所以我有一个代表这种情况的模型：
- 学生参加比赛。
- 比赛衡量某些技能。
- 在每场比赛中，每个学生都会获得所测量的每项技能的分数。
这是我的模型：
class Student < ActiveRecord::Base
# Include default devise modules. Others available are:
# :token_authenticatable, :encryptable, :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
# Setup accessible (or protected) attributes for your model
attr_accessible :email, :password, :password_confirmation, :remember_me
attr_accessible :name
has_and_belongs_to_many :skills
has_many :contest_participations
has_many :contests, :through => :contest_participations
has_many :contest_scores, :through => :contests
end
class Skill < ActiveRecord::Base
attr_accessible :name
has_and_belongs_to_many :students
end
class Contest < ActiveRecord::Base
attr_accessible :name, :contest_participations_attributes, :contest_scores_attributes
has_many :contest_participations
has_many :students, :through => :contest_participations
has_many :contest_skills
has_many :skills, :through => :contest_skills
has_many :contest_scores
accepts_nested_attributes_for :contest_participations, :contest_scores
end
class ContestParticipation < ActiveRecord::Base
attr_accessible :contest_id, :student_id
belongs_to :student
belongs_to :contest
end
class ContestScore < ActiveRecord::Base
attr_accessible :contest_id, :score, :skill_id, :student_id
has_and_belongs_to_many :contests
has_and_belongs_to_many :skills
has_and_belongs_to_many :student
end
在我的比赛编辑视图中，我正在尝试使用 formtastic 创建一个表格，该表格将显示所有比赛参与者，并允许用户为比赛中的每个技能添加分数，如下所示。
但我收到一个错误（student_id 无效符号）。如何更新学生成绩？
<%= semantic_form_for @contest do |f| %>
<%= f.input :name %>
<%= @contest.students.each do |student| %>
<%= @contest.skills.each do |skill| %>
<%= f.inputs :name => "Scores", :for => :contest_scores do |scores_form| %>
<%= scores_form.input :student_id => "student.id" %>
<%= scores_form.input :skill_id => "skill.id" %>
<%= scores_form.input :score, :label => "Score" %>
<% end %>
<br />
<% end %>
<% end %>
<%= f.actions do %>
<%= f.action :submit, :as => :button %>
<% end %>
<% end %>