Question

我的要求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Author，Title，Publisher等的简单表单，如果它发现作者已经在authors表中那么它应该只是引用该记录，如果它不在authors表中，那么它应该添加一条新记录并引用它。

存储我在日志文件中获取的值未经许可的参数：作者

Processing by BooksController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"8sxeOVMVJucl5nN+kMpSaT1cB1yDPnk5gfKElWPiT5k=", "book"=>{"book_name"=>"life ", "price"=>"20", "author"=>{"author_name"=>"swamy", "title"=>"LIFE", "publisher"=>"cta"}}, "commit"=>"Submit"}

swamy
LIFE
cta
  Author Load (1.6ms)  SELECT  "authors".* FROM "authors"  WHERE "authors"."author_name" = 'swamy' AND "authors"."title" = 'LIFE' AND "authors"."publisher" = 'cta' LIMIT 1
   (0.6ms)  BEGIN
  SQL (25.2ms)  INSERT INTO "authors" ("author_name", "created_at", "publisher", "title", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id"  [["author_name", "swamy"], ["created_at", "2015-07-01 03:53:22.712401"], ["publisher", "cta"], ["title", "LIFE"], ["updated_at", "2015-07-01 03:53:22.712401"]]
   (16.8ms)  COMMIT
Unpermitted parameters: author
   (0.7ms)  BEGIN
  SQL (1.0ms)  INSERT INTO "books" ("Author_id", "book_name", "created_at", "price", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id"  [["Author_id", 8], ["book_name", "life "], ["created_at", "2015-07-01 03:53:22.865106"], ["price", 20], ["updated_at", "2015-07-01 03:53:22.865106"]]
   (22.4ms)  COMMIT

我的代码 books_Controller

class BooksController < ApplicationController
  def new

  end
 def create

  @a=params[:author_name]
  puts @a
  b=params[:book][:author][:author_name]
  puts b
#   @c = @b.authors
#   @d = @c.author_name
   c=params[:book][:author][:title]
        d=params[:book][:author][:publisher]

  puts c
   puts d
   @author = Author.find_or_create_by(author_name: b,title: c, publisher: d)
   @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,:author_attributes => [:author_name, :title, :publisher])
end 
end

模型

class Author < ActiveRecord::Base

end

class Book < ActiveRecord::Base
  belongs_to :Author
  accepts_nested_attributes_for :Author
 # def author_name=(author_name)
  #  self.author = Author.find_or_create_by_name author_name
  #end
end

视图 books.html.erb

<%= 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 :author 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 %>
~

嗨，先生，我是新手，我知道它看起来很简单，但我找不到解决方案

〜
〜

Answer 1

这是因为books_params根据您的参数author_attributes时author为def books_params params.require(:book).permit(:book_name, :price, :author => [:author_name, :title, :publisher]) end。

这应该有效：

;
;  odbc.ini
;
[ODBC Data Sources]
NZSQL = NetezzaSQL

[NZSQL]
Driver                = /usr/local/nz/lib64/libnzodbc.so
Description           = NetezzaSQL ODBC
Servername            = 192.168.118.128
Port                  = 5480
Database              = TESTDB
Username              = admin
Password              = somepassword
ReadOnly              = false
ShowSystemTables      = false
LegacySQLTables       = false
LoginTimeout          = 0
QueryTimeout          = 0
DateFormat            = 1
NumericAsChar         = false
SQLBitOneZero         = false
StripCRLF             = false
ClientUserID=someuser
ClientWorkStnName=someworkstation
ClientApplName=someapplication
ClientAcctString=someacctstring

[ODBC]
IANAAppCodePage=4
InstallDir=/opt/odbc32v51
Trace=0
TraceDll=/opt/odbc32v51/lib/odbctrac.so
TraceFile=odbctrace.out
UseCursorLib=0

Answer 2

在视图文件中将authore更改为author_attributes，就像这样。

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

也分别在控制器中更改。我想，这已经足够了。

def create
  @book = Book.new(books_params) 
  @book.save 
  redirect_to root_url
end

Answer 3

我建议你debug你的代码

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

1：检查请求的参数

2：请核对params.require(:book)

请求的参数类似于

  Parameters: {"utf8"=>"✓", "authenticity_token"=>"8sxeOVMVJucl5nN+kMpSaT1cB1yDPnk5gfKElWPiT5k=", "book"=>{"book_name"=>"life ", "price"=>"20", "author_"=>{"author_name"=>"swamy", "title"=>"LIFE", "publisher"=>"cta"}}, "commit"=>"Submit"}

check with this link NestedAttributes

你的控制器就是这个

class BooksController < ApplicationController
  def new
  end

  def create
    @author = Author.create(params[:book])
    redirect_to root_url
  end

  private

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

Answer 4

您的代码充满了错误。跟随我的变化。

#book.rb
class Book < ActiveRecord::Base
  belongs_to :author
  accepts_nested_attributes_for :author
end

#books_controller.rb
def new
@book = Book.new
@book.build_author
end

def create
@book = Book.new(books_params)
 if @book.save 
   redirect_to root_url
 end
end

最后以表单将<%= form_for Book.new do |f| %>更改为<%= form_for @book do |f| %>

未经许可的参数：作者

4 个答案: