How can I compare 2 arrays inside a table and sort the results-CodePudding

I have to compare a table with candidates and a table with jobs, both tables has the field "skills", I want to see what job matches better with what worker, (the more skills in common, best fit).

I've tried to use arrays intersection, and create auxiliary tables like skills_worker and skill_jobs, but don't find the way to make it work.

Some help? Please?

CodePudding user response：

Newcomers to Rails seem to often create array columns where another table is better design. Your app is an example of where a skills table is suggested. You will need to create in a migration the skill_workers table, with integer fields worker_id and skill_id, and the job_skills table, with integer fields job_id and skill_id.

# app/models/job.rb
class job < ApplicationRecord
  has_many :job_skills, dependent: :destroy
  has_many :skills, through: :job_skills
end

# app/models/worker.rb
class Worker < ApplicationRecord
  has_many :worker_skills, dependent: :destroy
  has_many :skills, through: :worker_skills
end

# app/models/skill.rb
class Skill < ApplicationRecord
  has_many :skill_workers, dependent: :destroy
  has_many :workers, through: :skill_workers
  has_many :job_skills, dependent: :destroy
  has_many :jobs, through: :job_skills
end

With these tables populated, we ask the question "for a given worker, which job has the most matching skills".

worker = Worker.find(name: "Barney")
jobs = worker.skills.map(&:jobs).map(&:id) #=> [[3,9,22..],[3,18,22..],[18,28,53], ...] 
# which of the job ids appears most often?
tally = jobs.flatten.tally #=> {1 => 1, 3 => 2, 22=> 3, ...} # count of each job id
best_fit_id = tally.invert.sort.last[1] # that's the job id that has the most skills in common