Rails 4包括多个has_many和belongs_to index.html.erb
Rails 4 includes multiple has_many and belongs_to index.html.erb
我将如何处理包含以下内容的 belong_to。与其显示 product_colour_id id，不如显示相关的颜色（更新：解决了下面的这一部分）。 product_colour_id 在产品 table 中并匹配相应的 Product_colour id。
这是两个或多个 has_many 关联的情况，我无法解决。可以吗？
app/controller/home_controller.rb
class HomeController < ApplicationController
def index
products = Product.last(5)
product_ids = products.map(&:id)
@product_colour_ids = products.map(&:product_colour_id)
@allproduct_colours = ProductColour.all
@product_colour_map = ProductColour.find(@product_colour_ids)
@product_images = Product.includes(:product_images)
.where(product_images: {product_id: product_ids, :default_image => true})
end
end
/app/views/home/index.html.erb
<% @product_images.each do |pd| %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
<% end %> </div>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p> <%= pd.product_colour_id %></p>
</div>
<% end %>
<% end %>
</div>
我很难找到多个 has_many 包含的示例。我认为它有一个非常直接的模式，但无法从 apidock or api.rubyonrails.org 中计算出来。我遇到的问题是添加 Supply_company 这是一个 has_many :through 关系到我已经与 product_image include.
提前感谢您的建议
更新 我已经想出了如何显示 belongs_to...感觉有点笨，因为它很容易只是需要一些时间思考
<% pd.product_images.each do |pd| %>
<p> <%= pd.product_colour.product_colour %></p>
<% end %>
/app/models/product.rb
class Product < ActiveRecord::Base
belongs_to :product_type
belongs_to :product_category
belongs_to :product_colour
belongs_to :product_size
has_many :product_supply_companies, :foreign_key => 'product_id'
accepts_nested_attributes_for :product_supply_companies, :allow_destroy => true
has_many :supply_companies, :through => :product_supply_companies
accepts_nested_attributes_for :supply_companies
has_many :product_images, dependent: :destroy, :foreign_key => 'product_id'
accepts_nested_attributes_for :product_images, :allow_destroy => true
end
app/models/product_supply_company.rb
class ProductSupplyCompany < ActiveRecord::Base
belongs_to :product
belongs_to :supply_company
# accepts_nested_attributes_for :supply_company
# accepts_nested_attributes_for :product
end
app/models/supply_company.rb
class SupplyCompany < ActiveRecord::Base
has_many :products, :through => :product_supply_companies
has_many :product_supply_companies, :foreign_key => 'supply_company_id'
accepts_nested_attributes_for :products
accepts_nested_attributes_for :product_supply_companies, :allow_destroy => true
end
app/models/product_colour.rb
class ProductColour < ActiveRecord::Base
has_many :products
end
数据库模式
create_table "product_categories", force: true do |t|
t.string "product_category"
t.string "product_category_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_colours", force: true do |t|
t.string "product_colour"
t.string "product_colour_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_images", force: true do |t|
t.integer "product_id", null: false
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "product_image_file_name"
t.string "product_image_content_type"
t.integer "product_image_file_size"
t.datetime "product_image_updated_at"
t.boolean "default_image"
end
create_table "product_sizes", force: true do |t|
t.string "product_size"
t.string "product_size_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_supply_companies", force: true do |t|
t.integer "product_id"
t.integer "supply_company_id"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_types", force: true do |t|
t.string "product_type"
t.string "product_type_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "products", force: true do |t|
t.string "product_name"
t.text "product_description"
t.integer "product_type_id"
t.integer "product_category_id"
t.string "product_colour_id"
t.integer "product_size_id"
t.datetime "created_at"
t.datetime "updated_at"
end
@products = Product.includes(:product_images, :colour, :supply_companies)
.where(product_images: {product_id: product_ids, :default_image => true})
.select('products.*, product_colours.product_colour')
这是包含所有关联的查询。
index.html.erb
<% @products.each do |pd| %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
</div>
<% end %>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p><%= pd.product_colour %></p>
</div>
<% end %>
<% end %>
Product.rb
belongs_to :colour, class: 'ProductColor', foreign_key: 'product_colour_id'
