Duplicate key logic makes sense here.

src/engine/db/handlers/dbWarehouseHandler.java

@@ -87,10 +87,11 @@ public class dbWarehouseHandler extends dbHandlerBase {
         JSONObject warehouseJSON = new JSONObject(warehouse.resources);
 
         try (Connection connection = DbManager.getConnection();
-             PreparedStatement preparedStatement = connection.prepareStatement("UPDATE `dyn_warehouse` SET `warehouse` = ? WHERE `cityUID` = ?")) {
+             PreparedStatement preparedStatement = connection.prepareStatement("INSERT INTO `dyn_warehouse` (`cityUUID`, `warehouse`) VALUES (?, ?) " +
+                     "ON DUPLICATE KEY UPDATE `warehouse` = VALUES(`warehouse`)")) {
 
-            preparedStatement.setString(2, warehouseJSON.toString());
             preparedStatement.setInt(1, warehouse.city.getObjectUUID());
+            preparedStatement.setString(2, warehouseJSON.toString());
 
             return (preparedStatement.executeUpdate() > 0);
 

src/engine/objects/Warehouse.java

@@ -46,7 +46,7 @@ public class Warehouse {
             resources.put(resourceType, value);
         }
 
-        JSONArray lockedResources = (JSONArray) warehouse.get("locked");
+        JSONArray lockedResources = (JSONArray) warehouse.get("locks");
 
         if (lockedResources.isEmpty() == false)
             for (Object o : lockedResources)