PDOexception when updating a fresh quiz

Same error for max_score on any CRUD for the quiz.

I tried to look at the queries, not much I can say.

I was lucky to have a older dev version which is working.

Can't blame the developers, there is so much to do to make a good testing platform.

I added the following to quiz.module at the end of the quiz_validate($node) function for debugging:

if (is_null($max_score_for_random)) {
form_set_error('max_score_for_random', t('No max score is set for random questions.' . $max_score_result));
}

I'm guessing that the failing SQL query is the following, from quiz_update_max_score_properties($quizzes_to_update):

  db_update('quiz_node_properties')
    ->expression('max_score', 'max_score_for_random * number_of_random_questions + (
      SELECT SUM(max_score)
      FROM {quiz_node_relationship} qnr
      WHERE qnr.question_status = ' . QUESTION_ALWAYS . '
      AND parent_vid = quiz_node_properties.vid)')
    ->condition('vid', $quizzes_to_update, 'IN')
    ->execute();

The calculation would fail if "max_score_for_random" in "max_score_for_random * number_of_random_questions" were null.

I have temporarily fixed the problem by replacing the db_update above (around line 2566), adding a conditional which checks whether $max_score_for_random is null (drupal messages set for debugging). If $max_score_random is null, it sets a 'default' of 1 (value from quiz.install):

   // DEBUG: Conditional for null max_score_for_random
  if (!is_null($max_score_for_random)) {
  drupal_set_message("Max score is not NULL; updated.");
  db_update('quiz_node_properties')
    ->expression('max_score', 'max_score_for_random * number_of_random_questions + (
      SELECT SUM(max_score)
      FROM {quiz_node_relationship} qnr
      WHERE qnr.question_status = ' . QUESTION_ALWAYS . '
      AND parent_vid = quiz_node_properties.vid)')
    ->condition('vid', $quizzes_to_update, 'IN')
    ->execute();
  }
  else {
  drupal_set_message("Max score is NULL. Set manually to 1");
	 db_update('quiz_node_properties')
    ->expression('max_score', '1')
    ->condition('vid', $quizzes_to_update, 'IN')
    ->execute();
  }

I'm not sure whether this will have detrimental effects on other quiz behavior (will max_score be set properly if legitimate values become available?), but it did allow my test quiz (one multiple-choice question) to function.

There's probably a deeper error here, and maybe this workaround will help with debugging.

Fixed, thanks