Question

基本上我将书籍添加到数据库中，我想将作者存储在一个单独的表中。所以我有一个叫做作者的表，由表格书引用。

我想创建一个用于添加图书的rails表单，我希望它只是作者，标题，发布商等的简单表单，如果它发现作者已经在authors表中，那么它应该只引用该记录，如果它不在authors表中，那么它应该添加一条新记录并引用它。

它正在工作，但值不存储到authors表中？在检查表中的作者姓名时，我得到nil参数：

 {"utf8"=>"✓",       "authenticity_token"=>"/Tk87vLoJx+/EgPGVEa7x59IeGMGLikknBMcMTw90oo=",   "book"=>{"book_name"=>"y", "price"=>"1", "authors"=>{"author_name"=>"b",  "title"=>"k", "publisher"=>"s"}}, "commit"=>"Submit"}
        Author Load (1.9ms)  SELECT  "authors".* FROM "authors"  WHERE   "authors"."author_name" IS NULL LIMIT 1
 Unpermitted parameters: authors

  params[:authors_name] in method Author.find_or_create_by() value is nil
 but book column values are added to books table and author table id is only apears in author table

使用参考

创建模型

    rails generate model Author author_name:string{15} title:string{15} publisher:string{15}
    rails generate model Book book_name:string{15} price:integer Author:references

书籍 - 控制器

        class BooksController < ApplicationController
          def new

          end
         def create 
          # Client.find_or_create_by(first_name: 'Andy')
           @author = Author.find_or_create_by(:author_name =>     params[:author_name]) 
           @book = Book.new(books_params)
           @book.Author = @author
           @book.save
          redirect_to root_url

         end
        private

          def books_params
             params.require(:book).permit(:book_name, :price,:address => [:author_name, :title, :publisher])
        end
        end

型号代码

        class Book < ActiveRecord::Base
          belongs_to :Author
          accepts_nested_attributes_for :Author
        end

      class Author < ActiveRecord::Base
      end

book.html

<%= form_for Book.new  do |f| %>

  <p>
    <%= f.label :book_name %><br />
    <%= f.text_field :book_name %>
  </p>
  <p>
    <%= f.label :price %><br />
    <%= f.text_field :price %>
  </p>

  <%= f.fields_for :authors do |b| %>
     <p>
    <%= b.label :author_name%><br />
    <%= b.text_field :author_name %>
  </p>
<p>
    <%= b.label :title%><br />
    <%= b.text_field :title %>
  </p>
<p>
    <%= b.label :publisher%><br />
    <%= b.text_field :publisher%>
  </p>

  <% end %>
  <p><%= f.submit "Submit" %></p>
<% end %>
~

我的问题是

在testbox中输入author_name，同时在find_or_create中使用parama [：authors_name]访问此作者名称时，它在查询中给出nil？

2如何在authors表中保存authors列值？

使用一个表单添加到rails中的多个表

0 个答案: