Type of choice field Symfony2 - symfony

Question

I try to save values of one - three checkboxes in field category in database, but i get the error :
Notice: Array to string conversion in /var/www/OnTheWay/vendor/doctrine/dbal/lib/Doctrine/DBAL/Statement.php line 120
The field:
/**
* #ORM\Column(type="string", length=255, nullable=true)
*/
private $category;
Get & Set:
/**
* #return mixed
*/
public function getCategory()
{
return $this->category;
}
/**
* #param $category
*/
public function setCategory($category)
{
$this->category[] = $category;
}
Profile type:
namespace Vputi\UserBundle\Form\Type;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
class ProfileType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('fio');
$builder->add('birthDate', null, array('widget' => 'single_text'));
$builder->add('file');
$builder->add('yearOnRoad');
$builder->add('telephone');
$builder->add('contactMail');
$builder->add('role', 'choice', array('choices' => array(1 => 'За рулем') ,'expanded'=>true, 'multiple' => true,));
$builder->add('category', 'choice', array(
'choices' => array('A' => 'Категория А', 'B' => 'Категория B', 'C' => 'Категория C',),
'expanded' => true,
'multiple' => true,
));
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' =>'Vputi\UserBundle\Entity\Profile',
'cascade_validation' => true,
));
}
}
Here is my form type, I hope you help me, and iam ommit getName() method.

Answer 1

The problem is $category is defined as a string but you're using it like an array.
The solution depends on exactly what you want to accomplish. If you want it to be mapped as an array you have to do this:
/**
* #ORM\Column(type="array", nullable=true)
*/
private $category;
When using Doctrine's array type, make sure you take this into account: How to force Doctrine to update array type fields?