ActiveRecord::RecordNotFound in BookController#list

Question

我是 ruby​​ 和 rails 的新手，当我打开 localhost 链接 /book/list 时出现以下错误

ActiveRecord::RecordNotFound in BooksController#list
            Couldn't find Book with 'id'=all
class BookController < ApplicationController
def list
    @books = Book.find(:all) <------- problem is here
  end
  def show
    @book = Book.find(params[:id])

我的 books_controller.rb 文件。

class BookController < ApplicationController
def list
    @books = Book.find(:all)
  end
  def show
    @book = Book.find(params[:id])
  end
  def new
    @book = Book.new
    @subjects = Subject.find(:all)
  end
  #  private 
  def book_params
    params.require(:book).permit(:title,:price,:subject,:description)
  end
  def create
    @book = Book.new(book_params)
    if @book.save
      redirect_to :action => 'list'
    else
      @subjects = Subject.find(:all)
      render :action => 'new'
    end
  end
  def edit
    @book = Book.find(params[:id])
    @subjects = Subject.find(:all)
  end

  def book1_params
    params.require(:book).permit(:id)
  end

  def update
#below is the line I am getting the error....
@book = Book.find(params[:id])

if @book.update_attributes(book_params)
    redirect_to @book
else
    @subjects = Subject.all
render 'edit'
 end
end

end

list 方法中的@books = Book.find(:all) 行告诉Rails 搜索books 表并将它找到的每一行存储在@books 实例对象中。我在列表中出现错误，new 和all几乎所有的选项。它说找不到'id'=all 的书。

我的 list.html.erb 文件。

<% if @books.blank? %>
<p>There are not any books currently in the system.</p>
<% else %>
<p>These are the current books in our system</p>
<ul id="books">
<% @books.each do |c| %>
<li><%= link_to c.title, {:action => 'show', :id => c.id} -%></li>
<% end %>
</ul>
<% end %>
<p><%= link_to "Add new Book", {:action => 'new' }%></p>

我的 routes.rb 文件

Rails.application.routes.draw do
get 'book/new'
post 'book/create'
post 'book/update'
get 'book/list'
get 'book/show'
get 'book/edit'
get 'book/delete'
get 'book/update'
get 'book/show_subjects'

结束

我最近开始使用它，我在初始阶段非常感谢任何帮助。

Answer 1

.find() 方法将主键作为其参数。当您传递Book.find(:all) 时，您的应用正在尝试查找 ID 为“all”的Book 实例，因此您会看到错误消息。

正如 Anthony 指出的那样，您应该使用 Book.all 来返回 Book. 的所有实例 以后尝试搜索模型实例时，您可以使用this answer 作为参考。