Ruby Rails update an attribute into new database table - ruby-on-rails

Question

I migrated a new database table here it looks like this:
create_table "books", :force => true do |t|
t.string "books_title"
t.integer "books_count"
t.integer "user_id"
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
and my models/books.rb looks like this:
class Books < ActiveRecord::Base
attr_accessible :books_count, :books_title
end
and i'm trying to create new record using this code:
<%= form_for(#Books) do |f| %>
<%= f.label :books_title, 'Book Title' %>
<%= f.text_field :books_title %>
<% end %>
then i'm getting error: undefined method books_title for NilClass:Class
also my controllers/books_controller.rb looks like this:
class BooksController < ApplicationController
end
Please help me.I'm very new to ruby, what shoud I do what command i need to run? Thanks!

Answer 1

Its actually "#books" not "#Books"
and I dont see this line in your controller, "#books = Books.all"
(actually, it should be book, model names are singular and table names are plural)..
Welcome to rails...
I would do this, goto your app path and type,
rails g scaffold book title:string count:integer user_id:integer
The above command will generate everything for you from routes, model, migration, controller, view to test cases.
Need not worry about anything. Just
run rake db:migrate (it would probably throw an error since you already have "books" table, drop it)
Now visit, http://localhost:3000/books, you will see the books list(index view). Now, goto your books controller and start your learning method by method.

Answer 2

You must create #book instance for form_for method like this.
class StocksController < ApplicationController
def new
#book = Book.new
end
end
And view.
<%= form_for(#book) do |f| %>
<%= f.label :books_title, 'Book Title' %>
<%= f.text_field :books_title %>
<% end %>
And you must have create method in your books controller.
class StocksController < ApplicationController
# ...
def create
#book = Book.create(book_params)
end
private
def book_params
params.require(:book).permit(:books_title)
end
end
I recommend you to use :title instead of :books_title. Because it's a little redundant.

Answer 3

also my controllers/books_controller.rb looks like this:
class StocksController < ApplicationController
end
Rails has a naming convention, of using the same name for the file as for the controller, so you should either rename StocksController to BooksController or books_controller.rb to stocks_controller.
In any case, you are going to need an action in it, that initializes the book object for the form. And a create action, to save it. Another thing, it's standard to name your variable as a lowercase variable, and in singular, so it would be #book.
class BooksController < ApplicationController
def new
#book = Book.new
end
def create
#book = Book.create(params)
end
end
And update your form to be
<%= form_for(#book) do |f| %>
<%= f.label :books_title, 'Book Title' %>
<%= f.text_field :books_title %>
<% end %>