Ruby on Rails嵌套表格

Question

我有三种模型：Deal，Zipcode，DealIncludeZipcode。

现在，联想看起来象下面这样： -

新政型号：

class Deal < ActiveRecord::Base 
    has_many :deal_include_zipcodes, dependent: :destroy 
    has_and_belongs_to_many :zipcodes, dependent: :destroy 

    accepts_nested_attributes_for :deal_include_zipcodes,:reject_if => :reject_include_zipcodes, allow_destroy: true 

    private 
    def reject_include_zipcodes(attributes) 
     if attributes[:deal_id].blank? || attributes[:zipcode_id].blank? 
     if attributes[:id].present? 
      attributes.merge!({:_destroy => 1}) && false 
     else 
      true 
     end 
     end 
    end 
end 

class Zipcode < ActiveRecord::Base 
    has_and_belongs_to_many :deals 
end 


class DealIncludeZipcode < ActiveRecord::Base 
    belongs_to :deal 
    belongs_to :zipcode 
end 

鉴于我有一个复选框，取消勾选上它，我可以选择多个邮政编码从DealIncludeZipcode.But时选择

现在我保存它没有保存的数据。

我已经使用迁移加入邮编和交易模型，其中我的排除邮政编码功能工作正常。

请提供一个soloution.I已经尝试了各种方法，但没有成功。

Answer 1

has_and_belongs_to_many整点是你没有加入这两个部分的模型。

class Deal < ActiveRecord::Base 
    has_and_belongs_to_many :zipcodes 
end 

class Zipcode < ActiveRecord::Base 
    has_and_belongs_to_many :deals 
end 

可以通过一个名为deals_zipcodes “无头” 表连接。如果您想要加入模型，则需要使用has_many :through。

class Deal < ActiveRecord::Base 
    has_many :deal_zipcodes, dependent: :destroy 
    has_many :zipcodes, through: :deal_zipcodes 
end 

class DealZipcode < ActiveRecord::Base 
    belongs_to :deal 
    belongs_to :zipcode 
end 

class Zipcode < ActiveRecord::Base 
    has_many :deal_zipcodes, dependent: :destroy 
    has_many :deals, through: :deal_zipcodes 
end 

Answer 2

我认为马克斯的权利。所以，你的迁移应该是

create_table :deals do |t| 
    t.string :name 
    ... 
end 
create_table :zipcodes do |t| 
    t.string :zipcode 
    ... 
end 
create_table :deals_zipcodes do |t| 
    t.belongs_to :deal, index: true 
    t.belongs_to :zipcode, index: true 
end 

而且您的模型应该是

class Deal < ActiveRecord::Base 
    has_and_belongs_to_many :zipcodes 
end 
class Zipcode < ActiveRecord::Base 
    has_and_belongs_to_many :deals 
end 

你或许应该看一看的ActiveRecord guide，在那里你会找到更多的解释。