Rails: How do I create a default value for attributes in Rails activerecord's model? [duplicate]

You can set a default option for the column in the migration

....add_column :status, :string, :default => "P"....

OR

You can use a callback, before_save

class Task < ActiveRecord::Base  before_save :default_values  def default_values    self.status ||= 'P' # note self.status = 'P' if self.status.nil? might be safer (per @frontendbeauty)  endend

Because I encountered this issue just a little while ago, and the options for Rails 3.0 are a bit different, I'll provide another answer to this question.

In Rails 3.0 you want to do something like this:

class MyModel < ActiveRecord::Base  after_initialize :default_values  private    def default_values      self.name ||= "default value"    endend

When I need default values its usually for new records before the new action's view is rendered. The following method will set the default values for only new records so that they are available when rendering forms. before_save and before_create are too late and will not work if you want default values to show up in input fields.

after_initialize do  if self.new_record?    # values will be available for new record forms.    self.status = 'P'    self.featured = true  endend