diff --git a/include/matador/object/basic_object_info.hpp b/include/matador/object/basic_object_info.hpp
index 93eea29..02a4a0a 100644
--- a/include/matador/object/basic_object_info.hpp
+++ b/include/matador/object/basic_object_info.hpp
@@ -2,7 +2,7 @@
 #define BASIC_PROTOTYPE_INFO_HPP
 
 #include "matador/object/attribute.hpp"
-#include "matador/object/constraint.hpp"
+#include "matador/object/restriction.hpp"
 #include "matador/object/relation_endpoint.hpp"
 
 #include "matador/utils/identifier.hpp"
@@ -28,7 +28,7 @@ public:
   [[nodiscard]] std::string name() const;
   [[nodiscard]] std::shared_ptr<class object> object() const;
   [[nodiscard]] const std::list<attribute>& attributes() const;
-  [[nodiscard]] const std::list<class constraint>& constraints() const;
+  [[nodiscard]] const std::list<class restriction>& constraints() const;
 
   [[nodiscard]] bool has_primary_key() const;
   [[nodiscard]] const utils::identifier& primary_key() const;
diff --git a/include/matador/object/constraints_generator.hpp b/include/matador/object/constraints_generator.hpp
index 575d5d8..c914dc8 100644
--- a/include/matador/object/constraints_generator.hpp
+++ b/include/matador/object/constraints_generator.hpp
@@ -1,7 +1,7 @@
 #ifndef MATADOR_CONSTRAINTS_GENERATOR_HPP
 #define MATADOR_CONSTRAINTS_GENERATOR_HPP
 
-#include "matador/object/constraint.hpp"
+#include "matador/object/restriction.hpp"
 
 #include "matador/utils/access.hpp"
 #include "matador/utils/field_attributes.hpp"
@@ -17,20 +17,20 @@ class repository;
 
 class constraints_generator final {
 private:
-    constraints_generator(std::list<class constraint> &constraints, const repository &repo, const std::shared_ptr<object> &obj);
+    constraints_generator(std::list<class restriction> &constraints, const repository &repo, const std::shared_ptr<object> &obj);
 
 public:
     constraints_generator() = delete;
 
     template < typename Type >
-    static std::list<class constraint> generate(const repository &repo, object &obj) {
+    static std::list<class restriction> generate(const repository &repo, const std::shared_ptr<object> &obj) {
         Type t;
         return generate(t, repo, obj);
     }
 
     template < typename Type >
-    static std::list<class constraint> generate(const Type& t, const repository &repo, object &obj) {
-        std::list<class constraint> constraints;
+    static std::list<class restriction> generate(const Type& t, const repository &repo, const std::shared_ptr<object> &obj) {
+        std::list<class restriction> constraints;
         constraints_generator gen(constraints, repo, obj);
         access::process(gen, t);
         return constraints;
@@ -69,7 +69,7 @@ private:
     [[nodiscard]] std::list<attribute>::iterator find_attribute_by_name(const std::string &name) const;
 
 private:
-    std::list<class constraint> &constraints_;
+    std::list<class restriction> &constraints_;
     const repository &repo_;
     std::shared_ptr<object> obj_;
 };
diff --git a/include/matador/object/object.hpp b/include/matador/object/object.hpp
index b3fd7c5..1f85fa0 100644
--- a/include/matador/object/object.hpp
+++ b/include/matador/object/object.hpp
@@ -2,7 +2,7 @@
 #define MATADOR_OBJECT_HPP
 
 #include "matador/object/attribute.hpp"
-#include "matador/object/constraint.hpp"
+#include "matador/object/restriction.hpp"
 
 #include "matador/utils/identifier.hpp"
 
@@ -37,7 +37,7 @@ public:
 
   [[nodiscard]] bool has_constraints() const;
   [[nodiscard]] size_t constraint_count() const;
-  [[nodiscard]] const std::list<class constraint>& constraints() const;
+  [[nodiscard]] const std::list<class restriction>& constraints() const;
 
   friend std::ostream& operator<<(std::ostream& os, const object& obj);
 
