Mongoose and MongoDB 101

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

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

MongoDB – The 10,000 foot View

SQL to Mongo Terminology
In SQL

In Mongo

• Database

• Database

• Table

• Collection

• Record

• Document

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}


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

“C” is for Create

> db.users.insert( { firstName: "Will", lastName: "Button", username: "rekibnikufesin", password: "Password", avatar:
"images/will.png", position: "CEO" } )
>

“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" }
>

“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!

“D” is for Delete

> db.users.remove( { lastName: "Button" } )
> db.users.count()
0
>

mongoose
• MongoDB object modeling for node.js

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.

Go With The Flow:
Collections

Schema

Model

Documents

Documents

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

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

Schema
A schema maps to a MongoDB collection and defines the shape of the documents within
that collection

var userSchema = new mongoose.Schema({

})

Models
To use our schema definition, we need to convert our blogSchema into a Model we
can work with

app.db.model('user',userSchema) ;

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) ;
})

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');
});

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

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) ;
})
}
});

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.

Validations
})

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

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();

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 Communication= mongoose.model(‟Comm', communicationSchema);
var User= mongoose.model(‟User', userSchema);

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);
})

Thank You!
• Questions
• Comments
• More Info

Mongoose and MongoDB 101

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Mongoose and MongoDB 101

Similar to Mongoose and MongoDB 101 (20)

More from Will Button

More from Will Button (9)

Recently uploaded

Recently uploaded (20)

Mongoose and MongoDB 101

Editor's Notes