我有这个型号:
class Student < ActiveRecord::Base
has_many :tickets
has_many :movies, through: :tickets
end
class Movie < ActiveRecord::Base
has_many :tickets, dependent: :destroy
has_many :students, through: :tickets
belongs_to :cinema
end
class Ticket < ActiveRecord::Base
belongs_to :movie, counter_cache: true
belongs_to :student
end
class Cinema < ActiveRecord::Base
has_many :movies, dependent: :destroy
has_many :students, through: :movies
has_many :schools, dependent: :destroy
has_many :companies, through: :yard_companies
end
class School < ActiveRecord::Base
belongs_to :company
belongs_to :student
belongs_to :cinema, counter_cache: true
end
class Teacher < ActiveRecord::Base
belongs_to :movie, counter_cache: true
belongs_to :company
end
class Contract < ActiveRecord::Base
belongs_to :company
belongs_to :student
end
class Company < ActiveRecord::Base
has_many :teachers
has_many :movies, through: :teachers
has_many :contracts
has_many :students, through: :contracts
end
如果我在 movies_controller.rb 中写下这个:
@students = @movie.cinema.companies.students.all
我有这个错误:
未定义的方法'学生'为#Company :: ActiveRecord_Associations_CollectionProxy:0x00000007f13d88&gt;
如果我写这个:
@students = @movie.cinema.companies.find(6).students.all
它在我的select_collection中向我展示了正确的学生。
如何更好地了解这一过程?
更新:
我需要收集这部电影电影公司的每个学生的收藏。
怎么写?
答案 0 :(得分:4)
正如Nermin所描述的那样,您试图从一系列儿童中请求收集儿童。
您可以使用collect
从以下方面收集公司的学生:
@movie.cinema.companies.collect(&:students).flatten.uniq
但我认为你最好按照以下方式为你的学生模型添加一个范围:
scope :for_companies, ->(_companies) {joins(:companies).where(company: _companies)}
使用Student.for_companies(@movie.cinema.companies)
免责声明:未经测试,但应该是一个起点!