@@ -52,7 +52,7 @@ private:
   attribute* pk_attribute_{nullptr};
   utils::identifier pk_identifier_;
   std::list<attribute> attributes_;
-  std::list<class constraint> constraints_;
+  std::list<class restriction> constraints_;
 };
 }
 #endif //MATADOR_OBJECT_HPP
\ No newline at end of file
diff --git a/include/matador/object/object_generator.hpp b/include/matador/object/object_generator.hpp
index 534bb54..6228ca9 100644
--- a/include/matador/object/object_generator.hpp
+++ b/include/matador/object/object_generator.hpp
@@ -54,7 +54,7 @@ private:
 
 public:
     template < class Type >
-    static std::shared_ptr<object> generate(const repository &repo, const std::string &name, const std::string &alias = "") {
+    static std::shared_ptr<object> generate(repository &repo, const std::string &name, const std::string &alias = "") {
         return generate(std::make_unique<Type>(), repo, name, alias);
     }
 
diff --git a/include/matador/object/constraint.hpp b/include/matador/object/restriction.hpp
similarity index 88%
rename from include/matador/object/constraint.hpp
rename to include/matador/object/restriction.hpp
index 063dc99..63f94ef 100644
--- a/include/matador/object/constraint.hpp
+++ b/include/matador/object/restriction.hpp
@@ -15,10 +15,10 @@ class constraint_builder;
 class constraint_generator;
 class object;
 
-class constraint {
+class restriction {
 public:
-  constraint() = default;
-  explicit constraint(std::string name);
+  restriction() = default;
+  explicit restriction(std::string name);
 
   [[nodiscard]] const std::string& name() const;
   [[nodiscard]] const class attribute* attribute() const;
@@ -30,7 +30,7 @@ public:
   [[nodiscard]] const std::string& ref_table_name() const;
   [[nodiscard]] const std::string& ref_column_name() const;
 
-  friend std::ostream& operator<<(std::ostream& os, const constraint& c);
+  friend std::ostream& operator<<(std::ostream& os, const restriction& c);
 
 private:
   friend class constraint_builder;
@@ -54,7 +54,7 @@ public:
   constraint_builder& foreign_key(std::string name);
   constraint_builder& references(std::string table, std::string column);
 
-  operator class constraint() const;
+  operator class restriction() const;
 
 private:
   std::string constraint_name;
diff --git a/include/matador/orm/schema.hpp b/include/matador/orm/schema.hpp
index 15eb1cb..93a0a36 100644
--- a/include/matador/orm/schema.hpp
+++ b/include/matador/orm/schema.hpp
@@ -52,8 +52,8 @@ public:
   [[nodiscard]] utils::result<bool, utils::error> table_exists(const std::string &table_name) const;
 
 private:
-   sql::query_context build_add_constraint_context( const object::repository_node& node, const class object::constraint& cons ) const;
-   sql::query_context build_drop_constraint_context( const object::repository_node& node, const class object::constraint& cons ) const;
+   sql::query_context build_add_constraint_context( const object::repository_node& node, const class object::restriction& cons ) const;
+   sql::query_context build_drop_constraint_context( const object::repository_node& node, const class object::restriction& cons ) const;
 
 private:
   object::repository repo_;
diff --git a/include/matador/orm/session.hpp b/include/matador/orm/session.hpp
index e268744..9a52038 100644
--- a/include/matador/orm/session.hpp
+++ b/include/matador/orm/session.hpp
@@ -145,7 +145,7 @@ private:
   friend class query_select;
 
   static query::fetchable_query build_select_query(entity_query_data &&data);
-  static sql::query_context build_add_constraint_context(const std::string& table_name, const class object::constraint& cons, const sql::connection_ptr &conn) ;
+  static sql::query_context build_add_constraint_context(const std::string& table_name, const class object::restriction& cons, const sql::connection_ptr &conn) ;
 
 private:
   mutable sql::statement_cache cache_;
diff --git a/include/matador/query/builder.hpp b/include/matador/query/builder.hpp
index 3b9ccda..bbe0a87 100644
--- a/include/matador/query/builder.hpp
+++ b/include/matador/query/builder.hpp
@@ -64,9 +64,9 @@ using Boolean = typed_data_type<bool>;
 using Varchar = sized_typed_data_type<std::string>;
 using Blob = sized_typed_data_type<std::vector<std::byte>>;
 
