Delete action and create action for Rails version 2.3.2 - ruby-on-rails-3

Question

Just now I am starting to study Ruby on Rails.
ruby version=1.8.7
rails version =2.3.2
I created delete and create new user action but present some errors,
the errors are:
uninitialized constant User::Id
Extracted source (around line #19):
16: <td><%= user.fname %></td>
17: <td><%= user.lname %></td>
18: <td><%= user.dob %></td>
19: <td><%= button_to "delete", :url => {:controller => :users,:action => 'destroy',:id =>user.id}, :method => :delete %></td>
20: </tr>
21: <% end %>
22: </table>
My MySQL database table is:
id fname lname dob
1 kamal vimal 2012.02.12
2 rahu sharmi 2012.05.26
3 mithun kavi 2012.03.07
Class user:
class User < ActiveRecord::Base
set_primary_key :id
has_one :id
end
My controller is:
class UsersController < ApplicationController
def index
#users=User.all
end
def destroy
# User.primary_key='id'
#users=User.find(:id)
#users.destroy
flash[:notice] = "You have successfully Delete Recode"
end
def new
#users=User.new
end
def create
#users=User.new(params[:users])
if #user.save
redirect_to_users_path
flash[:notice] = "Your record is created!"
else
render :action => "index"
end
end
end
My view is:
<% #users.each do |user| %>
<%= button_to "delete", :url => {:controller => :users,:action => 'destroy',:id =>user.id}, :method => :delete %>
<% end %>
Anyone can help me?

Answer 1

I see a couple of misunderstanding.
Users Controller
If you look the delete method in the controller
def destroy
#users=User.find(:id)
[...]
You are passing a symbol to the find function instead of the id from the delete request. You can get the id by using params[:id], as you have done with the create function.
def destroy
#users=User.find(params[:id])
[...]
The following are only suggestions.
I will also change the instance variable name from #users to #user here and in the new and the create method, since you are getting/build a single user.
If your routes.rb is set like
ActionController::Routing::Routes.draw do |map|
map.resources :users
end
you don't need to specify the url specifying the controller and the action in the button_to helper, but you can use the path helpers
button_to "delete", user_path(user), :method => :delete
User model
You can remove both the statements.
You should user set_primary_key only if the primary key in the table differs from the default 'id'.
The association is misused.
With the has_one method you are telling Rails the User model is related with the model 'id' through a 1:1 relation which, I suppose, is not what you want.
Final Thoughts
Read carefully the Ruby on Rails guide if you did not, it's a good starting point.
In addition, you are using a really old version of Rails and Ruby, which are not supported anymore. If there aren't any specific reason, like working on a legacy project, I suggest you to study a more recent version like Rails 4 on ruby 2.2.