MongoDB, Mongoose and Atlas hosting

Homework

1. Review
   • Create, read, update and delete on Wikipedia
   • MVC definition on MDN
   • Model-view-controller
   • Using dotenv package to create environment variables
2. Introduction to CRUD and Mongoose
   • Read: NoSQL vs SQL Databases
   • Read: Mongoose CRUD (Create, Read, Update, Delete)
   • Reference: Mongoose Getting Started
3. MongoDB Atlas
   • Read: Get Started with Atlas
   • Read: How to host a RESTful Node.js server with MongoDB Atlas database on Heroku
     • Note:
       • CORS headers are often not needed with Atlas… but sometimes they are.
       • We will be connecting to Mongoose a little differently that what is shown in this article.

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Morning reflection

Housekeeping

• json enpoint review this afternoon
• No Dailies today (we’re only connecting with local code today)
• Goals for the day
  1. Connect successfully to MongoDB Atlas
  2. Import your gallery data into Atlas.

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1. NoSQL vs SQL

Learning Objectives

• Understand the difference between NoSQL and SQL (relational) databases.
• Define document databases and their terminology.
• Summarize the pros and cons to document databases and MongoDB in general.

Terminology

Document Database

A type of NoSQL (Not-only SQL) database that stores its data as documents on the file system. MongoDB is a json document database.

Database

Holds one or more collections.

Collection

A collection of documents (i.e. a fancy folder). Collections are analogous to tables in relational databases.

Document

MongoDB stores data in the form of json Documents (technically BSON documents). Each document is analagous to a row in a relational database.

Materials

• What is NoSQL?
• NoSQL vs SQL Databases

Key Takeaways

• MongoDB is a file database engine. It literally stores its data as a folder (i.e. Collection) of json files (i.e. Documents).
• Working with MongoDB is a little messy so we use the mongoose package to:
  • use a simpler syntax;
  • ensure the documents in a collection have the same structure;
  • hide the gritty details like promises and asynchronous things.

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2. Configuring MongoDB Atlas

Learning Objectives

• Create a MongoDB Atlas account.
• Configure Atlas for outside connections.
• Connect to Atlas with Mongoose.

Materials

• MongoDB Atlas Cheatsheet
• Setting up MongoDB Atlas
• hello-atlas

Key Takeaways

• The main error you will run into when connecting is Authentication Failed. Try the following:
  • Confirm you’ve set the correct username/password in your connection string. You can reset the password in the Atlas control panel.
  • Confirm you’ve changed the database in your connection string to winter-2021 or similar.
  • Confirm you’ve whitelisted all IPs in Atlas.

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3. Kitten models

Learning Objectives

• Understand the difference between Mongoose Schemas, Models and Instances.
• Create a Mongoose Schema.
• Compile a Mongoose Model from a Schema.
• Load data into a model from Atlas to create an Instance.

Terminology

Schema

A Javascript object that describes/defines the structure of a json document.

Model

A compiled Schema that facilitates communication with a MongdDB server.

Instance

A model that contains actual data, either assigned in your script or pulled from a MongoDB database.

Materials

• Mongoose Getting Started

Key Takeaways

• Defining your model is the first step to using mongoose (after you have successfully connected).
  • Example: This animal model describes this animal data.

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Open lab-time

Activities

1. Importing data into Atlas

   • Converting Javascript objects into json files

     Note: json files are for data only. Don’t include Javascript logic like =, const, etc. Stick to arrays and object values.

     Warning: MongoDB (and mongoose) assume you’ll be importing an array of objects. Any other data types will lead to unexpected results.

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Review Session: json API endpoints

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Dailies

• None today.