Ruby on Rails:多对多实例

Question

rails新手。我正在创建一个具有多个数据库表的项目，这些表都是相互关联的。我想知道如何在实例创建后将外键引用添加到实例。代码如下：

在架构中：

    class Blog < ActiveRecord::Base
      has_many :posts
      has_many :owners
      has_many :users, through: :owners
    end

    class Owner < ActiveRecord::Base
      belongs_to :user
      belongs_to :blog
    end

    class User < ActiveRecord::Base
       has_many :messages
       has_many :posts
       has_many :owners
       has_many :blogs, through: :owners
    end

型号：

class User < ActiveRecord::Base
   has_many :messages
   has_many :posts
   has_many :owners
   has_many :blogs, through: :owners
end

class Owner < ActiveRecord::Base
  belongs_to :user
  belongs_to :blog
end

class Blog < ActiveRecord::Base
  has_many :posts
  has_many :owners
  has_many :users, through: :owners
end

在rails控制台中：

blog1 = Blog.first
user1 = User.first
blog1.users = user1
NoMethodError: undefined method `each' for #<User:0x0000000487e9f8>