Resolve #74

belongs_to.md

@@ -0,0 +1,78 @@
+has_many<employee> <-> belongs_to<department>
+===================================================
+
+```
+struct employee
+{
+  oos::belongs_to<department> dep;
+
+  template < class S >
+  void serialize(S &s)
+  {
+    s.serialize("department", dep);
+  }
+};
+
+struct department
+{
+  oos::has_many<employee> emps;
+
+  template < class S >
+  void serialize(S &s)
+  {
+    s.serialize("employee", emps);
+  }
+};
+
+auto george    = ostore.insert(new employee("george"));
+auto insurance = ostore.insert(new department("insurance"));
+
+insurance->emps.push_back(george);
+
+```
+
+Analyze phase
+=============
+
+__Case 1: Department attached first__
+
+ * attach department
+ * prototype "employee" not found; prepare new
+ * mark as has many relation for "department" member "employees"
+ * attach employee
+ * prototype "employee found"
+ * if employee contains belongs_to for "department" tie prototypes
+ * else throw error
+
+__Case 2: Employee attached first__
+
+ * attach employee
+ * prototype "department" not found: prepare new
+ * mark as belongs relation for "employee" member "department"
+ * attach department
+ * prototype "department" found
+ * if department contains has_many for "employee" tie prototypes
+ * else throw error
+
+Business phase
+==============
+
+__Case 1: emplyoee sets a department__
+
+ * employee gets object type "department" with member name "employees" from prototype
+ * employee is added to departments employees container
+
+__Case 2: department adds an employee__
+
+ * department gets object type "employee" with member name "department" from prototype
+ * department is set for employee
+
+
+TODO
+====
+
+1. Add ```object_store::attach<T>(prototype_node, parent, [observer])```
+2. Add static
+ * ```prototype_node::make_node<T>()```
+ * ```prototype_node::make_relation_node<T>()```
+3. Adjust ```node_anaylzer```

include/oos/db/mysql/mysql_statement.hpp

@@ -76,28 +76,33 @@ class mysql_statement : public oos::detail::statement_impl
 
 private:
   template < class T >
-  void bind_value(MYSQL_BIND &bind, enum_field_types type, T value)
+  void bind_value(std::size_t index, enum_field_types type, T value)
   {
+//    std::cout << "binding [" << value << "] (index: " << index << ")\n";
+    MYSQL_BIND &bind = host_array[index];
     if (bind.buffer == nullptr) {
       // allocating memory
       bind.buffer = new char[sizeof(T)];
     }
     *static_cast<T*>(bind.buffer) = value;
     bind.buffer_type = type;
 	  bind.buffer_length = sizeof(T);
-    bind.is_null = 0;
+    is_null_vector[index] = false;
+    bind.is_null = &is_null_vector[index];
 	  bind.is_unsigned = std::is_unsigned<T>::value;
   }
-  void bind_value(MYSQL_BIND &bind, enum_field_types type, char x);
-  void bind_value(MYSQL_BIND &bind, enum_field_types type, unsigned char x);
-  void bind_value(MYSQL_BIND &bind, enum_field_types type, const oos::date &x);
-  void bind_value(MYSQL_BIND &bind, enum_field_types type, const oos::time &x);
-  void bind_value(MYSQL_BIND &bind, enum_field_types type, const char *value, size_t size);
+  void bind_value(std::size_t index, enum_field_types type, char x);
+  void bind_value(std::size_t index, enum_field_types type, unsigned char x);
+  void bind_value(std::size_t index, enum_field_types type, const oos::date &x);
+  void bind_value(std::size_t index, enum_field_types type, const oos::time &x);
+  void bind_value(std::size_t index, enum_field_types type, const char *value, size_t size);
+
+  void bind_null(std::size_t index);
 
 private:
   size_t result_size;
   size_t host_size;
-  std::vector<unsigned long> length_vector;
+  std::vector<my_bool> is_null_vector;
   MYSQL_STMT *stmt_ = nullptr;
   MYSQL_BIND *host_array = nullptr;
 };