class CourseSecondCategory < ApplicationRecord default_scope { order("course_second_categories.position ASC") } belongs_to :course belongs_to :course_module has_many :homework_commons validates :name, length: { maximum: 60 } def category_type_str category_type == "graduation" && name == "毕设选题" ? "graduation_topics" : ( category_type == "graduation" && name == "毕设任务" ? "graduation_tasks" : category_type ) end end