Dynamic search form for multiple columns of the same model in Rails 4

Question

I am trying to create a search form with multiple columns(all from the same model) Now I want to set the value of all other columns as nil if the category column is set to a particular value. Something like this-

#app/models/question.rb
if (cateogry.matches => 'Exam Questions')

query = query.where("name like ? AND course like ? AND year like ?", "%#{query}%", "%#{query}%", "%#{query}%") 

else

query = query.where("name like ?","%#{query}%")

end

---

The search form is a basic form using get method.

Answer 1

You could use scopes for that.

class Question < ActiveRecord::Base
  ...

  # Scope for searching by exam
  scope :by_exam, -> (name, course, year) {
       match(:name, name).
       match(:course).
       match(:year, year)
  }

  # Scope forsearching by nma
  scope :by_name, ->(name) { match(:name, name) }

  # Helper scope for matching
  scope :match, ->(key, value) { where(arel_table[key].matches("%#{value}%"} }

end

So in your controller

if (cateogry.matches => 'Exam Questions')
     Question.by_exam(params[:name], params[:course], params[:year])
else
     Question.by_name(params[:name])
end