use sql field names with tables where join happens

src/Repository/PlaceRepository.php

@@ -110,7 +110,7 @@ class PlaceRepository
         $selectUnvisited = new Select(\Container::$dbConnection, 'places');
         $selectUnvisited->leftJoin($selectPlacesByCurrentUser, ['places', 'id'], '=', ['places_by_current_user', 'place_id']);
         $selectUnvisited->where('map_id', '=', $mapId);
-        $selectUnvisited->where('last_time', '=', null);
+        $selectUnvisited->where(['places_by_current_user', 'last_time'], '=', null);
         $numberOfUnvisitedPlaces = $selectUnvisited->count();
 
         // look for as many new places as possible but maximum $n
@@ -174,8 +174,8 @@ class PlaceRepository
     {
         $select = new Select(\Container::$dbConnection);
         $select->innerJoin('place_in_challenge', ['places', 'id'], '=', ['place_in_challenge', 'place_id']);
-        $select->where('challenge_id', '=', $challenge->getId());
-        $select->orderBy('round');
+        $select->where(['place_in_challenge', 'challenge_id'], '=', $challenge->getId());
+        $select->orderBy(['place_in_challenge', 'round']);
         $select->limit(1, $round);
 
         return \Container::$persistentDataManager->selectFromDb($select, Place::class);
@@ -185,8 +185,8 @@ class PlaceRepository
     {
         $select = new Select(\Container::$dbConnection);
         $select->innerJoin('place_in_challenge', ['places', 'id'], '=', ['place_in_challenge', 'place_id']);
-        $select->where('challenge_id', '=', $challenge->getId());
-        $select->orderBy('round');
+        $select->where(['place_in_challenge', 'challenge_id'], '=', $challenge->getId());
+        $select->orderBy(['place_in_challenge', 'round']);
 
         yield from \Container::$persistentDataManager->selectMultipleFromDb($select, Place::class);
     }