From 95c555d03a19a7c6f460f35964cafdea166e01cb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sascha=20K=C3=BChl?= <s.kuehl@tms-bonn.de>
Date: Wed, 19 Nov 2025 16:17:25 +0100
Subject: [PATCH] compilation fixes

---
 .../matador/object/attribute_definition.hpp   |  7 --
 .../object/attribute_definition_generator.hpp |  2 +-
 include/matador/object/basic_object_info.hpp  |  8 +--
 include/matador/object/object_definition.hpp  |  1 +
 include/matador/object/repository.hpp         |  1 -
 include/matador/object/repository_node.hpp    | 24 +++----
 include/matador/orm/session.hpp               |  6 +-
 include/matador/query/builder.hpp             | 67 +++++++++++++++++--
 include/matador/query/query_compiler.hpp      |  2 +
 include/matador/utils/constraints.hpp         |  4 +-
 source/core/object/attribute_definition.cpp   |  3 +-
 source/core/object/basic_object_info.cpp      | 10 +--
 source/core/object/repository.cpp             | 19 ------
 source/core/object/repository_node.cpp        | 24 +++----
 source/orm/orm/schema.cpp                     |  2 +-
 source/orm/orm/session.cpp                    |  2 +-
 source/orm/query/builder.cpp                  |  4 +-
 test/orm/sql/ColumnTest.cpp                   |  7 +-
 test/orm/sql/FieldTest.cpp                    |  2 +-
 todo.md                                       |  3 +
 20 files changed, 118 insertions(+), 80 deletions(-)

diff --git a/include/matador/object/attribute_definition.hpp b/include/matador/object/attribute_definition.hpp
index 992f885..84dae91 100644
--- a/include/matador/object/attribute_definition.hpp
+++ b/include/matador/object/attribute_definition.hpp
@@ -4,10 +4,8 @@
 #include "matador/utils/basic_types.hpp"
 #include "matador/utils/default_type_traits.hpp"
 #include "matador/utils/field_attributes.hpp"
-#include "matador/utils/value.hpp"
 
 #include <memory>
-#include <vector>
 
 namespace matador::object {
 
@@ -95,14 +93,9 @@ public:
     return type() == utils::data_type_traits<Type>::type(attributes().size());
   }
 
-private:
-  using data_type_index = std::vector<utils::basic_type>;
-
 private:
   friend class object_definition;
 
-  static const data_type_index data_type_index_;
-
   std::string name_;
   std::shared_ptr<object_definition> object_{};
   attribute_options options_;
diff --git a/include/matador/object/attribute_definition_generator.hpp b/include/matador/object/attribute_definition_generator.hpp
index e563a57..756f716 100644
--- a/include/matador/object/attribute_definition_generator.hpp
+++ b/include/matador/object/attribute_definition_generator.hpp
@@ -8,7 +8,7 @@
 #include "matador/utils/error.hpp"
 #include "matador/utils/field_attributes.hpp"
 #include "matador/utils/primary_key_attribute.hpp"
-
+#include "matador/utils/result.hpp"
 
 #include <memory>
 #include <typeindex>
diff --git a/include/matador/object/basic_object_info.hpp b/include/matador/object/basic_object_info.hpp
index b3efd9d..7d657e4 100644
--- a/include/matador/object/basic_object_info.hpp
+++ b/include/matador/object/basic_object_info.hpp
@@ -24,7 +24,7 @@ public:
 
   [[nodiscard]] std::type_index type_index() const;
   [[nodiscard]] std::string name() const;
-  [[nodiscard]] const object_definition& definition() const;
+  [[nodiscard]] std::shared_ptr<object_definition> definition() const;
   [[nodiscard]] std::shared_ptr<attribute_definition> reference_column() const;
 
