students-for-unisend.rb

require 'csv'

options = {
  write_headers: true,
  headers: ['first_name', 'last_name', 'email', 'phone', 'purchased_courses'],
}

CSV.open("#{Rails.root}/users-for-unisender.csv", 'w', options) do |writer|
  User.find_each do |u|

    if u.type == 'Student'
      courses = u.transactions
        .where(payable_type: 'Course', status: 'confirmed')

      if courses.any?
        coursess_names = courses
          .map{ |x| x.payable.title }
          .join(', ')
      end
      
       writer << [u.name, u.surname, u.email, u.phone, coursess_names]
    end
  end
end