Rails Goodness : How to Test/Update Your Migration, Add a forgotten index

Once you have create a migration say,






class CreateEmployees < ActiveRecord::Migration



def change



create_table :employees do |t|



t.string :first_name



t.string :last_name



t.string :icon



t.integer :emp_id



t.timestamps



end



end



end











And now lets say you need to add an index to it, below are the steps



Step1. Rollback the current migration








 RAILS_ENV=development rake db:rollback            



Step2 Add the Index to the migration manually







class CreateEmployees < ActiveRecord::Migration



def change



create_table :employees do |t|



t.string :first_name



t.string :last_name



t.string :icon



t.integer :emp_id





t.timestamps



end



add_index :employees, [:first_name]



end



end





Step3. Test the migration by moving 10 steps behind in schema.rb and then redoing till current



















 RAILS_ENV=development rake db:migrate:redo STEP=10



The Steps can be any number, just to ensure robustness that schema.rb retains its current state



Thank you


































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