Building Your First
Application
Kevin Hanson
Solutions Architect, 10gen
Kevin@10gen.com
@hungarianhc

Step 1 - What is mongoDB??
• Scalable, High-Performance, Open Source, Document-
Oriented Database
– JSON (well... BSON) Storage Model
– Indexes and Full Query Language
– Easy for Developers to Pick Up
• More Features at http://www.mongodb.org/
• Overview Video: http://www.10gen.com/what-is-mongodb

Step 2 - Stop Thinking Relational

Tables to Documents
{
title: ‘MongoDB’,
contributors: [
{ name: ‘Eliot Horowitz’,
email: ‘eliot@10gen.com’ },
{ name: ‘Dwight Merriman’,
email: ‘dwight@10gen.com’ }
],
model: {
relational: false,
awesome: true
}
}

Parallels
RDBMS MongoDB
Table Collection
Row Document
Column Field
Index Index
Join Embedding / Linking
Schema Object

Rich Data Model
{ _id : ObjectId("4c4ba5c0672c685e5e8aabf3"),
author : "roger",
date : "Sat Jul 24 2010 19:47:11 GMT-0700 (PDT)",
text : "Spirited Away",
tags : [ "Tezuka", "Manga" ],
comments : [
{
author : "Fred",
date : "Sat Jul 24 2010 20:51:03 GMT-0700 (PDT)",
text : "Best Movie Ever"
}
]}

Querying
>db.posts.find()
{ _id : ObjectId("4c4ba5c0672c685e5e8aabf3"),
author : "roger",
date : "Sat Jul 24 2010 19:47:11 GMT-0700 (PDT)",
text : "Spirited Away",
tags : [ "Tezuka", "Manga" ] }
Notes:
- _id is unique, but can be anything you’d like

Secondary Indexes
Create index on any Field in Document
// 1 means ascending, -1 means descending
>db.posts.ensureIndex({author: 1})
>db.posts.find({author: 'roger'})
{ _id : ObjectId("4c4ba5c0672c685e5e8aabf3"),
author : "roger",
... }

Secondary Indexes
// Index nested documents
> db.posts.ensureIndex( “comments.author”:1 )
db.posts.find({‘comments.author’:’Fred’})
// Index on tags
> db.posts.ensureIndex( tags: 1)
> db.posts.find( { tags: ’Manga’ } )
// geospatial index
> db.posts.ensureIndex( “author.location”: “2d” )
> db.posts.find( “author.location” : { $near : [22,42] } )

Atomic Operations
• $set, $unset, $inc, $push, $pushAll, $pull, $pullAll,
$bit
> comment = { author: “fred”,
date: new Date(),
text: “Best Movie Ever”}
> db.posts.update( { _id: “...” },
$push: {comments: comment} );

Step 3 - Let’s Build A Sample App
Metadata Catalog
Q: Patients Matching Query
A: Patients
Patient Data
Metadata

Inserting a Document
var p = { name: “John Smith”,
address: “578 Broadway, 7th Floor”,
city: “New York”,
birthday: “2/15/2012”}
> db.patients.save(p)

Let’s Add Some Information
{ name: “John Smith”,
address: “578 Broadway, 7th Floor”,
city: “New York”,
birthday: “2/15/2012”,
clinics: [“Good Health Clinic”, “New York
General Care”]}

Geo Tags
{ name: “John Smith”,
address: “578 Broadway, 7th Floor”,
city: “New York”,
birthday: “2/15/2012”,
clinics: [“Good Health Clinic”, “New York
General Care”],
latlong: [40.0, 72.0]}

Doctor Notes
{ name: “John Smith”,
address: “578 Broadway, 7th Floor”,
city: “New York”,
birthday: “2/15/2012”,
clinics: [“Good Health Clinic”, “New York
General Care”],
latlong: [40.0, 72.0],
notes: [{doctor:”Kevin", time:3/15/2012,
note:”Patient seems healthy to me!"}]}

Updating Doctor Notes
db.places.update({name:”John Smith"},
{$push :{notes: {doctor:”Kevin", time:3/15/2012,
note:”Patient seems healthy to
me!"}}}}

Indexing / Querying Metadata
// List all people whose name is “John Smith”
> db.posts.ensureIndex( “name”:1 )
db.posts.find({‘name’:’John Smith’})
// List all people whose name is “John Smith”, sorted by
birthday descending
> db.posts.ensureIndex( name: 1, birthday: -1)
> db.posts.find( { name: ’John Smith’ } ).sort({birthday: -1})
// Return people that “Doctor Bob” made notes about, sorted
by their name
> db.posts.ensureIndex( notes.doctor: 1, name: 1)
> db.posts.find( “notes.doctor”: “Doctor Bob”).sort({name:1})

Demo ~ MongoDB Shell

Step 4 - Scale Your App w/
Replica Sets

Replica Sets

Replica Sets
Add Secondaries for High Availability / Read Scale
High Write Load / Big Data Set -> Use mongoDB Range
Based Auto Sharding (A Future Webinar / mongoDB Day)

More info at http://www.mongodb.org/
conferences, appearances, and meetups
http://www.10gen.com/events
Kevin Hanson
kevin@10gen.com
@hungarianhc
Facebook | Twitter | LinkedIn
http://bit.ly/mongofb @mongodb http://linkd.in/joinmongo