to_sql

# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 258
      def to_sql
        column_sql = "#{base.quote_column_name(name)} #{sql_type}"
        add_column_options!(column_sql, :null => null, :default => default) unless type.to_sym == :primary_key
        column_sql
      end