   [[nodiscard]] bool has_primary_key() const;
@@ -49,13 +49,13 @@ public:
   [[nodiscard]] bool endpoints_empty() const;
 
 protected:
-  basic_object_info(std::shared_ptr<repository_node> node, utils::identifier &&pk, const std::shared_ptr<attribute_definition> &pk_column, object_definition &&definition);
+  basic_object_info(std::shared_ptr<repository_node> node, utils::identifier &&pk, const std::shared_ptr<attribute_definition> &pk_column, const std::shared_ptr<object_definition> &definition);
   basic_object_info(std::shared_ptr<repository_node> node, utils::identifier &&pk, const std::shared_ptr<attribute_definition> &pk_column);
-  basic_object_info(std::shared_ptr<repository_node> node, object_definition &&definition);
+  basic_object_info(std::shared_ptr<repository_node> node, const std::shared_ptr<object_definition> &definition);
 
 protected:
   std::shared_ptr<repository_node> node_;            /**< prototype node of the represented object type */
-  object_definition definition_;
+  std::shared_ptr<object_definition> definition_;
   std::optional<utils::identifier> identifier_;
   std::shared_ptr<attribute_definition> pk_column_;
   t_endpoint_map relation_endpoints_;
diff --git a/include/matador/object/object_definition.hpp b/include/matador/object/object_definition.hpp
index 2cfc83d..29d3865 100644
--- a/include/matador/object/object_definition.hpp
+++ b/include/matador/object/object_definition.hpp
@@ -3,6 +3,7 @@
 
 #include "matador/object/attribute_definition.hpp"
 
+#include <optional>
 #include <unordered_map>
 
 namespace matador::object {
diff --git a/include/matador/object/repository.hpp b/include/matador/object/repository.hpp
index c101bf8..2f3e793 100644
--- a/include/matador/object/repository.hpp
+++ b/include/matador/object/repository.hpp
@@ -161,7 +161,6 @@ private:
   using t_type_index_node_map = std::unordered_map<std::type_index, node_ptr>;
 
   [[nodiscard]] utils::result<node_ptr, utils::error> attach_node(const node_ptr &node, const std::string &parent);
-  // [[nodiscard]] utils::result<node_ptr, utils::error> attach_node(const node_ptr &node, const std::type_index &type_index);
   [[nodiscard]] utils::result<node_ptr, utils::error> find_node(const std::string &name) const;
   [[nodiscard]] utils::result<node_ptr, utils::error> find_node(const std::type_index &type_index) const;
   template<typename Type>
diff --git a/include/matador/object/repository_node.hpp b/include/matador/object/repository_node.hpp
index fe0a48e..3bb0d2e 100644
--- a/include/matador/object/repository_node.hpp
+++ b/include/matador/object/repository_node.hpp
@@ -21,18 +21,18 @@ public:
     auto node = std::shared_ptr<repository_node>(new repository_node(repo, name, typeid(Type)));
 
     primary_key_resolver resolver;
-    object_definition obj{name, {}};
+    auto obj = std::make_shared<object_definition>(name);
     auto pk_info = resolver.resolve<Type>();
     auto ref_column = determine_reference_column(typeid(Type), name, pk_info, repo);
     const auto attributes = attribute_definition_generator::generate<Type>(repo);
     for (auto&& attr : attributes) {
-      obj.append(std::move(attr));
+      obj->append(std::move(attr));
     }
     auto info = std::make_unique<object_info<Type>>(
       node,
       std::move(pk_info.pk),
       ref_column,
-      std::move(obj),
+      obj,
       []{ return std::make_unique<Type>(); }
     );
     node->info_ = std::move(info);
@@ -41,8 +41,8 @@ public:
   }
 
   template < typename Type, typename CreatorFunc >
-  static utils::result<node_ptr, utils::error> make_relation_node(object::repository& tree, const std::string& name, CreatorFunc &&creator) {
-    const auto result = make_and_attach_node(tree, name, typeid(Type));
+  static utils::result<node_ptr, utils::error> make_relation_node(repository& repo, const std::string& name, CreatorFunc &&creator) {
+    const auto result = make_and_attach_node(repo, name, typeid(Type));
     if (!result) {
         return result;
     }
@@ -50,7 +50,7 @@ public:
     auto obj = creator();
     auto info = std::make_unique<object_info<Type>>(
         result.value(),
-        object_definition{attribute_definition_generator::generate(*obj, tree)},
+        std::make_shared<object_definition>(attribute_definition_generator::generate(*obj, repo)),
         std::move(creator)
     );
     result.value()->info_ = std::move(info);
@@ -58,7 +58,7 @@ public:
     return result;
   }
 
