Question

我正在尝试设置一个简单的has_many：through =＆gt;协会。

我有3个型号。 user.rb，icon.rb和user_icon.rb。

... user.rb

class User < ActiveRecord::Base
  has_many :user_icons
  has_many :icons, :through => :user_icons
end

... icon.rb

class Icon < ActiveRecord::Base
  has_many :user_icons
  has_many :users, :through => :user_icons
end

user_icon.rb

class UserIcon < ActiveRecord::Base
  belongs_to :User
  belongs_to :Icon
end

据我所知，我已经完成了所有事情，但是在尝试在rails控制台中运行以下内容时......

User.first.icons

我收到此错误....

1.9.2-p290 :002 > User.first.icons
ActiveRecord::HasManyThroughSourceAssociationNotFoundError: Could not find the source association(s) :icon or :icons in model UserIcon. Try 'has_many :icons, :through => :user_icons, :source => <name>'. Is it one of :User or :Icon?
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.1.1/lib/active_record/reflection.rb:517:in `check_validity!'
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.1.1/lib/active_record/associations/association.rb:27:in `initialize'
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.1.1/lib/active_record/associations/collection_association.rb:24:in `initialize'
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.1.1/lib/active_record/associations.rb:159:in `new'
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.1.1/lib/active_record/associations.rb:159:in `association'
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.1.1/lib/active_record/associations/builder/association.rb:41:in `block in define_readers'
    from (irb):2
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.1/lib/rails/commands/console.rb:45:in `start'
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.1/lib/rails/commands/console.rb:8:in `start'
    from /Users/jon/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.1/lib/rails/commands.rb:40:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

知道我在这里做错了吗？

Answer 1

您的问题出在UserIcon模型中的关联中。案例在定义关联时很重要。如果将模型更改为小写，则应该可以正常工作。

class UserIcon < ActiveRecord::Base
  belongs_to :user
  belongs_to :icon

has_many：通过关联错误

1 个答案: