为多个模型设置标记时出错
Error while setting up tagging for multiple models
我正在尝试在我的应用程序中设置多个标记。我使用了单个标签和标记模型，它可以很好地标记单个模型。
但是，在设置关联后，当我想创建一个实际上指向 <%= select_tag(:kategory_id, options_for_select(@kategories), :prompt => "Select Category", class: "form-control") %> 的新问题 undefined method map for nil:NilClass 时出现此错误。我不知道为什么它指向这个，因为它与标记无关。我可能在某个地方犯了一个我无法弄清楚的错误。
这是我进行设置的方法。
我在标签 table 中添加了 taggable_id 和 taggable_type。
class AddAttributesToTaggings < ActiveRecord::Migration[5.1]
def change
add_column :taggings, :taggable_id, :integer
add_column :taggings, :taggable_type, :string
add_index :taggings, [:taggable_type, :taggable_id]
end
end
Tag.rb
class Tag < ApplicationRecord
has_many :taggings
has_many :posts, through: :taggings, source: :taggable, source_type: Post
has_many :questions, through: :taggings, source: :taggable, source_type: Question
has_many :user_tags, dependent: :destroy
has_many :users, through: :user_tags
extend FriendlyId
friendly_id :name, use: :slugged
def should_generate_new_friendly_id?
name_changed?
end
end
tagging.rb
class Tagging < ApplicationRecord
belongs_to :tag
belongs_to :taggable, :polymorphic => true
end
Question.rb
class Question < ApplicationRecord
belongs_to :user
belongs_to :kategory
validates :title, :content, presence: true
is_impressionable counter_cache: true, unique: :all
Question.order('impressions_count DESC')
scope :most_recent, -> { order(created_at: :desc) }
extend FriendlyId
friendly_id :title, use: :slugged
def should_generate_new_friendly_id?
title_changed?
end
include Taggable
def related_questions
Question.joins(:tags).where(tags: { id: self.tags.pluck(:id) }).where.not(id: self.id)
end
end
models/concerns/taggable.rb
module Taggable
extend ActiveSupport::Concern
included do
has_many :taggings, :as => :taggable
has_many :tags, :through => :taggings
end
def tag_list
self.tags.collect do |tag|
tag.name
end.join(", ")
end
def tag_list=(tags_string)
tag_names = tags_string.split(",").collect{|s| s.strip.downcase}.uniq
new_or_found_tags = tag_names.collect { |name| Tag.friendly.find_or_create_by(name: name) }
self.tags = new_or_found_tags
end
end
标签和标签 table schema.rb
create_table "taggings", force: :cascade do |t|
t.bigint "tag_id"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "taggable_id"
t.string "taggable_type"
t.index ["tag_id"], name: "index_taggings_on_tag_id"
t.index ["taggable_type", "taggable_id"], name: "index_taggings_on_taggable_type_and_taggable_id"
end
create_table "tags", force: :cascade do |t|
t.string "name"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "slug"
t.index ["slug"], name: "index_tags_on_slug", unique: true
end
questions/_form
<%= form_with(model: question, local: true) do |form| %>
<% if question.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(question.errors.count, "error") %> prohibited this question from being saved:</h2>
<ul>
<% question.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<b><%= form.label "Category" %></b>
<%= select_tag(:kategory_id, options_for_select(@kategories), :prompt => "Select Category", class: "form-control") %>
</div>
<br>
<div class="field">
<b><%= form.label :title %></b>
<%= form.text_field :title, id: :question_title, class: "form-control" %>
</div>
<br>
<div class="field">
<%= form.label :content %>
<%= form.text_area :content, id: :question_content, class: "form-control" %>
</div>
<br>
<div>
<%= form.label :tag_list %>
<%= form.text_field :tag_list %>
</div>
<br>
<div class="actions">
<%= form.submit %>
</div>
<% end %>
questions_controller.rb
class QuestionsController < ApplicationController
before_action :set_question, only: [:show, :edit, :update, :destroy]
before_action :authenticate_user!
before_action :find_contacts
before_action :find_kategory
impressionist :actions=>[:show,:index]
# GET /questions
# GET /questions.json
def index
if params[:kategory].blank?
