Slides from November Phoenix MongoDB User Group

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