added join_column_index and inverse_join_column_index to object and table classes

source/core/object/object.cpp

@@ -10,8 +10,8 @@ const attribute& object::create_attribute(std::string name, const std::shared_pt
   return obj->attributes_.emplace_back(std::move(attr));
 }
 
-attribute* object::primary_key_attribute() const {
-  return pk_attribute_;
+const attribute* object::primary_key_attribute() const {
+  return pk_column_index_ != -1 ? &attributes_.at(pk_column_index_) : nullptr;
 }
 
 const utils::identifier& object::primary_key() const {
@@ -19,7 +19,19 @@ const utils::identifier& object::primary_key() const {
 }
 
 bool object::has_primary_key() const {
-  return pk_attribute_ != nullptr;
+  return pk_column_index_ != -1;
+}
+
+bool object::is_relation_object() const {
+  return join_column_index_ != -1 && inverse_join_column_index_ != -1;
+}
+
+const attribute * object::join_attribute() const {
+  return join_column_index_ != -1 ? &attributes_.at(join_column_index_) : nullptr;
+}
+
+const attribute * object::inverse_join_attribute() const {
+  return inverse_join_column_index_ != -1 ? &attributes_.at(inverse_join_column_index_) : nullptr;
 }
 
 const std::string& object::name() const {
@@ -38,7 +50,7 @@ size_t object::attribute_count() const {
   return attributes_.size();
 }
 
-const std::list<attribute>& object::attributes() const {
+const std::vector<attribute>& object::attributes() const {
   return attributes_;
 }
 
@@ -50,7 +62,7 @@ size_t object::constraint_count() const {
   return constraints_.size();
 }
 
-const std::list<restriction>& object::constraints() const {
+const std::vector<restriction>& object::constraints() const {
   return constraints_;
 }