title: rails db migration, undefined method `to_sym', can't figure out syntax
body: <p>Here is my original migration:</p>
  
  <pre><code>class CreateUsers &lt; ActiveRecord::Migration
    def self.up
      ActiveRecord::Base.transaction do
        create_table "users", :force =&gt; true do |t|
          t.string :login, :limit =&gt; 40
          t.string :name, :limit =&gt; 100, :default =&gt; '', :null =&gt; true
          t.string :email, :limit =&gt; 100
          t.string :crypted_password, :limit =&gt; 40
          t.string :salt, :limit =&gt; 40
          t.string :remember_token, :limit =&gt; 40
          t.datetime :remember_token_expires_at
          t.string :activation_code, :limit =&gt; 40
          t.datetime :activated_at, :datetime
          t.string :state, :null =&gt; :no, :default =&gt; 'passive'
          t.datetime :deleted_at
          t.integer :occupation_id, :null =&gt; :yes
          t.datetime :paid_up_to_date, :date
          t.timestamps
        end
  </code></pre>
  
  <p>I am trying to change the default of "state" to be "active" instead of passive
  Here is my second attempt;</p>
  
  <pre><code>class ChangeUserStateDefault &lt; ActiveRecord::Migration
    def self.up
      change_column :users, :state, :null =&gt; :no, :default =&gt; 'active'
  end
  </code></pre>