-  static std::shared_ptr<repository_node> make_null_node(repository& tree);
+  static std::shared_ptr<repository_node> make_null_node(repository& repo);
 
   repository_node(const repository_node& other) = delete;
   repository_node(repository_node&& other) = default;
@@ -81,20 +81,20 @@ public:
       return std::ref(static_cast<const object_info<Type>&>(*info_));
   }
 
-  [[nodiscard]] const object::repository& schema() const;
+  [[nodiscard]] const repository& schema() const;
 
   [[nodiscard]] bool has_children() const;
 
 private:
-  explicit repository_node(object::repository& tree);
-  repository_node(object::repository& tree, const std::type_index& ti);
-  repository_node(object::repository& tree, std::string name, const std::type_index& ti);
+  explicit repository_node(repository& repo);
+  repository_node(repository& repo, const std::type_index& ti);
+  repository_node(repository& repo, std::string name, const std::type_index& ti);
 
   void unlink();
 
   static utils::result<node_ptr, utils::error> make_and_attach_node(repository& repo, const std::string& name, const std::type_index& ti);
   static std::shared_ptr<attribute_definition> determine_reference_column(const std::type_index& ti,
-                                                                          object_definition& obj,
+                                                                          const std::shared_ptr<object_definition>& obj,
                                                                           const primary_key_info& pk_info,
                                                                           repository& repo);
 
diff --git a/include/matador/orm/session.hpp b/include/matador/orm/session.hpp
index c7e1630..28f8e35 100644
--- a/include/matador/orm/session.hpp
+++ b/include/matador/orm/session.hpp
@@ -246,7 +246,7 @@ utils::result<object::object_ptr<Type>, utils::error> session::update( const obj
     using namespace matador::utils;
     using namespace matador::query;
 
-    const auto col = sql::column(info.value().get().definition().primary_key()->name());
+    const auto col = column(info.value().get().definition().primary_key()->name());
     auto res = matador::query::query::update(info->get().name())
       .set(generator::column_value_pairs<Type>())
       .where(col == _)
@@ -272,7 +272,7 @@ utils::result<void, utils::error> session::remove( const object::object_ptr<Type
     using namespace matador::utils;
     using namespace matador::query;
 
-    const auto col = sql::column(info.value().get().definition().primary_key()->name());
+    const auto col = column(info.value().get().definition().primary_key()->name());
     auto res = matador::query::query::remove()
       .from( info->get().name() )
       .where(col == _)
@@ -301,7 +301,7 @@ utils::result<object::object_ptr<Type>, utils::error> session::find(const Primar
     const auto& type_info = info.value().get();
 
     session_query_builder eqb(*schema_, *this);
-    const sql::column col(sql::table{type_info.reference_column()->table_name()}, type_info.reference_column()->name());
+    const query::column col(query::table{type_info.reference_column()->table_name()}, type_info.reference_column()->name());
     using namespace matador::query;
     auto data = eqb.build<Type>(col == utils::_);
     if (!data.is_ok()) {
diff --git a/include/matador/query/builder.hpp b/include/matador/query/builder.hpp
index a1550bc..4c9d23e 100644
--- a/include/matador/query/builder.hpp
+++ b/include/matador/query/builder.hpp
@@ -1,11 +1,72 @@
 #ifndef MATADOR_BUILDER_HPP
 #define MATADOR_BUILDER_HPP
 
+#include "matador/object/attribute_definition.hpp"
+
 #include "matador/query/column.hpp"
 #include "matador/query/table.hpp"
 
