Super-newb needs help with has_many and other things

Rails
1

I am brand new to oop and am having a difficult time getting my head
around some ruby stuff. In specific, I am trying to create a library
style app that lists topics, articles and comments. I have a table
called topics, a table called articles and a table called comments. My
models, controller and view are all listed below. What I want to happen
is to have the list view list each topic along with the names of each
article below it. This app will not be used for anything, I am just
trying to get a feel for Ruby. I don’t have a clue where to start doing
this and any help would be much appreciated. I really feel like I am
spinning my wheels, but a good solid push might get me on track. Thanks!

***** Models: *****

class Topic < ActiveRecord::Base
has_many :articles
validates_presence_of :name, :creator, :creationdate
end

class Article < ActiveRecord::Base
has_many :comments
belongs_to :topic
end

class Comment < ActiveRecord::Base
belongs_to :topic
end

***** Controller: *****

class AdminController < ApplicationController
def index
list
render :action => ‘list’
end

GETs should be safe (see

URIs, Addressability, and the use of HTTP GET and POST)
verify :method => :post, :only => [ :destroy, :create, :update ],
:redirect_to => { :action => :list }

def list
@topic_pages, @topics = paginate :topics, :per_page => 10
end

def show
@topic = Topic.find(params[:id])
end

def new
@topic = Topic.new
end

def create
@topic = Topic.new(params[:topic])
if @topic.save
flash[:notice] = ‘Topic was successfully created.’
redirect_to :action => ‘list’
else
render :action => ‘new’
end
end

def edit
@topic = Topic.find(params[:id])
end

def update
@topic = Topic.find(params[:id])
if @topic.update_attributes(params[:topic])
flash[:notice] = ‘Topic was successfully updated.’
redirect_to :action => ‘show’, :id => @topic
else
render :action => ‘edit’
end
end

def destroy
Topic.find(params[:id]).destroy
redirect_to :action => ‘list’
end
end

***** View: *****

All Topics:

<% for topic in @topics %> <% end %>
<%=h(topic.name) %>
<%=h(topic.description) %>
<%= link_to 'Show', :action => 'show', :id => topic %> <%= link_to 'Edit', :action => 'edit', :id => topic %> <%= link_to 'Destroy', { :action => 'destroy', :id => topic }, :confirm => 'Are you sure? This will Destroy the topic and all related articles. This may be a poor idea...', :post => true %>

<%= link_to ‘Previous page’, { :page => @topic_pages.current.previous }
if @topic_pages.current.previous %>
<%= link_to ‘Next page’, { :page => @topic_pages.current.next } if
@topic_pages.current.next %>


<%= link_to ‘New topic’, :action => ‘new’ %>

***** Migrations: *****

001:

class CreateTopics < ActiveRecord::Migration
def self.up
create_table :topics do |t|
t.column :name, :string, :null => false
t.column :description, :string
t.column :creator, :string, :null => false
t.column :creationdate, :timestamp, :null => false
end
end

def self.down
drop_table :topics
end
end

002:

class CreateArticles < ActiveRecord::Migration
def self.up
create_table :articles do |t|
t.column :name, :string, :null => false
t.column :description, :string
t.column :body, :text, :null => false
t.column :creator, :string, :null => false
t.column :creationdate, :timestamp, :null => false
t.column :topicid, :integer, :null => false
end

execute "alter table articles
           add constraint fk_article_topics
           foreign key(topicid) references topics(id)"

end

def self.down
drop_table :articles
end
end

003:

class CreateComments < ActiveRecord::Migration
def self.up
create_table :comments do |t|
t.column :comment, :text, :null => false
t.column :creator, :string, :null => false
t.column :creationdate, :timestamp, :null => false
t.column :articleid, :integer, :null => false
end

execute "alter table comments
           add constraint fk_comment_articles
           foreign key(articleid) references articles(id)"

end

def self.down
drop_table :comments
end
end