Intro to Mongo

Motivation (Why?)

NoSQL databases are a popular and trending database technology and it gives us a full Javascript/JSON stack.

• Node - JavaScript
• Express - JavaScript
• jQuery - JavaScript
• AJAX - JSON (JavaScript)
• Mongo - JSON (JavaScript)
• AngularJS - JavaScript

Analogy (What?)

Imagine you're going to make a cake.

SQL is like shopping for the ingredients for the recipe. At the store, you have to go to many different aisles to get each ingredient.

Wouldn’t it be nicer if there was a store was organized by recipe, so you could go to one place in the store and grab everything you need from that one spot? That would be nice. And that would be like a NoSQL database.

mgoffin/Stack Overflow

NOTE: a "model" is like a JavaScript constructor for objects we will save to our database. Models are the 'data layer' of MVC frameworks. Want to access or store your data? Use a model.

Key Snippets

Enter a Node Server Console (REPL Console - Read-Eval-Print-Loop Console)

$ node

Connect a Server to Your Database

//
// index.js or server.js
//

var mongoose = require("mongoose");
mongoose.connect("mongodb://localhost/test");

Make a Model

//
//  models/dinosaur.js
//

var Schema = mongoose.Schema;
var DinosaurSchema = new Schema({
    name: String,
    period: String,
    description: String,
    height_in_inches: Integer
});

mongoose.model('Dinosaur', DinosuarSchema);

Get Documents using a Model

require('./models/dinosaur.js')

var Dinosaur = require('mongoose').model('Dinosaur');

var dinosaurs = Dinosaur.find().exec(function(err, dinosaurs) {
  console.log(dinosaurs)
})

Save a new Model Instance to DB

var Dinosaur = require('mongoose').model('Dinosaur');

var dinosaur = new Dinosaur({
    name: req.body.name
  , period: req.body.period
  , height: req.body.height_in_in
});
console.log(dinosaur);
dinosaur.save(function (err, dinosaur) {
  console.log('dinosaur saved')
  if (err) { return res.json(err) };
  res.status(201).json(dinosaur)
});

Challenges

Docs & Resources

• MongoDB Shell Quick Reference
• Mongoose Docs

Installation

Install MongoDB, a popular noSQL database.

• First we'll need to run brew update to update our brew packages.

  $ brew update
  

• Next we'll need to run brew install for MongoDB

  $ brew install mongodb
  

• Then we'll need a directory for MongoDB to save data.

  $ sudo mkdir -p /data/db
  

  • Finally we'll want to make sure we have permission to read and write to this directory.

  $ sudo chown -R $USER /data/db
  

  • Now you can start your mongo service

  $ mongod
  

Basic Mongo CLI Challenges

1. Open your mongo console with mongo.
2. Type help - can you find out how to show all your database names?
3. Type use awesomeshop - to specify that you want to use a new database for an imaginary ecommerce website.
4. Check which db you're in with db.show.
5. Look at your database names again. Is your new DB there?
6. Add a collection and item to your awesomeshop DB. db.products.insert({title:"iphone"})
7. Now check your database names.
8. Read this doc on MongoDB CRUD operations. (Ignore the "Related Features" section.)
9. Insert another 2 documents into two collections with at least two attributes each. E.g.

   book: { title:"title", published_on_year:1994 } }
   users: { name:"George", email:"[email protected]" } }
   

10. Query all your user documents.
11. Query only book documents published after 1990.

Basic Mongo/Express Challenges

1. Create a new node project with npm init.
2. Add express and mongoose to the project with npm install express mongoose --save.
3. Start your MongoDB database in a new terminal window with mongod.
4. Connect your node/express server to mongoDB using mongoose. See key snippets above.
5. Create a model for Book and include it in app.js. See key snippets above.
6. Let's create a get route to /books that returns a JSON array of all saved books. Use your existing code and the a key snippet above. Expected output: [] an empty array. Why is this empty?
7. Use your mongo console to insert 3 books into your database collection books. Remember that your database name is in the address you connected to with this line of code: mongoose.connect("mongodb://localhost/test");
8. Navigate your browser to /books - do you see your books?
9. Create a POST route in your express app that saves a new book. Use Postman to send in form data for a new book and save it.

Evening Challenge

1. Add Mongoose to your API projects query and create routes (POST and GET).

Remember to submit evening survey here