renamed foreign class to entity, introduced interface class query_result_reader

test/models/airplane.hpp

@@ -8,7 +8,7 @@
 #include "matador/utils/cascade_type.hpp"
 #include "matador/utils/field_attributes.hpp"
 
-#include "matador/sql/foreign.hpp"
+#include "matador/sql/entity.hpp"
 
 #include <string>
 
@@ -21,7 +21,7 @@ struct airplane
   : id(id)
   , brand(std::move(b))
   , model(std::move(m)) {}
-  unsigned long id;
+  unsigned long id{};
   std::string brand;
   std::string model;
 

test/models/flight.hpp

@@ -7,15 +7,15 @@
 #include "matador/utils/cascade_type.hpp"
 #include "matador/utils/field_attributes.hpp"
 
-#include "matador/sql/foreign.hpp"
+#include "matador/sql/entity.hpp"
 
 #include <string>
 
 namespace matador::test {
 
 struct flight {
-  unsigned long id;
-  sql::foreign<test::airplane> airplane;
+  unsigned long id{};
+  sql::entity<test::airplane> airplane;
   std::string pilot_name;
 
   template<class Operator>

test/models/product.hpp

@@ -8,7 +8,7 @@
 #include "matador/utils/cascade_type.hpp"
 #include "matador/utils/field_attributes.hpp"
 
-#include "matador/sql/foreign.hpp"
+#include "matador/sql/entity.hpp"
 
 #include <string>
 
@@ -17,8 +17,8 @@ namespace matador::test {
 struct product
 {
   std::string product_name;
-  sql::foreign<test::supplier> supplier;
-  sql::foreign<test::category> category;
+  sql::entity<test::supplier> supplier;
+  sql::entity<test::category> category;
   std::string quantity_per_unit;
   unsigned int unit_price;
   unsigned int units_in_stock;