abrahamhall84/music_lab

Use Sinatra and ActiveRecord to list your favorite musicians

Music Lab

In this lab you'll be creating a web application for saving some of your favorite music. You can keep track of your favorite Artists and your favorite Songs (as part of the bonus). Naturally, you'll be able to Create, Read, Update, and Delete these resources.

This will be a Sinatra app and we will be utilizing our newfound knowledge of ActiveRecord. We will be using ActiveRecord to create our database, create tables, and interact with the database.

Research

Before you start coding, look up the answers the following questions and place them inline below:

1. What are some books that Martin Fowler has written?
2. What's the difference between "active record" and "ActiveRecord"?
3. Is the "active record" pattern an ORM?
4. Why might we want to use an ORM in our code?
5. What gem do we need to allow Sinatra to interact with ActiveRecord?
6. What is rake?
7. What is a database migration?
8. What command can we use to create a new ActiveRecord migration?
9. What command runs our existing migrations?
10. What commands reverses a migration?
11. What command tells us which migrations have run and which have not?
12. Which class do we have to extend if we want to create a new model?
13. What's the difference between ActiveRecord's .new and .create methods?
14. What's the difference between ActiveRecord's .find and .find_by methods?
15. What's the difference between ActiveRecord's .find_by and .where methods?
16. What ActiveRecord method do we use to change a value in the database?
17. What ActiveRecord method do we use to remove an item from the database?

Steps

Create a Sinatra app.

Forget about ActiveRecord for this first step. Just get a Sinatra app up and running, make sure it works, and then commit it to Git.

Integrate ActiveRecord into your app.

Take your working Sinatra app and integrate ActiveRecord.

• Use the sinatra-activerecord gem.
• Create the Rakefile to make rake tasks available.
  • rake -T should list all the available tasks if setup properly.
• rake db:create should create your database if config/database.yml is setup properly.

Create the Artists table

• Create an ActiveRecord Migration for creating the Artists table.
  • Hint: rake -T might help you remember how.
• You'll need to run the migration in order for the table to actually be created.

Create all the CRUD routes for Artists.

• GET
  • /artists - reads all artists
  • /artists/new - display a form to create a new artist
  • /artists/:id - reads a single artist
  • /artists/:id/edit - display a form to edit an artist
• POST
  • /artists - create a new artist in the database
• PUT
  • /artists/:id - update the artist with the given id.
• DELETE
  • /artists/:id - remove an artist from the database.

This will feel very similar to your Squad lab refactor, but instead of writing SQL or writing your own ORM, you should use ActiveRecord to talk to the database. For instance, instead of writing @conn.exec "SELECT * FROM artists" or implementing your own Artist.all, you should use the Artist.all that comes built-in to ActiveRecod. Of course, in order to do this you'll need to create the Artist class that extends ActiveRecord::Base.

Bonus

The bonus is to implement the Songs component of this app. You should be able to add Songs to an Artist. Put another way, Artist has a 1-to-many relationship with Songs. How do you express relationships within ActiveRecord? Implement full CRUD operations on Songs.

Steps

You'll need:

• a migration to create the songs table.
• a foreign key in the songs table referencing the artists table.
• a Song model class
• routes such at /artists/:artist_id/songs, /artists/:artist_id/songs/:id, etc.

Even More Bonus

• Style it. It never hurts to practice your design skills.
• Use a seeds.rb file to help populate the database with initial values.