thehackingproject ruby ruby-on-rails chinook-database

Chinook Music db (100% finished)

A Ruby on rails project containing a music database (an Album model and a Track model). The data comes from the db>seeds.rb file.

General info

Made during The Hacking Project course on Week5 Day3.

Technologies

Project is created with

Ruby on Rails 5.2.3

Setup

First, go to the RoR project folder and type:

bundle install

then

rails c

Questions

Copy/paste the corresponding commands for each question in the console to display the answer.

😊 Easy level

What is the total number of Album objects contained in the database ?
```
Album.count
```
Who is the author of the song "White Room"?
```
Track.find_by(title: "White Room").artist
```
Which song lasts exactly 188133 milliseconds?
```
Track.find_by(duration: 188133).title
```
Which band released the album "Use Your Illusion II" ?
```
Album.find_by(title: "Use Your Illusion II").artist
```

🤨 Medium level

How many albums have "Great" in their title?

Album.where("title like ?", "%great%").count

eletes all the albums whose name contains "music".

Album.where("title like ?", "%music%").destroy_all

How many albums are there written by AC/DC ?
```
Album.where(artist: "AC/DC").count
```
How many songs last exactly 158589 milliseconds?
```
Track.where(duration: 158589).count
```

😵‍💫 Difficult level

puts in console all the titles of AC/DC.

Track.where(artist: "AC/DC").each do |track|
  puts track.title
end

puts in console all the titles of the album "Let There Be Rock".

Track.where(album: "Let There Be Rock").each do |track|
  puts track.title
end

Calculate the total price of this album and its total duration.

price = Track.where(album: "Let There Be Rock").sum(:price).round(2)
duration = Track.where(album: "Let There Be Rock").sum(:duration)
puts "#{price}, #{duration}"

Calculate the cost of the entire "Deep Purple" discography.
```
Track.where(artist: "Deep Purple").sum(:price).round(2)
```
Modify (via a loop) all the titles of "Eric Clapton" so that they are displayed with "Britney Spears" in artist.
```
Track.where(artist: "Eric Clapton").each do |track|
  track.update(artist: 'Britney Spears')
end
```

About

🚀💯 The Hacking Project - Chinook Music 🎸 🎵