class AddCourseIdToSwp < ActiveRecord::Migration
  def change
    add_column :student_work_projects, :course_id, :integer
    count = StudentWorkProject.all.count / 30 + 2
    transaction do
      for i in 1 ... count do i
      StudentWorkProject.page(i).per(30).each do |swp|
        if swp.homework_common && swp.homework_common.course
          swp.update_column("course_id", swp.homework_common.course_id)
        end
      end
      end
    end
  end
end