我有一张 field 表,我在 field 索引页面上将其显示为部分 field 。我还有一张评论表,其中一个 field 可以有很多评论,每条评论都有 1-5 分。
我试图让 field 显示在索引页面上,平均评分最高的 field 在顶部和降序。
Controller 代码如下所示:
field 管制员
def index
if
@venues = Venue.with_type(params[:venuetypes]).with_area(params[:areas]).joins(:reviews).order("reviews.rating DESC")
else
@venues = Venue.all
end
end
这给出了这样的结果:
在顶部显示 field 部分
列表。
一个 1 星评论它显示两个
部分,一个在顶部,一个
在列表底部。
一个 1 星评论它显示三个
部分,一个在顶部,一个在中间,一个
在列表底部。
我只想在每个 field 进行一次部分展示,但按平均评分在列表中定位,我觉得 .average 或某处缺少某些内容,我该如何实现?
感谢您的帮助,非常感谢!
编辑
field 模型
class Venue < ActiveRecord::Base
attr_accessible :name, :addressline1, :addressline2, :addressline3, :addressline4, :postcode, :phonenumber, :about, :icontoppx, :iconleftpx, :area_id, :venuetype_id, :lat, :long, :venuephotos_attributes
belongs_to :area
belongs_to :venuetype
has_many :reviews
has_many :venuephotos
accepts_nested_attributes_for :venuephotos, :allow_destroy => true
scope :with_type, lambda { |types|
types.present? ? where(:venuetype_id => types) : scoped }
scope :with_area, lambda { |areas|
areas.present? ? where(:area_id => areas) : scoped }
def to_param
"#{id}-#{name.gsub(/\W/, '-').downcase}"
end
def add_rating(rating_opts)
@venue.add_rating(:rating => rating, :reviewer => params[:rating][:reviewer])
self.reviews.create(rating_opts)
self.update_rating!
end
def update_rating!
s = self.reviews.sum(:rating)
c = self.reviews.count
self.update_attribute(:average_rating, s.to_f / c.to_f)
self.save(:validate => false)
end
end
添加评论的开发日志
Started POST "/venues/44-rating-test-5/reviews" for 127.0.0.1 at 2011-05-18 09:24:24 +0100
Processing by ReviewsController#create as JS
Parameters: {"utf8"=>"✓", "authenticity_token"=>"GZWd67b5ocJOjwKI6z9nJInBXxvQahHrjUtUpdm9oJE=", "review"=>{"rating"=>"5", "title"=>"5 star review"}, "venue_id"=>"44-rating-test-5"}
[1m[36mVenue Load (1.0ms)[0m [1mSELECT `venues`.* FROM `venues` WHERE (`venues`.`id` = 44) LIMIT 1[0m
[1m[35mUser Load (0.0ms)[0m SELECT `users`.* FROM `users` WHERE (`users`.`id` = 3) LIMIT 1
[1m[36mSQL (0.0ms)[0m [1mBEGIN[0m
[1m[35mSQL (2.0ms)[0m describe `reviews`
[1m[36mAREL (0.0ms)[0m [1mINSERT INTO `reviews` (`title`, `created_at`, `updated_at`, `venue_id`, `user_id`, `rating`) VALUES ('5 star review', '2011-05-18 08:24:24', '2011-05-18 08:24:24', NULL, 3, 5)[0m
[1m[35mSQL (27.0ms)[0m COMMIT
[1m[36mSQL (0.0ms)[0m [1mBEGIN[0m
[1m[35mAREL (0.0ms)[0m UPDATE `reviews` SET `venue_id` = 44, `updated_at` = '2011-05-18 08:24:24' WHERE (`reviews`.`id` = 90)
[1m[36mSQL (23.0ms)[0m [1mCOMMIT[0m
[1m[35mSQL (1.0ms)[0m SELECT COUNT(*) FROM `reviews` WHERE (`reviews`.venue_id = 44)
[1m[36mUser Load (0.0ms)[0m [1mSELECT `users`.* FROM `users` WHERE (`users`.`id` = 3) LIMIT 1[0m
Rendered reviews/_review.html.erb (9.0ms)
Rendered reviews/create.js.erb (22.0ms)
Completed 200 OK in 220ms (Views: 56.0ms | ActiveRecord: 54.0ms)
编辑
创建评论方法(评论 Controller )
def create
@review = current_user.reviews.create!(params[:review])
@review.venue = @venue
if @review.save
flash[:notice] = 'Thank you for reviewing this venue!'
respond_to do |format|
format.html { redirect_to venue_path(@venue) }
format.js
end
else
render :action => :new
end
end
最佳答案
添加到 NoICE's answer ,通过 Hook 到 :after_add
和 :after_remove
association callbacks , 不用记得打专门的add_rating
方法。
class Venue < ActiveRecord::Base
has_many :reviews, :after_add => :update_average_rating, :after_remove => :update_average_rating
def update_average_rating(review=nil)
s = self.reviews.sum(:rating)
c = self.reviews.count
self.update_attribute(:average_rating, c == 0 ? 0.0 : s / c.to_f)
end
end
此外,您需要检查计数为 0 以防止被零除。
创建评论时,必须附加
<<
或 concat
它到 field 对象的reviews
关联,以便触发回调。例如,这会将评论与 field 相关联,创建评论(插入到数据库中),并触发回调:@venue = Venue.find(params[:venue_id])
@venue.reviews << Review.new(params[:review])
这将创建评论但不会触发回调,即使
venue_id
是参数:Review.create(params[:review])
如果你真的想让你的 Action 触发回调,你可以将代码更改为:
def create
@review = Review.new(params[:review].merge({ :user => current_user, :venue => @venue })
if @review.valid? and @venue.reviews << @review
...
不过,为了方便地修复它,您可以添加
@review.venue.update_average_rating
就在该行之前 flash[:notice]
.
关于ruby-on-rails - 如何按平均评分对我的记录进行排序?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6008015/