@questions = Question.most_recent
else
@kategory_id = Kategory.find_by(name: params[:kategory]).id
@questions = Question.where(:kategory_id => @kategory_id).most_recent
end
end
# GET /questions/1
# GET /questions/1.json
def show
impressionist(@question)
@most_viewed = Question.order('impressions_count DESC').take(20)
end
# GET /questions/new
def new
@question = current_user.questions.build
@kategories = Kategory.all.map{ |k| [k.name, k.id] }
end
# GET /questions/1/edit
def edit
@kategories = Kategory.all.map{ |k| [k.name, k.id] }
end
# POST /questions
# POST /questions.json
def create
@question = current_user.questions.build(question_params)
@question.kategory_id = params[:kategory_id]
respond_to do |format|
if @question.save
flash[:success] = 'Your question was successfully posted.'
format.html { redirect_to @question }
format.json { render :show, status: :created, location: @question }
else
format.html { render :new }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /questions/1
# PATCH/PUT /questions/1.json
def update
respond_to do |format|
if @question.update(question_params)
flash[:success] = 'Your question was successfully updated.'
format.html { redirect_to @question }
format.json { render :show, status: :ok, location: @question }
else
format.html { render :edit }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end
# DELETE /questions/1
# DELETE /questions/1.json
def destroy
@question.destroy
respond_to do |format|
flash[:success] = 'Your question has been deleted.'
format.html { redirect_to questions_url }
format.json { head :no_content }
end
end
def most_viewed
@questions = Question.order('impressions_count DESC').take(20)
end
private
# Use callbacks to share common setup or constraints between actions.
def set_question
@question = Question.friendly.includes(:tags).find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def question_params
params.require(:question).permit(:title, :content, :kategory_id, :tag_list)
end
def find_contacts
@contacts = user_signed_in? ? current_user.all_active_contacts : ''
end
def find_kategory
@questions = Kategory.where(:kategory_id => @kategory_id)
end
end
更新：**我现在可以在不添加任何标签的情况下保存问题，但是添加标签后，我收到一个表单错误 tagging is invalid。 **标签在我编辑问题时正确加载。
错误日志：
Started POST "/questions" for 127.0.0.1 at 2018-07-13 12:01:01 +0100
Processing by QuestionsController#create as HTML
Parameters: {"utf8"=>"√", "authenticity_token"=>"hgLn8bzd6fVSzCIPtRd3P0Jp/LEso
/h5cKNBY0a80x3i4RF6tpLlRyqmls3xRFryqyP1/s/rLDVIt9C1/uK+qw==", "kategory_id"=>"1"
, "question"=>{"title"=>"Help!!! My Dell Inspiron 6400 is hanging", "content"=>"
Lorem ipsum dolor amet seitan offal ethical, beard viral lo-fi put a bird on it
salvia actually yr. Ethical ennui pitchfork fanny pack, gentrify seitan sartoria
l bespoke. Viral 90's church-key swag, you probably haven't heard of them banh m
i intelligentsia brunch DIY iceland wolf pitchfork. Everyday carry photo booth n
ormcore XOXO tumblr portland.\r\n\r\nBrooklyn heirloom kombucha, edison bulb leg
gings hell of DIY chartreuse austin tacos bitters. Blog hexagon copper mug blue
bottle cray. Post-ironic direct trade kale chips mumblecore. Craft beer squid cr
onut vape, hoodie bitters succulents ramps snackwave vegan small batch brunch ch
ia food truck umami. Chillwave blue bottle viral raclette authentic health goth
vape coloring book cardigan 3 wolf moon taxidermy. Gluten-free tote bag hella, l
