imports_controller.rb

class ImportsController < ApplicationController
  #...

  def create
    read_csv.each do |row|
      attributes = row.to_h.map { |k, v| [attributes_map[k], v] }.to_h
      attributes[:address] = "#{row['ulice']}, #{row['okres']}, #{row['misto']} #{row['psc']}"
      attributes = attributes.reject { |k, v| k == nil }

      Student.create_with(attributes).find_or_create_by(rodne_cislo: attributes[:rodne_cislo])
    end

    redirect_to students_path
  end
end