-2. Installing - railstutorial.org will help you install rails and get an application installed on Heroku.

-3. Creating a Rails app -- "rails new AppName". This command will create the directories for your rails app. The last line will reference "bundle install". Bundle install goes to the internet and installs of the apps dependencies -> gems.

-4. Rails commands. If you CD into the app directory, you can use rails commands. Generate (g), Server (s), Console (c), Database Console (db). If you add -h it gives you options, such as 'rails server -h'.

-7. Generate (g). You can generate scaffold, migration, helper, mailer, model. Generating scaffold syntax - rails g scaffold NAME field:type field:type.

Types refer to database types: string, text, integer, boolean, decimal, float, binary, date, time, datetime

Scaffolding creates several files.

Model: Invokes the ActiveRecord, creates the Model and the Migration

Routes: Creates Resources :AppName

Controller: Creates the Controller

Views: Creates New, Show, Edit, Index

-8. Migrations - How we make changes to the database from inside rails. Rails automatically creates the table with the primary key "Id". Rails also adds a timestamp to the migration which tracks when the table was created or updated. Timestamp is magic and rails automatically updates it.

-9. Need to run the migration file before you start the server. rake db:migrate

-10. Rails Console (c) - you can start the rails console and start running code model.Create(stock: "ABC", date: 1-29-78). Remember with Ruby, everything returns a value.

-11. Hash syntax for Rails 1.9 The old syntax { :name => "Michael" } new syntax { name: "Michael" }

-12. Writing Migrations - "rails g migration AddTo field:type"

-For example "rails g migration AddChangeToStocks change:integer" or "rails g migration AddChangeAndDelayToStocks change:integer delay:time"

The Migration File would look like:

class AddChangeAndDelayToStocks <ActiveRecord: :Migration

__def change

____add_column :stocks, :change, :integer, default: false (or 0)

____add_colums :stocks, :delay, :time, [migration options, like default]

__end

end

Migration options -- default: , limit: 30, null: true/false, first: true (position) after: :email (:email is a column, position), unique: true

-13. rake commands

rake db:migrate - this will run all the current migrations

rake db:rollback - rollback the current migrations = changes to the database

rake db:schema:dump - this is run when migrate happens. It summarizes the current database schema

rake db:setup - this creates the database and loads the schema

-14. More migration commands - rails g migration RemoveColumnFromTable

class RemoveColumnFromTable <ActiveRecord: :Migration __def up

____remove_column :table, :column

__end

__def down

____add_column :table, :column, :type

__end

Other Migration Commands:

• rename_column
• rename_table
• drop_table
• change_column
• change_column_default

More information on migrations is available at guides.rubyonrails.org