fixing postgres tests progress

include/matador/query/session.hpp

@@ -95,14 +95,14 @@ utils::result<object::object_ptr<Type>, utils::error> session::insert(object::ob
   }
 
   // Build dependency-ordered insert steps (deps first, root last)
-  query::insert_query_builder<Type> iqb(schema_, contexts_by_type_);
+  insert_query_builder<Type> iqb(schema_, contexts_by_type_);
   auto steps = iqb.build(obj);
   if (!steps.is_ok()) {
     return utils::failure(make_error(error_code::FailedToBuildQuery, "Failed to build insert dependency queries."));
   }
 
   // Execute all steps; for Identity steps read RETURNING and write pk back into the object
-  for (query::insert_step &step : *steps) {
+  for (insert_step &step : *steps) {
     if (step.pk_generator == utils::generator_type::Sequence || step.pk_generator == utils::generator_type::Table) {
       const auto conn = pool_.acquire();
       if (!conn.valid()) {

include/matador/query/table.hpp

@@ -43,13 +43,11 @@ public:
   [[nodiscard]] bool is_relation_table() const;
   [[nodiscard]] bool has_primary_key() const;
 
-  [[nodiscard]] std::optional<table_column*> primary_key_column() const;
+  [[nodiscard]] const table_column* primary_key_column() const;
   [[nodiscard]] const std::string& join_column_name() const;
   [[nodiscard]] const std::string& inverse_join_column_name() const;
 
 protected:
-  // static const table_column& create_column(class table& tab, const std::string& name);
-
   table(std::string  name, std::string  alias, const std::vector<table_column>& columns);
 
 private:
@@ -61,7 +59,7 @@ private:
   std::string schema_name_;
   std::vector<table_column> columns_;
 
-  std::optional<table_column*> pk_column_{std::nullopt};
+  int pk_column_index_{-1};
   std::string join_column_name_;
   std::string inverse_join_column_name_;
 };