一点背景：我最近作为一个Rails开发人员得到了一份新工作，这一切都很好和花花公子（我有一个Rails背景），但我遇到了一个问题，我无法理解。我参与的工作涉及接管公司其他人的项目，但从未完成。所以我的膝盖上有一个未完成的CRM应用程序，需要更有经验的开发人员的帮助才能指出我正确的方向。
当我尝试创建新作业时，我收到错误“ ActiveModel :: MissingAttributeError in Jobs＃new ”，然后是“无法写入未知属性`opportunity_id '”。
终端的错误是：
Started GET "/jobs/new" for 127.0.0.1 at 2016-08-17 10:07:44 -0700
Processing by JobsController#new as HTML
Rendered jobs/new.html.erb within layouts/application (2.0ms)
Completed 500 Internal Server Error in 10ms
ActionView::Template::Error (can't write unknown attribute `opportunity_id'):
1: <% @job[:opportunity_id] = params[:opportunity_id] %>
2: <% title "New #{@job.opportunity.name} Job"%>
3:
4: <%
app/views/jobs/new.html.erb:1:in `_app_views_jobs_new_html_erb__443350051_40007592'
Rendered C:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (1.0ms)
Rendered C:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.0ms)
Rendered C:/RailsInstaller/Ruby2.1.0/lib/ruby/gems/2.1.0/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb within rescues/layout (34.0ms)
错误来自第1行：
<% @job[:opportunity_id] = params[:opportunity_id] %>
更新：添加了作业模型和作业控制器，以及shcema.rb文件中的视图和作业表。
工作模式：
class Job < ActiveRecord::Base
mount_uploader :file1, AttachmentUploader
belongs_to :cost_proposal
has_many :opportunities
end
职位控制员：
class JobsController < ApplicationController
before_action :set_job, only: [:show, :edit, :update, :destroy]
skip_load_and_authorize_resource
# GET /jobs
# GET /jobs.json
def index
@jobs = Job.all
end
# GET /jobs/1
# GET /jobs/1.json
def show
end
# GET /jobs/new
def new
end
# GET /jobs/1/edit
def edit
end
# POST /jobs
# POST /jobs.json
def create
@job = Job.new(job_params)
respond_to do |format|
if @job.save
format.html { redirect_to @job, notice: 'Job was successfully created.' }
format.json { render :show, status: :created, location: @job }
else
format.html { render :new }
format.json { render json: @job.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /jobs/1
# PATCH/PUT /jobs/1.json
def update
respond_to do |format|
if @job.update(job_params)
format.html { redirect_to @job, notice: 'Job was successfully updated.' }
format.json { render :show, status: :ok, location: @job }
else
format.html { render :edit }
format.json { render json: @job.errors, status: :unprocessable_entity }
end
end
end
# DELETE /jobs/1
# DELETE /jobs/1.json
def destroy
@job.destroy
respond_to do |format|
format.html { redirect_to jobs_url, notice: 'Job was successfully deleted.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_job
@job = Job.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def job_params
params.require(:job).permit(:opportunity_id, :number, :name, :flight_date, :flight_sub, :camera, :roll, :map_type, :plan_only, :lab_only, :est_hrs_model, :due_date, :edge_job_id, :custom_trans, :comp_inhouse, :delivered_date, :done, :control_in, :control_status, :at_date, :control_results, :control_check, :scan_staff, :scan_date, :scan_check, :comp_staff, :comp_date, :comp_check, :comp_sub, :comp_sub_due_date, :comp_sub_rec, :img_staff, :img_date, :img_check, :edit_staff, :edit_date, :edit_check, :notes, :file1, :file2, :file3, :file4, :file5, :add_files)
end
end
schema.rb中的作业表：
create_table "jobs", force: true do |t|
t.integer "cost_proposal_id"
t.string "number"
t.string "name"
t.date "flight_date"
t.string "flight_sub"
