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Symfony2 – Franz Jordán 2011
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return new Response('Created product id '.$product->getId());
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}
If you're following along with this example, you'll need to create a route that points to this action
to see it in work.
Let's walk through this example:
lines 8-11 In this section, you instantiate and work with the $product object like any
other, normal PHP object;
line 13 This line fetches Doctrine's entity manager object, which is responsible for
handling the process of persisting and fetching objects to and from the database;
line 14 The persist() method tells Doctrine to "manage" the $product object. This does
not actually cause a query to be made to the database (yet).
line 15 When the flush() method is called, Doctrine looks through all of the objects that
it's managing to see if they need to be persisted to the database. In this example,
the $productobject has not been persisted yet, so the entity manager executes
an INSERT query and a row is created in the product table.
In fact, since Doctrine is aware of all your managed entities, when you call theflush() method, it
calculates an overall changeset and executes the most efficient query/queries possible. For
example, if you persist a total of 100 Product objects and then subsequently call flush(),
Doctrine will create a single prepared statement and re-use it for each insert. This pattern is
called Unit of Work, and it's used because it's fast and efficient.
When creating or updating objects, the workflow is always the same. In the next section, you'll
see how Doctrine is smart enough to automatically issue an UPDATE query if the record
already exists in the database.
Doctrine provides a library that allows you to programmatically load testing data into your
project (i.e. "fixture data"). For information, see DoctrineFixturesBundle.
Fetching Objects from the Database
Fetching an object back out of the database is even easier. For example, suppose you've
configured a route to display a specific Product based on its id value:
public function showAction($id)
{
$product = $this->getDoctrine()
->getRepository('AcmeStoreBundle:Product')
->find($id);
if (!$product) {
}
throw $this->createNotFoundException('No product found for id '.$id);
}
// do something, like pass the $product object into a template
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