Delete survey invitations on survey deletion

main/survey/survey.lib.php

@@ -664,6 +664,15 @@ class SurveyManager
 
         $table_survey = Database::get_course_table(TABLE_SURVEY);
         $table_survey_question_group = Database::get_course_table(TABLE_SURVEY_QUESTION_GROUP);
+        $table_survey_invitation = Database::get_course_table(TABLE_SURVEY_INVITATION);
+
+        $sql = "SELECT code
+                FROM $table_survey WHERE survey_id = $survey_id";
+        $res = Database::query($sql);
+        $row = Database::fetch_array($res);
+        if ($row) {
+            $survey_code = $row['code'];
+        }
 
         if ($shared) {
             $table_survey = Database::get_main_table(TABLE_MAIN_SHARED_SURVEY);
@@ -695,6 +704,11 @@ class SurveyManager
         // Deleting the questions of the survey
         self::delete_all_survey_questions($survey_id, $shared);
 
+        // Deleting invitations of the survey
+        $sql = "DELETE FROM $table_survey_invitation
+                WHERE c_id = $course_id AND survey_code = '".$survey_code."'";
+        Database::query($sql);
+
         // Update into item_property (delete)
         api_item_property_update(
             $course_info,