diff --git a/include/sqlpp11/column.h b/include/sqlpp11/column.h
index 0977d83c..da6f5b6e 100644
--- a/include/sqlpp11/column.h
+++ b/include/sqlpp11/column.h
@@ -86,16 +86,14 @@ namespace sqlpp
   };
 
   template<typename Table, typename ColumnSpec>
-  struct name_tag_of<column_t<Table, ColumnSpec>>
-  {
-    using type = typename ColumnSpec::_alias_t;
-  };
+  struct name_tag_of<column_t<Table, ColumnSpec>> : public name_tag_of<ColumnSpec>{};
 
   template<typename Table, typename ColumnSpec>
   struct has_default<column_t<Table, ColumnSpec>> : public ColumnSpec::has_default
   {
   };
 
+#warning: Do we need this?
   template<typename Table, typename ColumnSpec>
   struct has_name<column_t<Table, ColumnSpec>> : std::true_type
   {
diff --git a/include/sqlpp11/cte.h b/include/sqlpp11/cte.h
index 106ea380..290f3b27 100644
--- a/include/sqlpp11/cte.h
+++ b/include/sqlpp11/cte.h
@@ -88,10 +88,11 @@ namespace sqlpp
     using type = cte_ref_t<AliasProvider>;
   };
 
+#warning: Why can't we use FieldSpec directly? If not, does this one need to inherit from name_tag_base?
   template <typename FieldSpec>
   struct cte_column_spec_t
   {
-    using _alias_t = typename FieldSpec::_alias_t;
+    using _alias_t = name_tag_of_t<FieldSpec>;
 
     using _traits = make_traits<value_type_of_t<FieldSpec>>;
   };
@@ -155,7 +156,6 @@ namespace sqlpp
     using _required_ctes = detail::make_joined_set_t<required_ctes_of<Statement>, detail::type_set<AliasProvider>>;
     using _parameters = parameters_of<Statement>;
 
-    using _alias_t = typename AliasProvider::_alias_t;
     constexpr static bool _is_recursive = required_ctes_of<Statement>::template count<AliasProvider>();
 
     using _column_tuple_t = std::tuple<column_t<AliasProvider, cte_column_spec_t<FieldSpecs>>...>;
@@ -240,8 +240,6 @@ namespace sqlpp
     using _required_ctes = detail::make_type_set_t<AliasProvider>;
     using _provided_tables = detail::type_set<AliasProvider>;
 
-    using _alias_t = typename AliasProvider::_alias_t;
-
     template <typename Statement>
     auto as(Statement statement) -> make_cte_t<AliasProvider, Statement>
     {
diff --git a/include/sqlpp11/field_spec.h b/include/sqlpp11/field_spec.h
index d4e1e716..e08906ae 100644
--- a/include/sqlpp11/field_spec.h
+++ b/include/sqlpp11/field_spec.h
@@ -34,6 +34,7 @@
 
 namespace sqlpp
 {
+#warning: Do we need this? It should be possible to use name_tag_of_t and value_type_of_t somehow
   template <typename NameType, typename ValueType>
   struct field_spec_t
   {
diff --git a/include/sqlpp11/insert_value_list.h b/include/sqlpp11/insert_value_list.h
index a6b09f7e..381a0466 100644
--- a/include/sqlpp11/insert_value_list.h
+++ b/include/sqlpp11/insert_value_list.h
@@ -111,7 +111,7 @@ namespace sqlpp
         -> decltype(_columns)
     {
       (void)assignments;
-      return decltype(_columns)(std::get<Indexes>(assignments)._lhs...);
+      return decltype(_columns)(std::get<Indexes>(assignments)._l...);
     }
 
     auto columns_from_tuple(std::tuple<Assignments...> assignments) -> decltype(_columns)
@@ -125,7 +125,7 @@ namespace sqlpp
         -> decltype(_values)
     {
       (void)assignments;
-      return decltype(_values)(std::get<Indexes>(assignments)._rhs...);
+      return decltype(_values)(std::get<Indexes>(assignments)._r...);
     }
 
