我已经构建了一个包含商家的简单应用，这些商家有很多评论。我使用部分_form来创建/更新评论。 create动作正常，但更新操作会创建一个新的审阅，而不是按照应该更新的方式更新审阅。这是相关代码（为简洁起见，删除了相关代码）：
来自routes.rb的代码：
resources :businesses do
resources :reviews
end
来自models/business.rb的代码：
class Business < ActiveRecord::Base
has_many :reviews, dependent: :destroy
validates_associated :reviews
end
来自models/review.rb的代码：
class Review < ActiveRecord::Base
belongs_to :business
belongs_to :user
end
来自controllers/reviews_controller.rb的代码：
class ReviewsController < ApplicationController
load_and_authorize_resource
before_filter :load_business
def new
end
def index
end
def create
@review = @business.reviews.create(review_params)
@review.user_id = current_user.id
@review.reviewer = current_user.first_name + ' ' + current_user.last_name
if @review.save
redirect_to business_path(@business)
flash[:notice] = 'Review posted!'
else
redirect_to business_path(@business)
flash[:danger] = 'Your review has an error. Please double check!'
end
end
def edit
@review = @business.reviews.find(params[:id])
end
def update
@review = @business.reviews.find(params[:id])
if @review.update(params[review_params])
redirect_to businesses_path(@business)
flash[:notice] = 'Review updated!'
else
render :action => 'edit'
end
end
def destroy
@review = @business.reviews.find(params[:id])
@review.destroy
redirect_to business_path(@business)
flash[:notice] = "Review deleted."
end
private
def load_business
@business = Business.find(params[:business_id])
end
def review_params
params.require(:review).permit(:review, :rating)
end
end
`reviews / _form.html.erb的代码：
<%= simple_form_for([@business, @business.reviews.build]) do |f| %>
<%= f.error_notification %>
<p>
<%= f.input :review %>
</p>
<p>
<%= f.input :rating, collection: 1..10 %>
</p>
<p>
<%= f.submit :class => 'btn btn-primary' %>
</p>
<% end %>
评论在business＃show视图中呈现为部分。 `review / _review.html.erb的代码：
<% if !review.user_id.nil? %>
<div class="well">
<p>
<strong>Reviewer:</strong>
<%= review.reviewer %>
</p>
<p>
<strong>Review:</strong>
<%= review.review %>
</p>
<p>
<strong>Rating:</strong>
<%= review.rating %>
</p>
<span class = "timestamp">
posted <%= time_ago_in_words(review.created_at) %> ago.
</span>
<% if can? :update, review %>
<span class = "timestamp">
<%= link_to "Edit", [:edit, review.business, review], class: 'btn btn-small' %>|
<%= link_to "Delete", [review.business, review], method: :delete,
data: { confirm: 'Are you sure?' } %>
</span>
<% end %>
</div>
<% end %>
reviews/edit.html.erb的代码：
<h1>Edit Review</h1>
<%= render 'form', review: @review %>
<button type="button" class="btn btn-default"><%= link_to 'Back', businesses_path %></button>
奇怪的是，当我点击＆＃34;编辑＆＃34; _review.html.erb中的链接，生成的网址似乎是正确的，例如我获得了http://localhost:3000/businesses/10/reviews/82/edit。但是，_form.html.erb为空，我希望在其中填充当前数据以供审核＃82。此外，当我点击＆＃34;创建评论＆＃34;按钮，它会创建一个新评论，并且不会编辑评论＃82。
点击＆＃34;编辑＆＃34;点击服务器日志。对于现有的评论：
Started GET "/businesses/3/reviews/81/edit" for 127.0.0.1 at 2014-08-28 19:18:58 -0500
Processing by ReviewsController#edit as HTML
Parameters: {"business_id"=>"3", "id"=>"81"}
User Load (0.8ms) SELECT "users".* FROM "users" WHERE "users"."id" = 8 ORDER BY "users"."id" ASC LIMIT 1
Review Load (6.9ms) SELECT "reviews".* FROM "reviews" WHERE "reviews"."id" = $1 LIMIT 1 [["id", 81]]
Business Load (0.5ms) SELECT "businesses".* FROM "businesses" WHERE "businesses"."id" = $1 LIMIT 1 [["id", 3]]
Review Load (27.4ms) SELECT "reviews".* FROM "reviews" WHERE "reviews"."business_id" = $1 AND "reviews"."id" = $2 LIMIT 1 [["business_id", 3], ["id", 81]]
Rendered reviews/_form.html.erb (107.0ms)
Rendered reviews/edit.html.erb within layouts/application (143.4ms)