对于后面的人。 User123 给了我一些想法，最终提供了解决方案。我一直在想这个问题。
app/controller/home_controller.rb
class HomeController < ApplicationController
def index
products = Product.last(5) ## find last five products
product_ids = products.map(&:id) ## map their ids so I can retrieve
images with matching id's
## create array of products with corresponding default_images.
## Not necessary to include has_many, has_many :through or
## belongs_to as they can be added directly on index.html.erb page
@products = Product.includes(:product_images)
.where(product_images: {product_id: product_ids, :default_image => true}).last(5)
end
end
/app/views/home/index.html.erb
<% @products.each do |pd| #1st level directly access product_attributes %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| # 2nd access has_many with
foreign key in different table %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
</div>
<% end %>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p><%= pd.product_colour.product_colour #first level access
belong_to relationship attributes %></p>
<p><% pd.supply_companies.each do |sc| # 2nd level again to
access has_many :through relationship only done again for
layout purposes. %></p>
<%= sc.company_name %>
<% end %>
</div>
<% end %>
<% end %>
我将如何处理包含以下内容的 belong_to。与其显示 product_colour_id id，不如显示相关的颜色（更新：解决了下面的这一部分）。 product_colour_id 在产品 table 中并匹配相应的 Product_colour id。
这是两个或多个 has_many 关联的情况，我无法解决。可以吗？
app/controller/home_controller.rb
class HomeController < ApplicationController
def index
products = Product.last(5)
product_ids = products.map(&:id)
@product_colour_ids = products.map(&:product_colour_id)
@allproduct_colours = ProductColour.all
@product_colour_map = ProductColour.find(@product_colour_ids)
@product_images = Product.includes(:product_images)
.where(product_images: {product_id: product_ids, :default_image => true})
end
end
/app/views/home/index.html.erb
<% @product_images.each do |pd| %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
<% end %> </div>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p> <%= pd.product_colour_id %></p>
</div>
<% end %>
<% end %>
</div>
我很难找到多个 has_many 包含的示例。我认为它有一个非常直接的模式，但无法从 apidock or api.rubyonrails.org 中计算出来。我遇到的问题是添加 Supply_company 这是一个 has_many :through 关系到我已经与 product_image include.
提前感谢您的建议
更新 我已经想出了如何显示 belongs_to...感觉有点笨，因为它很容易只是需要一些时间思考
<% pd.product_images.each do |pd| %>
<p> <%= pd.product_colour.product_colour %></p>
<% end %>
/app/models/product.rb
class Product < ActiveRecord::Base
belongs_to :product_type
belongs_to :product_category
belongs_to :product_colour
belongs_to :product_size
has_many :product_supply_companies, :foreign_key => 'product_id'
accepts_nested_attributes_for :product_supply_companies, :allow_destroy => true
has_many :supply_companies, :through => :product_supply_companies
accepts_nested_attributes_for :supply_companies
has_many :product_images, dependent: :destroy, :foreign_key => 'product_id'
accepts_nested_attributes_for :product_images, :allow_destroy => true
end
app/models/product_supply_company.rb
class ProductSupplyCompany < ActiveRecord::Base
belongs_to :product
belongs_to :supply_company
# accepts_nested_attributes_for :supply_company
# accepts_nested_attributes_for :product
end
app/models/supply_company.rb
class SupplyCompany < ActiveRecord::Base
has_many :products, :through => :product_supply_companies
has_many :product_supply_companies, :foreign_key => 'supply_company_id'
accepts_nested_attributes_for :products
accepts_nested_attributes_for :product_supply_companies, :allow_destroy => true
end
app/models/product_colour.rb
class ProductColour < ActiveRecord::Base
has_many :products
end
数据库模式
create_table "product_categories", force: true do |t|
t.string "product_category"
t.string "product_category_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_colours", force: true do |t|
t.string "product_colour"
t.string "product_colour_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_images", force: true do |t|
t.integer "product_id", null: false
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "product_image_file_name"
t.string "product_image_content_type"
t.integer "product_image_file_size"
t.datetime "product_image_updated_at"
t.boolean "default_image"
end
create_table "product_sizes", force: true do |t|
t.string "product_size"
t.string "product_size_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_supply_companies", force: true do |t|
t.integer "product_id"
t.integer "supply_company_id"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "product_types", force: true do |t|
t.string "product_type"
t.string "product_type_description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "products", force: true do |t|
t.string "product_name"
t.text "product_description"
t.integer "product_type_id"
t.integer "product_category_id"
t.string "product_colour_id"
t.integer "product_size_id"
t.datetime "created_at"
t.datetime "updated_at"
end
@products = Product.includes(:product_images, :colour, :supply_companies)
.where(product_images: {product_id: product_ids, :default_image => true})
.select('products.*, product_colours.product_colour')
这是包含所有关联的查询。
index.html.erb
<% @products.each do |pd| %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
</div>
<% end %>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p><%= pd.product_colour %></p>
</div>
<% end %>
<% end %>
Product.rb
belongs_to :colour, class: 'ProductColor', foreign_key: 'product_colour_id'
对于后面的人。 User123 给了我一些想法，最终提供了解决方案。我一直在想这个问题。
app/controller/home_controller.rb
class HomeController < ApplicationController
def index
products = Product.last(5) ## find last five products
product_ids = products.map(&:id) ## map their ids so I can retrieve
images with matching id's
## create array of products with corresponding default_images.
## Not necessary to include has_many, has_many :through or
## belongs_to as they can be added directly on index.html.erb page
@products = Product.includes(:product_images)
.where(product_images: {product_id: product_ids, :default_image => true}).last(5)
end
end
/app/views/home/index.html.erb
<% @products.each do |pd| #1st level directly access product_attributes %>
<%= content_tag :div, :class => "col-md-3 col-sm-6 hero-feature" do %>
<% pd.product_images.each do |i| # 2nd access has_many with
foreign key in different table %>
<div class="thumbnail">
<%= image_tag (i.product_image(:medium)) %>
</div>
<% end %>
<div class="caption">
<h3><%= pd.product_name %></h3>
<p><%= pd.product_description %></p>
<p><%= pd.product_colour.product_colour #first level access
belong_to relationship attributes %></p>
<p><% pd.supply_companies.each do |sc| # 2nd level again to
access has_many :through relationship only done again for
layout purposes. %></p>
<%= sc.company_name %>
<% end %>
</div>
<% end %>
<% end %>