diff --git a/include/sqlpp11/from.h b/include/sqlpp11/from.h
index 74babb1e..00a9a2e7 100644
--- a/include/sqlpp11/from.h
+++ b/include/sqlpp11/from.h
@@ -28,6 +28,7 @@
 #define SQLPP_FROM_H
 
 #include <sqlpp11/type_traits.h>
+#include <sqlpp11/no_data.h>
 #include <sqlpp11/interpretable_list.h>
 #include <sqlpp11/interpret_tuple.h>
 #include <sqlpp11/detail/logic.h>
@@ -60,7 +61,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::from>;
 			using _recursive_traits = make_recursive_traits<Tables...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Tables), "at least one table or join argument required in from()");
 
diff --git a/include/sqlpp11/group_by.h b/include/sqlpp11/group_by.h
index 8e369b0c..f5c8bb56 100644
--- a/include/sqlpp11/group_by.h
+++ b/include/sqlpp11/group_by.h
@@ -62,7 +62,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::group_by>;
 			using _recursive_traits = make_recursive_traits<Expressions...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Expressions), "at least one expression (e.g. a column) required in group_by()");
 
diff --git a/include/sqlpp11/having.h b/include/sqlpp11/having.h
index d50f5600..9fc1d410 100644
--- a/include/sqlpp11/having.h
+++ b/include/sqlpp11/having.h
@@ -61,7 +61,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::having>;
 			using _recursive_traits = make_recursive_traits<Expressions...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Expressions), "at least one expression argument required in having()");
 			static_assert(::sqlpp::detail::all_t<is_expression_t<Expressions>::value...>::value, "at least one argument is not an expression in having()");
diff --git a/include/sqlpp11/insert_value_list.h b/include/sqlpp11/insert_value_list.h
index 831a6752..6a0f804c 100644
--- a/include/sqlpp11/insert_value_list.h
+++ b/include/sqlpp11/insert_value_list.h
@@ -106,7 +106,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::insert_list>;
 			using _recursive_traits = make_recursive_traits<typename Assignments::_column_t..., typename Assignments::_value_t...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			template<template<typename...> class Target>
 				using copy_assignments_t = Target<Assignments...>; // FIXME: Nice idea to copy variadic template arguments?
diff --git a/include/sqlpp11/into.h b/include/sqlpp11/into.h
index fd2a08e4..3c6c388c 100644
--- a/include/sqlpp11/into.h
+++ b/include/sqlpp11/into.h
@@ -29,6 +29,7 @@
 
 #include <sqlpp11/type_traits.h>
 #include <sqlpp11/no_value.h>
+#include <sqlpp11/no_data.h>
 #include <sqlpp11/prepared_insert.h>
 #include <sqlpp11/serializer.h>
 #include <sqlpp11/detail/type_set.h>
diff --git a/include/sqlpp11/noop.h b/include/sqlpp11/noop.h
index 74198fd0..e28ae330 100644
--- a/include/sqlpp11/noop.h
+++ b/include/sqlpp11/noop.h
@@ -33,20 +33,6 @@
 
 namespace sqlpp
 {
-#warning: Need extra include file for no_data
-	struct no_data_t {};
-
-	template<typename Context>
-		struct serializer_t<Context, no_data_t>
-		{
-			using T = no_data_t;
-
-			static Context& _(const T& t, Context& context)
-			{
-				return context;
-			}
-		};
-
 	struct noop 
 	{
 		using _traits = make_traits<no_value_t, ::sqlpp::tag::noop>;
diff --git a/include/sqlpp11/on.h b/include/sqlpp11/on.h
index 26b93a9f..69f91c11 100644
--- a/include/sqlpp11/on.h
+++ b/include/sqlpp11/on.h
@@ -40,7 +40,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, tag::on>;
 			using _recursive_traits = make_recursive_traits<Expr...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Expr), "at least one expression argument required in on()");
 			static_assert(detail::all_t<is_expression_t<Expr>::value...>::value, "at least one argument is not an expression in on()");
diff --git a/include/sqlpp11/order_by.h b/include/sqlpp11/order_by.h
index 0f9fdc75..a82ac900 100644
--- a/include/sqlpp11/order_by.h
+++ b/include/sqlpp11/order_by.h
@@ -62,7 +62,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::order_by>;
 			using _recursive_traits = make_recursive_traits<Expressions...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Expressions), "at least one expression (e.g. a column) required in order_by()");
 
