diff --git a/include/matador/query/schema.hpp b/include/matador/query/schema.hpp
index c17c038..d1fc108 100644
--- a/include/matador/query/schema.hpp
+++ b/include/matador/query/schema.hpp
@@ -102,12 +102,25 @@ public:
   const_iterator begin() const;
   const_iterator end() const;
 
-  iterator find(const std::type_index& ti) { return schema_nodes_.find(ti); }
-  const_iterator find(const std::type_index& ti) const { return schema_nodes_.find(ti); }
+  [[nodiscard]] size_t size() const;
+  [[nodiscard]] bool empty() const;
 
+  template<typename Type>
+  iterator find() { return find(typeid(Type)); }
+  iterator find(const std::type_index& ti);
   iterator find(const std::string& name);
+
+  template<typename Type>
+  const_iterator find() const { return find(typeid(Type)); }
+  const_iterator find(const std::type_index& ti) const;
   const_iterator find(const std::string& name) const;
 
+  [[nodiscard]] bool contains(const std::type_index &index) const;
+  template < typename Type >
+  [[nodiscard]] bool contains() const {
+    return contains(std::type_index(typeid(Type)));
+  }
+
   const object::repository &repo() const { return repo_; }
   object::repository &repo() { return repo_; }
 
diff --git a/source/orm/query/schema.cpp b/source/orm/query/schema.cpp
index 3336e37..410f3f5 100644
--- a/source/orm/query/schema.cpp
+++ b/source/orm/query/schema.cpp
@@ -200,6 +200,22 @@ schema::const_iterator schema::end() const {
   return schema_nodes_.end();
 }
 
+size_t schema::size() const {
+  return schema_nodes_.size();
+}
+
+bool schema::empty() const {
+  return schema_nodes_.empty();
+}
+
+schema::iterator schema::find(const std::type_index &ti) {
+  return schema_nodes_.find(ti);
+}
+
+schema::const_iterator schema::find(const std::type_index &ti) const {
+  return schema_nodes_.find(ti);
+}
+
 schema::iterator schema::find(const std::string &name) {
   const auto result = repo_.basic_info(name);
   if (!result) {
@@ -218,6 +234,10 @@ schema::const_iterator schema::find(const std::string &name) const {
   return schema_nodes_.find(result->get().type_index());
 }
 
+bool schema::contains(const std::type_index &index) const {
+  return schema_nodes_.count(index) == 1;
+}
+
 void schema::dump(std::ostream &os) const {
   repo_.dump(os);
 }
diff --git a/test/backends/QueryTest.cpp b/test/backends/QueryTest.cpp
index 4e4cea5..798f6b6 100644
--- a/test/backends/QueryTest.cpp
+++ b/test/backends/QueryTest.cpp
@@ -27,7 +27,7 @@ META_TABLE(recipe_ingredients, RECIPE_INGREDIENT, recipe_id, ingredient_id);
 META_TABLE(airplanes, AIRPLANE, id, brand, model);
 META_TABLE(flights, FLIGHT, id, airplane_id, pilot_name);
 META_TABLE(shipments, SHIPMENT, id, tracking_number)
-META_TABLE(packages, PACKAGE, id, weight, shipment)
+META_TABLE(packages, PACKAGE, id, weight, shipment_id)
 
 TEST_CASE_METHOD(QueryFixture, "Create table with foreign key relation", "[query][foreign][relation]") {
   auto result = repo.attach<airplane>("airplane")
@@ -593,10 +593,8 @@ TEST_CASE_METHOD(QueryFixture, "Select statement with many to many relationship"
 