-class constraint {
+class restriction {
 public:
-    explicit constraint(std::string name)
+    explicit restriction(std::string name)
     : name_(std::move(name)) {}
 
     [[nodiscard]] const std::string& name() const;
@@ -126,7 +126,7 @@ public:
   constraint_builder& references(std::string table, std::string column);
 
   // ReSharper disable once CppNonExplicitConversionOperator
-  operator object::constraint() const; // NOLINT(*-explicit-constructor)
+  operator object::restriction() const; // NOLINT(*-explicit-constructor)
 
 private:
   std::string constraint_name;
diff --git a/include/matador/query/intermediates/query_alter_table_intermediate.hpp b/include/matador/query/intermediates/query_alter_table_intermediate.hpp
index 0ce1f25..2d2683e 100644
--- a/include/matador/query/intermediates/query_alter_table_intermediate.hpp
+++ b/include/matador/query/intermediates/query_alter_table_intermediate.hpp
@@ -2,7 +2,7 @@
 #define MATADOR_QUERY_ALTER_TABLE_INTERMEDIATE_HPP
 
 #include "executable_query.hpp"
-#include "matador/object/constraint.hpp"
+#include "matador/object/restriction.hpp"
 #include "matador/query/intermediates/query_intermediate.hpp"
 
 namespace matador::query {
diff --git a/include/matador/query/intermediates/query_create_intermediate.hpp b/include/matador/query/intermediates/query_create_intermediate.hpp
index 9ea5509..babd778 100644
--- a/include/matador/query/intermediates/query_create_intermediate.hpp
+++ b/include/matador/query/intermediates/query_create_intermediate.hpp
@@ -6,7 +6,7 @@
 #include "matador/query/intermediates/executable_query.hpp"
 
 #include "matador/object/attribute.hpp"
-#include "matador/object/constraint.hpp"
+#include "matador/object/restriction.hpp"
 
 #include <list>
 
@@ -16,8 +16,8 @@ class query_create_table_columns_intermediate : public executable_query {
 public:
   using executable_query::executable_query;
 
-  executable_query constraints(std::initializer_list<class object::constraint> constraints);
-  executable_query constraints(const std::list<class object::constraint> &constraints);
+  executable_query constraints(std::initializer_list<class object::restriction> constraints);
+  executable_query constraints(const std::list<class object::restriction> &constraints);
 };
 
 class query_create_table_intermediate : public query_intermediate {
diff --git a/include/matador/query/internal/query_parts.hpp b/include/matador/query/internal/query_parts.hpp
index d226230..2d9fe77 100644
--- a/include/matador/query/internal/query_parts.hpp
+++ b/include/matador/query/internal/query_parts.hpp
@@ -10,7 +10,7 @@
 #include "matador/query/table.hpp"
 
 #include "matador/object/attribute.hpp"
-#include "matador/object/constraint.hpp"
+#include "matador/object/restriction.hpp"
 
 #include "matador/utils/placeholder.hpp"
 
@@ -392,15 +392,15 @@ private:
 
 class query_create_table_constraints_part final : public query_part {
 public:
-  explicit query_create_table_constraints_part(const std::list<class object::constraint> &constraints);
+  explicit query_create_table_constraints_part(const std::list<class object::restriction> &constraints);
 
-  [[nodiscard]] const std::list<class object::constraint>& constraints() const;
+  [[nodiscard]] const std::list<class object::restriction>& constraints() const;
 
 private:
   void accept(query_part_visitor &visitor) override;
 
 private:
-  std::list<class object::constraint> constraints_;
+  std::list<class object::restriction> constraints_;
 };
 
