create_boolean_domain

# File activerecord/lib/active_record/connection_adapters/firebird_adapter.rb, line 692
        def create_boolean_domain
          sql = "CREATE DOMAIN \#{boolean_domain[:name]} AS \#{boolean_domain[:type]}\nCHECK (VALUE IN (\#{quoted_true}, \#{quoted_false}) OR VALUE IS NULL)\n"
          execute sql rescue nil
        end