   select_result = query::select({r.id, r.name, ri.ingredient_id, i.name})
     .from(r)
-    .join_left(ri)
-    .on(r.id == ri.recipe_id)
-    .join_left(i)
-    .on(ri.ingredient_id == i.id)
+    .join_left(ri).on(r.id == ri.recipe_id)
+    .join_left(i).on(ri.ingredient_id == i.id)
     .where(r.id == 8)
     .fetch_all(db);
   REQUIRE(result.is_ok());
@@ -621,8 +619,6 @@ void print(std::ostream& out, const record& row) {
 TEST_CASE_METHOD(QueryFixture, "Test load entity with eager has many relation", "[query][has_many][eager]") {
   auto result = repo.attach<package>("packages")
     .and_then( [this] { return repo.attach<shipment>("shipments"); } );
-  // auto result = repo.attach<shipment>("shipments")
-  //   .and_then( [this] { return repo.attach<package>("packages"); } );
   REQUIRE(result.is_ok());
   tables_to_drop.emplace("shipments");
   tables_to_drop.emplace("packages");
@@ -675,10 +671,10 @@ TEST_CASE_METHOD(QueryFixture, "Test load entity with eager has many relation",
   REQUIRE(count.is_ok());
   REQUIRE(*count == 5);
 
-  auto pkgs = query::select({PACKAGE.id, PACKAGE.weight, PACKAGE.shipment, SHIPMENT.tracking_number})
+  auto pkgs = query::select({PACKAGE.id, PACKAGE.weight, PACKAGE.shipment_id, SHIPMENT.tracking_number})
     .from(PACKAGE)
     .join_left(SHIPMENT)
-    .on( PACKAGE.shipment == SHIPMENT.id )
+    .on( PACKAGE.shipment_id == SHIPMENT.id )
     .where( PACKAGE.weight > 20.0 && SHIPMENT.tracking_number == "0815" )
     .group_by({PACKAGE.id, SHIPMENT.tracking_number})
     .order_by(PACKAGE.weight).asc()
@@ -694,23 +690,28 @@ TEST_CASE_METHOD(QueryFixture, "Test load entity with eager has many relation",
   auto shipment_records = query::select({SHIPMENT.tracking_number, SHIPMENT.id, PACKAGE.weight, PACKAGE.weight})
     .from(SHIPMENT)
     .join_left(PACKAGE)
-    .on( SHIPMENT.id == PACKAGE.shipment )
+    .on( SHIPMENT.id == PACKAGE.shipment_id )
     .fetch_all(db);
 
   REQUIRE(shipment_records.is_ok());
 
   printer.print(*shipment_records);
 
-  auto shipment_result = query::select({SHIPMENT.id, SHIPMENT.tracking_number, PACKAGE.id, PACKAGE.weight, PACKAGE.shipment})
+  auto shipment_result = query::select({SHIPMENT.id, SHIPMENT.tracking_number, PACKAGE.id, PACKAGE.weight, PACKAGE.shipment_id})
     .from(SHIPMENT)
     .join_left(PACKAGE)
-    .on( SHIPMENT.id == PACKAGE.shipment )
+    .on( SHIPMENT.id == PACKAGE.shipment_id )
+    .order_by(SHIPMENT.id).asc()
     .fetch_all<shipment>(db);
 
   REQUIRE(shipment_result.is_ok());
 
+  size_t index{0};
+  std::vector<size_t> packages_sizes{2, 3};
   std::cout << "\n";
   for (const auto &s : *shipment_result) {
-    std::cout << s.id << " " << s.tracking_number << " packages: " << s.packages.size() << std::endl;
+    REQUIRE(s.id == shipments.at(index)->id);
+    REQUIRE(s.tracking_number == shipments.at(index)->tracking_number);
+    REQUIRE(s.packages.size() == packages_sizes.at(index++));
   }
 }
\ No newline at end of file
diff --git a/test/core/object/RepositoryTest.cpp b/test/core/object/RepositoryTest.cpp
index 55e9c37..5d38897 100644
--- a/test/core/object/RepositoryTest.cpp
+++ b/test/core/object/RepositoryTest.cpp
@@ -48,15 +48,15 @@ TEST_CASE("Test add type to prototype tree", "[schema_node][add]") {
 
   REQUIRE(repo.empty());
 
