From A Morning with MongoDB - Milan on October 24, 2012.

1. RESTful Web API
with MongoDB
Nicola Iarocci

2. Good Morning.

3. Italian edition
Il Piccolo
Libro di MongoDB
by Karl Seguin, traduzione di
Nicola Iarocci
http://nicolaiarocci.com/il-piccolo-libro-di-mongodb-edizione-italiana/

4. gestionaleamica.com
invoicing & accounting

5. Your Typical Old School
Desktop app...
... now going web & mobile

6. MongoDB
and REST
or
why we picked MongoDB
for our REST API

7. Similarity with
RDBMS
made NoSQL easy to grasp (even for a dumbhead like me)

8. Terminology
RDBMS Mongo
Database Database
Table Collection
Rows(s) JSON Document
Index Index
Join Embedding & Linking

9. JSON-style data store
true selling point for me

10. JSON & RESTful API
GET
Client Mongo
JSON JSON
accepted media type (BSON)
maybe we can push directly to client?

11. JSON & RESTful API
GET
Client API Mongo
JSON JSON/dict JSON
accepted media type maps to python dict (BSON)
almost.

12. JSON & RESTful API
POST
Client API Mongo
JSON JSON/dict JSON
maps to python dict
objects (BSON)
(validation layer)
also works when posting (adding) items to the database

13. What about Queries?
Queries in MongoDB are represented as JSON-style objects
// select * from things where x=3 and y="foo"
db.things.find({x: 3, y: "foo”});

14. JSON & RESTful API
FILTERING & SORTING
?where={x: 3, y: "foo”}
Client API Mongo
(very) thin
native parsing JSON
Mongo & validation (BSON)
query syntax
layer

15. JSON
all along the pipeline
mapping to and from the database feels more natural

16. Schema-less
dynamic objects allow for a painless evolution of our schema
(because yes, a schema exists at any point in time)

17. ORM
Where we’re going we don’t need ORMs.

18. PyMongo
official Python driver
MongoDB drivers are beautiful

19. Also in MongoDB
• setup is a breeze
• lightweight
• fast inserts, updates and queries
• excellent documentation
• great support by 10gen
• great community

20. Collections
API’s entry point + plural nouns
http://api.example.com/v1/contacts

21. Document
Documents are identified by ObjectID
http://api.example.com/v1/contacts/4f46445fc88e201858000000
And eventually by an alternative lookup value
http://api.example.com/v1/contacts/CUST12345

22. Collection GET
http://api.example.com/v1/contacts?where={“age”: {“$gt”: 20}}
def get_collection(collection):
documents = []
cursor = db(collection).find(**args)
for document in cursor:
documents.append(document)
return documents
find() accepts a python dict
as query expression, and
returns a cursor we can
iterate

23. PATCH
Editing a Resource

24. PATCHing
def patch_document(collection, original):
(...)
# Perform the update
db(collection).update({"_Id": ObjectId(object_id)},
{"$set": updates})
mongo update() method
commits updates to the
database.

25. PATCHing
def patch_document(collection, original):
(...)
# Perform the update
db(collection).update({"_Id": ObjectId(object_id)},
{"$set": updates})
udpate() takes the unique Id
of the document to update

26. PATCHing
def patch_document(collection, original):
(...)
# Perform the update
db(collection).update({"_Id": ObjectId(object_id)},
{"$set": updates})
$set accepts a dict
with the updates for the db
eg: {“active”: False}.
updates are atomic

27. POST
Creating Resources

28. POSTing
def post(collection):
(...)
for key, item in docs.items():
response[ID_FIELD] = db(collection).insert(item)
push document and get its
ObjectId back from Mongo.
like other CRUD operations,
inserting is trivial in
mongo.

29. Introducing
Eve
Open Source RESTful Web API
powered by MongoDB

30. in !
rk ess
wo gr
p ro
he r y
t t to
ge ll s !
u ere
f h
... stay tuned!

31. Wanna see it running?
Hopefully it won’t explode right into my face

32. Thank you.
english: @nicolaiarocci
italian: nicolaiarocci.com