How to set a default value for a datetime column to record creation time in a migration?

Question

Consider the table creation script below:

create_table :foo do |t|
  t.datetime :starts_at, :null => false
end

Is it\'s possible to set

Answer 1

You can add a function in a model like this:

  before_create :set_foo_to_now
  def set_foo_to_now
    self.foo = Time.now
  end

So that the model will set the current time in the model.

You can also place some sql code in the migration for setting the default value at the database level, something like:

execute 'alter table foo alter column starts_at set default now()'

Setting something like this:

create_table :foo do |t|
  t.datetime :starts_at, :null => false, :default => Time.now
end

causes executing the Time.now function during migrating so then the table in database is created like this:

create table foo ( starts_at timestamp not null default '2009-01-01 00:00:00');

but I think that it is not what you want.