From 3e052551a83b9039db2ad58918772c0264292ca8 Mon Sep 17 00:00:00 2001
From: Julio Montoya <gugli100@gmail.com>
Date: Thu, 25 Apr 2019 15:02:54 +0200
Subject: [PATCH] Add script to delete orphan questions from the platform
 BT#15534

---
 main/exercise/question.class.php          | 24 +++++++++++++++------
 tests/scripts/delete_orphan_questions.php | 26 +++++++++++++++++++++++
 2 files changed, 43 insertions(+), 7 deletions(-)
 create mode 100644 tests/scripts/delete_orphan_questions.php

diff --git a/main/exercise/question.class.php b/main/exercise/question.class.php
index 775ed51d81..16638f9b4a 100755
--- a/main/exercise/question.class.php
+++ b/main/exercise/question.class.php
@@ -1340,10 +1340,20 @@ abstract class Question
      * @author Olivier Brouckaert
      *
      * @param int $deleteFromEx - exercise ID if the question is only removed from one exercise
+     *
+     * @return bool
      */
     public function delete($deleteFromEx = 0)
     {
-        $course_id = api_get_course_int_id();
+        if (empty($this->course)) {
+            return false;
+        }
+
+        $courseId = $this->course['real_id'];
+
+        if (empty($courseId)) {
+            return false;
+        }
 
         $TBL_EXERCISE_QUESTION = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
         $TBL_QUESTIONS = Database::get_course_table(TABLE_QUIZ_QUESTION);
@@ -1357,7 +1367,7 @@ abstract class Question
             //update the question_order of each question to avoid inconsistencies
             $sql = "SELECT exercice_id, question_order 
                     FROM $TBL_EXERCISE_QUESTION
-                    WHERE c_id = $course_id AND question_id = ".intval($id);
+                    WHERE c_id = $courseId AND question_id = ".$id;
 
             $res = Database::query($sql);
             if (Database::num_rows($res) > 0) {
@@ -1366,7 +1376,7 @@ abstract class Question
                         $sql = "UPDATE $TBL_EXERCISE_QUESTION
                                 SET question_order = question_order-1
                                 WHERE
-                                    c_id = $course_id AND 
+                                    c_id = $courseId AND 
                                     exercice_id = ".intval($row['exercice_id'])." AND 
                                     question_order > ".$row['question_order'];
                         Database::query($sql);
@@ -1375,21 +1385,21 @@ abstract class Question
             }
 
             $sql = "DELETE FROM $TBL_EXERCISE_QUESTION
-                    WHERE c_id = $course_id AND question_id = ".$id;
+                    WHERE c_id = $courseId AND question_id = ".$id;
             Database::query($sql);
 
             $sql = "DELETE FROM $TBL_QUESTIONS
-                    WHERE c_id = $course_id AND id = ".$id;
+                    WHERE c_id = $courseId AND id = ".$id;
             Database::query($sql);
 
             $sql = "DELETE FROM $TBL_REPONSES
-                    WHERE c_id = $course_id AND question_id = ".$id;
+                    WHERE c_id = $courseId AND question_id = ".$id;
             Database::query($sql);
 
             // remove the category of this question in the question_rel_category table
             $sql = "DELETE FROM $TBL_QUIZ_QUESTION_REL_CATEGORY
                     WHERE 
-                        c_id = $course_id AND 
+                        c_id = $courseId AND 
                         question_id = ".$id;
             Database::query($sql);
 
diff --git a/tests/scripts/delete_orphan_questions.php b/tests/scripts/delete_orphan_questions.php
new file mode 100644
index 0000000000..27291bbe52
--- /dev/null
+++ b/tests/scripts/delete_orphan_questions.php
@@ -0,0 +1,26 @@
+<?php
+/* For licensing terms, see /license.txt */
+
+exit;
+
+require_once __DIR__ . '/../../main/inc/global.inc.php';
+
+$sql = 'SELECT iid, c_id, question 
+        FROM c_quiz_question 
+        WHERE iid not in (SELECT question_id from c_quiz_rel_question) 
+        ORDER BY iid';
+
+$result = Database::query($sql);
+$data = Database::store_result($result);
+$counter = 1;
+$totalQuestions = count($data);
+echo 'Questions to delete: '.$totalQuestions.PHP_EOL;
+foreach ($data as $row) {
+    $courseInfo = api_get_course_info_by_id($row['c_id']);
+    $question = Question::read($row['iid'], $courseInfo);
+    if (empty($question->exerciseList)) {
+        $question->delete(1);
+    }
+    echo 'Deleting question '.$counter.'/'.$totalQuestions.' -  #'.$row['iid'].PHP_EOL;
+    $counter++;
+}
\ No newline at end of file