How to start RoR project

1. start a new project

        rails new project_name

2. create scaffolds for your project, and notice your schema of the model

        rails generate scaffold scaffolding_name schema_name:schema_type

    ps1. if model_name is Photo, then table_name would be photos, controller_name would be PhotosController, and scaffolding_name would be photo. This is what we call "convention"!

    ps2. after we use scaffolds, we will get MVC, but the database is not generated yet until we use migrate command

    ps3. there is no int in schema_type, use integer instead

3. create database

       rails db:migrate