Prevent duplicate entries in miniplans and overlays

aleksis/apps/lesrooster/schema/__init__.py

@@ -225,7 +225,7 @@ class Query(graphene.ObjectType):
             Q(teachers=teacher) | Q(course__teachers=teacher),
             slot_start__time_grid_id=time_grid,
             slot_end__time_grid_id=time_grid,
-        )
+        ).distinct()
 
     @staticmethod
     def resolve_lesson_objects_for_room(root, info, room, time_grid):
@@ -236,7 +236,7 @@ class Query(graphene.ObjectType):
             rooms=room,
             slot_start__time_grid_id=time_grid,
             slot_end__time_grid_id=time_grid,
-        )
+        ).distinct()
 
     @staticmethod
     def resolve_lessons_objects_for_rooms_or_teachers(
@@ -253,7 +253,7 @@ class Query(graphene.ObjectType):
             Q(rooms__in=rooms) | Q(teachers__in=teachers) | Q(course__teachers__in=teachers),
             slot_start__time_grid_id=time_grid,
             slot_end__time_grid_id=time_grid,
-        )
+        ).distinct()
 
     @staticmethod
     def resolve_groups_by_time_grid(root, info, time_grid=None, **kwargs):