+#include "matador/utils/basic_types.hpp"
+
 #include <string>
 
+namespace matador::object {
+
+class entity {
+public:
+    explicit entity(std::string name)
+    : name_(std::move(name)) {}
+
+    [[nodiscard]] const std::string& name() const;
+
+private:
+    std::string name_;
+    std::string alias_;
+};
+
+class attribute {
+public:
+    attribute(std::string name, const utils::basic_type type)
+    : name_(std::move(name))
+    , type_(type) {}
+
+    [[nodiscard]] const std::string& name() const;
+    [[nodiscard]] utils::basic_type type() const;
+    [[nodiscard]] const attribute_options& options() const;
+
+private:
+    friend class entity;
+
+    std::string name_;
+    std::string alias_;
+    utils::basic_type type_{};
+    attribute_options options_;
+
+    entity* owner_{nullptr};
+};
+
+class constraint {
+public:
+    explicit constraint(std::string name)
+    : name_(std::move(name)) {}
+
+    [[nodiscard]] const std::string& name() const;
+    [[nodiscard]] const std::string& column_name() const;
+    [[nodiscard]] const utils::constraints& type() const;
+    [[nodiscard]] bool is_primary_key_constraint() const;
+    [[nodiscard]] bool is_foreign_key_constraint() const;
+    [[nodiscard]] bool is_unique_constraint() const;
+    [[nodiscard]] const std::string& referenced_table() const;
+    [[nodiscard]] const std::string& referenced_column() const;
+
+private:
+    std::string name_;
+    std::string column_name_;
+    utils::constraints type_{};
+    std::string referenced_table_;
+    std::string referenced_column_;
+};
+}
 namespace matador::query {
 
 class column_builder {
@@ -19,10 +80,6 @@ private:
   std::string column_name;
 };
 
-struct constraint {
-  std::string name;
-};
-
 class table_builder {
 public:
   explicit table_builder(std::string name);
@@ -45,7 +102,7 @@ public:
   constraint_builder& references(std::string table, std::string column);
 
   // ReSharper disable once CppNonExplicitConversionOperator
-  operator query::constraint() const; // NOLINT(*-explicit-constructor)
+  operator object::constraint() const; // NOLINT(*-explicit-constructor)
 
 private:
   std::string constraint_name;
diff --git a/include/matador/query/query_compiler.hpp b/include/matador/query/query_compiler.hpp
index c334552..b7f629f 100644
--- a/include/matador/query/query_compiler.hpp
+++ b/include/matador/query/query_compiler.hpp
@@ -8,6 +8,8 @@
 
 #include "matador/utils/placeholder.hpp"
 
+#include <optional>
+
 namespace matador::sql {
 class connection_impl;
 class dialect;
diff --git a/include/matador/utils/constraints.hpp b/include/matador/utils/constraints.hpp
index 247d0b9..aa7304d 100644
--- a/include/matador/utils/constraints.hpp
+++ b/include/matador/utils/constraints.hpp
@@ -14,8 +14,8 @@ enum class constraints : unsigned char {
 
 inline constraints operator|(constraints a, constraints b) { return static_cast<constraints>(static_cast<unsigned int>(a) | static_cast<unsigned int>(b)); }
 inline constraints operator&(constraints a, constraints b) { return static_cast<constraints>(static_cast<unsigned int>(a) & static_cast<unsigned int>(b)); }
-inline constraints& operator|= (constraints& a, constraints b) { return (constraints&)((int&)a |= (int)b); }
-inline constraints& operator&= (constraints& a, constraints b) { return (constraints&)((int&)a &= (int)b); }
+inline constraints& operator|= (constraints& a, constraints b) { return reinterpret_cast<constraints&>(reinterpret_cast<int&>(a) |= static_cast<int>(b)); }
+inline constraints& operator&= (constraints& a, constraints b) { return reinterpret_cast<constraints&>(reinterpret_cast<int&>(a) &= static_cast<int>(b)); }
 
 inline bool is_constraint_set(const constraints source, const constraints needle) { return static_cast<int>(source & needle) > 0; }
 
diff --git a/source/core/object/attribute_definition.cpp b/source/core/object/attribute_definition.cpp
index e2ac16b..cae01a9 100644
--- a/source/core/object/attribute_definition.cpp
+++ b/source/core/object/attribute_definition.cpp
@@ -35,8 +35,9 @@ attribute_definition::attribute_definition( std::string name, const utils::basic
 : attribute_definition(std::move(name), type, {}, {}, ref_column) {
 }
 
