First things first, AWS and Heroku are different things. AWS offer Infrastructure as a Service (IaaS) whereas Heroku offer a Platform as a Service (PaaS). What’s the difference? Very approximately, IaaS gives you components you need in order to build things on top of it; PaaS gives you an environment where you just push code … Read more
.nil? can be used on any object and is true if the object is nil. .empty? can be used on strings, arrays and hashes and returns true if: String length == 0 Array length == 0 Hash length == 0 Running .empty? on something that is nil will throw a NoMethodError. That is where .blank? … Read more
rename_column :table, :old_column, :new_column You’ll probably want to create a separate migration to do this. (Rename FixColumnName as you will.): script/generate migration FixColumnName # creates db/migrate/xxxxxxxxxx_fix_column_name.rb Then edit the migration to do your will: # db/migrate/xxxxxxxxxx_fix_column_name.rb class FixColumnName < ActiveRecord::Migration def self.up rename_column :table_name, :old_column, :new_column end def self.down # rename back if you need … Read more