">Person</span> <span class="l l-Scalar l-Scalar-Plain">employee</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">Employee</span> </pre></div> </div> </li> </ul> </div> </div> <div class="section" id="collection-per-class-inheritance"> <span id="id3"></span><h2>Collection Per Class Inheritance<a class="headerlink" href="#collection-per-class-inheritance" title="Permalink to this headline">¶</a></h2> <p>With collection per class inheritance, each document is stored in its own collection and contains all inherited fields:</p> <div class="configuration-block"> <ul class="simple"> <li><em>PHP</em><div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span> <span class="k">namespace</span> <span class="nx">Documents</span><span class="p">;</span> <span class="sd">/**</span> <span class="sd"> * @Document</span> <span class="sd"> * @InheritanceType("COLLECTION_PER_CLASS")</span> <span class="sd"> */</span> <span class="k">class</span> <span class="nc">Person</span> <span class="p">{</span> <span class="c1">// ...</span> <span class="p">}</span> <span class="sd">/**</span> <span class="sd"> * @Document</span> <span class="sd"> */</span> <span class="k">class</span> <span class="nc">Employee</span> <span class="k">extends</span> <span class="nx">Person</span> <span class="p">{</span> <span class="c1">// ...</span> <span class="p">}</span> </pre></div> </div> </li> <li><em>XML</em><div class="highlight-xml"><div class="highlight"><pre><span class="cp"><?xml version="1.0" encoding="UTF-8"?></span> <span class="nt"><doctrine-mongo-mapping</span> <span class="na">xmlns=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"</span> <span class="na">xmlns:xsi=</span><span class="s">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="na">xsi:schemaLocation=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping</span> <span class="s"> http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd"</span><span class="nt">></span> <span class="nt"><document</span> <span class="na">name=</span><span class="s">"Documents\Person"</span> <span class="na">inheritance-type=</span><span class="s">"COLLECTION_PER_CLASS"</span><span class="nt">></span> <span class="nt"></document></span> <span class="nt"></doctrine-mongo-mapping></span> <span class="cp"><?xml version="1.0" encoding="UTF-8"?></span> <span class="nt"><doctrine-mongo-mapping</span> <span class="na">xmlns=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"</span> <span class="na">xmlns:xsi=</span><span class="s">"http://www.w3.org/2001/XMLSchema-instance"</span> <span class="na">xsi:schemaLocation=</span><span class="s">"http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping</span> <span class="s"> http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd"</span><span class="nt">></span> <span class="nt"><document</span> <span class="na">name=</span><span class="s">"Documents\Employee"</span><span class="nt">></span> <span class="nt"></document></span> <span class="nt"></doctrine-mongo-mapping></span> </pre></div> </div> </li> <li><em>YAML</em><div class="highlight-yaml"><div class="highlight"><pre><span class="l l-Scalar l-Scalar-Plain">Documents\Person</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">type</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">document</span> <span class="l l-Scalar l-Scalar-Plain">inheritanceType</span><span class="p p-Indicator">:</span> <span class="l l-Scalar l-Scalar-Plain">COLLECTION_PER_CLASS</span> </pre></div> </div> </li> </ul> </div> <p>A discriminator is not needed with this type of inheritance since the data is separated in different collections.</p> </div> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <div id="searchbox" style=""> <h3>Search</h3> <form class="search" action="http://readthedocs.org/search/project/" method="get"> <input type="text" name="q" size="18"> <input type="submit" value="Go"> <input type="hidden" name="selected_facets" value="project:"> </form> </div> <h3><a href="../index.html">Table Of Contents</a></h3> <ul> <li><a class="reference internal" href="#">Inheritance Mapping</a><ul> <li><a class="reference internal" href="#mapped-superclasses">Mapped Superclasses</a></li> <li><a class="reference internal" href="#single-collection-inheritance">Single Collection Inheritance</a></li> <li><a class="reference internal" 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