added join_column_collector and implemented inverse has_many_to_many

test/models/order.hpp

@@ -1,7 +1,7 @@
 #ifndef QUERY_ORDER_HPP
 #define QUERY_ORDER_HPP
 
-#include "order_details.h"
+#include "order_details.hpp"
 
 #include "matador/utils/access.hpp"
 

test/models/order_details.hpp

@@ -1,5 +1,5 @@
-#ifndef QUERY_ORDER_DETAILS_H
-#define QUERY_ORDER_DETAILS_H
+#ifndef QUERY_ORDER_DETAILS_HPP
+#define QUERY_ORDER_DETAILS_HPP
 
 #include "product.hpp"
 
@@ -25,4 +25,4 @@ struct order_details
 };
 
 }
-#endif //QUERY_ORDER_DETAILS_H
+#endif //QUERY_ORDER_DETAILS_HPP

test/models/student.hpp

@@ -0,0 +1,68 @@
+#ifndef QUERY_STUDENT_HPP
+#define QUERY_STUDENT_HPP
+
+#include "matador/utils/access.hpp"
+#include "matador/utils/foreign_attributes.hpp"
+
+#include "matador/sql/entity.hpp"
+#include "matador/sql/has_many_to_many_relation.hpp"
+
+#include <utility>
+#include <vector>
+
+namespace matador::test {
+
+class course;
+
+struct student
+{
+  unsigned long id{};
+  std::string name;
+  std::vector<matador::sql::entity<course>> courses;
+
+  student() = default;
+  explicit student(unsigned long id, std::string name)
+    : id(id)
+    , name(std::move(name)) {}
+
+  template < class Operator >
+  void process(Operator &op)
+  {
+    namespace field = matador::utils::access;
+    field::primary_key(op, "id", id);
+    field::attribute(op, "name", name, 255);
+    field::has_many_to_many(op, "student_courses", courses, "student_id", "course_id", utils::fetch_type::LAZY);
+  }
+
+};
+
+struct course
+{
+  unsigned long id{};
+  std::string title;
+  std::vector<matador::sql::entity<student>> students;
+
+  course() = default;
+  explicit course(unsigned long id, std::string title)
+  : id(id)
+  , title(std::move(title)) {}
+
+  template < class Operator >
+  void process(Operator &op)
+  {
+    namespace field = matador::utils::access;
+    field::primary_key(op, "id", id);
+    field::attribute(op, "title", title, 255);
+    field::has_many_to_many(op, "student_courses", students, utils::fetch_type::EAGER);
+  }
+};
+
+class student_course : public sql::has_many_to_many_relation<student, course>
+{
+public:
+  student_course()
+    : has_many_to_many_relation("student_id", "course_id") {}
+};
+
+}
+#endif //QUERY_STUDENT_HPP