if (array_key_exists($name, self::$coursecatfields)) {
if ($this->$name === false) {
// property was not retrieved from DB, retrieve all not retrieved fields
- $notretrievedfields = array_diff(self::$coursecatfields, array_filter(self::$coursecatfields));
+ $notretrievedfields = array_diff_key(self::$coursecatfields, array_filter(self::$coursecatfields));
$record = $DB->get_record('course_categories', array('id' => $this->id),
join(',', array_keys($notretrievedfields)), MUST_EXIST);
foreach ($record as $key => $value) {