Completed 200 OK in 967ms (Views: 669.2ms | ActiveRecord: 35.6ms)
Started POST "/businesses/3/reviews" for 127.0.0.1 at 2014-08-28 19:19:23 -0500
Processing by ReviewsController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"<redacted>", "review"=>{"review"=>"Edit review #81.", "rating"=>"1"}, "commit"=>"Create Review", "business_id"=>"3"}
User Load (0.8ms) SELECT "users".* FROM "users" WHERE "users"."id" = 8 ORDER BY "users"."id" ASC LIMIT 1
Business Load (0.6ms) SELECT "businesses".* FROM "businesses" WHERE "businesses"."id" = $1 LIMIT 1 [["id", 3]]
(28.9ms) BEGIN
SQL (132.9ms) INSERT INTO "reviews" ("business_id", "created_at", "rating", "review", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["business_id", 3], ["created_at", "2014-08-29 00:19:23.470750"], ["rating", 1], ["review", "Edit review #81."], ["updated_at", "2014-08-29 00:19:23.470750"]]
(39.7ms) COMMIT
(0.3ms) BEGIN
SQL (0.9ms) UPDATE "reviews" SET "reviewer" = $1, "updated_at" = $2, "user_id" = $3 WHERE "reviews"."id" = 83 [["reviewer", "<redacted>"], ["updated_at", "2014-08-29 00:19:23.692880"], ["user_id", 8]]
(17.5ms) COMMIT
Redirected to http://localhost:3000/businesses/3
Completed 302 Found in 553ms (ActiveRecord: 221.6ms)
Started GET "/businesses/3" for 127.0.0.1 at 2014-08-28 19:19:23 -0500
Processing by BusinessesController#show as HTML
Parameters: {"id"=>"3"}
User Load (0.7ms) SELECT "users".* FROM "users" WHERE "users"."id" = 8 ORDER BY "users"."id" ASC LIMIT 1
Business Load (0.5ms) SELECT "businesses".* FROM "businesses" WHERE "businesses"."id" = $1 LIMIT 1 [["id", 3]]
(0.5ms) SELECT AVG("reviews"."rating") AS avg_id FROM "reviews" WHERE "reviews"."business_id" = $1 [["business_id", 3]]
Rendered reviews/_form.html.erb (5.7ms)
Review Load (0.6ms) SELECT "reviews".* FROM "reviews" WHERE "reviews"."business_id" = $1 ORDER BY "reviews"."id" DESC [["business_id", 3]]
Rendered reviews/_review.html.erb (58.1ms)
Rendered businesses/show.html.erb within layouts/application (173.5ms)
Rendered users/_avatar.html.haml (13.1ms)
Rendered layouts/_navigation.html.haml (30.9ms)
Rendered layouts/_messages.html.haml (1.5ms)
Rendered layouts/_footer.html.haml (16.5ms)
Rendered layouts/_analytics.html.haml (0.6ms)
Rendered layouts/_javascripts.html.haml (0.5ms)
Completed 200 OK in 421ms (Views: 391.5ms | ActiveRecord: 2.3ms)
很明显，服务器日志中的第二个操作是＆＃34;已开始POST ...＆＃34;这是不正确的。虽然我在谈论它，但我也可以提供rake routes的相关路线：
business_reviews GET /businesses/:business_id/reviews(.:format) reviews#index
POST /businesses/:business_id/reviews(.:format) reviews#create
new_business_review GET /businesses/:business_id/reviews/new(.:format) reviews#new
edit_business_review GET /businesses/:business_id/reviews/:id/edit(.:format) reviews#edit
business_review GET /businesses/:business_id/reviews/:id(.:format) reviews#show
PATCH /businesses/:business_id/reviews/:id(.:format) reviews#update
PUT /businesses/:business_id/reviews/:id(.:format) reviews#update
DELETE /businesses/:business_id/reviews/:id(.:format) reviews#destroy
我已经尝试过实现我在这里找到的每个答案，但无济于事。我发现几乎是我确切问题的最接近的是这一个，但它没有帮助：Rails: Use same partial for creating and editing nested items
非常感谢。
答案 0 :(得分：0)
根据你在控制台中的输出，你在更新stmt之前有一个sql insert stmt。表单中的代码会导致它。即使在编辑时，@business.reviews.build也会创建新的审核对象。
将您的form_for更新为：
<%= simple_form_for([@business, @review]) do |f| %>
而不是@business.reviews.build。您应该在控制器而不是视图中创建对象。
因此，您可能还需要在新操作中使用新的审核对象。
def new
@review = @business.reviews.build
end
我还有一些建议可以帮助您简化代码，使事情变得更轻松。
使用评论ID查找评论，而不是通过商家 比如编辑和更新中的代码，你可以：
def edit
@review = Reviews.find(params[:id])
end
def update
@review = Reviews.find(params[:id])
...
end