title: Symfony 2 class table inheritance fixture SQL error
body: <p>I'm new here and quite new to symfony 2.</p>
  
  <p>I try to build an Entity 'MailProcess' that inherits from an Entity 'Process'. Here are my Entity definitions:</p>
  
  <pre><code>// src/MW/TodoBundle/Entity/Process.php
  namespace MW\TodoBundle\Entity;
  
  use Doctrine\ORM\Mapping as ORM;
  
  /**
   * @ORM\Entity 
   * @ORM\InheritanceType("JOINED")
   * @ORM\DiscriminatorColumn(name="process_type", type="string")
   * @ORM\DiscriminatorMap({"mailprocess" = "MailProcess", "process" = "Process"})
   * @ORM\Table(name="process")
   * @ORM\HasLifecycleCallbacks 
   */
  class Process
  {
  
      /**
       *
       * @ORM\Id
       * @ORM\Column(type="integer", unique=true)
       * @ORM\GeneratedValue(strategy="AUTO") 
       */
      protected $id;
  
      /**
       *
       * @ORM\Column(type="string") 
       */
      protected $title;
  
      /**
       *
       * @ORM\Column(type="datetime") 
       */
      protected $created;
  
  
  
      /**
       *
       * @ORM\Column(type ="text", nullable= true)
       */
      protected $comment;
      protected $options;
  
      // Getters and Setters
  }
  
  // src/MW/TodoBundle/Entity/MailProcess.php
  namespace MW\TodoBundle\Entity;
  
  use Doctrine\ORM\Mapping as ORM;
  use MW\TodoBundle\Entity\Process;
  
  /**
   *
   * @ORM\Entity
   * @ORM\Table(name="process_mailprocess")
   */
  class MailProcess extends Process
  {
  
      /**
       *
       * @ORM\Column(type="string") 
       */
      protected $from;
  
      /**
       *
       * @ORM\Column(type="string") 
       */
      protected $to;
  
      /**
       *
       * @ORM\Column(type="string", nullable=true) 
       */
      protected $subject;
  
      /**
       *
       * @ORM\Column(type="text", nullable=true) 
       */
      protected $message;
  }
  </code></pre>
  
  <p>You can see the ORM Class Table Inheritance used: Two tables 'process' and 'process_mailprocess' with discriminator column 'process_type'.</p>
  
  <p>I do use 
      ´php app/console doctrine:schema:update --force´
  to update the schema to my MySQL database which works fine.</p>
  
  <p>But then there are my Data fixtures: I've stripped them down to one here, but be assured I have additional fixtures also testing the Entity 'Process' which are working fine.</p>
  
  <pre><code>// src/MW/TodoBundle/DataFixtures/ORM/ProcessFixtures.php
  
  namespace MW\TodoBundle\DataFixtures\ORM;
  
  use Doctrine\Common\DataFixtures\FixtureInterface;
  use Doctrine\Common\Persistence\ObjectManager;
  use MW\TodoBundle\Entity\Process;
  use MW\TodoBundle\Entity\MailProcess;
  
  class ProcessFixtures implements FixtureInterface
  {
  
      public function load(ObjectManager $manager)
      {
          $mp1= new MailProcess();
          $mp1-&gt;setTitle("Invoice from heaven")
              -&gt;setComment("sitebot: Irgendwer will was von euch!")
              -&gt;setCreated(new \DateTime())
              -&gt;setFrom("m")
              -&gt;setTo("m")
              -&gt;setSubject("m")
              -&gt;setMessage("m");
          $manager-&gt;persist($mp1);
          $manager-&gt;flush();
      }
  }
  </code></pre>
  
  <p>Alas, execution of
      ´php app/console doctrine:fixtures:load´
  confirming 'y' to purge gets me</p>
  
  <pre><code>  [Doctrine\DBAL\DBALException]
    An exception occurred while executing 'INSERT INTO process_mailprocess (id, from, to, subject, message) VALUES (?,
    ?, ?, ?, ?)' with params {"1":28,"2":"m","3":"m","4":"m","5":"m"}:
  
    SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your   SQL syntax; check the manual that
     corresponds to your MySQL server version for the right syntax to use near 'from, to, subject, message) VALUES ('28
    ', 'm', 'm', 'm', 'm')' at line 1
  
  
  
  
  
  
    [PDOException]
    SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that
     corresponds to your MySQL server version for the right syntax to use near 'from, to, subject, message) VALUES ('28
    ', 'm', 'm', 'm', 'm')' at line 1
  </code></pre>
  
  <p>I can see nothing wrong there, and besides, Doctrine and Symfony create the SQL query.
  Can anyone point me to what I am doing wrong here? This is a real head-scratcher for me.</p>