omo pinterest direct trade gastropub tattooed. Iceland hammock post-ironic, bush
wick cornhole tumeric dreamcatcher blog palo santo chartreuse 90's food truck sy
nth chicharrones.", "tag_list"=>"hardware"}, "commit"=>"Create Question"}
User Load (2.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ORDE
R BY "users"."id" ASC LIMIT [["id", 3], ["LIMIT", 1]]
Private::Conversation Load (2.9ms) SELECT "private_conversations".* FROM "pri
vate_conversations" WHERE ("private_conversations"."recipient_id" = OR "priva
te_conversations"."sender_id" = ) [["recipient_id", 3], ["sender_id", 3]]
Private::Message Load (2.0ms) SELECT "private_messages".* FROM "private_messa
ges" WHERE "private_messages"."conversation_id" IN (2, 3, 4, 6)
Group::Conversation Load (3.9ms) SELECT "group_conversations".* FROM "group_c
onversations" INNER JOIN "group_conversations_users" ON "group_conversations"."i
d" = "group_conversations_users"."conversation_id" WHERE "group_conversations_us
ers"."user_id" = [["user_id", 3]]
Group::Message Load (2.0ms) SELECT "group_messages".* FROM "group_messages" W
HERE "group_messages"."conversation_id" = 1
User Load (2.0ms) SELECT "users".* FROM "users" WHERE "users"."id" IN (2, 3,
5)
(40.0ms) SELECT "group_conversations"."id" FROM "group_conversations" INNER
JOIN "group_conversations_users" ON "group_conversations"."id" = "group_conversa
tions_users"."conversation_id" WHERE "group_conversations_users"."user_id" =
[["user_id", 3]]
CACHE (0.0ms) SELECT "group_conversations"."id" FROM "group_conversations" I
NNER JOIN "group_conversations_users" ON "group_conversations"."id" = "group_con
versations_users"."conversation_id" WHERE "group_conversations_users"."user_id"
= [["user_id", 3]]
User Load (2.9ms) SELECT "users".* FROM "users" INNER JOIN "contacts" ON "use
rs"."id" = "contacts"."contact_id" WHERE "contacts"."user_id" = AND "contacts
"."accepted" = [["user_id", 3], ["accepted", "t"]]
User Load (4.9ms) SELECT "users".* FROM "users" INNER JOIN "contacts" ON "use
rs"."id" = "contacts"."user_id" WHERE "contacts"."contact_id" = AND "contacts
"."accepted" = ORDER BY "users"."created_at" ASC [["contact_id", 3], ["accep
ted", "t"]]
Tag Load (2.0ms) SELECT "tags".* FROM "tags" WHERE "tags"."name" = LIMIT
[["name", "hardware"], ["LIMIT", 1]]
Kategory Load (10.7ms) SELECT "kategories".* FROM "kategories"
(1.0ms) BEGIN
Question Exists (4.9ms) SELECT 1 AS one FROM "questions" WHERE ("questions".
"id" IS NOT NULL) AND "questions"."slug" = LIMIT [["slug", "help-my-dell-
inspiron-6400-is-hanging"], ["LIMIT", 1]]
Kategory Load (5.9ms) SELECT "kategories".* FROM "kategories" WHERE "kategor
ies"."id" = LIMIT [["id", 1], ["LIMIT", 1]]
(0.0ms) ROLLBACK
Rendering questions/new.html.erb within layouts/application
Rendered questions/_form.html.erb (17.6ms)
Rendered questions/new.html.erb within layouts/application (141.6ms)
Rendered layouts/navigation/header/_toggle_button.html.erb (1.0ms)
Rendered layouts/navigation/header/_home_button.html.erb (30.3ms)
User Load (28.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIM
IT [["id", 5], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
73.2ms)
User Load (2.9ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIMI
T [["id", 3], ["LIMIT", 1]]
CACHE User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = $
1 LIMIT [["id", 5], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
109.4ms)
Rendered layouts/navigation/header/dropdowns/conversations/_group.html.erb (3.