-  // auto res = repo.attach<person>("person");
-  // REQUIRE(res.is_ok());
-  // res = repo.attach<student, person>("student");
-  // REQUIRE(res.is_ok());
-  // res = repo.attach<teacher, person>("teacher");
-  // REQUIRE(res.is_ok());
-  //
-  // REQUIRE(!repo.empty());
-  // REQUIRE(repo.size() == 3);
+  auto res = repo.attach<person>("person");
+  REQUIRE(res.is_ok());
+  res = repo.attach<student, person>("student");
+  REQUIRE(res.is_ok());
+  res = repo.attach<teacher, person>("teacher");
+  REQUIRE(res.is_ok());
+
+  REQUIRE(!repo.empty());
+  REQUIRE(repo.size() == 3);
 }
 
 TEST_CASE("Test next and previous of schema node", "[schema_node][next][previous]") {
diff --git a/test/models/shipment.hpp b/test/models/shipment.hpp
index 11f0f59..01fa646 100644
--- a/test/models/shipment.hpp
+++ b/test/models/shipment.hpp
@@ -35,7 +35,7 @@ struct package {
     namespace field = matador::access;
     field::primary_key(op, "id", id);
     field::attribute(op, "weight", weight);
-    field::belongs_to(op, "shipment", delivery, utils::CascadeAllFetchLazy);
+    field::belongs_to(op, "shipment_id", delivery, utils::CascadeAllFetchLazy);
   }
 };
 }
diff --git a/test/orm/CMakeLists.txt b/test/orm/CMakeLists.txt
index 9d6090f..a03bee7 100644
--- a/test/orm/CMakeLists.txt
+++ b/test/orm/CMakeLists.txt
@@ -28,6 +28,7 @@ add_executable(OrmTests
   utils/auto_reset_event.cpp
   utils/auto_reset_event.hpp
   query/GeneratorTests.cpp
+  query/SchemaTest.cpp
 )
 
 target_link_libraries(OrmTests matador-orm matador-core Catch2::Catch2WithMain)
diff --git a/test/orm/query/SchemaTest.cpp b/test/orm/query/SchemaTest.cpp
new file mode 100644
index 0000000..8816c1f
--- /dev/null
+++ b/test/orm/query/SchemaTest.cpp
@@ -0,0 +1,42 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include "matador/query/schema.hpp"
+
+#include "../../models/shipment.hpp"
+
+using namespace matador::query;
+using namespace matador::test;
+
+TEST_CASE("Test schema with belongs-to to has-many relation" "[schema][relation][belongs_to]") {
+  schema repo;
+  auto result = repo.attach<package>("packages")
+    .and_then( [&repo] { return repo.attach<shipment>("shipments"); } );
+  REQUIRE(result.is_ok());
+  REQUIRE(repo.size() == 2);
+  REQUIRE(repo.contains<shipment>());
+  REQUIRE(repo.contains<package>());
+
+  auto it = repo.find<shipment>();
+  REQUIRE(it != repo.end());
+  REQUIRE(it->second.name() == "shipments");
+  it = repo.find<package>();
+  REQUIRE(it != repo.end());
+  REQUIRE(it->second.name() == "packages");
+}
+
+TEST_CASE("Test schema with has-many to belongs-to relation" "[schema][relation][has_many]") {
+  schema repo;
+  auto result = repo.attach<shipment>("shipments")
+    .and_then( [&repo] { return repo.attach<package>("packages"); } );
+  REQUIRE(result.is_ok());
+  REQUIRE(repo.size() == 2);
+  REQUIRE(repo.contains<shipment>());
+  REQUIRE(repo.contains<package>());
+
+  auto it = repo.find<shipment>();
+  REQUIRE(it != repo.end());
+  REQUIRE(it->second.name() == "shipments");
+  it = repo.find<package>();
+  REQUIRE(it != repo.end());
+  REQUIRE(it->second.name() == "packages");
+}
\ No newline at end of file