# mod_quiz: Attempts with Drag and drop onto image breaks Results / Statistics page

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#### Details

• Bug
• Status: Open
• Minor
• Resolution: Unresolved
• 3.8.5, 4.0
• None
• None
• MOODLE_38_STABLE, MOODLE_400_STABLE

#### Description

The Quiz Results Statistics page is broken if there is an attempt that uses Drag and Drop Onto Image question.

Environment:
Moodle: 2021052500.14 | 4.0dev (Build: 20200918)
Database: mysql-server-5.7.31-0 amd64

Steps:
1. Create a course and enrol a student.
2. Turn editing on.
4. Edit the quiz and add a question:

• Question type: Drag and drop onto image
• Name: My D&D onto image question
• Question text: The engineer is preparing to draw the plan. What are the steps (in order) that needs to be completed?
• Upload a background image: Any image type.
• Shuffle drag items each time question is attempted: Ticked
• Draggable item 1, type: Draggable text, text: Gather the necessary materials
• Draggable item 2, type: Draggable text, text: Get previous sketches
• Multiple tries, Penalty for each incorrect try: 100%

6. Do not answer the question, just click Finish attempt... and click Submit all and finish.
7. As teacher/admin go to the Quiz activity. Click Results / Statistics.
OUTPUT:

 `Warning: Division by zero in /var/www/html/vanilla/question/type/ddimageortext/questionbase.php on line 152` ` ` `Warning: Division by zero in /var/www/html/vanilla/question/type/ddimageortext/questionbase.php on line 152` `Error writing to database` ` ` `More information about this error` `Debug info: Unknown column 'NAN' in 'field list'` `INSERT INTO mdl_question_statistics (hashcode,timemodified,questionid,slot,subquestion,s,effectiveweight,negcovar,discriminationindex,discriminativeefficiency,sd,facility,subquestions,maxmark,positions,randomguessscore,variant) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)` `[array (` `0 => '1afcbec028f7ca4b759200c2b2aa39303f30bdba',` `1 => 1600822611,` `2 => '1',` `3 => 1,` `4 => 0,` `5 => 2,` `6 => NULL,` `7 => 0,` `8 => NULL,` `9 => NULL,` `10 => 0.0,` `11 => 0.0,` `12 => '',` `13 => '1.0000000',` `14 => 1,` `15 => NAN,` `16 => NULL,` `)]` `Error code: dmlwriteexception ` `Stack trace:` ` ` ` line 489 of /lib/dml/moodle_database.php: dml_write_exception thrown` ` line 1357 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()` ` line 1403 of /lib/dml/mysqli_native_moodle_database.php: call to mysqli_native_moodle_database->insert_record_raw()` ` line 231 of /question/classes/statistics/questions/calculated.php: call to mysqli_native_moodle_database->insert_record()` ` line 259 of /question/classes/statistics/questions/all_calculated_for_qubaid_condition.php: call to core_question\statistics\questions\calculated->cache()` ` line 258 of /question/classes/statistics/questions/calculator.php: call to core_question\statistics\questions\all_calculated_for_qubaid_condition->cache()` ` line 645 of /mod/quiz/report/statistics/report.php: call to core_question\statistics\questions\calculator->calculate()` ` line 153 of /mod/quiz/report/statistics/report.php: call to quiz_statistics_report->get_all_stats_and_analysis()` ``` line 97 of /mod/quiz/report.php: call to quiz_statistics_report->display() ```

#### People

Unassigned
Joshua Ebarvia
Safat Shahin, Tim Hunt, Amaia Anabitarte, Bas Brands, Carlos Escobedo, Ferran Recio, Ilya Tregubov, Kevin Percy, Laurent David, Mathew May, Mihail Geshoski, Sabina Abellan, Sara Arjona (@sarjona), Shamim Rezaie, Tim Hunt, Amaia Anabitarte, Bas Brands, Carlos Escobedo, Ferran Recio, Ilya Tregubov, Kevin Percy, Laurent David, Mathew May, Mihail Geshoski, Sabina Abellan, Sara Arjona (@sarjona), Shamim Rezaie