diff -u a/Helper.php b/Helper.php
--- a/Helper.php	2018-04-20 10:57:44.000000000 +0200
+++ b/Helper.php	2019-07-17 18:42:19.396149000 +0200
@@ -42,9 +42,9 @@
 
   public static function getPageJsonForRoute($route_name, $url = NULL)
   {
-    $query = db_select('structured_data_json', 'sdj')
-      ->fields('sdj')
-      ->condition('route_name', $route_name);
+    $query = \Drupal::database()->select('structured_data_json', 'sdj');
+    $query->fields('sdj');
+    $query->condition('route_name', $route_name);
 
     if (empty($url))
     {
@@ -66,10 +66,11 @@
 
   public static function getPageJsonForEntity($bundle, $entity_id)
   {
-    $query = db_select('structured_data_json', 'sdj')
-      ->fields('sdj')
-      ->condition('bundle', $bundle)
-      ->condition('entity_id', $entity_id);
+    $query = \Drupal::database()->select('structured_data_json', 'sdj');
+
+    $query->fields('sdj');
+    $query->condition('bundle', $bundle);
+    $query->condition('entity_id', $entity_id);
 
     $result = $query
       ->execute()