Export all question and correct answer in csv for moodle.

export_moodle_question_answer.php

<?php
require_once 'config.php';
require_once($CFG->libdir.'/questionlib.php');
require_once($CFG->libdir.'/csvlib.class.php');
require_admin();
raise_memory_limit(MEMORY_HUGE);
ini_set('max_execution_time', 600);
$from  = optional_param("from",0,PARAM_INT);
$to  = optional_param("to",0,PARAM_INT);
$where= [] ;
$params = [];
if($from){
    $where[]  = " id >= ? ";
    $params[] =$from;
}
if($to){
    $where[]  = " id <= ? ";
    $params[] =$to;
}
$where = implode(" and ", $where);

$sql = "select * from {question} where 1 ";
if($where){
    $sql = $sql. " and ". $where;
}
if(!$from && !$to){
$sql = $sql. " limit 0, 1000";
}
$rs = $DB->get_recordset_sql($sql, $params);
$categories = $DB->get_records('question_categories', array(), '', 'id, name, parent');
$data = [];
foreach ($rs as $q){
    $csv_data = [];

    $qobj = question_bank::load_question($q->id);
    $context = context::instance_by_id($qobj->contextid);
    $course_name = '';
    if ($context->contextlevel == CONTEXT_COURSE) {
        $instanceid = $context->instanceid;
        $course_name = $DB->get_field('course', 'fullname', array('id' => $instanceid));
    }
    $qparents = question_categorylist_parents($qobj->category);

    $qparents_name = [];
    foreach($qparents as $qp){
        $qparents_name[$qp ] = $categories[$qp]->name;
    }
    $tags =  \core_tag_tag::get_item_tags_array('core_question', 'question', $q->id);

    $csv['sno'] = $q->id;
    $csv['subject'] =  $course_name;
    $csv['topic'] = implode(" > ", $qparents_name);
    $csv['tags'] =  implode(" , ", $tags);
    $csv['question_type'] =  $q->qtype;
    $csv['question_name'] = $qobj->name;
    $csv['question_text'] = $qobj->questiontext;
    $answers = $qobj->answers;

    for ($i=1;$i<=10;$i++){

        $csv['opt'.$i] = '';
        if($q->qtype == 'multichoice' && is_array($answers) && !empty($answers)){
            $ans = '';
            $ans = array_pop($answers);
            $csv['opt'.$i] = $ans->answer;
        }
    }

    $right_answer = [];
    switch($q->qtype){
        case 'multichoice':
            $k= 1;
            foreach ($qobj->answers as $ans){
               if($ans->fraction > 0 ){
                $right_answer[] = $k;
               }                    
               $k++;                                 
            }
            $csv['right_answer'] = implode(",", $right_answer);
            break;
            case 'truefalse':
                $right_answer = $qobj->get_correct_response();
                if(isset($right_answer['answer']) ){
                    if($right_answer['answer']){
                        $csv['right_answer'] = 1;
                    }else{
                        $csv['right_answer']  = 2;
                    }
                }

                break;
	default:

	    $right_answer = $qobj->get_correct_response();
	    if(is_array($right_answer)){
            	$csv['right_answer'] = $qobj->summarise_response($right_answer);
	    }else{
		$csv['right_answer'] = $right_answer;
	    }
    }
   
    $csv['explanation'] = $qobj->generalfeedback;
    $csv['correct_marks'] = $qobj->defaultmark;
    $csv['negative_marks'] = $qobj->penalty;

    $data[] = $csv;

}
print_object($data);die;
if(!empty($data)){
    $filename = date("dmy")."_questions.csv";
    output_csv($data, $header, $filename);
}else{
    echo $OUTPUT->box("No Data found!");
}


function output_csv($data,  $filename) {
    global $CFG;

    // Create CSV file
    $csv = new csv_export_writer();

    // Define headers
    $headers = array();
    foreach ($data[0] as $key => $value) {
        $headers[] = $key;
    }
    $csv->add_data($headers);

    // Add data rows
    foreach ($data as $row) {
        $csv->add_data($row);
    }

    // Set headers
    $csv->download_file($filename);
    die;
}