deleting a db, rake db:drop
removing the rails app, rm -rf app_name
when changing/ adding models to your app, do you have to type in save or does it just save?
rails generate migration
then rake add it to the db: rake db:migrate

SQL process - translating ruby into SQL
rake db:migrate - wfiling cabinet
rails generate migration - creates files; do skip this part;
seeds.rb - run db file; apllies data into the structure
do not use lightly: rake db:rollback (ASK FOR HELP)