Suppose a model is created as follows:
rails generate model Sales
rake db:migrate
What would be the best way to completely undo these changes, assuming
nothing else has changed in the meantime?

What is the difference between :dependent => :destroy and :dependent => :delete_all in Rails?

Which of the following methods is used to check whether an object is valid or invalid?

Which of the following is the correct way to rollback a migration?

Which of the following is the correct syntax for an input field of radio buttons in form_for?

Which is the best way to add a page-specific JavaScript code in a Rails 3 app? <%= f.radio_button :rating, 'positive', :onclick => '$('some_div').show();' %>

What is the output of the following code? test*5

In a has_many association, what is the difference between build and new? // user.rb has_many :posts // post.rb belongs_to :user

Which HTML template languages are supported by Ruby?

Which commands adds the data model info to the model file?

How can a value be stored so that it's shared across an entire request (i.e. make it accessible in controllers, views and models)?