Zend framework 2 model for database, separate model for each table? - database

Question

I looked through the manual of Zend Framework 2 about creating model to managing operations on table. Is the class with method exchangeArray() is necessary? It's only copy data :/ Can i create one model to manage a few tables?
I created two classes:
namespace Application\Model;
use Zend\Db\Adapter\Adapter;
use Zend\Db\Adapter\AdapterAwareInterface;
abstract class AbstractAdapterAware implements AdapterAwareInterface
{
protected $db;
public function setDbAdapter(Adapter $adapter)
{
$this->db = $adapter;
}
}
and:
namespace Application\Model;
class ExampleModel extends AbstractAdapterAware
{
public function fetchAllStudents()
{
$result = $this->db->query('select * from Student')->execute();
return $result;
}
}
I also add entries in Module.php:
'initializers' => [
'Application\Model\Initializer' => function($instance, \Zend\ServiceManager\ServiceLocatorInterface $serviceLocator){
if ($instance instanceof AdapterAwareInterface)
{
$instance->setDbAdapter($serviceLocator->get('Zend\Db\Adapter\Adapter'));
}
}
],
'invokables' => [
'ExampleModel' => 'Application\Model\ExampleModel'
],
I execute methods from model by:
$this->getServiceLocator()->get('ExampleModel')->fetchAllStudents();

Answer 1

You should do 2 things with your code. First, implement AdapterAwareInterface properly. Second, create an initializer which injects the adapter into your model. Consider the code below:
...
'initializers' => [
function($instance, ServiceLocatorInterface $serviceLocator){
if ($instance instanceof AdapterAwareInterface) {
$instance->setDbAdapter($serviceLocator->get('Zend\Db\Adapter\Adapter'));
}
}
]
...
abstract class AbstractModel implements AdapterAwareInterface
{
protected $db;
public function setDbAdapter(Adapter $adapter)
{
$this->db = adapter;
}
}
...
'invokables' => [
'ExampleModel' => 'Application\Model\ExampleModel'
]
As you can see from above, after all, you don't need a factory for each your model. You can either register invokables or create an Abstract Factory to instantiate your models. See an example below:
...
'abstract_factories' => [
'Application\Model\AbstractFactory'
]
...
class AbstractFactory implements AbstractFactoryInterface
{
public function canCreateServiceWithName(ServiceLocatorInterface $serviceLocator, $name, $requestedName)
{
return class_exists('Application\Model\'.$requestedName);
}
public function createServiceWithName(\Zend\ServiceManager\ServiceLocatorInterface $serviceLocator, $name, $requestedName)
{
$class = 'Application\Model\'.$requestedName();
return new $class
}
}
Hope this helps