fixed has many and belongs to eager loading via sql join

test/models/book.hpp

@@ -19,8 +19,7 @@ struct book {
     unsigned short published_in{};
 
     template<typename Operator>
-    void process(Operator &op)
-    {
+    void process(Operator &op) {
         namespace field = matador::access;
         field::primary_key(op, "id", id);
         field::attribute(op, "title", title, 511);

test/orm/orm/SessionQueryBuilderTest.cpp

@@ -1,7 +1,10 @@
+#include <iostream>
 #include <catch2/catch_test_macros.hpp>
 
 #include "matador/sql/backend_provider.hpp"
 #include "matador/sql/connection.hpp"
+#include "matador/sql/column.hpp"
+#include "matador/sql/table.hpp"
 
 #include "matador/query/query.hpp"
 
@@ -20,6 +23,7 @@
 
 using namespace matador::object;
 using namespace matador::orm;
+using namespace matador::query;
 using namespace matador::sql;
 using namespace matador::test;
 
@@ -36,7 +40,7 @@ TEST_CASE("Create sql query data for entity with eager has one", "[query][entity
   auto data = eqb.build<flight>(17U);
 
   REQUIRE(data.is_ok());
-  REQUIRE(data->root_table_name == "flights");
+  REQUIRE(data->root_table->name == "flights");
   REQUIRE(data->joins.size() == 1);
   const std::vector<column> expected_columns {
     { "flights", "id", "c01" },
@@ -51,7 +55,7 @@ TEST_CASE("Create sql query data for entity with eager has one", "[query][entity
   }
 
   std::vector<std::pair<std::string, std::string>> expected_join_data {
-    { "airplanes", R"("flights"."airplane_id" = "airplanes"."id")"}
+    { "airplanes", R"("t01"."airplane_id" = "t02"."id")"}
   };
 
   query_context qc;
@@ -81,7 +85,7 @@ TEST_CASE("Create sql query data for entity with eager belongs to", "[query][ent
   auto data = eqb.build<book>(17);
 
   REQUIRE(data.is_ok());
-  REQUIRE(data->root_table_name == "books");
+  REQUIRE(data->root_table->name == "books");
   REQUIRE(data->joins.size() == 1);
   const std::vector<column> expected_columns {
     { "books", "id", "c01" },
@@ -100,7 +104,7 @@ TEST_CASE("Create sql query data for entity with eager belongs to", "[query][ent
   }
 
   std::vector<std::pair<std::string, std::string>> expected_join_data {
-    { "authors", R"("books"."author_id" = "authors"."id")"}
+    { "authors", R"("t01"."author_id" = "t02"."id")"}
   };
 
   query_context qc;
@@ -116,7 +120,7 @@ TEST_CASE("Create sql query data for entity with eager belongs to", "[query][ent
   REQUIRE(cond == R"("books"."id" = 17)");
 
   auto q = matador::query::query::select(data->columns)
-    .from(data->root_table_name);
+    .from(data->root_table->name);
 
   for (auto &jd : data->joins) {
     q.join_left(*jd.join_table)
@@ -143,7 +147,7 @@ TEST_CASE("Create sql query data for entity with eager has many belongs to", "[q
   auto data = eqb.build<order>(17);
 
   REQUIRE(data.is_ok());
-  REQUIRE(data->root_table_name == "orders");
+  REQUIRE(data->root_table->name == "orders");
   REQUIRE(data->joins.size() == 1);
   const std::vector<column> expected_columns = {
     { "orders", "order_id", "c01" },
@@ -168,7 +172,7 @@ TEST_CASE("Create sql query data for entity with eager has many belongs to", "[q
   }
 
   std::vector<std::pair<std::string, std::string>> expected_join_data {
-    { "order_details", R"("orders"."order_id" = "order_details"."order_id")"}
+    { "order_details", R"("t01"."order_id" = "t02"."order_id")"}
   };
 
   query_context qc;
@@ -197,7 +201,7 @@ TEST_CASE("Create sql query data for entity with eager many to many", "[query][e
   auto data = eqb.build<ingredient>(17);
 
   REQUIRE(data.is_ok());
-  REQUIRE(data->root_table_name == "ingredients");
+  REQUIRE(data->root_table->name == "ingredients");
   REQUIRE(data->joins.size() == 2);
   const std::vector<column> expected_columns {
     { "ingredients", "id", "c01" },
@@ -241,7 +245,7 @@ TEST_CASE("Create sql query data for entity with eager many to many (inverse par
   auto data = eqb.build<course>(17);
 
   REQUIRE(data.is_ok());
-  REQUIRE(data->root_table_name == "courses");
+  REQUIRE(data->root_table->name == "courses");
   REQUIRE(data->joins.size() == 2);
   const std::vector<column> expected_columns {
     { "courses", "id", "c01" },
@@ -270,4 +274,64 @@ TEST_CASE("Create sql query data for entity with eager many to many (inverse par
   REQUIRE(data->where_clause);
   auto cond = data->where_clause->evaluate(db.dialect(), qc);
   REQUIRE(cond == R"("courses"."id" = 17)");
+}
+
+namespace matador::test::orm {
+
+struct employee;
+
+struct department {
+  unsigned int id{};
+  std::string name;
+  std::vector<object_ptr<employee>> employees;
+
+  template<typename Operator>
+  void process(Operator &op) {
+    namespace field = matador::access;
+    field::primary_key(op, "id", id);
+    field::attribute(op, "name", name, 63);
+    field::has_many(op, "employees", employees, "dep_id", utils::fetch_type::EAGER);
+  }
+};
+
+struct employee {
+  unsigned int id{};
+  std::string first_name;
+  std::string last_name;
+  object_ptr<department> dep;
+
+  template<typename Operator>
+  void process(Operator &op) {
+    namespace field = matador::access;
+    field::primary_key(op, "id", id);
+    field::attribute(op, "first_name", first_name, 63);
+    field::attribute(op, "last_name", last_name, 63);
+    field::belongs_to(op, "dep_id", dep, utils::fetch_type::EAGER);
+  }
+};
+
+}
+
+TEST_CASE("Test eager relationship", "[session][eager]") {
+  using namespace matador::test;
+  backend_provider::instance().register_backend("noop", std::make_unique<orm::test_backend_service>());
+  connection db("noop://noop.db");
+  schema scm("noop");
+  auto result = scm.attach<orm::department>("departments")
+    .and_then( [&scm] { return scm.attach<orm::employee>("employees"); } );
+
+  session_query_builder eqb(scm);
+
+  auto data = eqb.build<orm::department>();
+  REQUIRE(data.is_ok());
+
+  auto ctx = query::select(data->columns)
+  .from(*data->root_table)
+  .join_left(data->joins)
+  .where(std::move(data->where_clause))
+  .order_by(column{data->root_table, data->pk_column_name})
+  .asc()
+  .str(db);
+
+  std::cout << ctx << std::endl;
 }