Update a column, all rows

Question

I added a new column to my table but I forgot to add the :default option. Now I want to populate that column on every single row.

Is there a way to do with using the con

Answer 1

Of course you can use smth like Foo.update_all(:myattribute => "value"), but it'll modify only already created data. To set default value for all "future" data it's a good way to create a separate migration like this:

rails generate migration AddDefaultValueToFoo

Modify new migration (for ex. myattribute has a string type) like this:

class AddDefaultValueToFoo < ActiveRecord::Migration
  def self.up
    change_column :foos, :myattribute, :string, :default => "value"
    Foo.update_all(:myattribute => "value")
  end
end