diff --git a/include/sqlpp11/select_column_list.h b/include/sqlpp11/select_column_list.h
index fe832ab8..eb14feb1 100644
--- a/include/sqlpp11/select_column_list.h
+++ b/include/sqlpp11/select_column_list.h
@@ -129,8 +129,6 @@ namespace sqlpp
 	template<typename Database, typename... Columns>
 		struct select_column_list_data_t
 		{
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
-
 			select_column_list_data_t(Columns... columns):
 				_columns(columns...)
 			{}
@@ -159,12 +157,11 @@ namespace sqlpp
 
 			using _name_t = typename ::sqlpp::detail::select_traits<Columns...>::_name_t;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
+			static_assert(_is_dynamic::value or sizeof...(Columns), "at least one select expression required");
 			static_assert(not ::sqlpp::detail::has_duplicates<Columns...>::value, "at least one duplicate argument detected");
-
 			static_assert(::sqlpp::detail::all_t<(is_named_expression_t<Columns>::value or is_multi_column_t<Columns>::value)...>::value, "at least one argument is not a named expression");
-
 			static_assert(not ::sqlpp::detail::has_duplicates<typename Columns::_name_t...>::value, "at least one duplicate name detected");
 
 			struct _column_type {};
@@ -383,9 +380,6 @@ namespace sqlpp
 
 			static Context& _(const T& t, Context& context)
 			{
-				// check for at least one expression
-				static_assert(T::_is_dynamic::value or sizeof...(Columns), "at least one select expression required");
-
 				interpret_tuple(t._columns, ',', context);
 				if (sizeof...(Columns) and not t._dynamic_columns.empty())
 					context << ',';
diff --git a/include/sqlpp11/select_flag_list.h b/include/sqlpp11/select_flag_list.h
index 8147e5d2..8932b896 100644
--- a/include/sqlpp11/select_flag_list.h
+++ b/include/sqlpp11/select_flag_list.h
@@ -29,6 +29,7 @@
 
 #include <tuple>
 #include <sqlpp11/type_traits.h>
+#include <sqlpp11/no_data.h>
 #include <sqlpp11/select_flags.h>
 #include <sqlpp11/detail/type_set.h>
 #include <sqlpp11/interpret_tuple.h>
@@ -61,7 +62,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::select_flag_list>;
 			using _recursive_traits = make_recursive_traits<Flags...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(not ::sqlpp::detail::has_duplicates<Flags...>::value, "at least one duplicate argument detected in select flag list");
 
diff --git a/include/sqlpp11/single_table.h b/include/sqlpp11/single_table.h
index 31d667e2..e2a83a9e 100644
--- a/include/sqlpp11/single_table.h
+++ b/include/sqlpp11/single_table.h
@@ -29,6 +29,7 @@
 
 #include <sqlpp11/type_traits.h>
 #include <sqlpp11/no_value.h>
+#include <sqlpp11/no_data.h>
 #include <sqlpp11/serializer.h>
 #include <sqlpp11/prepared_insert.h>
 #include <sqlpp11/detail/type_set.h>
diff --git a/include/sqlpp11/statement.h b/include/sqlpp11/statement.h
index 52ddeb68..b5e1bc5a 100644
--- a/include/sqlpp11/statement.h
+++ b/include/sqlpp11/statement.h
@@ -43,8 +43,6 @@ namespace sqlpp
 	template<typename Db, typename... Policies>
 		struct statement_t;
 
-#warning STEPS:
-#warning deal with different return types in the connector (select could be a single value, update could be a range of rows)
 	namespace detail
 	{
 		template<typename Db = void, typename... Policies>
@@ -115,7 +113,7 @@ namespace sqlpp
 					using _required_tables = _required_tables;
 					using _provided_tables = detail::type_set<>;
 					using _extra_tables = detail::type_set<>;
-					using _parameters = detail::make_parameter_list_t<parameters_of<Policies>...>;
+					using _parameters = detail::make_parameter_tuple_t<parameters_of<Policies>...>;
 				};
 			};
 	}
@@ -161,9 +159,7 @@ namespace sqlpp
 
