Syntax - Syntax rails

Operation

# new rails
$ rails new MySite

#bundling
$bundle install

#running server
rails server

#create new controller
rails generate controller Pages
#for edit, on path: routes->controller->page

#create new model
rails generate model Message
#file in db/migrate

#migration
rake db:migrate

#seeder
rake db:seed

HTML

#show content model
<% @messages.each do |t| %>
 <h1>name: <%= t.name %></h1><br>
 description: <%= t.description %>
<% end %>

#show image
<%= image_tag t.image %>

#show link
<%= link_to "Learn more", tag_path(t) %>

Controller

#controller
def messages
 #show all field database
 @messages = Message.all

 #show field database with id
 def show
  @tag = Tag.find(params[:id])
  @destinations = @tag.destinations
 end

 #edit
 def update
  @destination = Destination.find(params[:id])
  if @destination.update(destination_params)
   redirect_to @destination
  else
   render 'edit'
  end
 end
 private 
    def destination_params 
      params.require(:destination).permit(:name, :description) 
    end
end

Model

#model
class Tag < ActiveRecord::Base
 has_many :destinations
 belongs_to :tag
end

Routes

#routes
Rails.application.routes.draw do
 get '/tags' => 'tags#index'
 post '/tags/create' => 'tags#create'
 get '/tags/:id' => 'tags#show', as: :tag
end

Seeder

#db:migrate
class CreateDestinations < ActiveRecord::Migration
  def change
    create_table :destinations do |t|
      t.string :name
      t.string :image
      t.string :description
      t.references :tag
      t.timestamps
    end
  end
end