title: Symfony Array Collection as Entity Property
body: <p>Is there a way to associate an ArrayCollection to a database column created by an Entity?</p>
  
  <p>For example, I have two entities: Household and Pet Type.</p>
  
  <p>Household current has a property for Pet Type, but it expects the Pet Type object, so only one can chosen at the moment.</p>
  
  <p>I'd like Household to be able to have multiple Pet Types. So instead of having to choose between a Dog or a Cat, they can choose Dog AND Cat.</p>
  
  <p>I have tried doing this, but I get the following error:</p>
  
  <blockquote>
    <p>Catchable Fatal Error: Argument 1 passed to
    Acme\CoreBundle\Entity\Household::setPetType() must be an instance of
    Acme\CoreBundle\Entity\PetType, instance of
    Doctrine\Common\Collections\ArrayCollection given</p>
  </blockquote>
  
  <p>I'm assuming I'd need to change property for petType in the Household entity in order to associate to more than one pet type?</p>