An introduction to MongoDB and the Doctrine MongoDB ODM.

1. Doctrine MongoDB ODM
Kris Wallsmith
October 19, 2010

2. @kriswallsmith
• Symfony Release Manager
• Doctrine Team
• Senior Software Engineer at
• 10 years experience with PHP and web development
• Open source evangelist and international speaker

3. This is MongoDB…

4. $mongo = new Mongo();
$db = $mongo->pdxphp;
$db->people->save(array(
'name' => 'Kris Wallsmith',
));

5. $cursor = $db->people->find();
print_r(iterator_to_array($cursor));

6. Array
(
[4cbdffdae84ded424f000000] => Array
(
[_id] => MongoId Object
[name] => Kris Wallsmith
)
)

7. MongoDB is where you
put your arrays for later.

8. $db->people->save(array(
'name' => 'Sam Keen',
'roles' => array(
'organizer',
'presenter',
),
));

9. $query = array('roles' => 'presenter');
$cursor = $db->people->find($query);
print_r(iterator_to_array($cursor));

10. Array
(
[4cbe03cfe84dedb850010000] => Array
(
[_id] => MongoId Object
[name] => Sam Keen
[roles] => Array
(
[0] => organizer
[1] => presenter
)
)
)

11. Me too!

12. $query = array(
'name' => 'Kris Wallsmith',
);
$kris = $db->people->findOne($query);
$kris['roles'] = array('presenter');
$db->people->save($kris);

13. $query = array('roles' => 'presenter');
$fields = array('name');
$cursor = $db->people->find($query, $fields);
print_r(iterator_to_array($cursor));

14. Array
(
[4cbe0a9de84ded7952010000] => Array
(
[_id] => MongoId Object
[name] => Sam Keen
)
[4cbe0a9de84ded7952000000] => Array
(
[_id] => MongoId Object
[name] => Kris Wallsmith
)
)

15. Be surgical.

16. $query = array('roles' => 'presenter');
$update = array(
'$push' => array(
'roles' => 'cool guy',
),
);
$db->people->update($query, $update);

17. Atomic Operators
• $inc • $addToSet
• $set • $pop
• $unset • $pull
• $push • $pullAll
• $pushAll • $rename

18. Advanced Queries

19. $roles = array('organizer', 'presenter');
$db->people->find(array(
'roles' => array('$all' => $roles),
));

20. Conditional Operators
• $ne • $size
• $in • $exists
• $nin • $type
• $mod • $or
• $all • $elemMatch

21. Cursor Methods

22. $cursor = $db->people->find();
$cursor->sort(array('name' => 1));
foreach ($cursor as $person) {
// ...
}

23. I like you, Sam.

24. $samRef = MongoDBRef::create('people', $samId);
$db->people->update(
array('_id' => $kris['_id']),
array(
'$addToSet' => array(
'likes' => $samRef,
),
)
);

25. $sam = $db->getDBRef($samRef);

26. $db->people->find(array(
'likes.$id' => $kris['_id'],
));

27. Terminology
RDBMS MongoDB
Database Database
Table Collection
Row Document
Foreign Key Database Reference

28. A document is an array.

29. Arrays are nice.

30. Objects are better.*
* Whenever objects are better.

31. The Doctrine MongoDB
Object Document Mapper
maps documents
to and from objects.

32. We just need to tell it how.

33. /** @Document(collection="people") */
class Person {
/** @Id */
public $id;
/** @String */
public $name;
/** @Collection */
public $roles = array();
/** @ReferenceMany */
public $likes = array();
/** @EmbedMany(targetDocument="Address") */
public $addresses = array();
}

34. POPO FTW!

35. $kris = new Person();
$kris->name = 'Kris Wallsmith';
$kris->roles[] = 'presenter';
$kris->likes[] = $sam;
$kris->addresses[] = $homeAddy;
$documentManager->persist($kris);
$documentManager->flush();

36. Wherefore art thou
->save()
?

37. Documents
Controller Document
Manager

39. ActiveRecord is more abstract.

40. Doctrine calculates the
optimal query for you.

41. $kris = $dm->findOne('Person', array(
'name' => 'Kris Wallsmith',
));
$kris->roles[] = 'cool guy';
$dm->flush();

42. $db->people->update(array(
'_id' => $kris->id,
), array(
'$push' => array(
'roles' => 'cool guy',
),
));

43. Query API

44. $query = $dm->createQuery('Person')
->field('name')->notEqual('Kris Wallsmith')
->field('roles')->equals('presenter')
->sort('name', 'asc');
$cursor = $query->execute();

45. Lifecycle Callbacks

46. /** @Document @HasLifecycleCallbacks */
class Foo
{
/** @Timestamp */
public $createdAt;
/** @PrePersist */
public function ensureCreatedAt() {
$this->createdAt = new DateTime();
}
}

47. OpenSky is Hiring!
http://engineering.shopopensky.com
Please contact me if you're interested.

48. OpenSky is Hiring!
http://engineering.shopopensky.com
Please contact me if you're interested.

49. mongodb.org
doctrine-project.org
symfony-reloaded.org