ruby-on-rails - NoMethodError : undefined method `each' for #

Question

尝试在个人资料和教育之间创建一对多关系。我在尝试向个人资料添加教育时遇到此错误。

.-(~/scratch/rails_projects/rezumei)-----------------------------------------------------------------------------------------------------------(patrick@tesla)-
`--> rails c
Loading development environment (Rails 4.0.2)
irb(main):001:0> patrick = User.new
=> #<User id: nil, email: "", encrypted_password: "", reset_password_token: nil, reset_password_sent_at: nil, remember_created_at: nil, sign_in_count: 0, current_sign_in_at: nil, last_sign_in_at: nil, current_sign_in_ip: nil, last_sign_in_ip: nil, created_at: nil, updated_at: nil, profile_id: nil>
irb(main):002:0> patrick.profile = Profile.new
=> #<Profile id: nil, first_name: nil, last_name: nil, interests: nil, headline: nil, created_at: nil, updated_at: nil, user_id: nil, profile_id: nil, maiden_name: nil, industry: nil, summary: nil, specialties: nil, picture_url: nil, email_address: nil, skills: nil, phone_numbers: nil, main_address: nil>
irb(main):003:0> patrick.profile.educations = Education.new
NoMethodError: undefined method `each' for #<Education id: nil, profile_id: nil, school_name: nil>
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/activemodel-4.0.2/lib/active_model/attribute_methods.rb:439:in `method_missing'
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.2/lib/active_record/attribute_methods.rb:152:in `method_missing'
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.2/lib/active_record/associations/collection_association.rb:333:in `replace'
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.2/lib/active_record/associations/collection_association.rb:42:in `writer'
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.2/lib/active_record/associations/builder/association.rb:78:in `educations='
    from (irb):3
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands/console.rb:90:in `start'
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands/console.rb:9:in `start'
    from /home/patrick/scratch/rails_projects/rezumei/vendor/bundle/ruby/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:62:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'
irb(main):004:0> 

class User < ActiveRecord::Base
    has_one :profile, dependent: :destroy
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable
end

class Profile < ActiveRecord::Base
    belongs_to :user
    has_many :educations, dependent: :destroy
end

class Education < ActiveRecord::Base
    belongs_to :profile
end

Answer 1

这可用于将 Education 添加到 educations 中:

patrick.profile.educations << Education.new