How to change primary key in rails migration file?
database-migration, rails-migrations, ruby-on-rails
Solution
You could execute arbitrary SQL in your migration:
execute "ALTER TABLE `products` DROP PRIMARY KEY"
and then add the new column:
add_column :products, :id, :primary_key
See:
Remove Primary Key in MySQL
how to add a primary key to a table in rails
http://thinkwhere.wordpress.com/2009/05/09/adding-a-primary-key-id-to-table-in-rails/
http://api.rubyonrails.org/classes/ActiveRecord/Migration.html
Problem
I need to migrate an old mysql table like this: ``` Products name (string, primary_key) ``` to this schema: ``` Products id (integer, primary_key, auto_generated) name (unique) ``` I need the Products.id values populated in the new table. How can i write the rails migration file? I am using Rails 3.2.7 I have 2 problems now: 1. I can't find a method to remove primary key in ActiveRecord::Migration 2. I don't know how to generate values for newly added primary key.