9ms)
User Load (30.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIM
IT [["id", 1], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
40.0ms)
CACHE User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = $
1 LIMIT [["id", 3], ["LIMIT", 1]]
User Load (2.9ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIMI
T [["id", 2], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
100.6ms)
Rendered layouts/navigation/header/dropdowns/_conversations.html.erb (983.4ms)
User Load (2.0ms) SELECT "users".* FROM "users" INNER JOIN "contacts" ON "use
rs"."id" = "contacts"."user_id" WHERE "contacts"."contact_id" = AND "contacts
"."accepted" = [["contact_id", 3], ["accepted", "f"]]
Rendered layouts/navigation/header/dropdowns/contact_requests/_no_requests.htm
l.erb (1.0ms)
Rendered layouts/navigation/header/dropdowns/_contact_requests.html.erb (374.0
ms)
Rendered layouts/navigation/header/_dropdowns.html.erb (1713.9ms)
Rendered layouts/navigation/_header.html.erb (2485.4ms)
Kategory Load (2.9ms) SELECT "kategories".* FROM "kategories"
Rendered layouts/navigation/collapsible_elements/_constant_links.html.erb (2.0
ms)
(2.0ms) SELECT COUNT(*) FROM "questions" INNER JOIN "save_questions" ON "que
stions"."id" = "save_questions"."question_id" WHERE "save_questions"."user_id" =
[["user_id", 3]]
Rendered layouts/navigation/collapsible_elements/_signed_in_links.html.erb (21
.5ms)
Rendered layouts/navigation/_collapsible_elements.html.erb (543.0ms)
Rendered layouts/_navigation.html.erb (3323.2ms)
Rendered layouts/application/_private_conversations_windows.html.erb (1.0ms)
Rendered layouts/application/_group_conversations_windows.html.erb (2.0ms)
Completed 200 OK in 22203ms (Views: 21796.6ms | ActiveRecord: 158.2ms)
在我看来，您的 @kategories 或其中的某些内容（可能是 name）为零，因此出现错误 :)（希望这是一件好事，一切都可能如此你的标签很好。）
确保 Kategory.all.map { |k| [k.name, k.id] } 在您的 new 操作中返回记录并且此错误应该消失。
N.B。您也可以在此处使用 options_from_collection_for_select。
# in the controller
def new
@question = current_user.questions.build
@kategories = Kategory.all
end
# and the view
<%= select_tag(:kategory_id, options_from_collection_for_select(@kategories, :name, :id), prompt: "Select Category", class: "form-control") %>
这样，如果您没有任何类别，您将不会收到错误 - 相反，您将没有任何可用选项。
您需要在创建和更新操作中定义 @kategories = Kategory.all.map{ |k| [k.name, k.id] }。如果无法保存问题，此操作将重新呈现 new/edit 个操作，并且需要 @kategories 进行重新呈现
如果您为创建操作提供完整的服务器日志，我可以尝试帮助您弄清楚 - 为什么无法保存@question
我正在尝试在我的应用程序中设置多个标记。我使用了单个标签和标记模型，它可以很好地标记单个模型。
但是，在设置关联后，当我想创建一个实际上指向 <%= select_tag(:kategory_id, options_for_select(@kategories), :prompt => "Select Category", class: "form-control") %> 的新问题 undefined method map for nil:NilClass 时出现此错误。我不知道为什么它指向这个，因为它与标记无关。我可能在某个地方犯了一个我无法弄清楚的错误。
这是我进行设置的方法。
我在标签 table 中添加了 taggable_id 和 taggable_type。
class AddAttributesToTaggings < ActiveRecord::Migration[5.1]
def change
add_column :taggings, :taggable_id, :integer
add_column :taggings, :taggable_type, :string
add_index :taggings, [:taggable_type, :taggable_id]
end
end
Tag.rb
class Tag < ApplicationRecord
has_many :taggings
has_many :posts, through: :taggings, source: :taggable, source_type: Post
has_many :questions, through: :taggings, source: :taggable, source_type: Question
has_many :user_tags, dependent: :destroy
has_many :users, through: :user_tags
extend FriendlyId
friendly_id :name, use: :slugged
def should_generate_new_friendly_id?
