Mongoose CRUD and Heroku/Atlas Config

Homework

1. Review
   • Read: NoSQL vs SQL Databases
   • Mongoose Getting Started
2. Introduction to CRUD and Mongoose
   • Using Callbacks: NodeJs CRUD Operations Using Mongoose and MongoDB Atlas
   • Using Promises: CRUD Operations with Mongoose and MongoDB Atlas
   • Reference: Mongoose Queries in the mongoose documentation.
     • Model.find()
     • Model.findOne()
3. POST Requests in Express
   • Read: Handle GET and POST Request in Express
4. MongoDB Atlas
   • How to host a RESTful Node.js server with MongoDB Atlas database on Heroku

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Morning reflection

Housekeeping

• Assignment 4 deadline extended to Sunday
• Saturday Review Session: 10am
• Presentation this afternoon!

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1. Setting up Atlas on Heroku

Learning Objectives

• Add Atlas DB User credentials to Heroku Config Vars panel

Instructions

1. Login to your Heroku account.
2. Open the Admin panel of your app.
3. Go to Settings.
4. Under the heading Config Vars, enter your connection string (as the value) under the name MONGODB_URL.
5. Now your app should be able to connect to Atlas.

Key Takeaways

• Heroku’s Config Vars panel is where it stores environment variables like the ones in your .env file.
• Important: You need to name your Atlas connection string MONGODB_URL. Otherwise, Heroku won’t connect to Atlas properly.

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2. CRUD Operations with Mongoose

Learning Objectives

• Refactor an API to use Mongoose and MongoDB Atlas.
  • Connect to Atlas using mongoose.connect().
  • Export an Atlas connection as a local module.
  • Load a mongoose connection into a route.
  • Retrieve all records from a Collection using Model.find().
  • Retrieve one record from a Collection using Model.findOne().

Materials

• Starter: Definitions API using a local module
• Gist: Mongoose - Reading MongoDB data in Express

Key Takeaways

• mongoose supports asynchronous connections using either callbacks or promises. If you pass it a callback function as an argument, it will automatically use that callback. If not, it will default to using a promise.

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3. Handling POST requests

Learning Objectives

• Submit form data using the post method.
• Capture form data using express.urlencoded().
• Handle a post request using app.get().
• Create a model instance using form data.
• Create an Atlas record using Model.save().

Materials

• Handle GET and POST Request in Express
• Starter: Atlas Definitions Sample Code
• Gist: Mongoose - Create document from form data in Express

Key Takeaways

• express.urlencoded() is available in Express v4.16.0 onwards. For earlier versions, you’ll need to install the body-parser package.
• There is a json version of this middleware if you’re expecting a form to be submitted using Javascript: express.json(). It performs the same functionality and adds submitted data to req.body.

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Open lab-time

• Ash’s presentation!

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Dailies

• Submit today’s Codepen/repo/gist to the Dailies section (in Assessments) in Brightspace.