Rails has_many: thông qua PG :: Lỗi: LRI: thông qua tham chiếu cột "id" là lỗi mơ hồ

Question

Tôi mới dùng đường ray và tôi đã cố gắng để có hai has_many: mặc dù các mối quan hệ để làm việc (trái ngược với việc sử dụng has_and_belongs_to_many như được giải thích qua đường bưu điện này http://blog.flatironschool.com/post/35346328762/why-you-dont-need-has-and-belongs-to-many) nhưng bây giờ chạy vào một lỗi Postgres:

PG::Error: ERROR: column reference "id" is ambiguous 
LINE 1: ...on_id" IS NULL AND "components"."id" = 1 ORDER BY id ASC LIM... 
                  ^
: SELECT 1 AS one FROM "components" INNER JOIN "collection_components" ON "components"."id" = "collection_components"."component_id" WHERE "collection_components"."collection_id" IS NULL AND "components"."id" = 1 ORDER BY id ASC LIMIT 1 
    Rendered collections/_form.html.haml (117.0ms) 
    Rendered collections/new.html.haml within layouts/application (143.5ms) 
Completed 500 Internal Server Error in 164ms 

ActiveRecord::StatementInvalid - PG::Error: ERROR: column reference "id" is ambiguous 
LINE 1: ...on_id" IS NULL AND "components"."id" = 1 ORDER BY id ASC LIM... 
                  ^

_form.html.haml

= form_for @collection do |f| 
    - if @collection.errors.any? 
    #error_explanation 
     %h1= "#{pluralize(@collection.errors.count, "error")} prohibited this collection from being saved:" 
     %ul 
     - @collection.errors.full_messages.each do |msg| 
      %li= msg 

    .field 
    - Component.all.each do |component| 
     = label_tag :component_ids, component.id 
     = check_box_tag :component_ids, component.id, @collection.components.include?(component), :name => 'collection[component_ids][]' 
    .field 
    = f.label :title 
    = f.text_field :title 
    .actions 
    = f.submit 'Save' 

collection_component.rb

class CollectionComponent < ActiveRecord::Base 
    attr_accessible :collection_id, 
        :component_id 

    belongs_to  :collection 
    belongs_to  :component 
end 

collection.rb

class Collection < ActiveRecord::Base 
    default_scope order('id ASC') 

    attr_accessible   :style_id, 
          :name, 
          :title, 
          :component 

    #has_and_belongs_to_many :components 

    has_many    :collection_components, :dependent => :destroy 
    has_many    :components, :through => :collection_components 

    belongs_to    :style 

    validates_presence_of :style 
    validates_presence_of :title 

    before_save    :create_name 

    private 

    def create_name 
    self.name = title.parameterize 
    end 
end 

component.rb

class Component < ActiveRecord::Base 
    default_scope order('id ASC') 

    attr_accessible   :category_id, 
          :name, 
          :title, 
          :collection, 
          :style 

    has_many    :collection_components, :dependent => :destroy 
    has_many    :collections, :through => :collection_components 

    has_many    :component_styles 
    has_many    :styles,  :through => :component_styles 

    belongs_to    :category 

    validates_presence_of :category 
    validates_presence_of :title 

    before_save    :create_name 

    private 

    def create_name 
    self.name = title.parameterize 
    end 
end 

collection_components bảng

Column  |   Type    |        Modifiers        
---------------+-----------------------------+-------------------------------------------------------------------- 
id   | integer      | not null default nextval('collection_components_id_seq'::regclass) 
collection_id | integer      | 
component_id | integer      | 
created_at | timestamp without time zone | not null 
updated_at | timestamp without time zone | not null 
Indexes: 
    "collection_components_pkey" PRIMARY KEY, btree (id) 

bộ sưu tập bảng

Column |   Type    |      Modifiers       
------------+-----------------------------+---------------------------------------------------------- 
id   | integer      | not null default nextval('collections_id_seq'::regclass) 
style_id | integer      | 
name  | character varying(255)  | 
title  | character varying(255)  | 
created_at | timestamp without time zone | not null 
updated_at | timestamp without time zone | not null 
Indexes: 
    "collections_pkey" PRIMARY KEY, btree (id) 

thành phần bảng

Column |   Type    |      Modifiers       
-------------+-----------------------------+--------------------------------------------------------- 
id   | integer      | not null default nextval('components_id_seq'::regclass) 
name  | character varying(255)  | 
title  | character varying(255)  | 
category_id | integer      | 
created_at | timestamp without time zone | not null 
updated_at | timestamp without time zone | not null 
Indexes: 
    "components_pkey" PRIMARY KEY, btree (id) 

Answer 1

Hãy thử điều này:

default_scope { order('collections.id ASC') } //collection.rb 
    default_scope { order('components.id ASC') } //component.rb 

Khi bạn thực hiện một tăng dần join trên id trở thànhCộtvì cả hai cột components và collections đều có cột id. Nó sẽ không biết sử dụng.