t.string "camera"
t.string "roll"
t.string "map_type"
t.integer "plan_only"
t.integer "lab_only"
t.integer "est_hrs_model"
t.date "due_date"
t.integer "edge_job_id"
t.integer "custom_trans"
t.integer "comp_inhouse"
t.date "delivered_date"
t.integer "done"
t.date "control_in"
t.string "control_status"
t.date "at_date"
t.string "control_results"
t.integer "control_check"
t.string "scan_staff"
t.date "scan_date"
t.integer "scan_check"
t.string "comp_staff"
t.date "comp_date"
t.integer "comp_check"
t.string "comp_sub"
t.date "comp_sub_due_date"
t.integer "comp_sub_rec"
t.string "img_staff"
t.date "img_date"
t.integer "img_check"
t.string "edit_staff"
t.date "edit_date"
t.integer "edit_check"
t.text "notes"
t.string "file1"
t.string "file2"
t.string "file3"
t.string "file4"
t.string "file5"
t.string "add_files"
t.datetime "created_at"
t.datetime "updated_at"
t.integer "flown"
t.integer "cust_trans"
t.integer "delivered"
t.string "at_staff"
t.integer "at_check"
end
schema.rb的机会表：
create_table "opportunities", force: true do |t|
t.integer "employee_id"
t.integer "emp2_id"
t.integer "emp3_id"
t.string "name"
t.datetime "prop_date"
t.integer "opp_status_id"
t.string "delay"
t.date "con_signed"
t.integer "quote_won_id"
t.float "total_cost"
t.date "exp_close"
t.integer "pri_comp_id"
t.text "notes"
t.datetime "created_at"
t.datetime "updated_at"
t.string "lost"
t.string "won"
t.string "location"
t.integer "pm_id"
end
作业新视图（发生错误的地方）：
<% @job[:opportunity_id] = params[:opportunity_id] %>
<% title "New #{@job.opportunity.name} Job"%>
<%
@job[:name] = @job.opportunity.name
@pm = @job.opportunity.pm_id
%>
<br><br>
<%= render 'form' %>
如果您需要项目中的更多文件，请与我们联系。提前谢谢！
答案 0 :(得分：1)
当您尝试在不存在的模型上设置属性时，会引发ActiveModel::MissingAttributeError。请记住ActiveRecord＆＃34;自动＆＃34;通过从数据库中读取模式来创建setter和getter。
最常见的原因是：
oportunity_id）在视图中为模型分配属性也是一个非常糟糕的代码味道。改为在控制器中执行：
class JobsController < ApplicationController
# ...
def new
@job = Job.new do |j|
if params[:opportunity_id].present?
j.opportunity_id = params[:opportunity_id]
end
end
end
# ...
end
答案 1 :(得分：0)
在您的观点的第2行，看起来您期望新工作已经有相关的机会。
<% title "New #{@job.opportunity.name} Job"%>
如果是这种情况，则作业路线应嵌套在机会下。所以在config/routes.rb
resources :opportunities do
resources :jobs
end
然后，您可以通过http://localhost:3000/opportunities/:id/jobs/new
在你的JobsController中：
def new
@opportunity = Opportunity.find(params[:opportunity_id])
@job = Job.new(opportunity: @opportunity)
# ...
答案 2 :(得分：0)
因此，当我查看您的两个表定义时，我看到1）工作中没有opportunity_id键，相反，2）机会中没有job_id键。要使has_many :opportunities生效，您需要在商机表中添加job_id字段。这是我的意思的一个非常简化的例子：
def Job < ActiveRecord::Base
has_many :opportunities
end
def Opportunity < ActiveRecord::Base
end # shown for completeness of answer only
您需要使用迁移将job_id外键添加到opportunity表中，例如：
class AddJobForeignKeyToOpportunities < ActiveRecord::Migration
def change
add_column :opportunities, :job_id, :integer
end
end
如果您不确定如何处理迁移，请查看rails command-line tool的Rails指南。一旦有了这些，Rails将自动为您提供访问与Job相关的机会，如您所料：
job = Job.first
job.opportunities
请注意，由于原始问题中的错误提及，您仍然无法访问job.opportunity_id。您设置的多对一关联要求Opportunity模型具有外键。但是，Rails将允许您访问job.opportunity_ids复数。
[edit]要为工作添加机会，您需要执行以下操作：
opportunity = Opportunity.find(params[:opportunity_id])
job.opportunities << opportunity
您应始终避免直接在关联模型上引用外键。有人在这里的另一个答案或评论中说了这个，但是我找不到它来归功于他们。
而是依赖于Rails提供的方法。在上面的示例中，<<运算符正在有效地设置job_id，以便将它们链接起来。