Rails: Scenic gem for Database Views

models.rb

class UserSalary < ApplicationRecord
  attr_reader :a_but_different_name, 
              :b,
              :c
end

class JobListing < ApplicationRecord
  attr_reader :a, 
              :b_but_different_name,
              :c
end

class MyCareersFutureJob < ApplicationRecord
  attr_reader :a, 
              :b,
              :c_but_different_name
end

salary_after.rb

class Salary < ApplicationRecord
  attr_reader :a, :b, :c
end

salary_before.rb

class Salary
  attr_reader :a, :b, :c

  def initialize(data)
    case data
    when UserSalary
      @a = data.a_but_different_name
      @b = data.b
      @c = data.c
    when JobListing
      @a = data.a
      @b = data.b_but_different_name
      @c = data.c
    when MyCareersFutureJob
      @a = data.a
      @b = data.b
      @c = data.c_but_different_name
    end
  end
end

view.sql

SELECT
  a_but_different_name AS "a",
  b,
  c
FROM user_salaries

UNION

SELECT
  a,
  b_but_different_name AS "b",
  c 
FROM job_listings

UNION

SELECT
  a,
  b,
  c_but_different_name AS "c" 
FROM my_careers_future_jobs

Check out Behind The Scenes of NodeFlair's Newly Launched Salaries Feature (Part Two)!

https://adriangohjw.github.io/posts/2021/05/19/ruby-scenic-gem.html