Keynote from the first Fullstack: Ruby on Rails meetup hosted by General Assembly. Presentation about how Rails and MongoDB fit together naturally and how to use MongoDB with Rails through the Mongoid ODM. http://www.meetup.com/FullStack-General-Assembly-NYC-Ruby-on-Rails/events/107952222/

1. Emily Stolfo
Ruby Engineer at 10gen
@EmStolfo

2. MongoDB and Rails fit
together naturally

3. Ruby engineer on the drivers team
art historian
consultant
adjunct faculty
at Columbia
web (Rails) developer

4. Learning Rails is unconventional
you have to be resourceful
○ example projects
○ online tutorials
○ community

5. Rails has conventions
DSL ActiveRecord
convention over rvm
configuration bundler
blackboxed gems community
DRY MVC
All http stuff was github
written already

6. ActiveRecord
● ActiveRecord bridges the gap between
OOP and a relational database
● mongodb is OO natively
● Rails was built for a relational database

7. what is ?
MongoDB comes from the word ______.
It is a ______ database that is highly
______ and released under the ______
license, making it ______.
It stores data in ______ format and is
often favored for the ______ experience
because it is ______.

8. What is Ruby?
Ruby was created by ______.
Ruby is extremely ______ and ______ to
use.
It is known for seeing everything as an
______ and for the ______ experience.

9. What is a mongodb driver?
1. connection pooling
2. serialization/deserialization
BSON<->hashes
3. wire protocol
4. classes for server stuff
ex: abstracts RS, sharded cluster
https://github.com/mongodb/mongo-ruby-driver/

10. @connection = MongoClient.new("localhost", 27017)
@data = @connection.db("data")
@users = @data.collection("users")

11. emily = {
:name => "Emily",
:age => 28,
:langs => ["Ruby", "Python", "C++"],
:favorites => {
:artists => ["George Bellows", "Rodin"],
:color => "Blue",
:movies => ["Old Boy", "Gladiator"]
}
}
@users.insert(emily)

12. @users.find({:name => "Emily"}) # name = "Emily"
@users.find({:age => {"$lt" => 30 } } ) # age < 30
@users.find({
:age => {"$lt" => 30 }, # ... AND ...
:langs => "Ruby", # look in array
"favorites.color" => "Blue", # reach into objects
} )

13. emily = @users.find_one({:name => "Emily"})
emily.langs << "Lisp"
@users.save(emily) # too late?
@users.update(
{ :name => "Emily" },
{ :$push => { :langs => "Lisp" } }
)

14. @sites.update(
{:url => "http://www.nytimes.com"},
{ :$inc => { :visits => 1 } },
:upsert => true )

15. Mongo::MongoReplicaSetClient.new(
['localhost:3000', 'localhost:3001', 'localhost:3002' ] )
Mongo::MongoShardedClient.new(
['localhost:3000', 'localhost:3001', 'localhost:3002' ]
)

16. ODM: Mongoid
How do we get Ruby, Rails, and
MongoDB to work together?
Object Document Mapper available
as a gem
Used to be community ODM, with its
own driver

17. User and Favorite
model files
class User
include Mongoid::Document
field :name, type: String
field :age, type: Integer
field :langs, type: Array
has_many :favorites
end
class Favorite
include Mongoid::Document
field :artists, type: Array
field :color, type: String
field :movies, type: Array
belongs_to :user
end

18. Docs in MongoDB
# The parent user document
{
"_id" : ObjectId("512e8fdab074c63e71dc6500"),
"name" : "Emily",
"age" : 28,
"langs" : ["Ruby", "Python", "C++"],
}
# The child favorite document
{
"_id" : ObjectId("512e8fdab074c63e71dc6501"),
"artists" : ["George Bellows", "Rodin"],
"color" : "Blue",
"movies" : ["Old Boy", "Gladiator"],
"user_id" : ObjectId("512e8fdab074c63e71dc6500")
}

19. User and Favorite
model files
class User
include Mongoid::Document
field :name, type: String
field :age, type: Integer
field :langs, type: Array
embeds_one :favorite
end
class Favorite
include Mongoid::Document
field :artists, type: Array
field :color, type: String
field :movies, type: Array
embedded_in :user
end

20. Docs in MongoDB
# The user info and favorites in a single document
{
"_id" : ObjectId("512e8fdab074c63e71dc6500"),
"name" : "Emily",
"age" : 28,
"langs" : ["Ruby", "Python", "C++"],
"favorite" : {
"artists" : ["George Bellows", "Rodin"],
"color" : "Blue",
"movies" : ["Old Boy", "Gladiator"],
}
}

21. Thanks!
Keep using resources and the community
Check out the ruby driver and submit a pull
request
https://github.com/mongodb/mongo-ruby-driver/
Try out mongoDB and Mongoid
Emily Stolfo
@EmStolfo