Quiz Results incorrectly calculated when you change the quiz settings

getting this same issue. would love a fix. looking into it as well...

I haven't received any errors when applying this patch and re-saving existing or adding new questions to the quiz. Can you elaborate where you notice the code failing?

I found out the patch in http://drupal.org/files/quiz-quiz.pages_.inc_.patch, This offers some kind of solution to this issue. Looking forward to officially fix this at the earliest.

Sabareesh.KF, it doesn't look like that patch worked. re-saves all entries incorrectly.

Using the patch from #6 I run into a PDO exception when saving a quiz node edit:

PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'score' cannot be null: UPDATE {quiz_node_results} r SET r.score = ROUND( 100 * ( SELECT SUM(a.points_awarded) FROM {quiz_node_results_answers} a WHERE a.result_id = r.result_id ) / ( SELECT max_score FROM {quiz_node_properties} qnp WHERE qnp.vid = r.vid ) ) WHERE r.vid IN(:quiz_vids_0); Array ( [:quiz_vids_0] => 491 ) in quiz_update_max_score_properties() (line 2567 of /path/to/quiz/quiz.module).

To follow up on my post in #7, it turns out there was a problem in my database and when working with a properly set up quiz the quiz node saves without error when edited. On mysql the query could be rewritten to avoid the NULL problem:

UPDATE {quiz_node_results} r SET r.score = IFNULL(ROUND( 100 * ( SELECT SUM(a.points_awarded) FROM {quiz_node_results_answers} a WHERE a.result_id = r.result_id ) / ( SELECT max_score FROM {quiz_node_properties} qnp WHERE qnp.vid = r.vid ) ), 0) WHERE r.vid IN(:quiz_vids_0);

I don't know how portable IFNULL() is, so it may not be practical.

There is still an issue with results calculations if a question is removed from the quiz after a user has taken the quiz. The simplest illustration of this is that a user with a 100% result before a question is removed will have a result of greater than 100% after a question is removed.

It is also an issue when you have "long answer" or "short answer" type questions in a quiz, and you edit it to score them.

 $expression = array(':points_awarded' => $points_awarded, ':max_score' => ($max_score > 0) ? $max_score : 1);
  db_update('quiz_node_results')
    ->expression('score', 'ROUND(100 * :points_awarded / :max_score)', $expression)
    ->condition('vid', $quizzes_to_update, 'IN')
    ->execute();

The actual problem starts here, quiz.module line 2552. I think this is a redundant query. I commented the execute() and tried in my local instance, it worked fine wit out any errors.
I am not sure how this has to be done in a proper way, waiting to get suggestion form you all.

I've commited a fix, but haven't done much testing.

Still incorrect for existing quiz with "long answer" or "short answer" type questions,since those quizzes are edited to score the questions. I am using alpha version quiz-7.x-4.0-alpha1.

Unless will always be wrong for old quizzes? Please confirm. Thanks.

New version doesn't fix existing quizzes, but I have commited another very important fix for this issue now.

I tried latest dev version, and it still incorrect for quiz with "long answer" or "short answer" type questions, since those quizzes are edited to score the questions.

Could not reproduce this in 7.x-5.0-alpha-1. Tested by editing a quiz with a long answer and removing a long answer.

If this is still happening with 7.x-4.x please provide steps to reproduce.

Seems to be fixed. Please re-open if the problem still exists.