name_changed?
end
end
tagging.rb
class Tagging < ApplicationRecord
belongs_to :tag
belongs_to :taggable, :polymorphic => true
end
Question.rb
class Question < ApplicationRecord
belongs_to :user
belongs_to :kategory
validates :title, :content, presence: true
is_impressionable counter_cache: true, unique: :all
Question.order('impressions_count DESC')
scope :most_recent, -> { order(created_at: :desc) }
extend FriendlyId
friendly_id :title, use: :slugged
def should_generate_new_friendly_id?
title_changed?
end
include Taggable
def related_questions
Question.joins(:tags).where(tags: { id: self.tags.pluck(:id) }).where.not(id: self.id)
end
end
models/concerns/taggable.rb
module Taggable
extend ActiveSupport::Concern
included do
has_many :taggings, :as => :taggable
has_many :tags, :through => :taggings
end
def tag_list
self.tags.collect do |tag|
tag.name
end.join(", ")
end
def tag_list=(tags_string)
tag_names = tags_string.split(",").collect{|s| s.strip.downcase}.uniq
new_or_found_tags = tag_names.collect { |name| Tag.friendly.find_or_create_by(name: name) }
self.tags = new_or_found_tags
end
end
标签和标签 table schema.rb
create_table "taggings", force: :cascade do |t|
t.bigint "tag_id"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "taggable_id"
t.string "taggable_type"
t.index ["tag_id"], name: "index_taggings_on_tag_id"
t.index ["taggable_type", "taggable_id"], name: "index_taggings_on_taggable_type_and_taggable_id"
end
create_table "tags", force: :cascade do |t|
t.string "name"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "slug"
t.index ["slug"], name: "index_tags_on_slug", unique: true
end
questions/_form
<%= form_with(model: question, local: true) do |form| %>
<% if question.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(question.errors.count, "error") %> prohibited this question from being saved:</h2>
<ul>
<% question.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<b><%= form.label "Category" %></b>
<%= select_tag(:kategory_id, options_for_select(@kategories), :prompt => "Select Category", class: "form-control") %>
</div>
<br>
<div class="field">
<b><%= form.label :title %></b>
<%= form.text_field :title, id: :question_title, class: "form-control" %>
</div>
<br>
<div class="field">
<%= form.label :content %>
<%= form.text_area :content, id: :question_content, class: "form-control" %>
</div>
<br>
<div>
<%= form.label :tag_list %>
<%= form.text_field :tag_list %>
</div>
<br>
<div class="actions">
<%= form.submit %>
</div>
<% end %>
questions_controller.rb
class QuestionsController < ApplicationController
before_action :set_question, only: [:show, :edit, :update, :destroy]
before_action :authenticate_user!
before_action :find_contacts
before_action :find_kategory
impressionist :actions=>[:show,:index]
# GET /questions
# GET /questions.json
def index
if params[:kategory].blank?