     auto values_from_tuple(std::tuple<Assignments...> assignments) -> decltype(_values)
diff --git a/include/sqlpp11/on.h b/include/sqlpp11/on.h
index ef6524d8..f40fd1e6 100644
--- a/include/sqlpp11/on.h
+++ b/include/sqlpp11/on.h
@@ -38,8 +38,7 @@ namespace sqlpp
   template <typename Expr>
   struct check_on
   {
-    using type = static_combined_check_t<static_check_t<is_expression_t<Expr>::value, assert_on_is_expression_t>,
-                                         static_check_t<is_boolean<Expr>::value, assert_on_is_boolean_expression_t>>;
+    using type = static_combined_check_t<static_check_t<is_boolean<Expr>::value, assert_on_is_boolean_expression_t>>;
   };
 
   template <typename Expr>
diff --git a/include/sqlpp11/postgresql/returning_column_list.h b/include/sqlpp11/postgresql/returning_column_list.h
index 7bc7feca..e6e4b9de 100644
--- a/include/sqlpp11/postgresql/returning_column_list.h
+++ b/include/sqlpp11/postgresql/returning_column_list.h
@@ -51,9 +51,6 @@ namespace sqlpp
       struct returning_traits
       {
         using _traits = make_traits<no_value_t, tag::is_returning_column_list, tag::is_return_value>;
-        struct _alias_t
-        {
-        };
       };
 
       template <typename Column>
@@ -64,7 +61,6 @@ namespace sqlpp
                                     tag::is_return_value,
                                     tag::is_expression,
                                     tag::is_selectable>;  // TODO: Is this correct?
-        using _alias_t = typename Column::_alias_t;
       };
     }  // namespace detail
 
@@ -96,7 +92,6 @@ namespace sqlpp
     {
       using _traits = typename detail::returning_traits<Columns...>::_traits;
       using _nodes = ::sqlpp::detail::type_vector<Columns...>;
-      using _alias_t = typename detail::returning_traits<Columns...>::_alias_t;
 
       struct _column_type
       {
@@ -157,6 +152,7 @@ namespace sqlpp
         template <typename AliasProvider>
         using _table_t = typename _deferred_table_t<AliasProvider>::table;
 
+#warning: review all the alias stuff here
         template <typename AliasProvider>
         using _alias_t = typename _deferred_table_t<AliasProvider>::alias;
 
@@ -203,6 +199,16 @@ namespace sqlpp
       };
     };
 
+    template <typename Column>
+    struct value_type_of<returning_column_list_t<Columns...>> : public value_type_of<Column>
+    {
+    };
+
+    template <typename Column>
+    struct name_tag_of<returning_column_list_t<Columns...>> : public name_tag_of<Column>
+    {
+    };
+
     namespace detail
     {
       template <typename... Columns>
diff --git a/include/sqlpp11/select_pseudo_table.h b/include/sqlpp11/select_pseudo_table.h
index bc71948b..ac0e11f9 100644
--- a/include/sqlpp11/select_pseudo_table.h
+++ b/include/sqlpp11/select_pseudo_table.h
@@ -35,9 +35,10 @@ namespace sqlpp
   //
   // provide type information for sub-selects that are used as named expressions or tables
   template <typename Select, typename NamedExpr>
-  struct select_column_spec_t
+  struct select_column_spec_t: public name_tag_base
   {
     using _alias_t = name_tag_of_t<NamedExpr>;
+    using has_default = std::false_type;
 
     static constexpr bool _depends_on_outer_table =
         detail::make_intersect_set_t<required_tables_of_t<NamedExpr>, typename Select::_used_outer_tables>::size::value >
diff --git a/include/sqlpp11/table.h b/include/sqlpp11/table.h
index 90b09caf..f2d57a4d 100644
--- a/include/sqlpp11/table.h
+++ b/include/sqlpp11/table.h
@@ -47,6 +47,9 @@ namespace sqlpp
     using _provided_tables = detail::type_set<Table>;
 
