title: Symfony, inherited entities and doctrine migration
body: <p>Under <strong>Symfony 5.0</strong>, I use generic entity classes to unify internal projects. My generic entity (e.g. Table) looks like this:</p>
  
  <pre><code>
  use Doctrine\Common\Collections\ArrayCollection;
  use Doctrine\Common\Collections\Collection;
  use Doctrine\ORM\Mapping as ORM;
  
  /**
   * @ORM\Entity(repositoryClass="App\Repository\TableRepository")
   * @ORM\InheritanceType("SINGLE_TABLE")
   * @ORM\DiscriminatorMap({"generic_table": "App\Entity\Generic\Table", "table": "App\Entity\Table"})
   */
  class Site
  {
      //protected properties and public methods
  }
  </code></pre>
  
  <p>And inherited class:</p>
  
  <pre><code>
  use App\Entity\Generic\Table as GenericTable;
  use Doctrine\ORM\Mapping as ORM;
  
  /**
   * @ORM\Entity(repositoryClass="App\Repository\TableRepository")
   */
  class Table extends GenericTable
  {
      //private properties and public methods
  }
  </code></pre>
  
  <p>However, when executing this command:</p>
  
  <pre><code>php bin/console make:migration
  </code></pre>
  
  <p>It returns the following:</p>
  
  <pre><code>Table mybd.table already exists.
  </code></pre>
  
  <p>Even if the table doesn't.</p>
  
  <p>Any idea? Have I forgotten an ORM statement?</p>