This document provides a summary of MongoDB and Mongoose 101 presented at a Phoenix MongoDB Meetup. It introduces the presenter and his background. It then provides a high-level overview of MongoDB and compares SQL and MongoDB terminology. The remainder of the document demonstrates basic CRUD operations in MongoDB using the Mongo shell and introduces Mongoose, an ORM for MongoDB, demonstrating how to define schemas and models and perform queries and validations. It also discusses subdocuments and population features in Mongoose.

1. MongoDB and Mongoose 101
Phoenix MongoDB Meetup
November 16, 2013
Will Button @wfbutton

2. About Me
• DevOps/IT/DBA for myList.com
• Founder of FitMeal.me – Meal Planning
• Extensive background in both development
and ops, specifically in scalability and
sustainability

3. MongoDB – The 10,000 foot View

4. SQL to Mongo Terminology
In SQL
In Mongo
• Database
• Database
• Table
• Collection
• Record
• Document

5. Basic CRUD Operations
Users:
Our dataset:
firstName:{type:String},
lastName:{type:String},
userName:{type:String, unique: true},
password:{type:String},
avatar:{type:String},
position:{type:String}

6. Basic CRUD Operations
Wills-MacBook-Pro:~ willbutton$ mongo
MongoDB shell version: 2.2.0
connecting to: test
> use myapp
switched to db myapp
>

7. Basic CRUD Operations
“C” is for Create
> db.users.insert( { firstName: "Will", lastName: "Button", username: "rekibnikufesin", password: "Password", avatar:
"images/will.png", position: "CEO" } )
>

8. Basic CRUD Operations
“R” is for Read
> db.users.find()
{ "_id" : ObjectId("5282dbceca316975c21907ef"), "firstName" : "Will", "lastName" : "Button", "username" : "rekibnikufesin",
"password" : "Password", "avatar" : "images/will.png", "position" : "CEO" }
> db.users.findOne()
{
"_id" : ObjectId("5282dbceca316975c21907ef"),
"firstName" : "Will",
"lastName" : "Button",
"username" : "rekibnikufesin",
"password" : "Password",
"avatar" : "images/will.png",
"position" : "CEO"
}
> db.users.find( { firstName: "Will" } )
{ "_id" : ObjectId("5282dbceca316975c21907ef"), "firstName" : "Will", "lastName" : "Button", "username" : "rekibnikufesin",
"password" : "Password", "avatar" : "images/will.png", "position" : "CEO" }
>

9. Basic CRUD Operations
“U” is for Update
> db.users.update( { firstName: "Will", lastName: "Button" }, { $set: { position: "Janitor" } } )
>
> db.users.find()
{ "_id" : ObjectId("5282dbceca316975c21907ef"), "avatar" : "images/will.png", "firstName" : "Will", "lastName" : "Button", "password"
: "Password", "position" : "Janitor", "username" : "rekibnikufesin" }
>
$set is your friend!

10. Basic CRUD Operations
“D” is for Delete
> db.users.remove( { lastName: "Button" } )
> db.users.count()
0
>

11. mongoose
• MongoDB object modeling for node.js

12. Why mongoose?
Let's face it, writing MongoDB validation, casting and business logic boilerplate is a
drag. That's why we wrote Mongoose.
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test');
var Cat = mongoose.model('Cat', { name: String });
var kitty = new Cat({ name: 'Zildjian' });
kitty.save(function (err) {
if (err) // ...
console.log('meow');
});
Mongoose provides a straight-forward, schema-based solution to modeling your
application data and includes built-in type casting, validation, query building, business
logic hooks and more, out of the box.

13. Go With The Flow:
Collections
Schema
Model
Documents
Documents

14. Putting it in action:
Use case:
• Build a CRM application using the M.E.A.N. stack
• Using Mongoose, provide basic CRUD operations inside the node stack

15. Database Schema
Database:
myapp
Collection:
users
Collection:
documents
Collection:
communications
firstName
lastName
username
password
avatar
position
docOwner
docType
dateSaved
description
fileLocation
commType
date
description
followUpDate
contact

16. Schema
A schema maps to a MongoDB collection and defines the shape of the documents within
that collection
var userSchema = new mongoose.Schema({
firstName:{type:String},
lastName:{type:String},
userName:{type:String, unique: true},
password:{type:String},
avatar:{type:String},
position:{type:String}
})

