ruby-on-rails - 在嵌套属性rails 2上计算父级

Question

我的enrollment.rb

attr_accessible :semester_id
has_many :studentpayments
has_many :student_deductions

我的studentpayment.rb

belongs_to :enrollment

我的student_deduction.rb

belongs_to :enrollment

我如何根据 has 或 has 获得唯一semester_id的enrollment注册studentpayment基础student_deduction？

Answer 1

@enrollment = Enrollment.find_by_semester_id(id) # find by semester_id

@enrollment.studentpayments.any? # if @enrollment has any student payments
@enrollment.student_deductions.any?