Rails: Adding an index after adding column

Question

Suppose I created a table table in a Rails app. Some time later, I add a column running:

rails generate migration AddUser_idColumnToTable user_i         


        

Answer 1

For references you can call

rails generate migration AddUserIdColumnToTable user:references

If in the future you need to add a general index you can launch this

rails g migration AddOrdinationNumberToTable ordination_number:integer:index

Generate code:

class AddOrdinationNumberToTable < ActiveRecord::Migration
  def change
   add_column :tables, :ordination_number, :integer
   add_index :tables, :ordination_number, unique: true
  end
end