17. Models
To use our schema definition, we need to convert our blogSchema into a Model we
can work with
app.db.model('user',userSchema) ;

18. Documents
Instances of Models are Documents
var user = req.app.db.model('user') ;
Documents have built-in methods:
var query = user.find() ;
query.sort({lastName:'asc'}) ;
query.exec(function(err,data){
if(err){
console.log(err);
res.send(500) ;
}
res.json(data) ;
})

19. Putting it all together
Open a connection
app.db = mongoose.createConnection('mongodb://localhost/myapp') ;
app.db.on('error', function() {
console.error.bind(console, 'mongoose connection error: ');
});
app.db.once('open', function () {
console.log('mongoose open for business');
});

22. Badass, Right?
But that only gets us so far.
Let’s explore some of the other features available to us, such as validations,
sub-documents, populations

23. Queries
var user = req.app.db.model('user') ;
try{
var id = req.params['userId'] ;
user.findOne({_id: id}, 'firstName userName', function(err,data){
console.log('find by id') ;
res.json(data) ;
});
}
catch(e){
console.log(e);
res.send(e) ;
}
var user = req.app.db.model('user');
// console.log(req.body) ;
var newuser = new user(req.body);
newuser.validate(function(error) {
if (error) {
res.json({ error : error });
} else {
delete req.body._id ;
user.findByIdAndUpdate({_id:newuser._id},{$set:req.body},function(err,data){
res.json(data) ;
})
}
});

24. Validations
Validation is defined in the SchemaType
Validation occurs when a document attempts to be saved, after defaults have been applied
Validation is asynchronously recursive; when you call Model#save, sub-document validation is executed as well
var user = req.app.db.model('user');
// console.log(req.body) ;
var newuser = new user(req.body);
newuser.validate(function(error) {
if (error) {
res.json({ error : error });
} else {
delete req.body._id ;
user.findByIdAndUpdate({_id:newuser._id},{$set:req.body},function(err,data){
res.json(data) ;
})
}
});
All SchemaTypes have the built in required validator.
Numbers have min and max validators.
Strings have enum and match validators.

25. Validations
var userSchema = new mongoose.Schema({
firstName:{type:String},
lastName:{type:String},
userName:{type:String, unique: true},
password:{type:String},
avatar:{type:String},
position:{type:String}
})

26. Sub-Documents
Documents within documents?!?!? What is this witchcraft you speak of???
Sub-documents are documents with their own schema and are elements of a
parent’s document array
• All the same features as normal documents
• Saved when parent document saved
• Errors bubble up to parent callback

27. Sub-Documents
var childSchema = new Schema({ name: 'string' });
var parentSchema = new Schema({
children: [childSchema]
})
Finding a sub-document
var doc = parent.children.id(id);
Add with standard array methods: push, addToSet, unshift
parent.children.push({ name: 'Liesl' });
Remove by id
var doc = parent.children.id(id).remove();

28. Population
Allows “joining” data from other collections
var communicationSchema = new mongoose.Schema({
commType:{type:String},
date:{type:Date},
description:{type:String},
followUpDate:{type:Date},
owner:[{type: mongoose.Schema.Types.ObjectId, ref:'user'}]
})
var userSchema = new mongoose.Schema({
firstName:{type:String},
lastName:{type:String},
userName:{type:String, unique: true},
password:{type:String},
avatar:{type:String},
position:{type:String}
})
var Communication= mongoose.model(‟Comm', communicationSchema);
var User= mongoose.model(‟User', userSchema);

29. Population
var stevie = new User({ _id: 0, firstName: “Stevie”, lastName: “Wonder” })
stevie.save(function (err){
if (err) return handleError(err);
var comm1 = new Communication({
commType: “Phone call”,
description: “I just called to say I love you”,
owner: stevie._id
});
comm1.save(function (err){
if (err) return handleError(err);
});
})
Communication
.findOne({ commType: “Phone call”})
.populate(„owner‟)
.exec(function (err,comm){
if(err) return handleError(err);
console.log(„Call owner is %s‟, communication.owner.firstName);
})

30. Thank You!
• Questions
• Comments
• More Info