change_column_null method is missing for activerecord-jdbcderby-adapter

module ::JdbcSpec::Derby  
  def change_column_null(table_name, column_name, null, default = nil)
    unless null || default.nil?
      execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
    end
    execute("ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} #{'NOT ' unless null}NULL")
  end
end

class ActiveRecordTest < Test::Unit::TestCase
  class TestMigrateChangeColumnNull < ActiveRecord::Migration
    def self.up
      change_column_null :assignments, :order_id, true
      change_count = execute "UPDATE assignments SET order_id = NULL WHERE id = 'started'"
      raise "update failure" unless change_count == 1
    end
    
    def self.down
      change_count = execute "UPDATE assignments SET order_id = 'started' WHERE id = 'started'"
      raise "update failure" unless change_count == 1
      change_column_null :assignments, :order_id, false
      begin
        execute "UPDATE assignments SET order_id = NULL WHERE id = 'started'"
        raise "Should raise exception"
      rescue
        # expected
      end
    end
  end
  
  def test_migrate_change_column_null
    TestMigrateChangeColumnNull.up
    TestMigrateChangeColumnNull.down
  end
  
end