📙 📖 Learn MongoDb

This repository will help you learn to query MongoDb collections. You will go through 32 exercises. For each exercise you will query a collection of Restaurants to return the desired data.

Intro to MongoDb

MongoDb is the leading NoSQL Database today. You'll find it supports SQL-like aggregation and is used by the big companies like Facebook and Expedia. Though used in enterprise-grade applications, it is also quick and easy for solo developers to get started with.

MongoDb stores data in JSON-like structures. This makes it a top-choice in the JavaScript world because it is so familiar and it fits hand-in-glove with the rest of a Javascript developer's toolkit. For example a database entry for a restaurant might look like:

{
  "address": {
     "building": "1007",
     "coord": [ -73.856077, 40.848447 ],
     "street": "Morris Park Ave",
     "zipcode": "10462"
  },
  "borough": "Bronx",
  "cuisine": "Bakery",
  "grades": [
     { "date": { "$date": 1393804800000 }, "grade": "A", "score": 2 },
     { "date": { "$date": 1378857600000 }, "grade": "A", "score": 6 },
     { "date": { "$date": 1358985600000 }, "grade": "A", "score": 10 },
     { "date": { "$date": 1322006400000 }, "grade": "A", "score": 9 },
     { "date": { "$date": 1299715200000 }, "grade": "B", "score": 14 }
  ],
  "name": "Morris Park Bake Shop",
  "restaurant_id": "30075445"
}

The example document above might live in a collection simply called Restaurants. In the same database might be another collection called Coffee Shops.

A collection in MongoDb is analagous to a table in a SQL database. A collection is a collection of related documents.

Getting Started

Exercises can be found here

In your terminal execute the following commands:

git clone https://github.com/peterbsmith2/learn-mongo.git
cd learn-mongo
git checkout exercise
npm i

After completing the above:

1. open server/controllers/restaurant.controller.js in your favorite text-editor
2. Notice the structure of the document and read through the directions
3. Begin writing queries and use the reference documentation

Running the Server

node index.js

then test in browser: http://localhost:3000/api/1

Checking Your Answers

This repository includes test code which you can find in the test folder. When you've successfully completed the queries for an exercise, the tests will pass. Until you have, they will fail. To run the tests you must have mocha installed globally.

npm i -g mocha

With mocha installed, run

npm test

NOTE: Some of the queries return 25,000+ results and therefore take up to 15 seconds to respond.* You may want to write a few queries at a time to reduce the amount of time you're waiting for the test suite to run. See the code in test/exercises.js for an additional tip if your tests are too slow.

*This repository uses a free database hosted at modulus. We are not worried about performance for the sake of this repository, only learning queries. It would be unwise in most situations to write queries which return 25,000+ results. (One way that developers reduce the size of responses is called pagination. This means that a request may only return up to 100 results. It will include in those results an endpoint to query to return the next 100 results. Exercise 7 reveals how this works.)

##Reference Documentation to help with queries

Mongoose
MongoDb

Stuck? Have a question?

Open an issue!