MongoDB hearts Django? (Django NYC)

A look at how to work with MongoDB and Django, and how we can make the interaction even better in the future.

1. open-source, high-performance,
schema-free, document-oriented
database
http://www.mongodb.org/

2. The Web framework for perfectionists
with deadlines
http://www.djangoproject.com/

4. “One size fits all”
no longer
RDBMS
(Oracle, MySQL)
New gen. OLAP
(vertica, aster, greenplum)
Non-relational
operational stores
(“NoSQL”)

5. NoSQL really means:
non-relational next generation
operational datastores and databases

6. Scaling out
no joins +
light transactional semantics =
horizontally scalable architectures

7. Data models
no joins +
light transactional semantics =
horizontally scalable architectures
important side e!ect :
new data models =
improved ways to develop
applications

8. Data models
Key/value
memcached, dynamo, voldemort
Tabular
bigtable, cassandra, hbase, hypertable
Document-oriented
couchdb,

10. MongoDB in two minutes
•Documents (think rows) are dicts:
•Collections (think tables) are schema-free
•Queries are dynamic
•Great single node performance
•Built in replication and auto-sharding
•No complex transactions
{“hello”: “world”}
{“hello”: “world”, “foo”: [{“bar”: 1}]}

11. ?

12. Yes...
...but also sometimes no

13. Similar to +
•A lot of Django doesn’t depend on django.db:
•URL dispatch, templates, I18N, caching, etc.
•Some things do:
•Models
•Auth
•Sessions
•Admin

14. settings.py
DATABASE_ENGINE = ''
DATABASE_NAME = ''
DATABASE_USER = ''
DATABASE_PASSWORD = ''
DATABASE_HOST = ''
DATABASE_PORT = ''
MIDDLEWARE_CLASSES = (
'django.middleware.common.CommonMiddleware',
# 'django.contrib.sessions.middleware.SessionMiddleware',
# 'django.contrib.auth.middleware.AuthenticationMiddleware',
)
INSTALLED_APPS = (
# 'django.contrib.auth',
'django.contrib.contenttypes',
# 'django.contrib.sessions',
'django.contrib.sites',
)

15. Representing a Poll
{'question': 'Do MongoDB + Django <3 each other?',
'pub_date': datetime.datetime(2010, 1, 21),
'choices': [{'votes': 35, 'choice': 'Yes!'},
{'votes': 2, 'choice': 'No...'}]}

16. models.py (PyMongo)
def save_poll(question):
return db.polls.insert({"question": question,
"pub_date": datetime.utcnow()})
def all_polls():
return db.polls.find()
def add_choice(poll_id, choice):
db.polls.update({"_id": poll_id},
{"$push": {"choices": {"choice": choice,
"votes": 0}}})
def add_vote(poll_id, choice):
db.polls.update({"_id": poll_id},
{"$inc": {"choices.%d.votes" % choice: 1}})
http://api.mongodb.org/python

17. models.py (MongoKit)
class Poll(mongokit.Document):
structure = {"question": str,
"pub_date": datetime,
"choices": [{"choice": str,
"votes": int}]}
required_fields = ["question"]
default_values = {"pub_date": datetime.utcnow()}
http://bytebucket.org/namlook/mongokit

18. models.py (Ming)
class Poll(ming.Document):
class __mongometa__:
session = session
name = "polls"
_id = ming.Field(ming.schema.ObjectId)
question = ming.Field(str, required=True)
pub_date = ming.Field(datetime.datetime,
if_missing=datetime.datetime.utcnow)
choices = ming.Field([{"choice": str,
"votes": int}])
http://merciless.sourceforge.net/

19. mango - sessions and auth
http://github.com/vpulim/mango
•Full sessions support
•mango provided User class
•supports is_authenticated(), set_password(), etc.

20. mango - sessions and auth
http://github.com/vpulim/mango
SESSION_ENGINE = 'mango.session'
AUTHENTICATION_BACKENDS = ( 'mango.auth.Backend' ,)
MONGODB_HOST = 'localhost'
MONGODB_PORT = None
MONGODB_NAME = 'mydb'

21. What about admin?
•No great solution... yet.
•Could replace admin app like mango does
for sessions / auth
•Or...

22. Supporting MongoDB
in django.db
•Best solution (long term)
•http://bitbucket.org/kpot/django-mongodb/
•http://bitbucket.org/wkornewald/django-nonrel/
•http://code.djangoproject.com/wiki/NonSqlBackends

23. 1.Download MongoDB
http://www.mongodb.org
2.Try it out!
3.(And help us make things work better with
Django!)

24. •http://www.mongodb.org
•irc.freenode.net#mongodb
•mongodb-user on google groups
•@mongodb, @mdirolf
•[email protected]
•http://www.slideshare.net/mdirolf
•http://github.com/mdirolf/djanMon/