 class query_create_schema_part final : public query_part {
diff --git a/source/core/CMakeLists.txt b/source/core/CMakeLists.txt
index 291557c..dbf433c 100644
--- a/source/core/CMakeLists.txt
+++ b/source/core/CMakeLists.txt
@@ -16,13 +16,13 @@ add_library(matador-core STATIC
   ../../include/matador/object/attribute.hpp
   ../../include/matador/object/attribute_generator.hpp
   ../../include/matador/object/basic_object_info.hpp
-  ../../include/matador/object/constraint.hpp
   ../../include/matador/object/constraints_generator.hpp
   ../../include/matador/object/error_code.hpp
   ../../include/matador/object/foreign_node_completer.hpp
   ../../include/matador/object/internal/shadow_repository.hpp
   ../../include/matador/object/many_to_many_relation.hpp
   ../../include/matador/object/object.hpp
+  ../../include/matador/object/object_generator.hpp
   ../../include/matador/object/object_info.hpp
   ../../include/matador/object/object_proxy.hpp
   ../../include/matador/object/object_ptr.hpp
@@ -32,6 +32,7 @@ add_library(matador-core STATIC
   ../../include/matador/object/repository.hpp
   ../../include/matador/object/repository_node.hpp
   ../../include/matador/object/repository_node_iterator.hpp
+  ../../include/matador/object/restriction.hpp
   ../../include/matador/sql/statement_cache.hpp
   ../../include/matador/utils/access.hpp
   ../../include/matador/utils/attribute_reader.hpp
@@ -80,15 +81,17 @@ add_library(matador-core STATIC
   object/attribute.cpp
   object/attribute_generator.cpp
   object/basic_object_info.cpp
-  object/constraint.cpp
   object/constraints_generator.cpp
   object/error_code.cpp
   object/foreign_node_completer.cpp
   object/internal/shadow_repository.cpp
+  object/object.cpp
+  object/object_generator.cpp
   object/relation_endpoint.cpp
   object/repository.cpp
   object/repository_node.cpp
   object/repository_node_iterator.cpp
+  object/restriction.cpp
   utils/default_type_traits.cpp
   utils/error.cpp
   utils/errors.cpp
@@ -107,9 +110,6 @@ add_library(matador-core STATIC
   utils/uuid.cpp
   utils/value.cpp
   utils/version.cpp
-  object/object.cpp
-  ../../include/matador/object/object_generator.hpp
-  object/object_generator.cpp
 )
 
 target_link_libraries(matador-core ${CMAKE_DL_LIBS})
diff --git a/source/core/object/basic_object_info.cpp b/source/core/object/basic_object_info.cpp
index 4ed04a0..461f905 100644
--- a/source/core/object/basic_object_info.cpp
+++ b/source/core/object/basic_object_info.cpp
@@ -25,7 +25,7 @@ const std::list<attribute>& basic_object_info::attributes() const {
   return object_->attributes();
 }
 
-const std::list<class constraint>& basic_object_info::constraints() const {
+const std::list<class restriction>& basic_object_info::constraints() const {
   return object_->constraints();
 }
 
diff --git a/source/core/object/constraints_generator.cpp b/source/core/object/constraints_generator.cpp
index 7c8dcae..3898b20 100644
--- a/source/core/object/constraints_generator.cpp
+++ b/source/core/object/constraints_generator.cpp
@@ -5,13 +5,13 @@
 #include <algorithm>
 
 namespace matador::object {
-constraints_generator::constraints_generator(std::list<class constraint> &constraints, const repository& repo, const std::shared_ptr<object> &obj)
+constraints_generator::constraints_generator(std::list<class restriction> &constraints, const repository& repo, const std::shared_ptr<object> &obj)
 : constraints_(constraints)
 , repo_(repo)
 , obj_(obj) {}
 
 void constraints_generator::create_pk_constraint(const std::string& name) const {
-  class constraint pk_constraint("PK_" + obj_->name());
+  class restriction pk_constraint("PK_" + obj_->name());
   pk_constraint.options_ |= utils::constraints::PrimaryKey;
   if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(obj_->attributes_)) {
       pk_constraint.attr_ = &*pk_attr;
@@ -26,7 +26,7 @@ void constraints_generator::create_fk_constraint(const std::type_index& ti, cons
     return;
   }
   const auto *pk_attribute = result.value().get().primary_key_attribute();
-  class constraint pk_constraint("FK_" + obj_->name() + "_" + name);
+  class restriction pk_constraint("FK_" + obj_->name() + "_" + name);
   pk_constraint.options_ |= utils::constraints::ForeignKey;
   if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(obj_->attributes_)) {
     pk_constraint.attr_ = &*pk_attr;
@@ -38,7 +38,7 @@ void constraints_generator::create_fk_constraint(const std::type_index& ti, cons
 }
 