-attribute_definition::attribute_definition( std::string name, const utils::basic_type type, const attribute_options& options, const std::shared_ptr<object_definition>& obj, const std::shared_ptr<attribute_definition>& ref_column )
+attribute_definition::attribute_definition(std::string name, const utils::basic_type type, const attribute_options& options, const std::shared_ptr<object_definition>& obj, const std::shared_ptr<attribute_definition>& ref_column)
 : name_( std::move( name ) )
+, object_( obj )
 , options_( options )
 , type_( type )
 , reference_column_( ref_column ) {
diff --git a/source/core/object/basic_object_info.cpp b/source/core/object/basic_object_info.cpp
index 03c7815..601914f 100644
--- a/source/core/object/basic_object_info.cpp
+++ b/source/core/object/basic_object_info.cpp
@@ -8,9 +8,9 @@ namespace matador::object {
 basic_object_info::basic_object_info(std::shared_ptr<repository_node> node,
                                      utils::identifier &&pk,
                                      const std::shared_ptr<attribute_definition> &pk_column,
-                                     object_definition &&definition)
+                                     const std::shared_ptr<object_definition> &definition)
 : node_(std::move(node))
-, definition_(std::move(definition))
+, definition_(definition)
 , identifier_(std::move(pk))
 , pk_column_(pk_column) {
 }
@@ -24,9 +24,9 @@ basic_object_info::basic_object_info(std::shared_ptr<repository_node> node,
 }
 
 basic_object_info::basic_object_info(std::shared_ptr<repository_node> node,
-                                     object_definition &&definition)
+                                     const std::shared_ptr<object_definition> &definition)
 : node_(std::move(node))
-, definition_(std::move(definition)) {}
+, definition_(definition) {}
 
 std::type_index basic_object_info::type_index() const {
   return node_->type_index();
@@ -36,7 +36,7 @@ std::string basic_object_info::name() const {
   return node_->name();
 }
 
-const object_definition &basic_object_info::definition() const {
+std::shared_ptr<object_definition> basic_object_info::definition() const {
   return definition_;
 }
 
diff --git a/source/core/object/repository.cpp b/source/core/object/repository.cpp
index b4e9ff5..72e1635 100644
--- a/source/core/object/repository.cpp
+++ b/source/core/object/repository.cpp
@@ -117,25 +117,6 @@ utils::result<repository::node_ptr, utils::error> repository::attach_node(const
   return utils::ok(node);
 }
 
-// utils::result<schema::node_ptr, utils::error> schema::attach_node(const std::shared_ptr<schema_node> &node,
-//                                                                   const std::type_index &type_index) {
-//   if (has_node(node)) {
-//     return utils::failure(make_error(error_code::NodeAlreadyExists, "Node '" + node->name() + "' already exists."));
-//   }
-//   auto result = find_node(type_index);
-//   if (!result.is_ok() && result.err().ec() != error_code::NodeNotFound) {
-//     return result;
-//   }
-//
-//   insert_node(*result, node);
-//
-//   // Todo: check return value
-//   nodes_by_name_.insert({node->name(), node})/*.first*/;
-//   nodes_by_type_.insert({node->type_index(), node});
-//
-//   return utils::ok(node);
-// }
-
 utils::result<repository::node_ptr, utils::error> repository::find_node(const std::string &name) const {
   // first search in the prototype map
   const auto i = nodes_by_name_.find(name);
diff --git a/source/core/object/repository_node.cpp b/source/core/object/repository_node.cpp
index 7d1ad09..1bcef2f 100644
--- a/source/core/object/repository_node.cpp
+++ b/source/core/object/repository_node.cpp
@@ -4,28 +4,28 @@
 #include "matador/object/repository_node.hpp"
 
 namespace matador::object {
-repository_node::repository_node(object::repository &tree)
-: repo_(tree)
+repository_node::repository_node(object::repository &repo)
+: repo_(repo)
 , type_index_(typeid(detail::null_type)){
 }
 
