has many fetch with join

source/orm/CMakeLists.txt

@@ -61,6 +61,7 @@ add_library(matador-orm STATIC
   ../../include/matador/sql/interface/statement_impl.hpp
   ../../include/matador/sql/internal/object_result_binder.hpp
   ../../include/matador/sql/internal/query_result_impl.hpp
+  ../../include/matador/sql/internal/query_result_pk_resolver.hpp
   ../../include/matador/sql/query_context.hpp
   ../../include/matador/sql/query_macro.hpp
   ../../include/matador/sql/query_result.hpp
@@ -121,6 +122,7 @@ add_library(matador-orm STATIC
   sql/interface/query_result_reader.cpp
   sql/interface/statement_impl.cpp
   sql/internal/object_result_binder.cpp
+  sql/internal/query_result_pk_resolver.cpp
   sql/object_parameter_binder.cpp
   sql/query_result.cpp
   sql/record.cpp

source/orm/sql/field.cpp

@@ -1,5 +1,7 @@
 #include "matador/sql/field.hpp"
 
+#include "matador/utils/constraints.hpp"
+
 #include <ostream>
 
 namespace matador::sql {
@@ -9,23 +11,24 @@ field::field(std::string name)
   , value_(nullptr)
 {}
 
-field::field(std::string name, const utils::basic_type dt, const size_t size, const int index)
-  : name_(std::move(name))
-  , index_(index)
-  , value_(dt, size) {}
+field::field(std::string name, const utils::basic_type dt, const field_type type, const size_t size, const int index)
+: name_(std::move(name))
+, type_(type)
+, index_(index)
+, value_(dt, size) {}
 
 field::field(field &&x) noexcept
-  : name_(std::move(x.name_))
-  , index_(x.index_)
-  , value_(std::move(x.value_))
-{
+: name_(std::move(x.name_))
+, type_(x.type_)
+, index_(x.index_)
+, value_(std::move(x.value_)) {
   x.value_ = nullptr;
   x.index_ = -1;
 }
 
-field &field::operator=(field &&x) noexcept
-{
+field &field::operator=(field &&x) noexcept {
   name_ = std::move(x.name_);
+  type_ = x.type_;
   index_ = x.index_;
   value_ = std::move(x.value_);
   x.index_ = -1;
@@ -39,6 +42,10 @@ const std::string &field::name() const
   return name_;
 }
 
+field_type field::type() const {
+  return type_;
+}
+
 size_t field::size() const
 {
   return value_.size();
@@ -55,6 +62,19 @@ std::ostream &operator<<(std::ostream &out, const field &col)
   return out;
 }
 
+utils::constraints field::determine_constraint(const field_type type) {
+    switch (type) {
+        case field_type::PrimaryKey:
+            return utils::constraints::PRIMARY_KEY;
+        case field_type::ForeignKey:
+            return utils::constraints::FOREIGN_KEY;
+        case field_type::Attribute:
+        default:
+            return utils::constraints::NONE;
+    }
+
+}
+
 std::string field::str() const
 {
   return as<std::string>().value_or("");
@@ -95,4 +115,17 @@ bool field::is_null() const
   return value_.is_null();
 }
 
+bool field::is_primary_key() const {
+  return type_ == field_type::PrimaryKey;
+}
+
+bool field::is_foreign_key() const {
+  return type_ == field_type::ForeignKey;
+}
+
+bool field::is_attribute() const {
+  return type_ == field_type::Attribute;
+}
+
+
 }

source/orm/sql/internal/query_result_pk_resolver.cpp

@@ -0,0 +1,30 @@
+#include "matador/sql/internal/query_result_pk_resolver.hpp"
+
+#include "matador/utils/value.hpp"
+
+namespace matador::sql::internal {
+void query_result_pk_resolver::on_primary_key(const char* id, std::string& /*value*/, const size_t size) {
+    if (!type_stack_.empty()) {
+        return;
+    }
+    std::string value;
+    utils::data_type_traits<std::string>::read_value(reader_, id, column_index_++, value, size);
+    pk_ = value;
+}
+
+void query_result_pk_resolver::on_attribute(const char *id, const utils::value &x, const utils::field_attributes &attr) {
+    if (is_constraint_set(attr.options(), utils::constraints::PRIMARY_KEY)) {
+        if (x.is_integer()) {
+            uint64_t val;
+            utils::data_type_traits<uint64_t>::read_value(reader_, id, column_index_++, val);
+            pk_ = val;
+        } else if (x.is_varchar()) {
+            std::string value;
+            utils::data_type_traits<std::string>::read_value(reader_, id, column_index_++, value, attr.size());
+            pk_ = value;
+        }
+    }
+    ++column_index_;
+}
+
+}

source/orm/sql/query_result.cpp

@@ -5,12 +5,27 @@
 
 namespace matador::sql::detail {
 
+field_type determine_field_type(const utils::constraints c) {
+    if (is_constraint_set(c, utils::constraints::FOREIGN_KEY)) {
+        return field_type::ForeignKey;
+    }
+    if (is_constraint_set(c, utils::constraints::PRIMARY_KEY)) {
+        return field_type::PrimaryKey;
+    }
+    return field_type::Attribute;
+}
+
 template<>
-record *create_prototype<record>(const std::vector<object::attribute_definition> &prototype)
-{
+record *create_prototype<record>(const std::vector<object::attribute_definition> &prototype) {
   auto result = std::make_unique<record>();
   for (const auto &col: prototype) {
-    result->append({col.name(), col.type(), col.attributes().size(), col.index()});
+    result->append({
+        col.name(),
+        col.type(),
+        determine_field_type(col.attributes().options()),
+        col.attributes().size(),
+        col.index()
+    });
   }
   return result.release();
 }