 		static constexpr size_t _get_static_no_of_parameters()
 		{
-#warning need to fix this
-			return 0;
-			//return _parameter_list_t::size::value;
+			return std::tuple_size<parameters_of<statement_t>>::value;
 		}
 
 		size_t _get_no_of_parameters() const
diff --git a/include/sqlpp11/type_traits.h b/include/sqlpp11/type_traits.h
index 9fd8376b..4cd4fdf2 100644
--- a/include/sqlpp11/type_traits.h
+++ b/include/sqlpp11/type_traits.h
@@ -126,7 +126,6 @@ namespace sqlpp
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(into);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(extra_tables);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(on);
-	SQLPP_IS_VALUE_TRAIT_GENERATOR(dynamic);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(where);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(group_by);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(having);
@@ -150,6 +149,9 @@ namespace sqlpp
 	SQLPP_CONNECTOR_TRAIT_GENERATOR(null_result_is_trivial_value);
 	SQLPP_CONNECTOR_TRAIT_GENERATOR(assert_result_validity);
 
+	template<typename Database>
+		using is_database = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+
 	template<typename T, template<typename> class IsTag>
 		using copy_type_trait = typename std::conditional<IsTag<T>::value, std::true_type, std::false_type>::type;
 
@@ -186,14 +188,13 @@ namespace sqlpp
 			};
 
 		template<typename... T>
-			struct make_parameter_list_impl
+			struct make_parameter_tuple_impl
 			{
 				using type = decltype(std::tuple_cat(std::declval<T>()...));
 			};
 
-#warning this will lead to confusion with ::sqlpp::make_parameter_list_t in parameter_list.h
 		template<typename... T>
-			using make_parameter_list_t = typename make_parameter_list_impl<T...>::type;
+			using make_parameter_tuple_t = typename make_parameter_tuple_impl<T...>::type;
 	}
 	template<typename T>
 		using value_type_of = typename detail::value_type_of_impl<T>::type;
@@ -222,7 +223,7 @@ namespace sqlpp
 			using _required_tables = detail::make_joined_set_t<required_tables_of<Arguments>...>;
 			using _provided_tables = detail::make_joined_set_t<provided_tables_of<Arguments>...>;
 			using _extra_tables = detail::make_joined_set_t<extra_tables_of<Arguments>...>;
-			using _parameters = detail::make_parameter_list_t<parameters_of<Arguments>...>;
+			using _parameters = detail::make_parameter_tuple_t<parameters_of<Arguments>...>;
 		};
 
 }
diff --git a/include/sqlpp11/update_list.h b/include/sqlpp11/update_list.h
index e09be547..a5f9b7a4 100644
--- a/include/sqlpp11/update_list.h
+++ b/include/sqlpp11/update_list.h
@@ -58,7 +58,7 @@ namespace sqlpp
 		{
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::update_list>;
 			using _recursive_traits = make_recursive_traits<Assignments...>;
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Assignments), "at least one assignment expression required in set()");
 
diff --git a/include/sqlpp11/using.h b/include/sqlpp11/using.h
index 0d345906..b8423bc0 100644
--- a/include/sqlpp11/using.h
+++ b/include/sqlpp11/using.h
@@ -60,7 +60,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::using_>;
 			using _recursive_traits = make_recursive_traits<Tables...>;
 
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Tables), "at least one table argument required in using()");
 
diff --git a/include/sqlpp11/where.h b/include/sqlpp11/where.h
index 8c9446e7..b19e7123 100644
--- a/include/sqlpp11/where.h
+++ b/include/sqlpp11/where.h
@@ -61,8 +61,7 @@ namespace sqlpp
 			using _traits = make_traits<no_value_t, ::sqlpp::tag::where>;
 			using _recursive_traits = make_recursive_traits<Expressions...>;
 
-#warning: is_dynamic should be using a template alias (making it easier to replace the logic)
-			using _is_dynamic = typename std::conditional<std::is_same<Database, void>::value, std::false_type, std::true_type>::type;
+			using _is_dynamic = is_database<Database>;
 
 			static_assert(_is_dynamic::value or sizeof...(Expressions), "at least one expression argument required in where()");
 			static_assert(sqlpp::detail::none_t<is_assignment_t<Expressions>::value...>::value, "at least one argument is an assignment in where()");