title: Symfony2: doctrine:mapping:import throws Doctrine\ORM\Mapping\MappingException - Table [...] has no primary key.
body: <p>I want to import a Doctrine mapping for a table called stores. I do:</p>
  
  <pre><code>./app/console doctrine:mapping:import MyBundle annotation --filter="stores" 
  </code></pre>
  
  <p>I get the error:</p>
  
  <pre><code>[Doctrine\ORM\Mapping\MappingException]                                                                              
    Table Cat_map has no primary key. Doctrine does not support reverse engineering from tables that don't have a prima  
    ry key. 
  </code></pre>
  
  <p>Am I using the filter incorrectly? I dont want doctrine to try and map any table other than 'stores'</p>
  
  <p>Requested create syntax:</p>
  
  <pre><code>CREATE TABLE `stores` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `storeid` int(11) NOT NULL,
    `store` text NOT NULL,
    PRIMARY KEY (`id`)
  ) ENGINE=MyISAM AUTO_INCREMENT=96 DEFAULT CHARSET=utf8;
  </code></pre>