-repository_node::repository_node(object::repository &tree, const std::type_index& ti)
-: repo_(tree)
+repository_node::repository_node(object::repository &repo, const std::type_index& ti)
+: repo_(repo)
 , type_index_(ti) {
 }
 
-repository_node::repository_node(object::repository &tree, std::string name, const std::type_index& ti)
-: repo_(tree)
+repository_node::repository_node(object::repository &repo, std::string name, const std::type_index& ti)
+: repo_(repo)
 , type_index_(ti)
-, first_child_(std::shared_ptr<repository_node>(new repository_node(tree)))
-, last_child_(std::shared_ptr<repository_node>(new repository_node(tree)))
+, first_child_(std::shared_ptr<repository_node>(new repository_node(repo)))
+, last_child_(std::shared_ptr<repository_node>(new repository_node(repo)))
 , name_(std::move(name)) {
   first_child_->next_sibling_ = last_child_;
   last_child_->previous_sibling_ = first_child_;
 }
 
-std::shared_ptr<repository_node> repository_node::make_null_node(object::repository &tree) {
-  auto node = std::shared_ptr<repository_node>(new repository_node(tree));
+std::shared_ptr<repository_node> repository_node::make_null_node(object::repository &repo) {
+  auto node = std::shared_ptr<repository_node>(new repository_node(repo));
   node->info_ = std::make_unique<null_info>(node, std::shared_ptr<attribute_definition>{});
 
   return node;
@@ -104,7 +104,7 @@ utils::result<repository_node::node_ptr, utils::error> repository_node::make_and
     return repo.attach_node(node, "");
 }
 
-std::shared_ptr<attribute_definition> repository_node::determine_reference_column(const std::type_index& ti, object_definition& obj, const primary_key_info& pk_info, repository& repo) {
+std::shared_ptr<attribute_definition> repository_node::determine_reference_column(const std::type_index& ti, const std::shared_ptr<object_definition>& obj, const primary_key_info& pk_info, repository& repo) {
     const auto it = repo.missing_references_.find(ti);
     if (it == repo.missing_references_.end()) {
         return std::make_shared<attribute_definition>(pk_info.pk_column_name, pk_info.type, attribute_options{utils::constraints::FOREIGN_KEY});
@@ -117,7 +117,7 @@ std::shared_ptr<attribute_definition> repository_node::determine_reference_colum
     ref_column->change_type(pk_info.type);
     ref_column->attributes() = utils::constraints::FOREIGN_KEY;
 
-    if (obj.name().empty()) {
+    if (obj->name().empty()) {
       repo.missing_references_.insert({ti, ref_column});
     }
 
diff --git a/source/orm/orm/schema.cpp b/source/orm/orm/schema.cpp
index 9506003..b100234 100644
--- a/source/orm/orm/schema.cpp
+++ b/source/orm/orm/schema.cpp
@@ -57,7 +57,7 @@ matador::utils::result<void, matador::utils::error> matador::orm::schema::create
     // std::cout << result.sql << std::endl;
     for (const auto &node: repo_) {
         auto ctx = query::query::create()
-          .table(node->name(), node->info().definition().columns())
+          .table(node->name(), node->info().definition()->columns())
           .compile(*c);
 
         for ( const auto& [sql, command] : ctx.additional_commands ) {
diff --git a/source/orm/orm/session.cpp b/source/orm/orm/session.cpp
index 4c46dd3..d1d7fa2 100644
--- a/source/orm/orm/session.cpp
+++ b/source/orm/orm/session.cpp
@@ -52,7 +52,7 @@ utils::result<void, utils::error> session::create_schema() const {
   auto c = cache_.pool().acquire();
   for (const auto &node: *schema_) {
     auto ctx = query::query::create()
-      .table(node->name(), node->info().definition().columns())
+      .table(node->name(), node->info().definition()->columns())
       .compile(*c);
 
     for ( const auto& [sql, command] : ctx.additional_commands ) {
diff --git a/source/orm/query/builder.cpp b/source/orm/query/builder.cpp
index d2fed9a..818936c 100644
--- a/source/orm/query/builder.cpp
+++ b/source/orm/query/builder.cpp
@@ -42,8 +42,8 @@ constraint_builder& constraint_builder::references( std::string table, std::stri
   return *this;
 }
 
