Delete attribute from model in Ruby on Rails

Create a new migration with

rails g migration migrationname

and in the migration's up method run the following

remove_column :users, :age

run rake db:migrate and you are good to go.

At least two choices:

1. You can run rake db:rollback, delete the field from the migration and then re-run rake db:migrate
2. You can create a new migration to delete the field with rails generate migration new_migration.