- Write Active Record Migrations
- Connect between tables using Active Record Associations
- Write class and instance methods using Active Record
- Use Active Record to query the database
For this assignment, we'll be working with a freebie domain.
As developers, when you attend hackathons, you'll realize they hand out a lot of free items (informally called freebies, or swag)! Let's make an app for developers that keeps track of all the freebies they obtain.
We have three models: Company
, Dev
, and Freebie
For our purposes, a Company
has many Freebie
s, a Dev
has many Freebie
s,
and a Freebie
belongs to a Dev
and to a Company
.
Company
- Dev
is a many to many relationship.
Note: You should draw your domain on paper or on a whiteboard before you start coding. Remember to identify a single source of truth for your data.
To get started, run bundle install
while inside of this directory.
Build out all of the methods listed in the deliverables. The methods are listed in a suggested order, but you can feel free to tackle the ones you think are easiest. Be careful: some of the later methods rely on earlier ones.
Remember! This code challenge does not have tests. You cannot run rspec
and you cannot run learn
. You'll need to create your own sample instances so
that you can try out your code on your own. Make sure your associations and
methods work in the console before submitting.
We've provided you with a tool that you can use to test your code. To use it,
run rake console
from the command line. This will start a pry
session with
your classes defined. You can test out the methods that you write here. You are
also encouraged to use the seeds.rb
file to create sample data to test your
models and associations.
Writing error-free code is more important than completing all of the deliverables listed - prioritize writing methods that work over writing more methods that don't work. You should test your code in the console as you write.
Similarly, messy code that works is better than clean code that doesn't. First, prioritize getting things working. Then, if there is time at the end, refactor your code to adhere to best practices.
Before you submit! Save and run your code to verify that it works as you expect. If you have any methods that are not working yet, feel free to leave comments describing your progress.
The starter code has migrations and models for the initial Company
and Dev
models, and seed data for some Company
s and Dev
s. The schema currently looks
like this:
Column | Type |
---|---|
name | String |
founding_year | Integer |
Column | Type |
---|---|
name | String |
You will need to create the migration for the freebies
table using the
attributes specified in the deliverables below.
Write the following methods in the classes in the files provided. Feel free to build out any helper methods if needed.
Deliverables use the notation #
for instance methods, and .
for class
methods.
Remember: Active Record give your classes access to a lot of methods already! Keep in mind what methods Active Record gives you access to on each of your classes when you're approaching the deliverables below.
Before working on the rest of the deliverables, you will need to create a
migration for the freebies
table.
- A
Freebie
belongs to aDev
, and aFreebie
also belongs to aCompany
. In your migration, create any columns yourfreebies
table will need to establish these relationships using the right foreign keys. - The
freebies
table should also have:- An
item_name
column that stores a string. - A
value
column that stores an integer.
- An
After creating the freebies
table using a migration, use the seeds.rb
file to
create instances of your Freebie
class so you can test your code.
Once you've set up your freebies
table, work on building out the following
deliverables.
Use Active Record association macros and Active Record query methods where
appropriate (i.e. has_many
, has_many through
, and belongs_to
).
Note: The plural of "freebie" is "freebies" and the singular of "freebies" is "freebie".
Freebie#dev
- returns the
Dev
instance for this Freebie
- returns the
Freebie#company
- returns the
Company
instance for this Freebie
- returns the
Company#freebies
- returns a collection of all the freebies for the Company
Company#devs
- returns a collection of all the devs who collected freebies from the Company
Dev#freebies
- returns a collection of all the freebies that the Dev has collected
Dev#companies
- returns a collection of all the companies that the Dev has collected freebies from
Use rake console
and check that these methods work before proceeding. For
example, you should be able to call Dev.first.companies
and see a list of the
companies for the first dev in the database based on your seed data; and
Freebie.first.dev
should return the dev for the first freebie in the database.
Freebie#print_details
- should return a string formatted as follows:
{insert dev's name} owns a {insert freebie's item_name} from {insert company's name}
- should return a string formatted as follows:
Company#give_freebie(dev, item_name, value)
- takes a
dev
(an instance of theDev
class), anitem_name
(string), and avalue
as arguments, and creates a newFreebie
instance associated with this company and the given dev
- takes a
Company.oldest_company
- returns the
Company
instance with the earliest founding year
- returns the
Dev#received_one?(item_name)
- accepts an
item_name
(string) and returns true if any of the freebies associated with the dev has thatitem_name
, otherwise returns false
- accepts an
Dev#give_away(dev, freebie)
- accepts a
Dev
instance and aFreebie
instance, changes the freebie's dev to be the given dev; your code should only make the change if the freebie belongs to the dev who's giving it away
- accepts a