Ruby on rails 计算嵌套属性rails 2上的父级_Ruby On Rails

Ruby on rails 计算嵌套属性rails 2上的父级

ruby-on-rails

Ruby on rails 计算嵌套属性rails 2上的父级,ruby-on-rails,Ruby On Rails,我的注册。rb attr_accessible :semester_id has_many :studentpayments has_many :student_deductions belongs_to :enrollment belongs_to :enrollment 我的studentpayment.rb attr_accessible :semester_id has_many :studentpayments has_many :student_deductions belo

我的

注册。rb

attr_accessible :semester_id
has_many :studentpayments
has_many :student_deductions

belongs_to :enrollment

belongs_to :enrollment

我的

studentpayment.rb

attr_accessible :semester_id
has_many :studentpayments
has_many :student_deductions

belongs_to :enrollment

belongs_to :enrollment

我的

student\u扣减.rb

attr_accessible :semester_id
has_many :studentpayments
has_many :student_deductions

belongs_to :enrollment

belongs_to :enrollment

如何根据

学期id

获取唯一的注册，以及

注册是否有学生付款
或学生扣减

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

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