-constraint_builder::operator struct query::constraint() const {
-  return {constraint_name};
+constraint_builder::operator object::constraint() const {
+  return object::constraint{constraint_name};
 }
 
 constraint_builder constraint( std::string name ) {
diff --git a/test/orm/sql/ColumnTest.cpp b/test/orm/sql/ColumnTest.cpp
index a308246..f9af913 100644
--- a/test/orm/sql/ColumnTest.cpp
+++ b/test/orm/sql/ColumnTest.cpp
@@ -1,6 +1,7 @@
 #include <catch2/catch_test_macros.hpp>
 
 #include "matador/object/attribute_definition.hpp"
+#include "matador/object/object_definition.hpp"
 
 using namespace matador::object;
 using namespace matador::utils;
@@ -33,7 +34,7 @@ TEST_CASE("Test copy and move column", "[column]") {
   REQUIRE(c.index() == 2);
   REQUIRE(c.reference_column());
   REQUIRE(c.reference_column()->name() == "author");
-  REQUIRE(c.reference_column()->table_name() == "books");
+  REQUIRE(c.reference_column()->object()->name() == "books");
   REQUIRE(c.type() == basic_type::type_varchar);
   REQUIRE(c.attributes().size() == 255);
 
@@ -42,7 +43,7 @@ TEST_CASE("Test copy and move column", "[column]") {
   REQUIRE(c2.index() == 2);
   REQUIRE(c2.reference_column());
   REQUIRE(c2.reference_column()->name() == "author");
-  REQUIRE(c2.reference_column()->table_name() == "books");
+  REQUIRE(c2.reference_column()->object()->name() == "books");
   REQUIRE(c2.type() == basic_type::type_varchar);
   REQUIRE(c2.attributes().size() == 255);
 
@@ -51,7 +52,7 @@ TEST_CASE("Test copy and move column", "[column]") {
   REQUIRE(c3.index() == 2);
   REQUIRE(c3.reference_column());
   REQUIRE(c3.reference_column()->name() == "author");
-  REQUIRE(c3.reference_column()->table_name() == "books");
+  REQUIRE(c3.reference_column()->object()->name() == "books");
   REQUIRE(c3.type() == basic_type::type_varchar);
   REQUIRE(c3.attributes().size() == 255);
 
diff --git a/test/orm/sql/FieldTest.cpp b/test/orm/sql/FieldTest.cpp
index cb5ba29..582a91a 100644
--- a/test/orm/sql/FieldTest.cpp
+++ b/test/orm/sql/FieldTest.cpp
@@ -37,7 +37,7 @@ TEST_CASE("Test field", "[field]") {
   REQUIRE(bool_val.has_value());
   REQUIRE(bool_val.value());
 
-  f = sql::field("name", utils::blob{ 7,8,6,5,4,3 }, sql::field_type::Attribute, 0, 1);
+  f = sql::field("name", utils::blob{ 7,8,6,5,4,3 }, utils::constraints::NONE, 0, 1);
   REQUIRE(f.index() == 1);
   REQUIRE(!f.is_null());
   REQUIRE(!f.is_integer());
diff --git a/todo.md b/todo.md
index cbd7924..7248b6c 100644
--- a/todo.md
+++ b/todo.md
@@ -1,5 +1,7 @@
 # Todo
 
+- move `object_definition` and `attribute_definition` to `table` and `column` in query
+  and add `contraint` class
 - replace mk_column with builder style (see `query/builder.hpp`)
 - fix corresponding tests
 - enhance query helper macro to look like the `book` class below
@@ -14,6 +16,7 @@
 - implement lazy loading
 - implement polymorphic class hierarchies
 - finish `schema` and `schema_repository` classes (move add/drop from `session` to `schema`)
+- implement a flag class for enumerations
 
 ## book class
 ```cpp