FlowFlorent / node-mysql-workshop

NodeJS + MySQL

NodeJS + MySQL workshop

This is our sequel to the databases workshops :)

Basic instructions

• Fork this repository and create a new Cloud9 project by cloning your fork
• All exercises to be done on master, in a file called exercise-#.js
• Some exercises may require NPM packages. You will need to use npm install --save to get these packages. The package.json should be part of the same commit where you start using the required package(s). For example, if one of the exercises requires the use of the request library, then the package.json for that submission should contain the dependency, and it should be committed at the same time as the exercise-#.js that requires it.
• A boilerplate.js file is made available to you. It contains the base code to load the MySQL library, make a first query, extract the rows as well as close the connection. You may copy this file for each exercise so that you have a base to get started from.

Before starting

Before starting the exercises, import the file called data.sql in MySQL. This will create a database called addressbook. The database will contain a few tables. Explore all the tables using describe to get a feel for this address book schema. Don't come back here until you know the table structure well! It'll make it easier to do the exercises.

Exercise 1: Getting started!

1. Write a program that fetches all the databases in MySQL and prints them nicely on the screen.
2. Don't hesitate to use colors or cli-table or any other module of your choice to make the output nicer.

Exercise 2: Getting back our data

1. Write a program that fetches the first 5 accounts in the addressbook database
2. For each account, console.log a line with the account's ID and email, like this: #1:[e-mail]
3. Use the colors NPM module with the .bold option to achieve this effect

Exercise 3: Joining up the data, part 1

1. Write a program that fetches all the accounts and their addressbooks.
2. Output one line for each account as in Exercise 4, followed by a listing of all the address book names for that account, one per line
3. Make the output look nice in any way you like
4. Here is an example:

#1: [e-mail]
  business contacts
  friends
#2: [e-mail]
  ...

Exercise 4: More about joins...

1. Notice that for the previous exercise, Account #5 did not appear in the listing. Don't come back here until you have re-checked the previous exercise and noticed for yourself that Account #5 is missing.
2. The reason for this is because Account #5 does not have any AddressBook, so doing the JOIN left it out.
3. Read and understand this article on SQL JOINs, more specifically about the LEFT JOIN.
4. Based on your new understanding, create a similar program to Exercise #4.
5. The only difference, if an account does not have any address book, print it like this:

#3: [e-mail]
  --no address books--

CHALLENGE: Joining up the data, part 2

1. Write a program that fetches all accounts, their addressbooks, and entries.
2. Hint #1: you will have two JOINs in your query.
3. Hint #2: you will need to use AS to give each column a unique name
4. Once you receive your results in JavaScript land, transform them into an array of accounts with nested relations.
5. Here is an example of the end result we are looking for. Note you will probably need to use some of these array methods we saw together in week 1. This is a good time to remind yourself of them, specifically map and reduce.

[
  {
    id: 1,
    email: '[e-mail]',
    addressBooks: [
      {
        id: 1,
        name: 'business contacts',
        entries: [
          {
            id: 1,
            firstName: 'John',
            lastName: 'Connor'
          },
          {
            id: 10,
            firstName: 'Sarah',
            lastName: 'Connor'
          }
        ]
      },
      {
        // another address book for account 1...
      }
    ]
  },
  {
    // another account...
  }
]