Scaffolding - rails generate - data migrate def in class

Question

I'm new to Rails - I started a new rails app rails new test, then rails generate scaffold Name column1:datatype column2:datatype

In the tutorial once I open the 12345678timestamp_create_names.rb file I have def change, but the tutorial has both def self.up and def self.down

Why is that? And what is the difference? And should I edit my app now? And in the future?

Answer 1

migrations has changed from rails2 to rails3, now rails3 is smart enough to understand how it should response with your command

So, consider change as a combination of up and down

if you say

rake db:migrate it will consider it as up

rake db:rollback it will consider it as down

read more here