     static_assert(sizeof...(ColumnSpec) > 0, "at least one column required per table");
+    template<typename T> struct require_insert : std::integral_constant<bool, not has_default<T>::value>{};
+    using _required_insert_columns =
+        typename detail::make_type_set_if<require_insert, column_t<Table, ColumnSpec>...>::type;
     using _column_tuple_t = std::tuple<column_t<Table, ColumnSpec>...>;
     template <typename AliasProvider, typename T>
     using _foreign_table_alias_t = table_alias_t<AliasProvider, T, ColumnSpec...>;
@@ -102,7 +105,7 @@ namespace sqlpp
   template <typename Context, typename Table, typename... ColumnSpec>
   Context& serialize(Context& context, const table_t<Table, ColumnSpec...>& /*unused*/)
   {
-    context << Table::_alias_t::_name_t::template char_ptr<Context>();
+    context << name_tag_of_t<Table>::_name_t::template char_ptr<Context>();
     return context;
   }
 }  // namespace sqlpp
diff --git a/include/sqlpp11/union.h b/include/sqlpp11/union.h
index 9da41bbb..ab91aa84 100644
--- a/include/sqlpp11/union.h
+++ b/include/sqlpp11/union.h
@@ -64,10 +64,6 @@ namespace sqlpp
     using _traits = make_traits<no_value_t, tag::is_union, tag::is_return_value>;
     using _nodes = detail::type_vector<Lhs, Rhs>;
 
-    using _alias_t = struct
-    {
-    };
-
     using _data_t = union_data_t<Flag, Lhs, Rhs>;
 
     // Base template to be inherited by the statement
diff --git a/include/sqlpp11/verbatim.h b/include/sqlpp11/verbatim.h
index 80990fa0..b85fa736 100644
--- a/include/sqlpp11/verbatim.h
+++ b/include/sqlpp11/verbatim.h
@@ -55,6 +55,12 @@ namespace sqlpp
     std::string _verbatim;
   };
 
+  template <typename ValueType>
+    struct value_type_of<verbatim_t<ValueType>>
+    {
+      using type = ValueType;
+    };
+
   template <typename Context, typename ValueType>
   Context& serialize(Context& context, const verbatim_t<ValueType>& t)
   {
diff --git a/include/sqlpp11/verbatim_table.h b/include/sqlpp11/verbatim_table.h
index b1931593..4a820642 100644
--- a/include/sqlpp11/verbatim_table.h
+++ b/include/sqlpp11/verbatim_table.h
@@ -48,6 +48,7 @@ namespace sqlpp
         };
       };
       using _traits = make_traits<no_value_t>;
+      using has_default = std::false_type;
     };
   }  // namespace detail
 
diff --git a/tests/core/serialize/CMakeLists.txt b/tests/core/serialize/CMakeLists.txt
index e55ae742..eab643df 100644
--- a/tests/core/serialize/CMakeLists.txt
+++ b/tests/core/serialize/CMakeLists.txt
@@ -34,9 +34,9 @@ set(test_files
     Exists.cpp
     Float.cpp
     #ForUpdate.cpp
-    #From.cpp
+    From.cpp
     In.cpp
-    #Insert.cpp
+    Insert.cpp
     IsNotNull.cpp
     IsNull.cpp
     Lower.cpp
@@ -48,7 +48,7 @@ set(test_files
     SelectColumns.cpp
     SelectFlags.cpp
     Sum.cpp
-    #TableAlias.cpp
+    TableAlias.cpp
     Trim.cpp
     Upper.cpp
     Where.cpp
diff --git a/tests/core/serialize/Insert.cpp b/tests/core/serialize/Insert.cpp
index 0561b4e8..131da36d 100644
--- a/tests/core/serialize/Insert.cpp
+++ b/tests/core/serialize/Insert.cpp
@@ -34,7 +34,7 @@ namespace
   auto getTrue() -> std::string
   {
     MockDb::_serializer_context_t printer = {};
-    return serialize(sqlpp::value(true), printer).str();
+    return serialize(printer, sqlpp::value(true)).str();
   }
 }
 
@@ -45,7 +45,7 @@ int Insert(int, char* [])
   compare(__LINE__, insert_into(bar).default_values(), "INSERT INTO tab_bar DEFAULT VALUES");
   compare(__LINE__, insert_into(bar).set(bar.textN = "cheesecake", bar.boolNn = true),
           "INSERT INTO tab_bar (text_n,bool_nn) VALUES('cheesecake'," + getTrue() + ")");
-  compare(__LINE__, insert_into(bar).set(bar.textN = ::sqlpp::null, bar.boolNn = true),
+  compare(__LINE__, insert_into(bar).set(bar.textN = ::sqlpp::compat::nullopt, bar.boolNn = true),
           "INSERT INTO tab_bar (text_n,bool_nn) VALUES(NULL," + getTrue() + ")");
   sqlpp::compat::string_view cheeseCake = "cheesecake";
   compare(__LINE__, insert_into(bar).set(bar.textN = std::string(cheeseCake), bar.boolNn = true),