 void constraints_generator::create_unique_constraint(const std::string& name) const {
-  class constraint pk_constraint("UK_" + obj_->name() + "_" + name);
+  class restriction pk_constraint("UK_" + obj_->name() + "_" + name);
   pk_constraint.options_ |= utils::constraints::Unique;
   if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(obj_->attributes_)) {
     pk_constraint.attr_ = &*pk_attr;
diff --git a/source/core/object/object.cpp b/source/core/object/object.cpp
index f16c2ec..6ab3b91 100644
--- a/source/core/object/object.cpp
+++ b/source/core/object/object.cpp
@@ -72,7 +72,7 @@ size_t object::constraint_count() const {
   return constraints_.size();
 }
 
-const std::list<class constraint>& object::constraints() const {
+const std::list<class restriction>& object::constraints() const {
   return constraints_;
 }
 
diff --git a/source/core/object/object_generator.cpp b/source/core/object/object_generator.cpp
index fa5f50c..94f3e37 100644
--- a/source/core/object/object_generator.cpp
+++ b/source/core/object/object_generator.cpp
@@ -14,7 +14,7 @@ void object_generator::on_revision(const char* id, uint64_t& rev) {
 }
 
 void object_generator::create_pk_constraint(const std::string& name) const {
-    class constraint pk_constraint("PK_" + object_->name());
+    class restriction pk_constraint("PK_" + object_->name());
     pk_constraint.options_ |= utils::constraints::PrimaryKey;
     if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(object_->attributes_)) {
         pk_constraint.attr_ = &*pk_attr;
@@ -26,7 +26,7 @@ void object_generator::create_pk_constraint(const std::string& name) const {
 void object_generator::create_fk_constraint(const std::type_index& ti, const std::string& name) const {
     const auto obj = fk_object(ti);
     const auto *pk_attribute = obj->primary_key_attribute();
-    class constraint pk_constraint("FK_" + object_->name() + "_" + name);
+    class restriction pk_constraint("FK_" + object_->name() + "_" + name);
     pk_constraint.options_ |= utils::constraints::ForeignKey;
     if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(object_->attributes_)) {
         pk_constraint.attr_ = &*pk_attr;
@@ -41,7 +41,7 @@ void object_generator::create_fk_constraint(const std::type_index& ti, const std
 }
 
 void object_generator::create_unique_constraint(const std::string& name) const {
-    class constraint pk_constraint("UK_" + object_->name() + "_" + name);
+    class restriction pk_constraint("UK_" + object_->name() + "_" + name);
     pk_constraint.options_ |= utils::constraints::Unique;
     if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(object_->attributes_)) {
         pk_constraint.attr_ = &*pk_attr;
diff --git a/source/core/object/constraint.cpp b/source/core/object/restriction.cpp
similarity index 72%
rename from source/core/object/constraint.cpp
rename to source/core/object/restriction.cpp
index d9369af..2a32158 100644
--- a/source/core/object/constraint.cpp
+++ b/source/core/object/restriction.cpp
@@ -1,15 +1,16 @@
-#include "matador/object/constraint.hpp"
+#include "matador/object/restriction.hpp"
+
 #include "matador/object/attribute.hpp"
 
 namespace matador::object {
-constraint::constraint(std::string name)
+restriction::restriction(std::string name)
 : name_(std::move(name)) {}
 
-const std::string & constraint::name() const {
+const std::string & restriction::name() const {
   return name_;
 }
 
-const class attribute* constraint::attribute() const {
+const class attribute* restriction::attribute() const {
   if (std::holds_alternative<class attribute*>(attr_)) {
     return std::get<class attribute*>(attr_);
   }
@@ -17,7 +18,7 @@ const class attribute* constraint::attribute() const {
   return nullptr;
 }
 
-std::string constraint::column_name() const {
+std::string restriction::column_name() const {
     if (std::holds_alternative<class attribute*>(attr_)) {
         return std::get<class attribute*>(attr_)->name();
     }
@@ -28,31 +29,31 @@ std::string constraint::column_name() const {
     return "";
 }
 
-std::shared_ptr<object> constraint::owner() const {
+std::shared_ptr<object> restriction::owner() const {
   return owner_;
 }
 
