http://doctrine-project.org/jira This file is an XML representation of an issue en-us 5.2.7 850 21-02-2013 http://doctrine-project.org/jira/browse/DDC-2245 Doctrine 2 - ORM <p>When EntityManager#getReference is called with SINGLE_TABLE inherited entity, it tries to get a loaded entity by calling unitOfWork-&gt;tryGetById($sortedId, $class-&gt;rootEntityName). The call may return an entity object of root entity class which is not what is asked, then it ends up returning NULL instead of going further.</p> DDC-2245

EntityManager#getReference returns NULL on SINGLE_TABLE inheritance

Bug Major Resolved Invalid Benjamin Eberlei Masaki Fujimoto Tue, 15 Jan 2013 21:48:20 +0000 Sun, 20 Jan 2013 17:30:28 +0000 Sun, 20 Jan 2013 11:58:25 +0000 2.3.2 ORM 0 3 <p>This looks quite serious. On the other side, `getReference` should probably call `find` on inheritances.</p> <p>Do you have any example code for this?</p> <p>Yes, following line returns NULL with entity classes I have(it's a part of Symfony2 project):</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java"> $entity = $em-&gt;getRepository('EnjoitechBaseBundle:MCode')-&gt;find('01') <span class="code-comment">// load an entity of root entity class </span>$ref = $em-&gt;getReference('Enjoitech\BaseBundle\Entity\MCodeModule', '01'); <span class="code-comment">// <span class="code-keyword">try</span> to get reference of sub entity with same ID, <span class="code-keyword">this</span> <span class="code-keyword">return</span> NULL </span> <span class="code-comment">// $ref =&gt; NULL </span> <span class="code-comment">// MCode.php </span>&lt;?php namespace Enjoitech\BaseBundle\Entity; use \PDO; use Doctrine\ORM\Mapping as ORM; /** * @ORM\Entity * @ORM\Table(name=<span class="code-quote">"M_CODE"</span>) * @ORM\InheritanceType(<span class="code-quote">"SINGLE_TABLE"</span>) * @ORM\DiscriminatorColumn(name=<span class="code-quote">"CLASS"</span>, type=<span class="code-quote">"string"</span>, length=2) * @ORM\DiscriminatorMap({<span class="code-quote">"00"</span> = <span class="code-quote">"MCode"</span>, <span class="code-quote">"01"</span> = <span class="code-quote">"MCodeModule"</span>}) */ class MCode { /** * @ORM\Id * @ORM\Column(type=<span class="code-quote">"string"</span>, length=2) */ <span class="code-keyword">protected</span> $CODE; /** * @ORM\Column(type=<span class="code-quote">"string"</span>, length=128) */ <span class="code-keyword">protected</span> $DESCRIPTION; <span class="code-keyword">public</span> function getCODE() { <span class="code-keyword">return</span> $<span class="code-keyword">this</span>-&gt;CODE; } } /** * @ORM\Entity */ class MCodeModule <span class="code-keyword">extends</span> MCode { } </pre> </div></div> <p>I also saw a post that mentioned a similar/same issue at <a href="https://groups.google.com/forum/#!msg/doctrine-user/55IkFJlADh8/79QpCIH1Ag4J" class="external-link">https://groups.google.com/forum/#!msg/doctrine-user/55IkFJlADh8/79QpCIH1Ag4J</a></p> <p>This is the correct behavior, if you fetch MCodeModule and its "only" a MCode, then returning null is correct, because you assume to retrieve a MCodeModule or nothing.</p> <p>I am not assuming getReference is supposed to fetch/retrieve/load anything. Shouldn't it return a reference to an entity object even the target entity hasn't been loaded yet? getReference won't return null because you'll never know if the entity exists in database in my opinion.</p> <p><a href="http://doctrine-project.org/jira/secure/ViewProfile.jspa?name=mak8" class="user-hover" rel="mak8">Masaki Fujimoto</a> that doesn't work with inheritances, since you will need to query the discriminator column to know what object to instantiate</p> <p>I see, thanks for clarifying that. That was what I thought as far as I see in code; $sortedId array doesn't include discriminator column and value at all. So basically getReference won't guarantee its behaviour when the target is inheritances correct? I should rather use find() maybe. Will you keep that policy for future?</p> <p>I also encountered few more issues related to SINGLE_TABLE inheritance. something like find() returns entities of other inheritance class that were loaded earlier. I needed to clear entityManager each time before I get entities of another subclassed of MCode. I guess there may be same sort of implementation without considering discriminator column. Are these all known issues or it's just how it is intended?</p> <p><a href="http://doctrine-project.org/jira/secure/ViewProfile.jspa?name=mak8" class="user-hover" rel="mak8">Masaki Fujimoto</a> repeated calls to `find` give you the same instances for same identifiers. If you changed something, you'll need to `clear`, though it looks like you're doing a lot of unconventional stuff in there.</p> <p>I think that on STI/JTI, `getReference` could short-circuit to `find`, not sure if we want it.</p> <p>I have just one code table. PK is a combination of CLASS and CODE columns. I use CLASS column as discriminator, and CODE column is ID of each inheritance. value in CODE column won't be unique by itself in the table but I thought SINGLE_TABLE inheritance can cover that. If this structure is unconventional, I'll have to look for workaround. thanks for all your help</p>