@questions = Question.most_recent
else
@kategory_id = Kategory.find_by(name: params[:kategory]).id
@questions = Question.where(:kategory_id => @kategory_id).most_recent
end
end
# GET /questions/1
# GET /questions/1.json
def show
impressionist(@question)
@most_viewed = Question.order('impressions_count DESC').take(20)
end
# GET /questions/new
def new
@question = current_user.questions.build
@kategories = Kategory.all.map{ |k| [k.name, k.id] }
end
# GET /questions/1/edit
def edit
@kategories = Kategory.all.map{ |k| [k.name, k.id] }
end
# POST /questions
# POST /questions.json
def create
@question = current_user.questions.build(question_params)
@question.kategory_id = params[:kategory_id]
respond_to do |format|
if @question.save
flash[:success] = 'Your question was successfully posted.'
format.html { redirect_to @question }
format.json { render :show, status: :created, location: @question }
else
format.html { render :new }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /questions/1
# PATCH/PUT /questions/1.json
def update
respond_to do |format|
if @question.update(question_params)
flash[:success] = 'Your question was successfully updated.'
format.html { redirect_to @question }
format.json { render :show, status: :ok, location: @question }
else
format.html { render :edit }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end
# DELETE /questions/1
# DELETE /questions/1.json
def destroy
@question.destroy
respond_to do |format|
flash[:success] = 'Your question has been deleted.'
format.html { redirect_to questions_url }
format.json { head :no_content }
end
end
def most_viewed
@questions = Question.order('impressions_count DESC').take(20)
end
private
# Use callbacks to share common setup or constraints between actions.
def set_question
@question = Question.friendly.includes(:tags).find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def question_params
params.require(:question).permit(:title, :content, :kategory_id, :tag_list)
end
def find_contacts
@contacts = user_signed_in? ? current_user.all_active_contacts : ''
end
def find_kategory
@questions = Kategory.where(:kategory_id => @kategory_id)
end
end
更新：**我现在可以在不添加任何标签的情况下保存问题，但是添加标签后，我收到一个表单错误 tagging is invalid。 **标签在我编辑问题时正确加载。
错误日志：
Started POST "/questions" for 127.0.0.1 at 2018-07-13 12:01:01 +0100
Processing by QuestionsController#create as HTML
Parameters: {"utf8"=>"√", "authenticity_token"=>"hgLn8bzd6fVSzCIPtRd3P0Jp/LEso
/h5cKNBY0a80x3i4RF6tpLlRyqmls3xRFryqyP1/s/rLDVIt9C1/uK+qw==", "kategory_id"=>"1"
, "question"=>{"title"=>"Help!!! My Dell Inspiron 6400 is hanging", "content"=>"
Lorem ipsum dolor amet seitan offal ethical, beard viral lo-fi put a bird on it
salvia actually yr. Ethical ennui pitchfork fanny pack, gentrify seitan sartoria
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nth chicharrones.", "tag_list"=>"hardware"}, "commit"=>"Create Question"}
User Load (2.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ORDE
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Private::Conversation Load (2.9ms) SELECT "private_conversations".* FROM "pri
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Private::Message Load (2.0ms) SELECT "private_messages".* FROM "private_messa
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Group::Message Load (2.0ms) SELECT "group_messages".* FROM "group_messages" W
HERE "group_messages"."conversation_id" = 1
User Load (2.0ms) SELECT "users".* FROM "users" WHERE "users"."id" IN (2, 3,
5)
(40.0ms) SELECT "group_conversations"."id" FROM "group_conversations" INNER
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[["user_id", 3]]
CACHE (0.0ms) SELECT "group_conversations"."id" FROM "group_conversations" I
NNER JOIN "group_conversations_users" ON "group_conversations"."id" = "group_con
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= [["user_id", 3]]
User Load (2.9ms) SELECT "users".* FROM "users" INNER JOIN "contacts" ON "use
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User Load (4.9ms) SELECT "users".* FROM "users" INNER JOIN "contacts" ON "use
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Tag Load (2.0ms) SELECT "tags".* FROM "tags" WHERE "tags"."name" = LIMIT
[["name", "hardware"], ["LIMIT", 1]]
Kategory Load (10.7ms) SELECT "kategories".* FROM "kategories"
(1.0ms) BEGIN
Question Exists (4.9ms) SELECT 1 AS one FROM "questions" WHERE ("questions".