-bool constraint::is_primary_key_constraint() const {
+bool restriction::is_primary_key_constraint() const {
   return utils::is_constraint_set(options_, utils::constraints::PrimaryKey);
 }
 
-bool constraint::is_foreign_key_constraint() const {
+bool restriction::is_foreign_key_constraint() const {
   return utils::is_constraint_set(options_, utils::constraints::ForeignKey);
 }
 
-bool constraint::is_unique_constraint() const {
+bool restriction::is_unique_constraint() const {
   return utils::is_constraint_set(options_, utils::constraints::Unique);
 }
 
-const std::string& constraint::ref_table_name() const {
+const std::string& restriction::ref_table_name() const {
   return ref_table_name_;
 }
 
-const std::string& constraint::ref_column_name() const {
+const std::string& restriction::ref_column_name() const {
   return ref_column_name_;
 }
 
-std::ostream & operator<<(std::ostream &os, const class constraint &c) {
+std::ostream & operator<<(std::ostream &os, const class restriction &c) {
   os << "constraint " << c.name_ << " for column " << c.column_name();
   return os;
 }
@@ -81,8 +82,8 @@ constraint_builder & constraint_builder::references(std::string table, std::stri
   return *this;
 }
 
-constraint_builder::operator class constraint() const {
-  class constraint c;
+constraint_builder::operator class restriction() const {
+  class restriction c;
   c.name_ = constraint_name;
   c.attr_ = column_name;
   c.options_ = options_;
diff --git a/source/orm/orm/schema.cpp b/source/orm/orm/schema.cpp
index a2b34f9..fb5d119 100644
--- a/source/orm/orm/schema.cpp
+++ b/source/orm/orm/schema.cpp
@@ -181,7 +181,7 @@ utils::result<bool, utils::error> schema::table_exists(const std::string& table_
     return c->exists(repo_.name(), table_name);
 }
 
-sql::query_context schema::build_add_constraint_context( const object::repository_node& node, const class object::constraint& cons ) const {
+sql::query_context schema::build_add_constraint_context( const object::repository_node& node, const class object::restriction& cons ) const {
   if (cons.is_foreign_key_constraint()) {
     return query::query::alter()
       .table(node.name())
@@ -200,7 +200,7 @@ sql::query_context schema::build_add_constraint_context( const object::repositor
   return {};
 }
 
-sql::query_context schema::build_drop_constraint_context( const object::repository_node& node, const class object::constraint& cons ) const {
+sql::query_context schema::build_drop_constraint_context( const object::repository_node& node, const class object::restriction& cons ) const {
     return query::query::alter()
       .table(node.name())
       .drop_constraint(cons.name())
diff --git a/source/orm/orm/session.cpp b/source/orm/orm/session.cpp
index e3cae40..7fd785f 100644
--- a/source/orm/orm/session.cpp
+++ b/source/orm/orm/session.cpp
@@ -76,7 +76,7 @@ utils::result<void, utils::error> session::create_schema() const {
   return utils::ok<void>();
 }
 
-sql::query_context session::build_add_constraint_context(const std::string& table_name, const class object::constraint& cons, const sql::connection_ptr &conn) {
+sql::query_context session::build_add_constraint_context(const std::string& table_name, const class object::restriction& cons, const sql::connection_ptr &conn) {
   if (cons.is_foreign_key_constraint()) {
     return query::query::alter()
       .table(table_name)
diff --git a/source/orm/query/builder.cpp b/source/orm/query/builder.cpp
index 17cf5ef..87aba7f 100644
--- a/source/orm/query/builder.cpp
+++ b/source/orm/query/builder.cpp
@@ -48,8 +48,8 @@ constraint_builder& constraint_builder::references( std::string table, std::stri
   return *this;
 }
 
-constraint_builder::operator object::constraint() const {
-  return object::constraint{constraint_name};
+constraint_builder::operator object::restriction() const {
+  return object::restriction{constraint_name};
 }
 
 constraint_builder constraint( std::string name ) {
diff --git a/source/orm/query/intermediates/query_create_intermediate.cpp b/source/orm/query/intermediates/query_create_intermediate.cpp
index d4f945b..d641943 100644
--- a/source/orm/query/intermediates/query_create_intermediate.cpp
+++ b/source/orm/query/intermediates/query_create_intermediate.cpp
@@ -18,27 +18,31 @@ executable_query query_create_intermediate::schema( const std::string& schema_na
   return {context_};
 }
 
