/**
* Load cached statistics from the database.
*
* @param $qubaids \qubaid_condition
* @return calculated The statistics for overall attempt scores or false if not cached.
*/
public function get_cached($qubaids)
{
global $DB;
$timemodified = time() - self::TIME_TO_CACHE;
$fromdb = $DB->get_record_select('quiz_statistics', 'hashcode = ? AND timemodified > ?', array($qubaids->get_hash_code(), $timemodified));
$stats = new calculated();
$stats->populate_from_record($fromdb);
return $stats;
}