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Kategory Load (5.9ms) SELECT "kategories".* FROM "kategories" WHERE "kategor
ies"."id" = LIMIT [["id", 1], ["LIMIT", 1]]
(0.0ms) ROLLBACK
Rendering questions/new.html.erb within layouts/application
Rendered questions/_form.html.erb (17.6ms)
Rendered questions/new.html.erb within layouts/application (141.6ms)
Rendered layouts/navigation/header/_toggle_button.html.erb (1.0ms)
Rendered layouts/navigation/header/_home_button.html.erb (30.3ms)
User Load (28.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIM
IT [["id", 5], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
73.2ms)
User Load (2.9ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIMI
T [["id", 3], ["LIMIT", 1]]
CACHE User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = $
1 LIMIT [["id", 5], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
109.4ms)
Rendered layouts/navigation/header/dropdowns/conversations/_group.html.erb (3.
9ms)
User Load (30.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIM
IT [["id", 1], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
40.0ms)
CACHE User Load (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = $
1 LIMIT [["id", 3], ["LIMIT", 1]]
User Load (2.9ms) SELECT "users".* FROM "users" WHERE "users"."id" = LIMI
T [["id", 2], ["LIMIT", 1]]
Rendered layouts/navigation/header/dropdowns/conversations/_private.html.erb (
100.6ms)
Rendered layouts/navigation/header/dropdowns/_conversations.html.erb (983.4ms)
User Load (2.0ms) SELECT "users".* FROM "users" INNER JOIN "contacts" ON "use
rs"."id" = "contacts"."user_id" WHERE "contacts"."contact_id" = AND "contacts
"."accepted" = [["contact_id", 3], ["accepted", "f"]]
Rendered layouts/navigation/header/dropdowns/contact_requests/_no_requests.htm
l.erb (1.0ms)
Rendered layouts/navigation/header/dropdowns/_contact_requests.html.erb (374.0
ms)
Rendered layouts/navigation/header/_dropdowns.html.erb (1713.9ms)
Rendered layouts/navigation/_header.html.erb (2485.4ms)
Kategory Load (2.9ms) SELECT "kategories".* FROM "kategories"
Rendered layouts/navigation/collapsible_elements/_constant_links.html.erb (2.0
ms)
(2.0ms) SELECT COUNT(*) FROM "questions" INNER JOIN "save_questions" ON "que
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[["user_id", 3]]
Rendered layouts/navigation/collapsible_elements/_signed_in_links.html.erb (21
.5ms)
Rendered layouts/navigation/_collapsible_elements.html.erb (543.0ms)
Rendered layouts/_navigation.html.erb (3323.2ms)
Rendered layouts/application/_private_conversations_windows.html.erb (1.0ms)
Rendered layouts/application/_group_conversations_windows.html.erb (2.0ms)
Completed 200 OK in 22203ms (Views: 21796.6ms | ActiveRecord: 158.2ms)
在我看来，您的 @kategories 或其中的某些内容（可能是 name）为零，因此出现错误 :)（希望这是一件好事，一切都可能如此你的标签很好。）
确保 Kategory.all.map { |k| [k.name, k.id] } 在您的 new 操作中返回记录并且此错误应该消失。
N.B。您也可以在此处使用 options_from_collection_for_select。
# in the controller
def new
@question = current_user.questions.build
@kategories = Kategory.all
end
# and the view
<%= select_tag(:kategory_id, options_from_collection_for_select(@kategories, :name, :id), prompt: "Select Category", class: "form-control") %>
这样，如果您没有任何类别，您将不会收到错误 - 相反，您将没有任何可用选项。
您需要在创建和更新操作中定义 @kategories = Kategory.all.map{ |k| [k.name, k.id] }。如果无法保存问题，此操作将重新呈现 new/edit 个操作，并且需要 @kategories 进行重新呈现
如果您为创建操作提供完整的服务器日志，我可以尝试帮助您弄清楚 - 为什么无法保存@question