title: How to set db adapter to Validator RecordExists in Zend Framework 2
body: <p>I'm trying to add validator RecordExists to my form but I get error 'no db adapter present'. How can I set db adapter to this validator? I use examples from skeleton application and I'm trying to do something like this (yes, I know that $dbAdapter is undefined :) I'm searching solution how to change this variable to db adapter resource ):</p>
  
  <pre><code>namespace Album\Model;
  
  use Zend\InputFilter\Factory as InputFactory;     // &lt;-- Add this import
  use Zend\InputFilter\InputFilter;                 // &lt;-- Add this import
  use Zend\InputFilter\InputFilterAwareInterface;   // &lt;-- Add this import
  use Zend\InputFilter\InputFilterInterface;        // &lt;-- Add this import
  
  class Album implements InputFilterAwareInterface
  {
      public $id;
      public $artist;
      public $title;
      protected $inputFilter;                       // &lt;-- Add this variable
  
  public function exchangeArray($data)
  {
      $this-&gt;id     = (isset($data['id']))     ? $data['id']     : null;
      $this-&gt;artist = (isset($data['artist'])) ? $data['artist'] : null;
      $this-&gt;title  = (isset($data['title']))  ? $data['title']  : null;
  }
  
  // Add content to this method:
  public function setInputFilter(InputFilterInterface $inputFilter)
  {
      throw new \Exception("Not used");
  }
  
  public function getInputFilter()
  {
      if (!$this-&gt;inputFilter) {
          $inputFilter = new InputFilter();
          $factory     = new InputFactory();
  
          $inputFilter-&gt;add($factory-&gt;createInput(array(
              'name'     =&gt; 'id',
              'required' =&gt; true,
              'filters'  =&gt; array(
                  array('name' =&gt; 'Int'),
              ),
              'validators' =&gt; array(
                  array(
                      'name'    =&gt; 'Db\RecordExists',
                      'options' =&gt; array(
                          'table' =&gt; 'album',
                          'field' =&gt; 'title',
                          'adapter' =&gt; $dbAdapter
                      ),
                  ),
              ),
          )));
  
          $this-&gt;inputFilter = $inputFilter;
      }
  
      return $this-&gt;inputFilter;
  }
  </code></pre>
  
  <p>}</p>