Fix queries, fix database.lib.php

public/main/admin/course_information.php

@@ -105,8 +105,7 @@ Display::display_header($tool_name);
     </div>
 <?php
 
-echo Display::page_header(get_lang('Course usage'));
-
+/*echo Display::page_header(get_lang('Course usage'));
 $table = new SortableTableFromArray(
     get_course_usage($courseInfo, $sessionId),
     0,
@@ -117,7 +116,7 @@ $table->set_additional_parameters(['code' => $courseInfo['code']]);
 $table->set_other_tables(['user_table', 'class_table']);
 $table->set_header(0, get_lang('tool'), true);
 $table->set_header(1, get_lang('number of items'), true);
-$table->display();
+$table->display();*/
 
 /*
  * Show all users subscribed in this course.

public/main/inc/lib/database.lib.php

@@ -315,7 +315,7 @@ class Database
      *
      * @return mixed
      */
-    public static function result(Statement $resource, $row, $field = '')
+    public static function result($resource, $row, $field = '')
     {
         if ($resource->rowCount() > 0) {
             $result = $resource->fetchAll(PDO::FETCH_BOTH);