-executable_query query_create_table_columns_intermediate::constraints( std::initializer_list<class object::constraint> constraints ) {
+executable_query query_create_table_columns_intermediate::constraints(const std::initializer_list<class object::restriction> constraints) {
   return this->constraints(std::list(constraints));
 }
 
-executable_query query_create_table_columns_intermediate::constraints( const std::list<class object::constraint>& constraints ) {
+executable_query query_create_table_columns_intermediate::constraints(const std::list<class object::restriction>& constraints) {
 
   context_->parts.push_back(std::make_unique<internal::query_create_table_constraints_part>(constraints));
   return {context_};
 }
 
-query_create_table_columns_intermediate query_create_table_intermediate::columns( std::initializer_list<object::attribute> columns ) {
+query_create_table_columns_intermediate query_create_table_intermediate::columns(std::initializer_list<object::attribute> columns) {
   context_->parts.push_back(std::make_unique<internal::query_create_table_columns_part>(columns));
   return {context_};
 }
 
-query_create_table_columns_intermediate query_create_table_intermediate::columns( const std::list<object::attribute>& columns ) {
+query_create_table_columns_intermediate query_create_table_intermediate::columns(const std::list<object::attribute>& columns) {
   context_->parts.push_back(std::make_unique<internal::query_create_table_columns_part>(columns));
   return {context_};
 }
 
-query_create_table_columns_intermediate query_create_table_intermediate::columns( std::initializer_list<column> columns ) {}
-
-query_create_table_columns_intermediate query_create_table_intermediate::columns( const std::list<column>& columns ) {}
+query_create_table_columns_intermediate query_create_table_intermediate::columns(std::initializer_list<column> columns) {
+  return {context_};
+}
+
+query_create_table_columns_intermediate query_create_table_intermediate::columns(const std::list<column>& columns) {
+  return {context_};
+}
 }
diff --git a/source/orm/query/internal/query_parts.cpp b/source/orm/query/internal/query_parts.cpp
index 28023c5..45dd29c 100644
--- a/source/orm/query/internal/query_parts.cpp
+++ b/source/orm/query/internal/query_parts.cpp
@@ -370,11 +370,11 @@ void query_create_table_columns_part::accept(query_part_visitor& visitor) {
   visitor.visit(*this);
 }
 
-query_create_table_constraints_part::query_create_table_constraints_part(const std::list<class object::constraint>& constraints)
+query_create_table_constraints_part::query_create_table_constraints_part(const std::list<class object::restriction>& constraints)
 : query_part( sql::dialect_token::Constraint )
 , constraints_(constraints) {}
 
-const std::list<class object::constraint>& query_create_table_constraints_part::constraints() const {
+const std::list<class object::restriction>& query_create_table_constraints_part::constraints() const {
   return constraints_;
 }
 
diff --git a/source/orm/query/query_compiler.cpp b/source/orm/query/query_compiler.cpp
index 2329594..697ba89 100644
--- a/source/orm/query/query_compiler.cpp
+++ b/source/orm/query/query_compiler.cpp
@@ -294,7 +294,7 @@ void query_compiler::visit(internal::query_create_part &/*create_part*/)
 }
 
 std::string build_create_column(const object::attribute &col, const sql::dialect &d);
-std::string build_constraint(const class object::constraint &cons, const sql::dialect &d);
+std::string build_constraint(const class object::restriction &cons, const sql::dialect &d);
 
 void query_compiler::visit(internal::query_create_table_part &part)
 {
@@ -392,7 +392,7 @@ std::string build_create_column(const object::attribute &col, const sql::dialect
   return result;
 }
 
-std::string build_constraint(const class object::constraint& cons, const sql::dialect& d) {
+std::string build_constraint(const class object::restriction& cons, const sql::dialect& d) {
     std::string result;
     if (!cons.name().empty()) {
         result.append(d.constraint()).append(" ").append(cons.name()).append(" ");